Free tuning and ECU service for a CTSC owner that's willing to innovate.

[sr5guy]

Looking for a Comptech Supercharger equipped semi-local NSX owner (I'm in Bristol, CT) to be the first to assist in coming up with a solution to dump the antiquated rising rate FPR, fuel pump module, check valve, etc that comes with the CTSC kit in favor of a factory ECU tuned solution.

Ideally the owner would be able to arrange and pay for time at the dyno shop of his choice (approximately 3-4 hours) and be willing to upgrade to RDX 440CC injectors, a factory or aftermarket non-rising-rate fuel pressure regulator and a 3 bar map sensor on site (which I could install if necessary). I would provide free, safe and conservative but somewhat experimental tuning services in exchange for developing a base map for other NSX CTSC owners.

Let me know if you would be interested and I will provide more details.

If you haven't been following my thread over the last few years, here is the link:

http://www.nsxprime.com/forum/showthread.php/143407-Interest-in-Tuning-for-Boost-with-the-Stock-ECU

Thanks,

Matt

 

[jwmelvin]

OBD2 included or OBD1 only?

 

[sr5guy]

Sorry I didn't specify OBD1 91-94 NSX's only.

-Matt

 

[Aaron94T]

I definitely agree that their are components of the old CT fuel system that are band aids. However, what is wrong with a rising rate FPR?

 

[RYU]

If I was in your hood Matt...I WOULD TOTALLY JUMP AT THIS OPPORTUNITY!!!

 

[sr5guy]

I definitely agree that their are components of the old CT fuel system that are band aids. However, what is wrong with a rising rate FPR?

The biggest band aid is the rising rate FPR. Not only does fuel pressure approach 90PSI at full boost, the linear rise in boost to pressure ratio doesn't match up to the engine's volumetric efficiency fuel requirements. There are other intangibles such as increased wear to the fuel pump and increased injector latency at the higher pressure as well. I do realize and respect that this has been an adequate solution for the NSX for longer than I have been wrenching on cars, but if you were to ask ANY professional tuner about a rising rate and you may get laughed at or even hung up on. Finally, tuning a fuel map to give repeatable results with a rising rate regulator installed is not possible.

IMHO, the only reason they were used on the CTSC kit was for cost effectiveness and inability to re-program the stock ECU, which I've thoroughly cracked.

Forgive my lack of research, have any members with the CTSC gone standalone and documented their progress with a before and after dyno? This tuning should accomplish the same type of gains without the costs or disadvantages of the standalone.

-Matt

 

[Aaron94T]

The biggest band aid is the rising rate FPR.

Not following the logic of this. As an old school Supra guy, RR FPR's have been a staple. As the boost rises fuel will need to increase every time, period. Not sure I see the benefit of doing it all with tuning as your maps would have huge fuel increases as boost ramps versus more gradual ones. Also, from a pump wear perspective the CT runs so little boost that the max FP would be a small increase over static, percentage wise. If the pump can handle static I am sure it can handle max. This would be more of a concern with a high boost turbo car and even there I have never heard of it as a problem.

My point is, just make sure you don't throw the baby out with the bathwater in your testing. (Baby being the RR FPR :tongue I do think what you are doing with the stock ECU is the best way to tune as stand alones are a PITA. I am probably going to get a piggy back as my car is currently unturned. When I get the piggyback I will keep the RR FPR as that is the not problem, the lack of fuel and timing map adjustment is.

 

[RYU]

I would hate to see this effort derailed. The fact is Matt is doing the entire community a great service here and his method provides for a higher resolution tune with the OEM ecu.

Arguing the merits of the CTSC fueling components is besides the point really.

- - - Updated - - -

BTW I believe i am one of the first using the RDX injectors at roughly the OEM rail pressure with a 7psi CTSC. Has been working well so far.

 

[sr5guy]

Not following the logic of this. As an old school Supra guy, RR FPR's have been a staple. As the boost rises fuel will need to increase every time, period. Not sure I see the benefit of doing it all with tuning as your maps would have huge fuel increases as boost ramps versus more gradual ones. Also, from a pump wear perspective the CT runs so little boost that the max FP would be a small increase over static, percentage wise. If the pump can handle static I am sure it can handle max. This would be more of a concern with a high boost turbo car and even there I have never heard of it as a problem.

My point is, just make sure you don't throw the baby out with the bathwater in your testing. (Baby being the RR FPR :tongue I do think what you are doing with the stock ECU is the best way to tune as stand alones are a PITA. I am probably going to get a piggy back as my car is currently unturned. When I get the piggyback I will keep the RR FPR as that is the not problem, the lack of fuel and timing map adjustment is.

Rising rate FPR - a hack designed to make the stock injectors flow more than they were designed - is cool with you because it's been a staple? The fuel requirements of the motor don't match the linear ramp of the RRFPR - period. Did you notice I specified larger, better atomizing RDX injectors in my first post? There is absolutely no logic in installing larger injectors _and_ retaining the RRFPR. I am going to refuse tuning the ECU if it has a rising rate installed.

You should consider getting a second opinion on the RRFPR from a more seasoned tuner, or Google.

-Matt

 

[Lamchop168]

I have a standard Comptech whipple with basic installation. I wish I understand what this is all about. Does it give better performance, longevity of the SC, etc? I would do anything for free, but mine is an 03. :smile:

 

[Aaron94T]

Rising rate FPR - a hack designed to make the stock injectors flow more than they were designed - is cool with you because it's been a staple? The fuel requirements of the motor don't match the linear ramp of the RRFPR - period. Did you notice I specified larger, better atomizing RDX injectors in my first post? There is absolutely no logic in installing larger injectors _and_ retaining the RRFPR. I am going to refuse tuning the ECU if it has a rising rate installed.

You should consider getting a second opinion on the RRFPR from a more seasoned tuner, or Google.

-Matt

Matt,
Wow, your fired up! What I bolded are the gem's from your post.

I guess having a discussion about RR FPR's is out of the question with you. You do know you can use a RR FPR with upgraded injectors and a standalone which is what Supra's have been doing since the dawn of time? Any who, obviously you have everything figured out so no need to have a discussion with actual owners. You seam like a pretty flexible guy... As you were.

 

[NSX-Files]

sr5guy is not the only one who thinks Comptech's rising rate FPR and boost-a-pump solution are band-aids and are not the ideal way to handle fueling for a forced induction NSX. It works, but that doesn't make it the "right" way to do it. The CT FPR bumps up the rail pressure to about 90-100 psi which is about twice the pressure a 1:1 FPR would produce, more than a "small increase." The oem injectors were not designed for that. The boost-a-pump spikes fuel pump voltage to about 20v, right? Those conditions can't be beneficial to the longevity of the pump.

 

[Aaron94T]

sr5guy is not the only one who thinks Comptech's rising rate FPR and boost-a-pump solution are band-aids and are not the ideal way to handle fueling for a forced induction NSX. It works, but that doesn't make it the "right" way to do it. The CT FPR bumps up the rail pressure to about 90-100 psi which is about twice the pressure a 1:1 FPR would produce, more than a "small increase." The oem injectors were not designed for that. The boost-a-pump spikes fuel pump voltage to about 20v, right? Those conditions can't be beneficial to the longevity of the pump.

Wait, what? I am not defending the CT fuel system as I know all about the components and it is the one thing I have wanted to change on my car for years. However, the anti-RRFPR speak has me a bit stumped as I have never heard anyone say anything bad about them in the past 15 years of messing with high HP forced induction cars. Are you looking for a option that will allow you to pull yours of your SOS SCer setup?

I definitely agree that their are components of the old CT fuel system that are band aids. However, what is wrong with a rising rate FPR?

 

[sr5guy]

Wait, what? I am not defending the CT fuel system as I know all about the components and it is the one thing I have wanted to change on my car for years. However, the anti-RRFPR speak has me a bit stumped as I have never heard anyone say anything bad about them in the past 15 years of messing with high HP forced induction cars. Are you looking for a option that will allow you to pull yours of your SOS SCer setup?

http://lmgtfy.com/?q=why+fmus+suck

-Matt

 

[NSX-Files]

Are you looking for a option that will allow you to pull yours of your SOS SCer setup?

No I don't have a RR FPR. I have an AEM 1:1 adjustable FPR, RC 550 injectors and Walbro 255 HP pump. I have the AEM EMS with dual Wideband AFRs and have a very good tuner for it (Mase). It's only been tuned initially and I don't really have any "deal breaker" drivability issues - in fact it's tuned pretty well (maybe a tad conservative and overly rich) but in no way is it the same as when it was NA on the Honda ECU. I could go for a retune, but I'm lazy and Mase is usually pretty busy. So I can see the merit in being able to "tweak" the stock ECU for boost but retaining all its other drivability attributes, plus it would save the $ of the EMS.

I don't have strong feelings against the RR FPR, but I don't think it's as precise a tuning mechanism as using electronics to do the same task. Plus I worried about "pushing" a fuel pump with extra voltage and pressure. But I know plenty of buddies with the CTSC who are totally happy with it.

 

[RYU]

But I know plenty of buddies with the CTSC who are totally happy with it.

Ignorance is bliss and I can totally respect that.

My issues with the CT tune didn't present themselves until I dynoed the car and after the 3rd run it started misfiring entering Vtec. It was mild but the small but sharp dips were felt inside the car and presented itself on the dyno graphs. It was that moment I knew I really needed to upgrade into something with a better resolution tune. If I didn't drive my NSX hard and it was more a easy wknd car/grocery getter i'd probably never noticed the heatsoak, etc...

 

[Prospeed]

http://lmgtfy.com/?q=why+fmus+suck

-Matt

I agree with you Matt, It's a band-aid and a stand alone engine management system or cracked ecu (hondata or what you have done) is superior there is no question about it. I personally stay away from FMU's as much as possible. But I guess for some people band aid's are good enough :smile: Keep hacking away brother!

 

[BrianB]

I'm very interested in this, I just wish I had seen this post before I went FIC and 550 injectors on my new CTSC setup on my auto nsx.
The shop that did the tune kept the RRFPR disconnected the booster pump, replaced the fuel pump with a warlbro 255, I've had it tuned 2 times to get the idle and mid throttle smoothed out. I had lowered the fuel pressure as I was idling too rich, the tuner added fuel now cold idle is alittle rich again.
Also 3 days after I picked up the car it blew a fuel line at the push fitting, so I replaced them all with braided. I asked if we needed the rising rate fuel regulator and he said it didn't hurt anything.
My car was horribly lean above 5k rpm because if the extra load of the auto trans. We did the FIC and injectors on a recommendation from Nate. The only other issue I have is my alternator at idle only puts out 11.9 to 11.5 volts! So every once and awhile it will shut off going into gear on low voltage. I've got a email into Nate about that.
Sucks because I just bought all this other stuff. I'm in DE so it'd be a drive.
Hopefully you find someone closer I'd love to look at this as a better option in the future. After not having my NSX for 3 months just making this work I want to enjoy it alittle before going back under the knife lol.

 

[shawn110975]

in my life when someone explodes at valid questions or opinions that don't line up with their thinking, I walk away.

short fuse equals problems

my 2 cents

 

[Honcho]

I would so jump on this if I was still in NYC.

 

[shawn110975]

wish you were in FL LOL good buddy

 

[DDozier]

Since you local guys are not able to help I will, I am taking steps to move this project forward for the benefit of the NSX Community. Logistically a car local to Matt would have been better but since that has not panned out the project will be tested and hopefully proven in the midwest. Hope we can prove a viable tuning solution that may pave the way for OBDII ECU cracking.

PM sent to SR5Guy, thanks again for your efforts.

Dave

 

[RYU]

Fantastic!

 

[njX95]

Hey, not sure if this is an option, but I have a 1991 auto which I'd like to upgrade to ctsc,, headers, exhaust. You're welcome to use it for testing if you can get the ctsc installed. (I will pay for that, of course). PM me if that would work. I live in NJ
ed

 

[Turbophein]

Just came from a Cars and Coffee Event in Boston (Brookline). there was 3 NSX's there including mine, the other 2 were comptech supercharged and i mentioned this thread to both of them. so a bump to the top to make it easier to find! Wish i was Supercharged!