My throttle body / ported intake manifold project (08/14/2013 Update)
- Thread starter L_RAO
- Start date
Non-VTEC lobes are the same.
I haven't pushed it hard into VTEC. Not until I get it tuned. But the crossover into VTEC is definitely more noticeable now.
I haven't pushed it hard into VTEC. Not until I get it tuned. But the crossover into VTEC is definitely more noticeable now.
Yeah, I was trying for the "ultimate NA build", but after riding in gsrboy's ITB'd car, I had to change my goal to "ultimate plenum'd NA build." LOL.
I know i've read it before somewhere but can you remind us what happened to your engine, where it was (mods wise), and what you would have done different (if any)? Kind of like a "lessons learned" synopsis.
If you could be so kind........
What kind of ITB setup does gsrboy have? What made you not want to go the ITB route? Just curious.
Science of Speed makes just about the only ITB you're going to find for this car, and so far, not many have them. I had the privlidge of riding in one of the first cars to have it installed. At the time, I believe the only mods on the engine were the ITBs and headers/exhaust. The ITBs after a tune netted a whopping 62 lbs. ft gain in peak torque, and a 42 whp gain in peak power. The car weighed 2800 lbs. It was a thrill to ride in, for sure. Power comes on and builds strong, and it pulls hard all the way to redline.
He's probably put off by the cost of ITBs (the SoS set costs $4700, not including the EMS, injectors, tune, etc).
He's probably put off by the cost of ITBs (the SoS set costs $4700, not including the EMS, injectors, tune, etc).
He runs Custom made Jenveys Itbs, SOS is not the only one that makes itbs. there is a company called Hayward performance that also makes itbs for the NSX for a more reasonable price.
I had the iem comptech package.The biggest mistake i made was thinking that the moving parts of the heads were set and forget.The valve springs cracked and I got the floating valve thing.....so for anyone going aftermarket cams/springs.....periodically check those...maybe every two years...or just replace.My first engine blown was a spun bearing at pocono....the infamous weak oiling of # 5 ....or was it #3 piston/rod bearing? I forget now.
+1
There are I recall two companies in Japan offering ITB's for ages (one being TODA)
Any updates? Did you ever get tuned?
Yes, I thought I posted it.
Anyways, about a year ago (August '13) Brian (Prospeed) and I met up at Bisimoto for a tuning session.
We went from:
Headers/Exhaust/RDX injectors/Prospeed Stage 3 (January '12, 264 wHP at 7100 RPM, 64 degrees ambient temps)
to:
+Comptech camshafts/+ported intake manifold assembly (no VVIS)/+74 mm throttle body
It was 103 degrees that day. We made 285 wHP at 8000 RPM, but the powerband was still climbing. Brian, Bisi and I agreed that we shouldn't push past 8000 RPM on the OEM oil pump gear. In addition, we lost a lot of mid-range due to lack of VVIS. Yes, I am publicly confirming, NA cars NEED the VVIS plate.
Since then, I've been hoarding parts, but here's what will be installed in the coming months:
Comptech-spec valvesprings (WPC treated)
Newer style LMAs (WPC treated)
WPC treated rocker shafts
New OEM Honda oil pump housing, blue-printed by John G. of HyTech Exhaust and WPC treated
Toda oil pump gear (WPC treated)
I may or may not have another (yes, I have a few laying around) intake manifold. This one will feature ported runners only, keeps the divider, and keeps the VVIS.
WOW!
Thanks for the update.
Would you mind posting the dyno sheets so I can compare with my NA dyno sheet?
Thanks for doing this man!
Insane! The tq curve took a huge hit.
I would recommend putting the stock intake manifold and putting the car back on the dyno. This would confirm that its that manifold that is causing loss in power.
This way at least you can have a new base line to compare with, even without tuning the ecu you should be able to see the power difference.
Good luck bro.
I would recommend putting the stock intake manifold and putting the car back on the dyno. This would confirm that its that manifold that is causing loss in power.
This way at least you can have a new base line to compare with, even without tuning the ecu you should be able to see the power difference.
Good luck bro.
That might be hard to pull off. After having the cams + current intake manifold installed, the car ran so poorly (from the "old" tune) that I could't take it past 5000 RPM when I drove her home.
Brian had to spend 2 hours on the dyno just dialing in the ECU for the "no more VVIS" maps.
Basically, VVIS vs. no-VVIS, the fueling/timing maps become so dramatically different that you can't really compare one vs. the other.
The only viable comparison I could make is:
1. Install VVIS on current manifold (no divider, 74 mm TB) and compare it against:
2a. Ported manifold that does retain divider plate, but has stock TB (keep VVIS in)
2b. (use gutted VVIS)
In either case, you don't really get a great scientific study.
Finally, dyno time is expensive. My budget is getting thin for all these "ultimate NA" projects.
Looks like you are close to your goal! Hopefully another 500-750 RPMs will get you there.
For the valvesprings, what retainers are you going to use?
I wouldn't shim the oil pump bypass spring. Something to ask John, but I'm sure he'll agree. Also, while you are blueprinting the pump housing, I have some awesome metallic epoxy that can withstand long-term oil environments at up to 350F. I'll look it up where I got it (somewhere in UK). Otherwise, you are just smoothing some edges and not taking full advantage of reducing pump suction and discharge losses. You can also do the same treatment in the oil pump pedestal. I have a brand-new housing and gear that has been WPC-treated, filled/blueprinted, and pickup modified that I will never use since I went dry-sump... sigh.
Finally, make sure your pan/pickup have the correct clearance and your pickup screen is clean. A new pickup o-ring is essential, as well as making sure there are no cracks in the seams that could cause pump suction cavitation.
Good luck!
Oh - Completely agree on the VVIS. I was wrong in some of my older posts about it's effectiveness until I messed around with it. Now, I even retained it with my boosted setup by changing the springs and normally closed/open position in conjunction with a clever vacuum source. I'm surprised nobody retains it even for boosted application. Sure, it's the easy/lazy way, but the resonance tuning still works well for the smaller/larger plenums even with a slight change in intake charge density due to boost.
For the valvesprings, what retainers are you going to use?
I wouldn't shim the oil pump bypass spring. Something to ask John, but I'm sure he'll agree. Also, while you are blueprinting the pump housing, I have some awesome metallic epoxy that can withstand long-term oil environments at up to 350F. I'll look it up where I got it (somewhere in UK). Otherwise, you are just smoothing some edges and not taking full advantage of reducing pump suction and discharge losses. You can also do the same treatment in the oil pump pedestal. I have a brand-new housing and gear that has been WPC-treated, filled/blueprinted, and pickup modified that I will never use since I went dry-sump... sigh.
Finally, make sure your pan/pickup have the correct clearance and your pickup screen is clean. A new pickup o-ring is essential, as well as making sure there are no cracks in the seams that could cause pump suction cavitation.
Good luck!
Oh - Completely agree on the VVIS. I was wrong in some of my older posts about it's effectiveness until I messed around with it. Now, I even retained it with my boosted setup by changing the springs and normally closed/open position in conjunction with a clever vacuum source. I'm surprised nobody retains it even for boosted application. Sure, it's the easy/lazy way, but the resonance tuning still works well for the smaller/larger plenums even with a slight change in intake charge density due to boost.
I think I would have hit 290 wHP easily if it were 64 degrees that day like it was at the other dyno session.
Not sure yet on the retainers, I'm open to suggestions. The person I was consulting with for the build recently passed away; he was not a fan of Supertech or Ferrea, nor was he a fan of Ti retainers in general. In addition, if I'm not mistaken someone lost an engine due to the retainer that came with the old Comptech package. I should probably do more homework on that.
John has a shop near his that makes steel retainers that are just about indestructible, however I would need to order 20 sets for them to consider my job.
John is not going to shim it.
You could very easily sell that set-up. Hell, you should have sold it to me and saved me some $$$.
Jim Cozzolino will be putting everything together for me. I'd like to think that luck is no longer part of the equation once you throw enough money at something.
I still think that this particular configuration is perfect for any turbocharged NSX out there.
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shawn110975
Suspended
well I must say your almost to your 300 goal :wink: sorry about the Tbromley's car thing
you have brought some great stuff to the table and the NSX community thanks you.
keep up the good work
you have brought some great stuff to the table and the NSX community thanks you.
keep up the good work
No need to apologize. I understand where he was coming from.
That's very nice of you. I just hope others are inspired to try things off the beaten path.
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That was docjohn I thought.
FYI - Rob also attributed two destroyed engines to failed keepers or retainers. For me, I was reusing my stock cams, not exceeding 8k RPM, and not boosting more than 15psi. Therefore, no need to go to aftermarket springs, retainers, and keepers... although I replaced those with new OEM components.
Sorry that's not much help, but I specifically wanted to stay away from that potential nightmare of high-lift cams and aftermarket springs... especially Ti retainers. That's why I said "good luck."
Personally, I would just bump up the redline by no more than 250RPM, keep your existing valvetrain or replace the springs/retainers/keepers with new OEM stuff, and then adjust your cam timing for the remaining last bit of power. That should be a safe route.
I haven't looked at the specs for the Comptech cams, but I guess the OEM springs are compatible for lift? I looked once at the Comptech springs (the link I gave you earlier for the eibach specs IIRC), and the springs looked to be overly stiff. But I am certainly no expert in this stuff.
My $0.02.
Dave
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I am still alive...I still have those heads with the cams...some day i will just sell them ,but have held on to them because I am hoarder....and I still enjoy the thought of building another strong NA motor.
