Rolling Road...298bhp

[Silver Surfer]

Just been on the local rolling road for £22.50

91' 3.0L 5 speed manual car (red/black) with a 3.2 manifold and bypass pipes and original backbox. Procar airbox.

Thought I check before I receive and fit the Larini exhaust (if it arrives!).

298bhp at the crank and 242bhp at the wheel at 8000 rpm in 4th gear with 56bhp transmission loss!

Is this correlating with the other NSX?

SS

[markc]

Is this correlating with the other NSX?

SS

That's a can of worms you're opening there ;)

Check the Dyno Day article... http://www.nsxcb.co.uk/index.php?categoryid=26

A Rototest hub dyno, preferably TDI's one, is the only acceptable basis for our power/torque comparisons :)

Your run does provide you with a baseline to compare against when you've fitted the new exhaust though.

Cheers

Mark

[NoelWatson]

Your run does provide you with a baseline to compare against when you've fitted the new exhaust though.



But does it? As you know, my car gave ~284 standard, and >320bhp on the same rolling road when modified. I think TDI is the only way to compare before and after.

[AR]

Strange as my car got 249.42 at the wheels yet the calculation made gives 295.62 at the crank???

Mark explain :) please.

Cheers,

Ary

[Silver Surfer]

Strange as my car got 249.42 at the wheels yet the calculation made gives 295.62 at the crank???

Mark explain :) please.

Cheers,

Ary

Different transmission loss? :dunno:

SS

[markc]

Strange as my car got 249.42 at the wheels yet the calculation made gives 295.62 at the crank???


Different transmission loss? :dunno:

Calculated transmission loss is the best explanation and is entirely possible as the transmission includes tyres (brand, pressure, tread depth etc), suspension alignment (toe, camber) and rollers (grip, tie down force). There shouldn't be much differance in gearboxes/diffs/hub frcition between NSX's.

Correction factor, for ambient temperature/pressure/humidity, will come into it as well. Depends which one they decide to use DIN, ECC, SAE, ISO... no wonder it creates so much debate :)

I think we're all agreed that a Rototest hub dyno is the only valid source for cross comparison but that an RR session is useful to determine that your car if running correctly ie not running rich or lean or pinking/det'ing etc.

Mark

[AR]

Mark could it have being caused by my TE-37s GSD3 combination helping the car put dowm more power at the wheels?

Cheers,

Ary

[markc]

Mark could it have being caused by my TE-37s GSD3 combination helping the car put dowm more power at the wheels?

Cheers,

Ary

No... well actually sort of but it's nothing to do with the wheels (weight makes no differance here) rather the grip/rolling restistance afforded by the tyres. Lower "transmission" loss suggests lower rolling resistance, of the tyres, which often implies lower grip!

I'm no more than an "armchair expert" here so please don't take my advice as certified knowledge, I just like to try and understand these things :)

Mark

[Senninha]

.........I'm no more than an "armchair expert" here so please don't take my advice as certified knowledge, I just like to try and understand these things :)

Mark

And you do a very fine job helping the rest of us understand this stuff!!

Isn't one of the reasons we use the hub for reference to stop all this over/under inflate tyre concerns etc?

[Senninha]

Kare,

Have you sorted the duct yet?

regards, Paul

[markc]

Isn't one of the reasons we use the hub for reference to stop all this over/under inflate tyre concerns etc?

Yes, the tyres and the contact they make with the steel rollers of a normal chassis dynamometer is a big variable. Obviously this is completely eliminated with a hub dyno.

Mark