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Supercharger Performance Question

24 February 2000
Valhalla, New York
I'm considering either a 4.55 ring & pinion or a CT Supercharger, not both on my 98 coupe. I test drove a 97+ with a CT Supercharger yesterday and found that below 3500 it had no better acceleration then my normally aspirated NSX. Above 3500, however, it pulled like a bear. I kind of expected more low end torque from 2000 RPM and up.

Is this normal performance characteristics for a supercharged car?

Also, if I use the 4.55 ring & pinion, is there a different speedometer gear?

[This message has been edited by dswartz (edited 10 April 2001).]
With the CT unit, boost is only 3 PSI at 2000 RPM. Full boost is reached at 4000 RPM and higher. That's why it pulls so strong from about 3500 on, but feels closer to stock at the bottom of the RPM range. That is normal operation and is how superchargers achieve such smooth power increases.

The R&P does not affect your speedometer; speed is measured after the R&P.
If you're looking for more torque, the GruppeM supercharger will give you more than the Comptech unit. This was the topic of discussion at the last NSXCA meeting. They had 3 NSXs (comptech, gruppeM, vortec) all lined up, and the pros/cons of each were explained. I'm not technical enough to tell you exactly why, but it was explained very well by Larry. Something to do with all the extra airflow because of the tubing that the comptech lacks. You have to take off the engine cover though.
is that discussion posted up anywhere? i would like to know the differences and pros/cons between each.
and the vortec kit is custom right?


You guys make it easy for me when you don't even bother looking there first...
I'm sure there have been many discussions on Comptech vs. GruppeM, but nothing in writing from the last meeting. It's more of an informal get together. There were 3 NSXs lined up, each with a different supercharger (comptech, gruppem, vortec). Larry had done the installation and tuning on all of them. He went over all aspects of each one for the group. He's the guy that fixed a problem on the GruppeM supercharger that they couldn't figure out, so he knows what he's talking about.
Then we went to Shabu Shabu for dinner.

The next meeting is this Thursday. I think they will be discussing something about oil.
Then again, dinner.

Larry is very busy, but if you can get him on the line and get him into the discussion, he'll wax poetic about it for hours. He loves what he does... he's just very busy.
If you live in the area, the best way to get his undivided attention is to stop by and see him. Only make sure he'll be there. He's not always in the shop.
I think 286 NSX was referring to the discussion at the group meeting at Team NSX, but that's a good thread with some useful info.
The individual at the shop with the Vortec setup was still in the tuning stage as I recall. It was a new setup, but all chrome and very nice looking. Similar to the GRuppeM in that it had a lot of large tubing and probably produced lots of torque as well.

IMO, Alex's GruppeM SC looks so awesome I'd choose it over others for looks alone. It probably cost extra to get it looking that nice though. You really have to see it in person. He has the baddest NSX I've seen yet.
I started that thread a long time ago..definately some good info...faqnazi..can you find me anything in the faq's about naked women and nsx's
Since some of us live outside CA., I would love for someone to give me an updated version of SC comparisons as relating to a 3.2 liter engine. The FAQ has not been updated recently. I'm in the market for this upgrade and would like to spend my money wisely. Need more info on Gruppe M and have not seen anything on vortec. Ilya help! Can you possibly post this info from your meetings? Thanks
Just call Larry at Team NSX. He'll tell you everything you need to know about the GruppeM, Vortec, Comptech. Since he actually does the work he will be able to give you quotes on labor and cost as well. I haven't known anyone yet to charge me less than he does for great work. He also works extremely fast because he knows what he's doing and that saves money in labor.

That one meeting already happened and unless someone recorded it, there's no real record. The next meeting is about something completely different. I'm sure if you called him he would give you all the info you wanted and point you in the right direction. He's a very nice guy, just busy.
Their number is (714)842-9135

Ask for Larry. If you're lucky you may find him.

GruppeM (Alex) on this forum has the GruppeM SC installed by Larry. He is also the gruppeM distributor. If you private him he could help you as well. I don't know enough about them personally to give correct advice. I can only repeat what I hear the pros explain.
The only SC choices for the 3.2 cars at present are:

1. Comptech
2. A custom setup

The GM unit is only available for the 3.0s.

[This message has been edited by Lud (edited 11 April 2001).]
Originally posted by Lud:
The only SC choices for the 3.2 cars at present are:

1. Comptech
2. A custom setup

The GM unit is only available for the 3.0s.

[REPLY]Just a clarification, the GRUPPE M is indeed available for the 3.2 liter motor. More specifically, it is available for all OBD-II, throttle by wire NSXs (including the '95 to 96 3.0 liter motors) for $1000 more than the kit for the pre-'95 NSXs.

With that you get special electronics (a different ECU, boost and timing control, etc.), and a different strut tower brace that will clear the supercharger.

Hope this helps.


Anyone in here know what kind of numbers does the supercharged 3.0 and 3.2 put out for the 1/4ET and 0-60.

[This message has been edited by YoungS2K (edited 12 April 2001).]
Originally posted by GruppeMUSA:
Just a clarification, the GRUPPE M is indeed available for the 3.2 liter motor.

Are there any in the US?

FYI I was basing my comment on:

1. The Dali site only shows one to choose from

2. The PDF installation instructions specify C30A motor only
Originally posted by Lud:
Are there any in the US?

[REPLY]Not yet. But there are several in Japan.

FYI I was basing my comment on:

1. The Dali site only shows one to choose from

[REPLY]Then I should get on his case and get his site updated! :)

2. The PDF installation instructions specify C30A motor only

[REPLY]The original instructions were written pre-'94. The only difference in installation would be the strut tower brace, and some minor plumbing (no throttle cable to re route). Otherwise, it is very similar.

Hope this helps.