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Comptech Dyno Results!

13 May 2001
Mesa, AZ
Well, I paid a visit to the Dyno today to run my Supercharger (stock PSI), Intake, Exhaust, and Headers. Needless to say, the numbers were FAR different from what Comptech evangalizes on their website. I have a '00 Targa.

Now, I didn't dyno my car stock (sorry about that), but I did Dyno it with just the Supercharger. It came out to be 313RWHP @7900. OK. That wasn't too thrilling, but definitely a different car.

Well, I spent $4,700 and put on the Comptech Headers, Intake, and Exhaust, and today it came out to 327.1RWHP @7900.

Call me irritated, but 14RWHP from these parts just doesn't do it for me. In addition to this, 327.1RWHP is a FAR cry from Comptech's website posted 367RWHP. Personally, I think they're smoking crack - so do a number of people who I've talked with.

BTW this was done on a Dynojet 246 Chassis Dyno. The first run (with just the SC) was at 104.5 Degrees. Today's run was at 91 Degrees.

Oh, and it gets better. Dynotech runs the test in 4th gear. I talked with Shad and he said that Comptech runs all of their tests in 3rd. So, we decided to run the test in 3rd. It actually came out to be LESS than 4th doing 322RWHP @7900. Go figure.

14RWHP increase from close to $5K worth of Intake, Exhaust, and Headers on a Supercharged car? Comptech boasts 34RWHP from the Intake, Headers, and Exhaust WITHOUT a Supercharger.

Needless to say I want to know what's going on here... Any feedback would be great.


David Allen
'00 Silverstone NSX-T
Well, I can understand your frustration. The dollar cost per incremental hp for the NSX is pretty steep no matter what route you take.

In CT's defense, while their numbers are probably a bit high (what aftermarket company's aren't?) the real difference is that they have the opportunity for pretty much unlimited tuning. I promise you that your car will make 340hp + at the wheels with proper tuning. My 3.0L motor did with the same mods.

While you were on the dyno, did you take the time to measure the A/F ratio accross the entire rpm range? Do so. Then get the parts to adjust the FMU and use it to optimize the relationship between your boost curve and the fuel curve.

An alternative to messing with the FMU is to adapt a system similar to the one on the Bell kit. Add a couple of injectors with a Rebic or Haltech controller and you can dial in the fuel curve perfectly instead of 'guesstimating' with the current system. I have not seen Doug H.'s car in person, but I believe that is the setup he is using to get 390hp or so at the wheels. This type of fuel system will allow you to machine a pulley giving you significantly more boost as well.

If you can find a shop in your area that does good blower installs on muscle cars, they may be familiar with this type of fuel system modification. It is really pretty simple.

Hope this helps.

By the way, you might talk to AZ Speed and Marine about the fuel system setup I mentioned. If they can't do it, they can hook you up with someone who can.

[This message has been edited by David (edited 29 May 2001).]
As David mentioned, Larry does an awesome job of getting the most out of the various superhcharger setups like on Doug's car.
He is the guy who figured out the problem GruppeM was having with their supercharger for them.
You may want to call him at Team NSX and get some good advice. That is.... if you can ever reach him. He works till 2am so you have plenty of time to try.
A well-known NSX mechanic (who shall remain nameless, though I'm sure you can guess...), when queried about the gains to expect when installing the I/H/E setup on an SC 97(+) NSX w/3.2L engine, suggested that the improvement would be pretty much along the lines that you experienced. So the incremental increase doesn't sound out of whack with other people's experience though it may not be totally in line with the expectations that Comptech may have set.

To keep things in perspective though, at the end of the day you still have a very fast (instead of merely fast) and civilized sports car. I'd still be inclined to do as David suggests re: checking air/fuel, not only for tuning optimization but also for the peace of mind in knowing that you don't have any latent lean conditions that may bite you later.

I appreciate everyone's feedback!

I guess my main gripe is the misleading numbers on the website. As the dyno guy said "they're smoking crack to think they get 367 RWHP with this setup".

I'm definitely going to arrange a time to get together with Mark Basch when he gets back and do some performance tuning.

I'll definitely let everyone know what the results are.

Dave - thanks for the tuning information!

David Allen
'00 Silverstone NSX-T
Isn't it great having Basch Acura Service right here in our own backyard. Mark Basch is the only person I would let touch my NSX. He is probably the best man for the job.

Keep us posted.
David --

Long time no talk stranger. Crack heads? I think we're all crack heads. That being said... due to the high temps you're in (and dry air) it may be wise to check out the A/F ratio that the car is determining what is best. I don't think your numbers and CT's numbers are equilized for the same air temp (and pressure of course).

High recommendation for Mark Basch. He knows his stuff.

BTW, I drove two 3.2L cars with the stock R/P and 4.55 R/P. Good lord was the 4.55 R/P nice with the 6-spd.

That being said, I'm surprised that you got 14 hp gain to tell you the truth. The headers on a 97+ 3.2L car have not historically made much of a difference due to the major revamp of the header/manifold design on the 3.2L cars.

Good luck, and let us know how it goes. Work with CT... they have been very helpful to me and friends to diagnose a problem. Like every aftermarket, non-factory part, performance can never be 100% assured.

If I could only convince Santa that superchargers DO fit in stockings. Sigh...

-- C


www.ScienceofSpeed.com - Click for more info
www.NSXClassifieds.com - The internet's only exclusive NSX Classified site!

[This message has been edited by ScienceofSpeed (edited 30 May 2001).]
Hey Chris! How are you doing? Well I hope!

I love going to the Pacific Northwest NSX Club page - a picture of a bunch of cars on wet road with clouds everywhere hehe - you've got to spend some time here in Arizona!

I'm currently talking with Shad at Comptech to find out what's 'going on'. It's going to take some time to do the proper research, and when I'm done, I'll be sure to let everyone know. If it was just 10-20RWHP difference, I'd think that it was ambient variables, or even the dyno itself, but 40RWHP is just WAY too much.

I talked with Bob at Basch Acura today (amazing how Basch and Comptech both have their 'Bob') and he said Mark is about 2 weeks behind, so it's going to be a bit before he can get involved.

Shad just sent me a scan of a dyno that was from a diffferent setup/company of a Zenardi NSX with all of my mods - it came out to 355.4RWHP.


I'll post when I have more!

David Allen
'00 Silverstone NSX-T

Having owned and tuned several forced-induction cars, I found it surprising that the $9-11K Comptech S/C kit comes with only a rising rate fuel pressure regulator (FMU) and a gizmo that ups the volts to the car's fuel pump to serve all fuel needs. A $350 fuel system for a ~$10,000 supercharger kit on an $88K (97+) car...

Actually, it's really not the cost of the fuel system that's the trouble, it's the lack of adjustability. No 2 performance cars run identically, even with the exact same mods, and few of us have cars with the exact same mods as each other anyway. Yet, the kit only comes with 1 pre-set fuel system to "fit all".

Chances are good that you will be able to increase your power output once you tune your fuel in. My car is a boosted late-gen NSX as well, and I can tell you that the car can have a less-than-ideal fuel curve but still "feel fine" and have no audible signs of knocking/running lean. (It's made it tougher for me to tune by seat of the pants.. It's going to require dyno time). Since I have a cockpit adjustable fuel system though, I can play with the fuel and suddenly find the car accelerating better than when it already "seemed fine" before. Chances are, you'll hit the same thing once you begin tuning (gains in power where it otherwise seemed to be running fine before).

As Chris mentioned, the headers aren't doing you much good, the 97+ already have "headers" from the factory.

Once you have the ability to tune the fuel for your car, you should be able to squeak out another 20-25hp. And, you simply can't go wrong with Mark Basch.

Looking forward to hearing how it goes!

97 NSX-T Twin Turbo
Originally posted by SpeedDemon:
... Marc
97 NSX-T Twin Turbo


I see you have a Twin Turbo. Is it the BEGI? What fuel system do you use? The BEGI now comes with a Link injector controller but when installed it disrupts the tach signal from the ECU, thereby killing both the tach and itself. Do you have a better solution?
Originally posted by SpeedDemon:
Actually, it's really not the cost of the fuel system that's the trouble, it's the lack of adjustability.

97 NSX-T Twin Turbo

Marc, I agree, however my CT kit came with an aftermarket (Paxton) FMU and you can buy a bag of parts to adjust it for a couple of bucks. It comes with seveal plates, etc. and a chart that shows the curve for each. With the car on the dyno, it is easy to drop in the correct one and get a much better match. You are correct that the parts and instructions to adjust it should come with the kit. I guess they are too focused on 'plug and play.'

Aren't you using a Rebic controller on your car?
Originally posted by sjs:

I see you have a Twin Turbo. Is it the BEGI? What fuel system do you use? The BEGI now comes with a Link injector controller but when installed it disrupts the tach signal from the ECU, thereby killing both the tach and itself. Do you have a better solution?

I have the Bell kit, minus the Bell fuel system (I supplied my own). As David (Austin) noted, one of my fuel components is a Rebic 4 fuel controller. It controls a couple of additional injectors. I currently have two 315cc injectors, but I'm going to increase that to 550cc units, the 315's are already getting close to 80 percent duty cycle in a couple areas and I'm only running around 4psi.

The Rebic 4 is without a doubt a far better setup than anything Bell has ever supplied and is in fact "a solution"

The Rebic 4 has a variety of features that have made tuning easier. It comes with a built in "similator", where you can basically give it a hypothetical boost and rpm setting (ie, 4psi at 7200 rpm) and it will tell you what the injector duty cycle is based on the current program you've made.. So, you can simulate conditions without running the car & you can see if fuel is where it should be.

At any time, you can hit a "hold" button and the rpm, boost, and injector duty cycle are instantly stored, which has helped me for tuning since I just step on the gas, and if I feel a slight hesitation/lull or if the car feels strong, I press the hold button during that time and can then later look at what the fuel/boost was. It also has peak hold so you can see the highest values you've run.

There are a couple different adjustable boost points you can play with for setting the fuel graph, and there's also an RPM function where you can specify a particular rpm range and modify the fuel just for that range.

You can also set warning alarms for boost pressure, rpm, and injector duty cycle. If you hit the limits you set, the unit gives an audible alarm and stores info showing why/where you hit that alarm.

There's a digital display for monitoring your choice of boost pressure, rpm, or injector duty cycle.

That's the general scoop on the unit. It costs around $600 dollars I believe. (I bought mine in the $500-range but it was a special deal, or so I was told.. Grin)

97 NSX-T Twin Turbo
Originally posted by SpeedDemon:
The Rebic 4 is without a doubt a far better setup than anything Bell has ever supplied and is in fact "a solution"

Thanks! It sounds pretty good for the $. Certainly far better than the Link, even if it worked as designed.

[This message has been edited by sjs (edited 31 May 2001).]