RYU's "properly molested" NSX build thread

[RYU]

On another note, for the end tanks, I think you drew the diagram wrong for the top/bottom end tank design. I believe all production cars have the hot water go IN the TOP then the cooled water comes OUT of the BOTTOM. Could you elaborate on how the cross flow radiator cools better than the top-down?

I might have drawn it wrong. That's just how the flow that I believe Nick told me. I haven't confirmed but are you sure yourself on the flow? In any event, I think the flow direction is sort of irrelevant.

- - - Updated - - -

Finally home. Boy, that was a long day at work...

I'll attempt to answer your questions as best I can.

You mentioned the FXMD car is able to sustain cool temps with 1 fan at idle/cooldown. The FXMD car is a 100% a race car with likely lots of ducting and lots of low pressure venting. I don't think it's an appropriate comparison just as when you thought comparing the PWR to the MASiV, in the context of this thread, was not. If you can tell me that the FX car can sit on the 10 fwy, in July, in SoCal, going 0-15mph, with virtually zero air flow, with the A/C on, in bumper to bumper, when it's 109F outside AND it still doesn't overheat with that 1 fan, then i'll explore that setup some more because there's some magic going on there. Please don't forget, i'm trying to test this rad to fulfill all conditions I plan to put my car thru. Driving in heavy traffic is certainly one of them for me...unfortunately

Having said that ^^ Here's my hypothesis. I think the radiator FX is using is a thicker, Alum radiator with a relatively low fin density. The low fin density probably doesn't allow radiator to heatsoak just sitting there at idle. With the MASiV radiator, we had a lot of parameters to address and solve for. This called for a semi-dense fin density and a lot of modification and testing of the fin pitch. Due to it small size, we had to maximize the better heat transfer coefficient of copper, but that requires airflow...at least some air flow. I could be totally wrong here because i'm making a guess at the FX rad. I have no idea what Ken is using. $0.02..

In terms of the direction of coolant flow in an OEM configuration....Not sure why that matters in the context of this discussion but i'm sure it's easy enough to check in the NSX manual. I also can't explain the difference in why the end tank location makes a difference in terms that might make more sense. Maybe ask an engineer who understands fluid flow and pressure variances or thermodymanics or fluid mechanics

I think you're focusing on the details that are far beyond the scope of this thread. The goal was to create a radiator that fits 100% in the stock form factor that supports a high horsepower NSX during track driving conditions and street driving conditions. That was my goal in searching for a radiator for my car. Jim has helped taken that a step further since it works on his car for his driving conditions as well.

Again, we know the radiator setup Jim and I are using will work with 2 fans, no shroud, configuration. We know that in my supercharged NSX, I sustained 77-82C, with peak around 86C when it was 85F ambient at BW all while using the OEM fan and shroud. That's good enough for me, because I know if I ever had a problem with cooling (in low speed, low air flow conditions) I can simply slap on two fans in there or possibly use my modified OEM shroud with the aftermarket fan... in other words, i've got options.

I should try to get you one Billy. When is your car going to be ready to hit the track again?

 

[bngl3rt]

Actually the HKS F-Con iS is a pure piggyback. I'm considering upgrading to a HKS F-Con VPro which can function as a piggyback or a full stand-alone. As I get more educated on tuning, I just want to do more and more. It's a disease! haha

Where did you get the wiring harness to piggyback it off your OEM ECU?

 

[RYU]

bought the harness from Dali. Fastraxturbo modified it to use with the F-Con and my OBD1 ECU.

 

[xsn]

After 8yrs of ownership and nearly 2 decades of idolizing the NSX I realized this year that i'm nearly done with building the perfect supercar for me. Building a Type R would have been cool but if I couldn't have a real Type R (complete with blueprinted, balanced NA motor, etc) it just wouldn't be a Type R, Yet I wanted to stay true to what a type R really is; an exercise in balance and engineering. I also wanted a comfortable car which some say a Type R is not. This mantra helped me determine I wanted the lightest NSX possible but still maintain the creature comforts of a street car. I wanted to stay under 400wHP yet build a car that is easy to drive FAST. This goal helped me select my suspension, brakes, gear set, power adders, and maintain the overall direction of the build. Through many trial and errors, never before built on an NSX custom parts, and countless late nights spent in the garage I think I'm finally happy.

Over the next few months i'll document the different stages of proper molestation that my NSX was subject to. I'll try to post a portion of the build every few weeks and describe my rationale and goal for each modification.

Mission Statement: To build a streetable and versatile supercar in which longevity, value, and quality engineering determined the proper combination of parts, whereby the parts together are more than the sum of their individual pieces.

Your plans sound fantastic. Looking forward to pics and updates!

 

[stuntman]

I might have drawn it wrong. That's just how the flow that I believe Nick told me. I haven't confirmed but are you sure yourself on the flow? In any event, I think the flow direction is sort of irrelevant.

- - - Updated - - -

Finally home. Boy, that was a long day at work...

I'll attempt to answer your questions as best I can.

You mentioned the FXMD car is able to sustain cool temps with 1 fan at idle/cooldown. The FXMD car is a 100% a race car with likely lots of ducting and lots of low pressure venting. I don't think it's an appropriate comparison just as when you thought comparing the PWR to the MASiV, in the context of this thread, was not. If you can tell me that the FX car can sit on the 10 fwy, in July, in SoCal, going 0-15mph, with virtually zero air flow, with the A/C on, in bumper to bumper, when it's 109F outside AND it still doesn't overheat with that 1 fan, then i'll explore that setup some more because there's some magic going on there. Please don't forget, i'm trying to test this rad to fulfill all conditions I plan to put my car thru. Driving in heavy traffic is certainly one of them for me...unfortunately

Having said that ^^ Here's my hypothesis. I think the radiator FX is using is a thicker, Alum radiator with a relatively low fin density. The low fin density probably doesn't allow radiator to heatsoak just sitting there at idle. With the MASiV radiator, we had a lot of parameters to address and solve for. This called for a semi-dense fin density and a lot of modification and testing of the fin pitch. Due to it small size, we had to maximize the better heat transfer coefficient of copper, but that requires airflow...at least some air flow. I could be totally wrong here because i'm making a guess at the FX rad. I have no idea what Ken is using. $0.02..

In terms of the direction of coolant flow in an OEM configuration....Not sure why that matters in the context of this discussion but i'm sure it's easy enough to check in the NSX manual. I also can't explain the difference in why the end tank location makes a difference in terms that might make more sense. Maybe ask an engineer who understands fluid flow and pressure variances or thermodymanics or fluid mechanics

I think you're focusing on the details that are far beyond the scope of this thread. The goal was to create a radiator that fits 100% in the stock form factor that supports a high horsepower NSX during track driving conditions and street driving conditions. That was my goal in searching for a radiator for my car. Jim has helped taken that a step further since it works on his car for his driving conditions as well.

Again, we know the radiator setup Jim and I are using will work with 2 fans, no shroud, configuration. We know that in my supercharged NSX, I sustained 77-82C, with peak around 86C when it was 85F ambient at BW all while using the OEM fan and shroud. That's good enough for me, because I know if I ever had a problem with cooling (in low speed, low air flow conditions) I can simply slap on two fans in there or possibly use my modified OEM shroud with the aftermarket fan... in other words, i've got options.

I should try to get you one Billy. When is your car going to be ready to hit the track again?

First off, I don't mean to derail the thread but hopefully add comments and thoughts to help you on your journey to come up with the best setup possible and I think you're doing a great thing for the community by developing this radiator. I hope my comments are viewed with good intentions and helpful and not critical or negative.

Nick would know for sure but I think radiators whether top-bottom or cross flow typically have the hot water enter the rad at the top and then exit cooler out of the bottom.

You're right that the FXMD car has proper ducting and does not have A/C so it's not comparable to your car (does Jim's have AC?). However, proper ducting probably has no significant benefit at idle or stop-and-go traffic so the ability to cool at idle during hot track days after a session is somewhat relevant. A/C units do release a lot of heat infront of the radiator which effectively is like raising the ambient temperature from the radiator's standpoint. So a non-vented hood and A/C would probably be the most demanding for a fan setup -so you have a valid point there.

I believe the higher the fin count per inch, the higher the fin density, the better it cools due to more surface area of the fins, but having the downsides of plugging up from sand, small rocks, dirt, etc...

As far as fans go, It would be good to know the CFM capability of the stock fan and then compare that to the CFM of your specific 2 fan setup. Which fans are you using by the way? In general, fans pull a lot of AMPs and it's probably better to not tax the alternator by using 1 fan if you can get away with it from a more efficient layout. This is why i've been asking about your fan test conditions and mounting because as my previous post said, if you just remove or disable one of the fans on Jim's radiator shroud, the remaining fan would suck air in from the gap between it and the radiator face and not effectively cool the radiator where if it were mounted directly to the rad, all of the fan's CFMs would pull directly through the fins might be enough to cool it.

Again, your hard work and development is great and I too will be in need of a good radiator so i'm also trying to learn or help you any way I can to develop your setup to have one of the most efficient and effective packages out there.

 

[RYU]

First off, I don't mean to derail the thread but hopefully add comments and thoughts to help you on your journey to come up with the best setup possible and I think you're doing a great thing for the community by developing this radiator. I hope my comments are viewed with good intentions and helpful and not critical or negative.

Nick would know for sure but I think radiators whether top-bottom or cross flow typically have the hot water enter the rad at the top and then exit cooler out of the bottom.

You're right that the FXMD car has proper ducting and does not have A/C so it's not comparable to your car (does Jim's have AC?). However, proper ducting probably has no significant benefit at idle or stop-and-go traffic so the ability to cool at idle during hot track days after a session is somewhat relevant. A/C units do release a lot of heat infront of the radiator which effectively is like raising the ambient temperature from the radiator's standpoint. So a non-vented hood and A/C would probably be the most demanding for a fan setup -so you have a valid point there.

I believe the higher the fin count per inch, the higher the fin density, the better it cools due to more surface area of the fins, but having the downsides of plugging up from sand, small rocks, dirt, etc...

As far as fans go, It would be good to know the CFM capability of the stock fan and then compare that to the CFM of your specific 2 fan setup. Which fans are you using by the way? In general, fans pull a lot of AMPs and it's probably better to not tax the alternator by using 1 fan if you can get away with it from a more efficient layout. This is why i've been asking about your fan test conditions and mounting because as my previous post said, if you just remove or disable one of the fans on Jim's radiator shroud, the remaining fan would suck air in from the gap between it and the radiator face and not effectively cool the radiator where if it were mounted directly to the rad, all of the fan's CFMs would pull directly through the fins might be enough to cool it.

Again, your hard work and development is great and I too will be in need of a good radiator so i'm also trying to learn or help you any way I can to develop your setup to have one of the most efficient and effective packages out there.

Thanks Billy! All valid points! I've got a long day at work ahead of me so i'll try to reply in chunks later today or this wknd. Have a great day!

---------- updated -----------
Agree with you again here Billy. In terms of the higher density fins the issue of plugging up with dirt/debris is a concern. Even puncture from rock impact can be an issue. I'm using a SOS radiator shield mesh screen and after about 15k miles of street and track driving it seems that has sustained the lion's share of the impact. It works pretty well and does not impede airflow as much as I thought it would. The good thing about a copper/brass radiator is the ease of repair. I can take it to virtually any radiator repair shop and they can solder it and fix it in a jam. That's a worse case scenario. I believe MASiV uses a special higher melting point solder and brazing process. In terms of the cleanup from dirt. Yes, that is a concern. I haven't seen this been an issue for me but time will tell. Low pressure water spray is probably the best way to clean.

I've been trying to find the OEM CFM rating but have had no luck. One thing I forgot to mention. In my setup I did bypass the low speed fan resistor. When my OEM fan comes on, it's normal speed (aka. high speed). BTW, yes, agree again on the amperage. That was a big concern for us and a downside to running two fans. We have worked with an Italian OEM manufacturer (will email you their name if you're interested) but our design criteria was to stay below 30amp of draw with both fans to not need to run external relays. As you know, it's not always a good thing to just put a bunch of high amperage fans on there. That's the easy thing to do and most people do it w/o knowing the consequences. In my car, it's even a bigger concern because i'm running a puny 90AMP Honda Prelude Alternator that comes with the CTSC kit as well as all the electronics required to run the HKS F-Con and the Denso "Supra" big daddy fuel pump. I'm very aware of my current draw in my car especially running a small 680 Odyssey battery. I monitor my voltage when I have the lights on, the AC blowers on and other accessories. Next on my list is to upgrade the alternator. I know my alternator is working overtime, hence why I really want to run the low amperage OEM fan.

In terms of running just one, unducted fan.. I'm still under the believe that, in this configuration, only about ~50% of the coolant is being cooled. Again, this assumes a low speed, no natural air flow condition. Cooling 50% of the radiator is not enough to cool the other 50% that mixes thru the radiator that's hot. I will admit.. I have not tested this in the latest radiator Jim and I have. So who know, it might just work but i'm personally, wishing for it, but not hopeful. If one fan, unshrouded can be used in this denser MASiV radiator it would so many fitment problems.

 

[stuntman]

Thanks Billy! All valid points! I've got a long day at work ahead of me so i'll try to reply in chunks later today or this wknd. Have a great day!

No problem FYI - My NSX is up and running with a stock motor while Applied Nick & Jim are putting together my built turbo motor.

 

[bngl3rt]

bought the harness from Dali. Fastraxturbo modified it to use with the F-Con and my OBD1 ECU.

Cool. I already know the HKS box *looks* more modern than anything from AEM, and that I have seen HKS systems in more tuned-up race cars (whereas AEM, for me, triggers associations of riced-out Civics), but other than that I don't really know why it's preferable - could you explain? Better PC software? Built in VGA output?

 

[RYU]

No problem FYI - My NSX is up and running with a stock motor while Applied Nick & Jim are putting together my built turbo motor.

I walked into Nick's barn a few months ago and said.... WHOA, who's motor build is that??? I guess I was looking at yours man! It's going to be an insanely good motor. I'm excited for you. Please share (or put up a build thread) when it's in the car. In any case, you have the ability to overheat the stock cooling system better than any of us so i'm curious what radiator you're using now (OEM?).

BTW, I updated the thread above with my 0.02 pesos.

Cool. I already know the HKS box *looks* more modern than anything from AEM, and that I have seen HKS systems in more tuned-up race cars (whereas AEM, for me, triggers associations of riced-out Civics), but other than that I don't really know why it's preferable - could you explain? Better PC software? Built in VGA output?

Before I go into HKS vs. other EMS's... Let me say, your tune is only as good as your tuner. Secondary is the equipment he has to work with. You also get what you pay for. With that said, the HKS systems are much more expensive. Again, the theme to my build was not to find the cheapest components but to find the best value. I struggled with AEM FIC vs. AEM EMS vs. ProEFI vs. HKS F-Con is vs. HKS F-Con Vpro vs. Motec. To me the HKS was the best value by a long shot. Notice I did not mention the AEM Infinity 10. I hear that system was a complete overhaul of their software and hardware. I would consider that if I was in the market now.

In general HKS has very good hardware and software. AEM was known to have buggy software requiring a lot of updates and a lot of warranty returns/refurbish.

In terms of piggybacks.. you can't compare the AEM FIC between the HKS F-Con iS. The FIC is so old now. AEM has pretty much ignored that platform for maybe near a decade. It's like a Motorola Startac phone vs. a Nexus 5. The AEM is a basic fuel injector controller. The HKS iS controls ignition timing (you can advance the timing), controls the injectors, reads all the OEM OBD1 and OBD2 factory Honda sensors (Throttle Position, RPM, Coolant Temp, MAP/load/boost, Speed, etc). The HKS also has many more available trim maps. Those trim maps are also more granular and precise. It's a pretty amazing "piggyback". It can even Autotune for those brave guys

The reason why HKS isn't very popular here is because of the dealer support and their proprietary software. Its not an "open" platform like the AEM which any Civic owner can tinker with. More about the features of the iS here.

--------------------------------------------------------------------
The iS series is HKS's correction / trim only ECU.

It features:
• 4 24x16 INJECTION trim maps (8x in total, for AFM or MAP), for different fuel octane ratings.
• 4 24x16 IGNITION trim maps (8x in total, for AFM or MAP), for different fuel octane ratings.
• 24x16 INJECTION and IGNITION trim maps, for scramble mode.
• 12x8 INJECTION and IGNITION correction map based on throttle change and RPM.
• 24x16 INJECTION correction map, applied by AFR-target map.
• 24x16 AFR target map for wideband-controller feedback correction, applied to the 24x16 fuel trim map.

It also features 2 optional voltage outputs suitable for:
• Airflow.

Injection (fuel) and ignition (spark) trim and correction can be individually enabled and disabled by:
• VPC
• Throttle change correction map
• Scramble map
• GCC (graphical control computer)
• IAT correction map
• ECT correction map
• Fuel trim map A
• Fuel trim map B

The iS series also features a cool feature that does not require having the optional Navigator unit. Basically there is S-Video output to display specs and numbers to a mini-TV, a popular item in Japan and slowly becoming popular in Australia and elsewhere around the world.

- - - Updated - - -

Also Ben, HKS is a huge company in Japan. They consult for OEMs a big part of their revenue stream. They bought from Honda the NSX ECU code base which is why the iS can read all the OEM sensors even on the OBD1. There are also many happy AEM EMS people (not sure there are many happy FIC users though, and of the happy ones, i'm not sure how hard they really drive their NSXs). You get what you pay for but I don't think the EMS unit is "bad" per say.

 

[RYU]

Let's talk suspension

One of my favorite topics (because I know so little about it!)

Back in 2009 when I first learned the limits of a mostly stock setup I began to research what kind of suspension mods made sense on this car. In the past my cars suffered from bumpsteer when lowered, or poor alignment options (i.e. McPherson struts), or just mediocre geometry to begin with. Throughout the years when I became more comfortable with the tires I wanted to run (Starspecs, NT-05, RE11s, Azenis, Federal RSR, etc...which are all basically high performance street tires) I eventually settled on a coilover setup I liked. Taking it a step further I also began to narrow down on the an alignment I like (but this is still a WIP). The sway bar selection are also WIP. I did decide I wanted to get rid of all the compliance bushings in the car. Hey, the car was old anyway.

I ended up with a set DG5s which I really like. Thanks Stephen! I like that even on very stiff Swift springs they can still be very compliant on the street. Suspension is one of those things that can be very subjective for the novice enthusiast so i'll just claim "ignorance is bliss" on this one. My exhaust and the DG5 coilovers are probably in the top 3 of my favorite mods on my car

One of my favorite mods was the non-compliance swap. I used TiDave's clamps, bushings, tie-rods, and sway bar end links. Thanks to Track Addict who came up with an ingenious removal and installation tool the rear bushing swap was done on the car and very cleanly! I'm also still currently on that alignment as you see below.

Track Addict made the remove of this bushing easy!

You really can't beat TiDave's parts. They are nice.

Offset bushings allow for some added camber adjustment as well.

Tie Rods (i forgot what they're really called)

The front non-compliance clamps.

 

[RYU]

More misc mods

I use to have an aluminum tank but after thinking thru potential cooling system failure points I realized I wanted the OEM coolant tank back in; a new one. I ordered the NSX-R coolant tank cover due to my open engine bay.

After my 2nd dyno session we noticed fuel pressure was dropping off at the higher RPM. The crappy Walbro 255 fuel pump was to blame. I upgraded to the Denso fuel pump. Commonly called the "Supra" pump since it was OEM on a Supra. This thing works great but make sure you double up on your wiring. This pump will draw more power. It's also considerably bigger than the Walbro. If you want my advice, don't ever buy a Walbro...why? removing the fuel tank is one of the biggest PITA things to do on the NSX especially if you don't have a hoist

These are the SOS engine mounts. I only did the front and back mounts since those are the ones most affected. You will notice a bit more NVH. I believe the OEM are around 80 durometer but the SOS ones are 90 durometer - a bit stiffer but not a lot stiffer. You will definitely notice the subtle firmness. I reckon bad/worn OEM mounts was a contributing factor to me grenading my transmission at the track back in 2010.

Comptech CARB approved headers and high grade gold heat shielding around the oil pan. I recommend not using the cheap gold shielding stuff because they either crumble, crack, or might even start a fire...yikes

 

[Coz]

Just got back today from spending a week in Cocoa Beach Florida.
I have some catching up to do.

Which I will do tomorrow regarding the results from the testing with 1 vs 2 fans, OEM Shroud vs the current shroud, how I have mine wired and the amp draw I see as I've experienced.

 

[Coz]

I originally wired mine threw all the OEM connections and quickly learned that running 2 SPA fans would continually blow the fan fuse. The SPA fans I have draw 13 amps a piece. Although this totals 26 AMPS and it's a 30 AMP fuse circuit, the system couldn't handle the surge. So the changes I made was to use the OEM temp sensor to run the fans at temp and also bypassed the low speed fan resister (1 fan only in my case) When temp hits the 178 degree mark, they both come on. I also wired both fans through dual relays directly to the battery.

Thanks Billy! All valid points! I've got a long day at work ahead of me so i'll try to reply in chunks later today or this wknd. Have a great day!

---------- updated -----------
Agree with you again here Billy. In terms of the higher density fins the issue of plugging up with dirt/debris is a concern. Even puncture from rock impact can be an issue. I'm using a SOS radiator shield mesh screen and after about 15k miles of street and track driving it seems that has sustained the lion's share of the impact. It works pretty well and does not impede airflow as much as I thought it would. The good thing about a copper/brass radiator is the ease of repair. I can take it to virtually any radiator repair shop and they can solder it and fix it in a jam. That's a worse case scenario. I believe MASiV uses a special higher melting point solder and brazing process. In terms of the cleanup from dirt. Yes, that is a concern. I haven't seen this been an issue for me but time will tell. Low pressure water spray is probably the best way to clean.

I've been trying to find the OEM CFM rating but have had no luck. One thing I forgot to mention. In my setup I did bypass the low speed fan resistor. When my OEM fan comes on, it's normal speed (aka. high speed). BTW, yes, agree again on the amperage. That was a big concern for us and a downside to running two fans. We have worked with an Italian OEM manufacturer (will email you their name if you're interested) but our design criteria was to stay below 30amp of draw with both fans to not need to run external relays. As you know, it's not always a good thing to just put a bunch of high amperage fans on there. That's the easy thing to do and most people do it w/o knowing the consequences. In my car, it's even a bigger concern because i'm running a puny 90AMP Honda Prelude Alternator that comes with the CTSC kit as well as all the electronics required to run the HKS F-Con and the Denso "Supra" big daddy fuel pump. I'm very aware of my current draw in my car especially running a small 680 Odyssey battery. I monitor my voltage when I have the lights on, the AC blowers on and other accessories. Next on my list is to upgrade the alternator. I know my alternator is working overtime, hence why I really want to run the low amperage OEM fan.

In terms of running just one, unducted fan.. I'm still under the believe that, in this configuration, only about ~50% of the coolant is being cooled. Again, this assumes a low speed, no natural air flow condition. Cooling 50% of the radiator is not enough to cool the other 50% that mixes thru the radiator that's hot. I will admit.. I have not tested this in the latest radiator Jim and I have. So who know, it might just work but i'm personally, wishing for it, but not hopeful. If one fan, unshrouded can be used in this denser MASiV radiator it would so many fitment problems.

- - - Updated - - -

Yes, this shroud seems to be working perfectly.

I did try at one time unplugging one fan when we were doing the testing. But what I found in the version 2 MASIV is that it was fine as long as I was driving the car on or off track. The problem I encountered was stop and go traffic and cool off times after a track session. One fan was just not enough to cool my car down, but I really believe this was just a situation of the turbo generating so much heat that when coming off the track that it just couldn't pull enough air through the radiator to cool it down properly or quick enough and it would just linger at over 200 for quite some time.

It's something I should try again with the MASIV version 3.

Yes, plan on totally sealing every thing around the MASIV now.

Hmmm, that's not a bad thought about using both side vents for airflow through an oil cooler. I am going to look into that. Just have to figure out where to mount the air to oil cooler. Most of the plumbing is already in place, will just need longer hoses.

Yes, I still have AC (From another post)...which I was considering removing, welding AN bungs on both AC condensers and using them for air to oil cooling.

Coz - Thank you for the kind words. I'm looking forward to testing your and Shanghai's cars hopefully sooner than later! Kristy will hopefully come out as well. I'm also antsy about my motor build.

That shroud should work alright. FWIW, removing the fan itself will improve your cooling at speed by a noticeable amount. If 1 fan is enough to keep your engine cool at low speeds or when parked, you can improve your overall efficiency by removing a fan. But this takes testing (or simply unplugging one to see if its enough before removing one).

Taping up the big gaps will help but once you make the sealing AIR TIGHT from bumper-radiator then radiator-hood, you'll see HUGE gains in cooling and front downforce.

Why not mount an air-oil cooler in the rear of your car and duct your side vents to the oil cooler?

 

[RYU]

Thanks for the feedback Jim! I'm a lot more comfortable knowing my data is accurate with you as a spot check. I installed the OEM non-vented hood this weekend. I'll be driving it a lot this Thanksgiving break but unfortunately it's not suppose to get over 70 degs ambient here.

- - - Updated - - -

I've wanted to do this for a while and finally getting around to it. It will be interesting to see the results from Blackstone. I've been running the RS*R Ran-Up additive for the last 7k miles as well.

Btw.. I ordered my OS Giken twin disc clutch. Hope that doesn't get stuck in customs! That will be installed with a JDM 5-speed rebuilt by Nick @ Applied. Fun stuff

 

[9doors]

So the changes I made was to use the OEM temp sensor to run the fans at temp and also bypassed the low speed fan resister (1 fan only in my case) When temp hits the 178 degree mark, they both come on. I also wired both fans through dual relays directly to the battery.

Yes, this shroud seems to be working perfectly.

I did try at one time unplugging one fan when we were doing the testing. But what I found in the version 2 MASIV is that it was fine as long as I was driving the car on or off track. The problem I encountered was stop and go traffic and cool off times after a track session. One fan was just not enough to cool my car down, but I really believe this was just a situation of the turbo generating so much heat that when coming off the track that it just couldn't pull enough air through the radiator to cool it down properly or quick enough and it would just linger at over 200 for quite some time.

It's something I should try again with the MASIV version 3.

Yes, plan on totally sealing every thing around the MASIV now.

I have the same wiring setup as Coz for the dual SPALs. As for temps, it's gotta be the turbo. I very quickly drop under 200 for both oil and water w/the PWR after I come into the pits and let her idle.

 

[RYU]

I have the same wiring setup as Coz for the dual SPALs. As for temps, it's gotta be the turbo. I very quickly drop under 200 for both oil and water w/the PWR after I come into the pits and let her idle.

I had the same problem also with the V2. Don't have that issue with the V3. So far so good for Coz and I. Will try to drive the NSX tomorrow. It will be stop and go traffic again but it'll only be about 70deg outside but I also have the OEM hood on.

Btw.. bummed about our Dec 14th track session Nick! Let's definitely rain check for early next year.

 

[Mac Attack]

Very well thought-out modifications Regan. Congrats!

Dave

 

[RYU]

Thanks Dave, for letting me bounce ideas of you but more importantly thanks for all the education. It's been an incredibly fun process.

---------------------------------------------

Did more testing at SOW yesterday. Car held together very well. I was at about 2mm of brake pad left with surprisingly even wear between front and rear so I didn't really push it in the braking zones. I'm locking up the front wheels and understeering even with my front Type R bar/OEM rear and a 9k/12k rear biased spring set. Tire wear looks good though so i'm liking my alignment settings. Tire temps were even and pressure were at 32psi hot all around. Have more tweaking to do but overall I had a good time out there.

In terms of cooling...IAT temps were a little too cold at around 36-42C but the temp compensation tables in the F-Con tune did their job. AFRs were solid. I hope by next year i'll have all my sensors wired up so I can report if my side mount oil cooler is working. It was in the high 30s F in the morning and quickly warmed up to the mid 70s F. I installed the OEM radiator single fan and reinstalled the factory non-vented OEM hood with the latest MASiV radiator prototype. At track speeds I had no issues with overheating. Car maintained good temps under 85-90C. I think for hotter months a vented hood will required and a stronger fan(s) will be needed for cool down in the pits.

---------------------------------------------

Also, very sad to say a few of us were at the charity event/Toy Drive our friend Sean L. (fellow NSX owner) hosted at Paul Walker and Roger Rodas shop AE Performance. Paul was a part of the socal carguy community and his loss will be deeply missed... but never forgotten. Many of us in Socal are deeply affected. He would often show up to track events and pass up everyone in his track cars (R32 or S15)!

Here was a pic of my NSX at AE.

For many of you who'd like to know more about Paul's life outside of the movies here's something.
http://popwatch.ew.com/2013/12/01/the-sides-of-paul-walker-you-may-have-missed/

I will be running this sticker in honor of ROWW, his charity. It's the only sticker to ever be put on the NSX. I hope some of you are able to take a moment to make a donation.

 

[stuntman]

I was a little incorrect with my previous post. You can't exactly remove or unplug 1 fan (when mounted on a shroud like Jim's) without greatly affecting the cooling ability of the remaining fan. Since air takes the path of least resistance, the fan would pull a lot of ambient air though the large inactive hole from the secondary unplugged fan and not through the fins of the radiator:

• A single fan can be mounted directly to the radiator.
  - Will offer the least amount of resistance at speed (>45mph). *Best option if capable of cooling in stop and go traffic.

• A single fan can be mounted to a shroud.
  - Will cool better than an unshrouded fan in stagnant (stop & go) traffic - due to larger surface area.

• A dual fan setup can be mounted to a shroud
  - Both must be functional.
  - Comparable to the single fan in terms of stagnant cooling ability & at speed restriction
  (if the shroud is the same size and fans are the same CFM)

• A dual fan setup can be mounted directly to the radiator
  -one or both can be running.
  -Comparable to the single fan (mounted directly to the radiator) if the CFMs are the same -in most cases its more

Jim -the holes you have in your shroud would also be affected to a large degree in terms of its cooling ability in stagnant air. I can't really think of an easy way for you to test if a single fan would cool enough for you in the paddock short of ditching the whole shroud and fan setup and mounting one directly to the radiator itself. I'm not surprised that one was not enough when you simply unplugged the other (look at the above picture). I'd still like to see if one fan would be enough when mounted to the rad.

FWIW, I bench tested a 16" Curved-blade SPAL fan (30A) and it spiked to 95A!!! at startup. I have one on my E36 M3 which I rarely turn on (because the factory pusher fan does most the work), but the one on my 1990 Mustang 5.0 actually dims the headlights, you can feel the load on the motor, and the volt meter drops for a second or two before stabilizing back at normal values.

 

[RYU]

FWIW, agree with you again Billy. I think the ideal fan setup for ALL conditions is to have 2 fans as close to the core as possible with no shroud. This is assuming one can balance the current draw of the two fans. I have been toying with the idea of building a shroud with these types of flaps (see bottom corner of fender here). If the flaps are placed properly then when the car is at speed the fans open but when the fans are On the flaps will close themselves due to the low pressure in front of the shroud. This way you can get the best of both worlds while only using 1 fan. Maybe if I wasn't so darn busy at work...

I'm shocked at the spike in the draw. 95amps is a lot. That might be enough to trip a breaker but it might not be a sustained 95amps enough to burn the fuse. Most electrical components will have a spike like this and most fuses will hold high current for a few milliseconds but 95amps is still a lot!

Good luck this wknd at Buttonwillow! I hope to come to support you and FX if work permits.

 

[stuntman]

It would be great to see you! I think Ryan is trying to come out Saturday. Yes 95 is crazy. It's the 16" spal fan we use on the NASCAR cup cars. I was trying to use a 45A AC-DC converter to power it for a project I was working on, and it kept tripping the fuse. I put the fan on a nice bench test unit at Roush and was suprised to see the initial spike draw. It's not enough of a sustained draw to break the 30A fuse I have on it in my street cars since it stabalizes at <30A (~25A) but like I said, you can see the headlights dim briefly when you turn it on.

I think the goal is to use one big fan or a twin setup mounted directly to the rad. -And find out which CFM is enough when paired with radiator X at Demand Y. I don't think we have collectively tested a proper 1-fan yet.

 

[RYU]

I think Willem is trying to make it too. I've coordinated with Jon K but I think he's going to support you guys for both days. I can barely try to make one!

I had a light bulb pop up in my head in regards to using one fan. I think a shrouded setup like this might just work. Again, my ideas are worthless w/o testing.

 

[stuntman]

Can you double check with Nick, but I think the hot water goes IN the TOP and the cold water goes OUT the BOTTOM. I'm no engineer, but I think the shroud just has to do with surface area. I like the idea of minimizing the shroud size on the sides but I'm not sure how well it will cool that column of fins when its exposed to such a short section. It may not cool anymore than an equivalently sized square shroud with the same surface area. Maybe an engineer can chime in to confirm or deny.

 

[RYU]

Billy - Would it matter (from a cooling perspective) if it flowed top to bottom vs bottom to top? I can see where it would make a big difference flowing from side to side vs. top to bottom. I am checking with Nick btw..

Here's a picture of a side to side flowing radiator. In this configuration a 1 fan, non-shrouded setup would work I reckon.

Coz - do you know by chance if the FX radiator flows side to side?

Edit: Here's a better pic of a side to side, 1 fan, no shroud setup. I think this setup will work, if he used a different fan/shroud setup, because the flow is going side to side and 100% of the coolant is in contact with fins/tubes being cooled by the fan. In a top/down or bottom/up flowing radiator, in say, heavy stop/go traffic conditions a good portion, say 40%, of hot coolant flows thru fins/tubes that are not cooled by the fan. This is why my car was overheating in a 1 fan, no shroud setup but why it doesn't overheat in a 1 fan, shrouded setup.

 

[Coz]

Cooled coolant flows from the top of the radiator.

The airflow diagram you posted Billy makes a lot of sense.
Whats interesting is now with the V3 coming off track and sitting in the paddock, my cool down times are quick, which I contribute to fin spacing and density in the V3 revision. Since going to the latest V3, Track temps are now in the 205 to 210 range after a 30 minute session. So cool down time is very quick since its not getting that hot to begin with. (220+) Even at 210, sitting at idle, fans running, cool down to 190 takes about 3 or 4 minutes. At a stand still, in traffic or just sitting and idling, I never see anything above 180.

So if the problem of stagnet air cool down time has been solved, then the holes in my shroud should in fact help airflow to some degree on track, correct ? (According to the diagram posted)

I was a little incorrect with my previous post. You can't exactly remove or unplug 1 fan (when mounted on a shroud like Jim's) without greatly affecting the cooling ability of the remaining fan. Since air takes the path of least resistance, the fan would pull a lot of ambient air though the large inactive hole from the secondary unplugged fan and not through the fins of the radiator:

• A single fan can be mounted directly to the radiator.
  - Will offer the least amount of resistance at speed (>45mph). *Best option if capable of cooling in stop and go traffic.

• A single fan can be mounted to a shroud.
  - Will cool better than an unshrouded fan in stagnant (stop & go) traffic - due to larger surface area.

• A dual fan setup can be mounted to a shroud
  - Both must be functional.
  - Comparable to the single fan in terms of stagnant cooling ability & at speed restriction
  (if the shroud is the same size and fans are the same CFM)

• A dual fan setup can be mounted directly to the radiator
  -one or both can be running.
  -Comparable to the single fan (mounted directly to the radiator) if the CFMs are the same -in most cases its more

Jim -the holes you have in your shroud would also be affected to a large degree in terms of its cooling ability in stagnant air. I can't really think of an easy way for you to test if a single fan would cool enough for you in the paddock short of ditching the whole shroud and fan setup and mounting one directly to the radiator itself. I'm not surprised that one was not enough when you simply unplugged the other (look at the above picture). I'd still like to see if one fan would be enough when mounted to the rad.

FWIW, I bench tested a 16" Curved-blade SPAL fan (30A) and it spiked to 95A!!! at startup. I have one on my E36 M3 which I rarely turn on (because the factory pusher fan does most the work), but the one on my 1990 Mustang 5.0 actually dims the headlights, you can feel the load on the motor, and the volt meter drops for a second or two before stabilizing back at normal values.

- - - Updated - - -

Not sure what configuration they are using now. Last time I was at the shop I believe it was either a Ron Davis or Driving Ambitions Dual Pass, in a lay down position.
Its impossible to compare our set ups and FXMD's for any data.

Billy - Would it matter (from a cooling perspective) if it flowed top to bottom vs bottom to top? I can see where it would make a big difference flowing from side to side vs. top to bottom. I am checking with Nick btw..

Here's a picture of a side to side flowing radiator. In this configuration a 1 fan, non-shrouded setup would work I reckon.

Coz - do you know by chance if the FX radiator flows side to side?

Edit: Here's a better pic of a side to side, 1 fan, no shroud setup. I think this setup will work because the flow is going side to side and 100% of the coolant is in contact with fins/tubes being cooled by the fan. In a top/down or bottom/up flowing radiator, in say, heavy stop/go traffic conditions a good portion, say 40%, of hot coolant flows thru fins/tubes that are not cooled by the fan. This is why my car was overheating in a 1 fan, no shroud setup but why it doesn't overheat in a 1 fan, shrouded setup.