Supercharged NSX

[AR]

Just wondering if any fellow board members had superchaged an NSX, and if so who did it for you.

The Comptech kit looks like a nice X - mas present.

Cheers

AR

[tommy]

janspeed at salisbury quoted me around ten grand to do mine, but i would only gain about 20% more power. i dont think its worth it somehow.

[ctrlaltdelboy]

spend some time browsing this section (http://www.nsxprime.com/forums/forumdisplay.php?f=28) over at Prime - there's loads of experienced FI gurus who hang out there, plus loads of projects, installs, pics, ideas, recommendations, warnings etc etc.

[Kevin]

Superchargers are great but....

It seems the problem with all FI systems is long term effects on the engine, and track use. You will notice that the cars that have turbos the owners use them on drag strips, and dynos. I've been told the difficulty is getting enough fuel in over extended periods of time like track use.

You may or may not of course be interested in track driving.

The only supercharged car I know personally is Gerard's in Holland. He races his car. It, and so do the others, require a lot of tinkering and tweaking to keep running well.

I would rather perform an engine rebuild, with new pistons, bored out block and new cams than use FI. There are some new parts out now which enable this, while a couple of years ago the only way to go was FI.

[AR]

On that subject, are there any NSX tuners in the UK ?

[710]

More power, no supercharging? If I ever have to rebuild my NSX engine, I will take the following route. The only problem is, my car is still nice, and doesn’t need a rebuild. It feels like it will go another 100,000!
The compression ratio is really low on the NSX and I get the feeling the cam (the higher rev cam) profile can be a lot more aggressive. So if I rebuild an engine, I would do the pistons (got to do the rods too), cams and ECU (I imagine a new ECU map would probably be necessary).
I looked at Accralite pistons (pretty cheap about £200 for one-offs) and beautiful Farndon H-rods (about £250 each for one offs) because with the new pistons I probably wouldn’t be able to use the stock Honda rods. I hear they are connected to the pistons permanently. Anyway, with one off pistons, they might be able to match the stock rods, don’t know yet). And if I can find standard Farndon rods, the price goes down to £170 each.
I suppose Kent or Piper can regrind a more aggressive cam profile. With 11.1:1 compression (instead of the very low 10:1 compression made for the American market), better cam profile, you would be able to burn much more fuel. There are many ECU makers at the moment (about £500 to £1000) and mapping it would be easy to do too. All this has been advancing rapidly in the last years and in the UK is very easy. I would certainly try to use the same manifold and sensor locations.
I would expect about 350hp minimum (just raising the compression ratio increases the power a lot, plus with the new cam profile…). Is it possible the power would be more? I don’t know. Maybe.
The flywheel weighs a ton, I have lightened many flywheels on all sorts of cars, and it only improves things, with no drawbacks.
I would then have a normally aspirated engine, it would look normal, be cheaper than if I had replaced pistons and rods etc with Honda stuff, and would have proper power. Is the basic engine/clutch strong enough for 350hp? I would expect so. Anyway, it would cost less than the supercharger set up and it would be a “drive and forget” engine, not tricky to maintain.
I would really like to do this sometime, does anyone have a spare engine?
Peter

[710]

By the way, I need a '91-'94 NSX RHD steering rack. Complete less tie rods and rod ends. Doesn’t matter if it’s a little damaged or worn. Does anyone have one?
Peter

[Kevin]

Is it worth getting someone to do a cam regrind, rather than using some that are in production in the States already? Same goes for the pistons etc.

Who's up for contacting Jenvey Dynamics for some ITBs?

[710]

Good idea. Does someone there already build a normal compression (normal for us, high compression for them) engine. And if so, how much power does it bring?

[Kevin]

Both Dali and SoS are showing engine rebuild packages. I don't know who is doing the work for them. However these people http://www.kingmotorsports.com look like they do engines (possibly).

[710]

Thanks Kevin this is a good link, I’ll keep it for when I need it. You are right about the pistons and rods being on there.
But $3600 for rods when we have plenty of rods right here in England (UK, the Capital of Racing Stuff) and pistons $3000 too. And those are the production series prices, if the acralite pistons were a standard product as are the Toda ones on the site, they would be about $1200 here, rods from Farndon $1500. Even as special one-offs, they are cheaper here. Probably better too. whew, what a price difference! Anyway, thanks, it’s a good link with tons of cool stuff. Did you see the picture of their engine (of course it has an extra pair of cylinders…)?
peter

[AR]

Maybe if we could get a few of us together we could then get a discount the comptech kit and find a good mechanic to install it. I wonder how many would be needed for a discount ???

[Kevin]

Peter:

I was going to say the UK is the centre of world motorsport, but I guessed you knew that already.

You're right regarding price and expertise. However everything done here will have some element of development involved.

My harness bar was specially made, but even so came out cheaper than getting one from the States. The thing to do is go to real motorsports places/fabricators and not the suppliers/motorsports wannabe's that advertise in the glossy magazines.

I'm sure any decent engine builder here can fit the cams/sleeves and pistons required, once the parts have been sourced.

Did you contact Quaife about a LSD?

[710]

Kevin,
Quaife; yes, they can do 10-off @ about £500 each I think. It was a while ago and I don’t have the prices in front of me, but it was about the same price as all the other diffs from Quaife. They said they needed an example from an NSX though. They said it should be no problem for them.
The Mugen one is about £3000 and it’s a plate type. The Quaife diff would be a TorSen type, which I would prefer because I’ve got that type in a couple of other cars and had only good results (including the rally car).
Peter

[ctrlaltdelboy]

I have this diff (http://daliracing.com/v666-5/catalog/boy_racer/os-giken-lsd/index.cfm?focus=1380) in my car

it's great!!

reviews here

http://www.nsxprime.com/forums/showthread.php?t=36003
http://www.nsxprime.com/forums/showthread.php?t=39249

[Kevin]

I know the OS Giken LSD is out there, and you have one. However Quaife is Quaife. Hundreds of racing cars with Quaife LSDs can't be wrong. I thought the OS LSD was a bit over priced, though it does include a new R&P.

I wonder if the a Quaife diff from another Honda will fit the NSX.

Darren do you still have your old diff?

[ctrlaltdelboy]

agreed, the OSG is not cheap, incidentally, the 4.4 final drive is actually part of the diff itself rather than a bolt-on ring.

had I not already done the OSG and a good diff came up from quaife at this sort of money I would probably be going that route.

my old diff is inside my old gearbox on a pallet to go to Dali for recycling.

[710]

That sounds like a good package, with the 4.4 crown and pinion too! And I notice the price has come down on the short gear set too. Hummm…
Good links too, thanks
Peter

[710]

I wonder if the a Quaife diff from another Honda will fit the NSX. Darren do you still have your old diff?
Quaife are very reasonable, they explained that if, after inspection of a stock NSX diff, if a similar Quaife diff already exists from a different car (Honda or otherwise), they would use that. And the price may come down, or at least they wouldn’t have to make 10 of them…
If someone posts a stock diff to them, they will measure it and make a quote. They will know then if a new diff needs to be made, or if they can use parts from a different one. That’s the only way things are going to happen, really, because no one has any technical drawings of a stock diff. If someone posts their stock diff to Quaife, I will make the payment for production and sell the first 10 on to you. Production of more after that is possible too.
Are all the available crown gears the same bolt pattern, or do I have to put extra holes in there to match all possibilities? For example, do some Japanese manufactures of LSDs have their own crown/ring gear bolt pattern?
After measuring, we will give your stock diff back to you. Put your name and details on it, and attach my name to it if you want, they know me. I also have an appointment with them on the Monday 15 August 2005 about something else. So if the diff arrives there before then, I will discuss it with them and then we can get some concrete info.
I would also like a diff, because just this weekend I was skidding on the grass (stock NSX). I was surprised how much it skidded, and how easily I got stuck on the grass. And my car/diff only has 50,000 miles on it. I believe plate type LSDs must be adjusted periodically because the clutch plates in them wear. Does anyone know how periodically?
Beware, though, that the Torsen diff (Quaife uses that design) does not lock up 100%. It will slip if one wheel is completely without grip (like if the wheel were in the air, but applying a little friction from the ground or the brakes slightly would make the diff function again). But on snow it seems to grip and function like an LSD. My rally car will climb out of anything with the Quaife diff, even ditches where one wheel is in the air so I don’t know what’s going on there. They have always worked for me, even on really slippery surfaces. They seem to be smooth and don’t upset road driving/drifting etc. and they don’t jerk or snap.
I get the idea (through hearsay) that they are smooth in comparison with a plate LSD that may suddenly engage, this sudden engaging would not be good on the street during a drift. Is this true? Although I have heard plate types are quite linier, so that’s good.
Does anyone else have thoughts/experience about the Torsen (Quaife) diff compared to a plate type diff? I have heard that a plate type diff can be set “tighter” and because of it’s design, will never let one wheel spin free, but that for street, they must be set more loose otherwise they introduce too much friction (equals tyre and petrol consumption) when turning sharply in town. I believe that’s why the stock NSX diff is set so loose. Tightening it would introduce understeer too. The Torsen (Quaife) never locks, so can’t introduce understeer. Also the Torsen diff has no clutches or plates to wear. It is 100% mechanical so won't need to be adjusted and won't change characteristics through time.
That’s about all I know about diffs. Shall we go for it? Are there 10 people out there to help me recoup my investment costs?
Peter

[Paul_dc2]

Who's up for contacting Jenvey Dynamics for some ITBs?

Jenvey would be my personal route in tuning one of these beasts.

Im currently running a set of Jenvey's on my DC2 in conjunction with an AEM standalone ECU. I would have thought, well I know the ECU is good enough to power a V10 so a V6 should be ok. Can you imagine the noise 8), I also put a reverie carbon airbox to help things stay cool.

All I need is the NSX, its coming, just got to find a good one for the right price.

I will get around to my newbee post honest :wink:

[modarr]

I'd be more than happy to purchase a Quaife LSD. The're in Sevenoaks I believe which is local.

The plate diff in my NSX ('91) lets the inside wheel spin like crazy on tight corners and really is a bit too loose for the track. Its pretty safe though.

I have a Torsen diff in the supercharged MX5 and that will not let this happen on the same track. It's definitely better IMHO. The rear end of the MX5 developes real 'bite' in tight corners, whereas the NSX will just let one wheel go. Sticky rubber and the 'R' suspension has reduced this tendency greatly.

Mo

[kane]

Hi guys just wanted to let you know I am a comptech dealer. Drop me a line for the BEST prices on any of their stuff.

kane@nsxpro.com

[NSXGOD]

Just wondering if any fellow board members had superchaged an NSX, and if so who did it for you.
The Comptech kit looks like a nice X - mas present.
Cheers
AR

Why wait till Xmas? The new version of the SC kits are shipping now - we get one tomorrow.
:mrgreen: