Pre-97 Mod: Supercharger or 6 Speed

[NSXY]

Hey People:

Recently we have read great NSX Prime threads on common pre-97 NSX mods, two of which give major improvements to acceleration performance: 1) engine supercharging, and 2) conversion of the 5 speed transmission to a 6 speed.

In either case, several of you have expressed astonishment at your increased acceleration, often with 1/4 mile numbers to back your claims, etc. My memory is that the cost of a CompTech supercharger, plus the added intake, headers, exhaust, etc. is ~$20, whereas the 6 speed transmission conversion might be around half that at ~$8,000.

So here's my question: If you could do your pre-97 mod thing all over again, but use only one of these, which one would it be and why?

I'm thinking 6 speed, because of the relative simplicity of installation and lower cost of installation and mantainance, but I have an open mind.

Which mod will give me the best bang for my buck?

------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Stock, except Dunlaptya SP9000s

 

[biophase]

I believe the SC, h-e-i runs around $12000 installed, nowhere near $20k. I don't see how changing to 6-spd can be compared to getting a SC. In my mind the 5-6spd change is like gearing whereas the SC increases engine power. You wont get more hp by going from 5-6spd. It may feel faster cause you shift alot but it'll be nowhere close to the SC feeling!! I'd do the SC in a second.

 

[M5150]

well im thinking SC because firstly if my memory serves me right a gruppe M is only ~10k and the purpose of a 6 speed is to get to the power band of the NSX which is the VTEC, and with an SC the power band starts low so theres no need to jump up as quickly, you'll definately get more bang for your buck with an SC, just look at doug hayashi, he dropped 10 seconds off his lap time just from an SC, its definately worth the money

------------------
me want NSX, me 15, me no have NSX =( but me do 3d art http://members.home.com/mcudich

 

[nsx1]

I just checked the Comptech web site. Comptech Supercharger kit (which includes the intake manifold) would be $10,800 for NSXY's NSX-T ($9,800 for a coupe). Heads are ~$5,000 with exchange, and headers are ~$1,600. That's ~$17,400. Comptech also recommends the cat-back exhaust ~$1,300, and carbon-fiber airbox ~$700, bring to total to ~$19,400... and that doesn't include the high flow cat for ~$750.

You wont get more hp by going from 5-6spd.

That's only true if you're talking about engine HP. Gearing can effect wheel HP. If NSXY is interested in "acceleration performance", the gearing and number of gears can effect acceleration (not just the feeling of it from having an extra gear). Example: Imagine an identical pair of stock 2000 NSX's with manual transmissions (i.e. same HP). One accelerates using all the gears while the other accelerates using only 4th gear. Certainly an exaggeration, but nevertheless, a good example of why gearing has an effect on acceleration performance.

In the final analysis, I would not imagine that the 6-speed upgrade would have as dramatic effect on acceleration as the supercharger would. I don't race my NSX and to me, 5th and 6th gears are almost meaningless while tooling around town in my everyday driving... I either don't use them, or I can hardly notice a difference between them. So, I can't imagine that the extra gear would give you much "bang" for your buck. On the other hand, if you want bang, a supercharger would add more "grunt" to whichever gear you were in... not to mention the additional sound effects

.

------------------
nsx1
2000 Yellow/Black/6-sp #172
http://www.nsx1.com

 

[TampaBayNSX-R]

I opted for the six speed conversion for my '94 and threw in the 4.55 R&P for good measure. For those who think this conversion only effects "perceived" acceleration I'm here to tell you you're mistaken. For example, I recently raced another '94 with a 70rwhp NOS kit and ended up dead even with them at 100mph. I got such a big jump off the line that it neutralized the 70hp advantage the NOS provided. Now, for most typical street encounters, the quick launch off the line and pull through second maybe third gear, is all you will have time/room/sanity to run against another car. Also, for road course use, there is a definite advantage when coming out of lower speed corners. During the track event at NSXPO @Road Atlanta I was able to come off of turn seven and stay right with S/C cars all the way up to 120mph. I have in car camera footage to back this up! <grin> More food for thought in what has to be one of the most debated subjects relating to our cars. Let's face it, if you do either of these conversions you'll be driving a car that will provide you with incredible performance and miles of smiles.

 

[nsxtasy]

Compare the numbers in the chart "What are the numbers" in http://www.nsxprime.com/FAQ/Performance/gears.htm It shows you get way better acceleration by adding 20 hp than by changing gearing. And the supercharger adds 60 hp, not 20 hp. Makes it pretty cut and dry...

Also, for road course use, there is a definite advantage when coming out of lower speed corners. During the track event at NSXPO @Road Atlanta I was able to come off of turn seven and stay right with S/C cars all the way up to 120mph.

I was in the fastest run group at NSXPO. There were three cars who passed me, and I passed everyone else. Without a supercharger, with the stock five-speed, and street tires. All it takes to stay with the S/C cars on the back straight is a better trackout exiting turn seven.

 

[Jason Weaver]

Tampa Bay NSX-R, Your post gets me kind of excited, I have a 91 with I/H/E, ecu and RM NOS kit, and If the 6speed gave you that kind of neglible advantage with a NOS car imagine how well your car would run with that same 70 shot! Was that a case of a better launch and shifting skill on your part or do you believe the cars truly are equal? This makes me want the short gears even worse now!

------------------
Jason

 

[Khuang]

Originally posted by Jason Weaver:
Tampa Bay NSX-R, Your post gets me kind of excited, I have a 91 with I/H/E, ecu and RM NOS kit, and If the 6speed gave you that kind of neglible advantage with a NOS car imagine how well your car would run with that same 70 shot! Was that a case of a better launch and shifting skill on your part or do you believe the cars truly are equal? This makes me want the short gears even worse now!

His car has the ability to get off the line faster. A friend of my has (2) SC NSX, one with 5 speed and one with six speed & 4.55 R&P. He ran 13.1@112 with stock 5 speed and 12.4@112 mph with six speed & 4.55 R&p, same driver. So if you have gears, I would think you will run mid to low 12's. Also since you run nos, your first to second gear shift should not hurt you as much as SC cars. I believe you have alot more torque and low end power.

 

[Khuang]

I was in the fastest run group at NSXPO. There were three cars who passed me, and I passed everyone else.

Was one of them a black NSX with technomagnesium wheels?

 

[nsxtasy]

I was in the fastest run group at NSXPO. There were three cars who passed me, and I passed everyone else.

Was one of them a black NSX with technomagnesium wheels?

One was McPherson's black NSX but I forget what wheels he had. The other two were red.

 

[NSXY]

Kuang:

What are your mods?

------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Stock, except Dunlaptya SP9000s

 

[NSXY]

NSXTACY:

What are your mods?

------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Stock, except Dunlaptya SP9000s

 

[NSXY]

Khuang and NSXTASY

I'm sorry for misspelling your names. Let me try again. What are your mods? Thanks.

------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Stock, except Dunlaptya SP9000s

 

[Khuang]

Originally posted by NSXY:
Khuang and NSXTASY

I'm sorry for misspelling your names. Let me try again. What are your mods? Thanks.

My perf. mods are: CT header, exhaust, SC, K&N drop in filter, Dali F&R sway bars, Eibach springs, Bilstein shocks.

Wish list mods are: six speed & 4.55 R&P, non-compliant bushing and Brembo brakes

 

[nsxtasy]

Khuang and NSXTASY

I'm sorry for misspelling your names.

No prob. I wasn't ignoring you ('specially wouldn't worry about misspelling), just trying to get through the various topics here one at a time.

My '91 has PowerSlot slotted rotors, RM Racing pads, brake cooling ducts, and a Dinan chip which does nothing noticeable. I have a set of track tires on 15"/16" wheels that I didn't bring to NSXPO 2000, and 16"/17" '94+ OEM wheels with OEM (Yokohama A022H) tires. I also have window stickers from each of the NSXPO's, and each sticker reduces time in the quarter mile by 0.5 seconds.

 

[Edo]

NSXTASY: How do you like those powerslot Rotors? And how do they compare to the OEM rotor's? Are they worth it?
Do the slots make THAT much of a difference?

 

[nsxtasy]

They're very good. I don't think there's any difference in stopping distance. But I think they probably dissipate heat better because they seem to be more resistant to brake shudder problems. For a while I was changing the OEM rotors about every four track events, due to shudder. I switched to these rotors and haven't had shudder since... although I also installed cooling ducts and am more religious about cleaning/lubing the calipers during brake pad changes, so it's not necessarily entirely due to the rotors.

Keep in mind that I track my car a lot. If you're only driving on the street, you might never have problems with shudder on the OEM rotors.

Also, the slotted rotors eventually crack from track use. But they last a lot longer than the OEM rotors; I typically get 8-12 track events on a set of slotted ones.

[This message has been edited by nsxtasy (edited 15 December 2000).]

 

[PUREVIL]

My $.02, if you can spend 10K on a supercharger, I think eventually you can get the 5K for the 6 speed later on. Either way you'll be much happier! Am I right?

[This message has been edited by PUREVIL (edited 16 December 2000).]

 

[Andrie Hartanto]

I didn't have good expererience with powerslot. I warped them at every event. I guess I just work the brake harder than nsxtasy, or am I going faster

However, I opted to turn them every time. It's been turned 3 times and been to 3 track events. Now it started to have hairline cracks, so I only use it for the street. I'm still in search of a better rotor. IMO, the cross drilled works better cooling wise. I didn't warped them But I managed to cracked them after a couple of events.

I am yet to try stock rotors.

But, I don't think I will ever, cause I'm putting big brake kit soon

 

[nsxtasy]

I opted to turn them every time.

I never turn my rotors because that makes them more susceptible to warping. If and when they are shuddering severely, I replace them.

 

[1BADNSX]

I run Powerslot rotors up front and they have performed great after four days at Mid-Ohio, two days at Putnam, and two days at Road Atlanta. I agree with NSXTASY, they are cheaper than OEM and last longer without shudder. For the stock rotor size, the key is to get good air flow. I removed the dust shields and added the Dali air deflectors. I believe there is another brand called Powerstop (?) that other people had trouble with.

Bob Butler

 

[nsxtasy]

I removed the dust shields and added the Dali air deflectors.

I cut a hole in the dust shields and welded a flange to it. I added air ducts that run from the front air dam, over the radiator core support at the bottom corner of the radiator, and connect to the flange.

 

[---Litespeed---]

Personally i think you are all crazy and working with a flawed medium. For 20k i ran into an Olds Aurora Indy IRL engine from the company that built them in Indiannapolis which was dynoed over 750hp and 685 torque this was detuned to run gas and lost around 10%hp and torque , tipping the scales at less weight than the nsx engine. After sitting in my garage awaiting its tub, i picked up a clean used ( blown engine) nsx for 18k and went to work with some friends. Added 20k in tranny,transfer,gearing and other massaging. Still waiting on the brakes from a friend who can smuggle me some older 2x6piston Alcons for what i hope to be less than 15k. When the brakes come we are off to the track to run with the GT2porshces. Coming in at around the price of a new NSX i hope to take it to the GT2 Porsches at twice the price.
For now im limited to the streets and finding motorcycles to chase around.

personally i would rethink any mods costing that much and adding only 100horses.

 

[nsxtasy]

Personally i think you are all crazy and working with a flawed medium

That depends on whether you like having your mechanic rebuild your engine every few hundred miles.

 

[David]

Comptech builds the Aurora Indy motors. They are not in Indianapolis. How much more of your post did you make up?