Today's rolling road

[m666 edd]

I went to a rolling road day at Bridgwater today and got some strange results.

Since I bought the car from Kev I had used a couple of tanks of normal 95 octane fuel then since I've used shell vpower.

My thought behind it was as this car has a mugen chip, surely it's mapped to take advantage of higher octane fuel otherwise there'd be little point / benefit. My other car has different software and is recommended to use 99 octane fuel so this also made me think this. Since using the 99 octane fuel it certainly has felt faster.

I know these results bare little relevance to other figures on this forum but thought they might be of interest:

http://www.ripper.eclipse.co.uk/nsx/graph.jpg

I can't really believe it has 100bhp transmission losses. They had trouble finding somewhere to strap the car down and I'm not sure what they strapped it to in the end. I certainly wasn't impressed by their knowledge either.

The flywheel figures always seem pretty good from this particular rolling road (used it 2 or 3 times in the past). Standard cars were getting the figures they were supposed to and there were a fair few people getting less than they were expecting.

I believe Kev got ~280bhp? last time he had it rolled at TDI and I think the changes since then are the exhaust manifolds and the fuel?

Guess I need to go to TDI but its stupidly far away :)

[NSX 2000]

That doesn't look right to me either, but I'm sure Noel or Mark will read this soon and will be able to make sense of it.

[greenberet]

Your transmission loss is similar to what a Maha dyno showed for Procar’s NSX in Germany.

http://www.nsxprime.com/photopost/data/500/medium/5576LMP_1.gif

Your NSX: 32.0% transmission loss on a Maha rolling road dyno
Procar's NSX: 26.6% transmission loss on a Maha rolling road dyno
For comparison:
Austrian Type-R's NSX: 16.3% transmission loss on a Bosch rolling road dyno
My NSX: 10.4% transmission loss on a Bosch rolling road dyno

I cannot believe the transmission losses vary so much among NSXs. It simply cannot be that your transmission swallows three times as much power as mine. Unless your transmission is filled with sand and mine with Teflon, the loss measurements must be wrong.

Personally, I don’t trust the power measurements at the wheel, either. A Clayton Hydrokinetic Chassis Roll Dynamometer measured 408 hp at the rear wheels of my NSX. Fantastic! A Bosch FLA-203 rolling road dyno only measured 270 rwhp, but that’s still good. The Dynolicious app on my iPhone spat out 238 rwhp. And my car was in the same state of tune for all three of those supposedly accurate “measurements”. So I don’t think you can compare results from different dynos.

Almost no dynos are regularly calibrated, so God only knows how far out of calibration a specific dyno will be when your car is on it. It’s better to compare the results from one and the same dyno but even that can be problematic if the measurements were carried out at different points in time. LoveFab in the US developed a new exhaust system for the NSX in 2009 and measured the gain versus stock. First they measured the stock rwhp and came up with 229.0 rwhp. Then they built and installed their new exhaust system and went back to the same dyno: 274.5 rwhp, or a gain of 45.5 hp at the wheels. Just to be sure, they went back to the dyno and carried out both measurements on the same day. This time, they only came up with a gain of 22.3 hp at the wheels. The stock measurement was higher than before and the modified measurement was lower. LoveFab’s lesson learned was, “The best comparison results can only be gathered by testing components as close to back-to-back as possible.”

Therefore, measuring on the same dyno on the same day is a great tool for comparing differences. If you go to a TDI dyno day, you can get a very good idea what kind of power your NSX puts out compared to other NSXs.

[forumadmin]

Dude, don't be questioning the figures. You got the bragging rights now, 312bhp. It's on paper, don't question it. :)

The oil in the gearbox is not standard. Because of the requirements of the diff, the oil is thicker than normal Honda MTF.

I have never tested it at TDI. It was tested at Power Engineering before. The exhaust headers are the only thing added to the car since I dynoed it, but I also added the cats as well.

[m666 edd]

I might take it down to AP Motors in Plymouth at some point. They have a better setup, know what they're doing and explain things.

The car certainly got a lot of attention considering I took it to a primarily Astra meet and was easily the loudest.

A nice pic that was taken:

http://www.t610wap.co.uk/online/ostsr12.jpg

Note theres no orange in the front indicators anymore. Still haven't removed the fogs though!

[forumadmin]

Easily the loudest? You need to drop the cats out one day and put the test pipes in!! As I have fitted stainless bolts to the cats, you can swap them in 10 minutes.

You don't know loud until you do that.

[m666 edd]

I thought you might say something like that.

I'm really tempted to stick them in and see what it's like with the inserts in. If it's ok then I can have fun more easily :laugh:

[TheSebringOne]

On a seperate note, the car looks fab! :thumbsup:

[NSXGB]

Car looks really good and the white wheels suit it well. I nearly bought a black NSX, very sleek colour.

Would have gone for the smoke coloured indicators instead of white, but definitely an improvement on the amber ones.

[NSX 2000]

Easily the loudest? You need to drop the cats out one day and put the test pipes in!! As I have fitted stainless bolts to the cats, you can swap them in 10 minutes.

You don't know loud until you do that.


Dude, don't be questioning the figures. You got the bragging rights now, 312bhp. It's on paper, don't question it. :)

The oil in the gearbox is not standard. Because of the requirements of the diff, the oil is thicker than normal Honda MTF.

I have never tested it at TDI. It was tested at Power Engineering before. The exhaust headers are the only thing added to the car since I dynoed it, but I also added the cats as well.


I might take it down to AP Motors in Plymouth at some point. They have a better setup, know what they're doing and explain things.

The car certainly got a lot of attention considering I took it to a primarily Astra meet and was easily the loudest.


There was a clip of us at that dyno day, do you still have it? The pictures I had were on my old lap top that got nicked:angry:

[forumadmin]

OK, I have found them, and YouTube'd them all.

Go to YouTube and search for NSXCB. Then list all the videos uploaded by NSXCB, and you will find the dyno day videos. Watch the black nsx one last. :)

[m666 edd]

They all sound standard except for Paul's.

Now I just want to decat it sooner haha. Be even louder now I guess with the headers.


A video that was taken with someone's camera I think:
http://s604.photobucket.com/albums/tt129/supersterl/rolling%20road/?action=view&current=MOV00019.flv

I think the guy in the blue gets scared by the rev limiter but you can't really tell on the vid. That's what all the laughing is about.

[markc]

That doesn't look right to me either, but I'm sure Noel or Mark will read this soon and will be able to make sense of it.

I missed this thread until now.

I have to say I don't understand how these Maha machines work or rather how they calculate transmission losses. I get that transmission loss isn't linear but >30% transmission loss does seem excessive from a layout (transverse engine, diff/gearbox in one unit, no steering components) that is about as efficient as it gets.

I know the tyres are in the mix but 100hp lost through the transmission has to go somewhere, primarily as heat. How hot would the gearbox oil get!!!

From chasing J14 around Silverstone last year I can vouch that it is indeed very fit and healthy but it also means I have more than 312hp ;)

Cheers

Mark