Sale pending, my first project (should be a good one)

[sparky]

thanks although the final graphs are on page 3 in your post 73. Obviously I should have read the whole thread before posting!

So how much did the RDX kit from RyWire cost?

 

[Nero Tenebre]

My Install

I just wanted to report my results and impressions.

I have a 95 w/ OBDII ECU, Uni-Filter+AIS, Comptech Headers, Taitec GTLW, and Fidanza Aluminum Flywheel. Baseline dyno on dynojet reported ~263whp/198lbft which I thought was pretty decent considering stock is usually around 225whp.

My dyno information won't be as scientific as one would prefer because I changed other variables at the same time. I swapped my stock cats+GTLW for test pipes+STMPO Messiah exhaust system and also had my intake manifold and throttle body cleaned while performing the RDX injector and FIC install and required tuning. Still, I think I am the only one running this on OBDII right now so some data is better than no data.

My "after" dyno results showed about 277whp/206lbft with a lot of gains in low-end torque. Actually there is a lot of gain everywhere you look across the rev-band, which is no doubt a huge improvement. I don't know how much "area under the curve" was gained exactly but you can see from the plot that it would be an impressive number. At 4800rpm, you can see the TQ delta is about 20lbft (half of the previous dyno's max delta around the same rpm but still excellent gain). Overall there is about a 50whp improvement over a stock NSX so that is definitely a sizable improvement!! Not to mention the weight reduction that comes with headers/exhaust/test pipes, meaning the delta in power:weight ratio is pretty decent for just bolt-ons.

After driving the car in different conditions, those numbers did indeed translate to noticeable power increase. Before I did this, I kept thinking that if the power gains are similar to what you can expect from adding headers (very noticeable) it would be worth it- and this jump is exactly what this felt like. The car pulls stronger in every gear and every condition, even top gear acceleration is improved on the fwy and I definitely noticed the extra TQ driving around the city because I didn't need to shift as much. I will say it does feel like a bigger motor in those regards.

I wish that I could find out how much I gained from just the tune and then just the injectors, but of course I didn't separate the two bc I would have had to pay for tuning twice. IMO, the ideal dyno would show I/H/E+chip and then I/H/E+Injectors/Re-chip. I don't remember if LRAOs dyno had a tune on it prior to the injector install but I know I have seen around 10whp gains with just a tune and LRAO said at the beginning he expected to see about a 5whp gain from the injectors. That makes sense to me still, so if you are planning to fight for every bit of NA power then this is still a great buy for a $400 kit plus the chip cost and you can install without dyno time (so DIY). For OBDII, the value return drops off steeply as the kit, plus FIC, plus boomslang harness, plus tuning runs about $1600. Although... by NA standards it may still be good value considering headers are about $1500 too and yield similar results. And once you've got headers, this is the next cheapest thing you can do that actually yields power results in a noticeable way. Plus, this mod can still be useful in other ways...

Alas, I am now fairly certain that I am abandoning the arduous path of seeking NA power gains and this is where I will draw the line at spending money on NA power. I had been on the fence recently about it and figured this would help me decide. What's really nice about these injectors and FIC is that it's not money wasted as you can still use the components for a sub-400whp turbo build if you choose to diverge paths and "go to the dark side" . Or, if you want to go for more boost, you can re-sell these knowing they are a worthy mod and there will be demand.

After much research (and hats off to LRAO for his persistence) it just looks like there is no good endgame in the NA arena. There is A LOT of spending/downtime involved and not a lot of return (which was figured out years ago by Comptech customers btw). There have been some exciting developments in the NA arena lately with this and ITBs. Actually I have been the biggest fan of ITBs and keeping this car NA but when I look at the ITB results there is no way I would buy that over a turbo kit. Actually, I am making more power now than some of the cars with ITBs+supporting mods that I have seen and the driving experience is very similar too.

I'm pretty certain with ITBs I could reach the 300whp mark. However, I am drive by wire so I would have to retrofit a throttle cable and probably get a full EMS, making the cost over $10k for 25whp ($6k for ITBs, $2k for the retrofit, $2k for EMS, then add labor/tuning on top) and the throttle response wouldn't even be that much better than now. Add to that, cams/headwork, built internals, etc. and you can see what it costs to achieve 400whp (my personal goal). I'm not trying to discourage anyone here, only to give a realistic picture of things. Most of the die-hard NA guys know what they are getting into actually- I am just discovering and doing research so I can make the right decisions for me. Hopefully this has helped others do the same and it's relevant in that context Sorry for the tangential thinking, let's not turn this thread into an NA vs Turbo debate.

 

[L_RAO]

Those are some great results. Some thoughts:

1. Not sure how much of a difference there is going to be between OEM cats + GTLW vs. test pipes & the Messiah exhaust. The key here, IMO, is that you were running something other than the OEM exhaust.

2. You're making about 13 wHP more than I am, though I am making about 3 more peak wTQ. Of course we tested on different dynos, but nonetheless there is something to compare to, finally.

3. Do you have the AFR plots?

4. We picked up 2 wHP by advancing the timing, which the AEM FIC is unable to do.

5. My intake manifold / throttle body project should hopefully be worth about 12-14 wHP, and should cost me about $900 total, so if that proves to be true there is another mod for the NA guys that comes in at less than $100 per wHP, which is my guideline for price/value ratio.

 

[Nero Tenebre]

Those are some great results.

Thanks, I am grateful that you looked into this and shared with all of us.

1. Not sure how much of a difference there is going to be between OEM cats + GTLW vs. test pipes & the Messiah exhaust. The key here, IMO, is that you were running something other than the OEM exhaust.

I think test pipes may yield 1-2HP at most, there may be data out there. I didn't throw any CEL afterwards nor is there any smell so far, but the car sounds like it is in full race mode now!

2. You're making about 13 wHP more than I am, though I am making about 3 more peak wTQ. Of course we tested on different dynos, but nonetheless there is something to compare to, finally.

It may be in the flywheel too since we are talking WHP. There was a noticeable improvement at fwy speeds when I installed it. Could be worth looking into since you are looking to extract every bit of performance, and it was only $300. Also, I would stick with the dual disc OEM clutch if 300whp is your goal, just work the gearing like Honda did.

3. Do you have the AFR plots?

I think I can get them this weekend, they didn't have it printed for me but I discussed them with the tuner and they seemed similar to yours. I'll just get them and edit this post so we can compare hard results. I need to go back to have my valve covers swapped out anyways.

4. We picked up 2 wHP by advancing the timing, which the AEM FIC is unable to do.

You are correct! All I could do is add fuel. Extra expense and less versatile for us OBDII guys

5. My intake manifold / throttle body project should hopefully be worth about 12-14 wHP, and should cost me about $900 total, so if that proves to be true there is another mod for the NA guys that comes in at less than $100 per wHP, which is my guideline for price/value ratio.

Actually I am very interested in this result too. I don't see that much in it personally, unless you are FI and that little bit of extra space is packed with densely compressed intake charge. Although if you get 14whp out of it for another $1k I will probably just make that where I draw the line since it will be another noticeable gain and be forward-compatible with FI benefits. :biggrin: Kudos again for your pioneering efforts and I hope you can prove me wrong! How soon will you have results?

 

[L_RAO]

I will be meeting up with Brian (Prospeed) hopefully in the next 2 months at Bisi's (again). We will try to conduct "clean" tests.

1. Prospeed exhaust (over baseline, which is an NA2 OEM exhaust)
2. Prospeed intake (over baseline, which is an OEM airbox with K&N filter + Cantrell AIS)
3. We will then install the ported intake manifold & Blox 74 mm TB.

Ponyboy was nice enough to lend me a LT5 (ZR-1 Corvette) dual oval throttle body. I have a spare manifold that I will try to create a flange for (so I don't have to weld the TB on - Ponyboy probably wouldn't like that :biggrin and test that as well.

 

[Nero Tenebre]

I will be meeting up with Brian (Prospeed) hopefully in the next 2 months at Bisi's (again). We will try to conduct "clean" tests.

1. Prospeed exhaust (over baseline, which is an NA2 OEM exhaust)
2. Prospeed intake (over baseline, which is an OEM airbox with K&N filter + Cantrell AIS)
3. We will then install the ported intake manifold & Blox 74 mm TB.

Many thanks to you and Brian again, that data separated out will be valuable and will help him sell his products if they work out. I didn't realize you were on OEM exhaust-- that's probably 10 of the 13whp difference right there! http://www.scienceofspeed.com/products/exhaust_airflow_products/NSX/TAITEC/JGTC_Parallel_Exit/JGTC_Dyno.gif

And I thought the Prospeed intake system was snaked into the rear of the wheel well (eliminating the airbox and using a cone filter)?

 

[L_RAO]

Yeah, I was waiting for HyTech to build an exhaust system that featured an X-pipe, but we might put a human on Mars before HyTech ever gets around to the NSX. I was very excited when the Prospeed system came out.

Yes, the Prospeed intake snakes towards the rear of the car in the fender, unlike the typical behind-the-side-scoop configuration. IMO, this gives it the critical extra pipe length that the motor wants/needs.

 

[naaman]

This is so cool!

 

[Nero Tenebre]

I thought that the FIC was adding fuel and the larger injector was injecting more fuel in the combustion mixture which would result in more power and more fuel consumption (since it was supposedly running lean with typical I/H/E mods). But the way tuning was explained to me, the larger injector is not injecting any more fuel, it is just scaled back to run at a lower capacity. It would make sense if the AFR shows the same evidence that the gains were from efficiency then. Have I misunderstood how the tuning is done? I'm still wondering how much would be gained from just a tune too.

 

[BBVNSX]

Those are great results!

But below 4k rpm how does the engine power feels? was drivability affected? any issues with idling?

 

[Nero Tenebre]

It is exactly the same at idle- quiet and smooth. It feels the same everywhere (meaning the power curves are similar) except with more power and less effort required to move the car. If you've experienced the NSX before/after headers it's just like that.

 

[L_RAO]

I thought that the FIC was adding fuel and the larger injector was injecting more fuel in the combustion mixture which would result in more power and more fuel consumption (since it was supposedly running lean with typical I/H/E mods). But the way tuning was explained to me, the larger injector is not injecting any more fuel, it is just scaled back to run at a lower capacity. It would make sense if the AFR shows the same evidence that the gains were from efficiency then. Have I misunderstood how the tuning is done? I'm still wondering how much would be gained from just a tune too.

Tuning an ECU is the process of adjusting your maps - first, you're trying to get your AFR as close to 14.7 as possible - that's where "ideal" power is made. That being said, most tuners like to err on the side of a being a little rich.

The map we refer to primarily when dealing with injectors is the duty cycle, that is, how much (of a %) the injector is given power. So, an injector that receives 100% duty cycle is constantly being supplied with power. The end goal of tuning is to program the map so that your at 13.2-13.6 throughout the entire RPM range.

The problem with the OEM 240 cc/hr injectors is that they are close to being maxed out with respect to their fuel capacity, and that's with a stock motor. Brian and I found the stock AFRs to be really lean on my car, and all it had at the time were Comptech headers. Maybe that was be design for gas mileage - who knows? But my car was much happier after the tune and the injectors.

I believe Honda probably went too cheap with their modular approach; the NSX injectors are the same injectors as the B16A, B18C - those engines are 400 cc and 450 cc/cylinder. The NSX is 500 cc/cylinder (533 cc/cylinder in the 3.2L).

 

[greenberet]

The map we refer to primarily when dealing with injectors is the duty cycle, that is, how much (of a %) the injector is given power. So, an injector that receives 100% duty cycle is constantly being supplied with power.

Are you sure about that? At 100% duty cycle the injector is spraying fuel continuously? In a four stroke engine the intake valve is only open about 25% of the time. So at 100% duty cycle the injector would be spraying at the back of the closed intake valve 75% of the time. I know Porsche installed CIS (constant injection system) fuel injection in 911s in the 1970’s that actually did spray fuel continuously. That would be terribly inefficient if the injectors are as close to the intake ports as they are in an NSX.

I’d hope “duty cycle” means how many milliseconds the injectors are open (the pulse width) at full throttle and maximum revs compared to how many milliseconds the intake valves are open at maximum revs or something like that. If the injectors are continually open at 100% duty cycle that would be horrible.

 

[Nero Tenebre]

I thought injector duty cycle referred to the % of volume (CC) that was being injected through the injector and the 410/220/etc was the max volume it was capable of... but I was just assuming.

Hey Loc, is this what you got to experiment with?
http://www.nsxprime.com/forum/showthread.php?t=120821&highlight=throttle+body

You should see what they did to that guys Race motor, they kept it all NA! http://www.nsxprime.com/forum/showthread.php?t=116661&highlight=shad

 

[sparky]

Has anyone heard from Prospeed (or his offsider frumpybumps) lately?

I'm waiting to get my ECU and new injectors back here, but I haven't heard from them for a few weeks now and frumpy is not answering my emails