Speed Limiter And Dyno Results

[Links]

As some of you may or may not know - Satanic - R34 gtt, myself - R33 SII and Doodz - R33 SI went to a dyno day..

We all managed to dyno within 2kw of each other:

Satanic: 156.0rwkw

Myself: 156.5rwkw

Doodz: 158rwkw

Now I thought - "shit that's alright - running pretty close for reasonably stock cars"..

The only problem with this is that Satanic's car is an R34 gt-t running @ 10psi which should give it a atleast 10-20kw more than mine and doodz's car..

From this I checked out our dynos and noticed that the peak of the curve was @ pretty much 180kmph - or as some of you know the speed cut off for R33 and R34 gts-t and gt-t's..

I than went and checked out the datalogging from my car when I had the consult cable in and noticed that my car reached 180kmph @ 5,500rpm - and flat lined from there to redline 6,800rpm..

*****************************************************************

Could it be possible that what happened is our cars all reached the same power level @ 5,500rpm or 180kmph and than the power dropped because the car was no longer accelerating as it was at it's speed limit?

*****************************************************************

There was a second R34 gt-t there that ran 170kw pretty much stock - this would be more inline with a 208kw RB25DET NEO engine - which is what satanic has.. I've got a feeling his speed limiter had been removed as his car had what looked like some slight changes in the engine bay - but running stock boost..

Thoughts people.. I want your thoughts..

What level in shootout mode did people dyno @ in their stock R33/R34's..

cheers,

Links

[Busky2k]

I thought it was purely a speed cut. Ie wont let the car go above 180kmh so theoretically the line should have stopped there.

[Beer Baron]

yeah, if you were reaching the speed cut the line would just stop dead. mostly i have found the nissan speed cut sometimes come in as late as 190 odd kph even with stock size tyres and wheels. when you go to bigger wheels you can go faster still before the cut.

[Links]

Well the ecu line does - however there will be overspeed where the momentum of the Dyno + the cars engine will keep it speeding for a little bit than it will stop doing it..

i'll post up the dyno sheet + ecu info..

[Links]

dyno graph..

As you can see the speed maxes out at 180kmph @ 5500rpm..

[paulr33]

yeah it sounds about right, it wont much much more power over 5500 anyway

[fresh]

your graph starts going down before your car hits 180, and yeah even running 1 bar on the stock turbo my car keeps increasing power till 6200rpm where it stops because the turbo can't supply more air, so i dunno why yours drops off so early, there is still 1500rpm before redline, shouldn't be dropping off so fast so early

[Links]

True..

Still - would be interested in seeing what it would do without the speed cut..

[hijaked]

hey fellas.

in just reading about the speed cut.

one lonely day on the highway, i wanted to test to see what this speed limiter did.

ive ben in some cars where, the engine stop putting power to the wheels, and the rev gauge dies down quickly.

however when i put my foot to the floor, the needle was pretty much verticle (bout 220 km/h), and the car didnt want to stop at all.

so waht is that spose to mean? has the limiter been removed? i have 19's, iv'e heard bigger wheels can mess with it??

sorry to be off topic...

rgds, Dave

[xRHETTx]

It means the speed limiter has been removed. Simple as that, its only cutting a wire after all.

[R31Nismoid]

however when i put my foot to the floor, the needle was pretty much verticle (bout 220 km/h), and the car didnt want to stop at all.

so waht is that spose to mean? has the limiter been removed? i have 19's, iv'e heard bigger wheels can mess with it??

it either means the wire is cut as stated, or your speedo is out.

I'd place a bet @ speedo. I could get a fair way around 180 before i got a cut

[R31Nismoid]

Oh, and revs wouldnt increase once you hit the limiter

[Links]

They won't increase - hmm.. so it puts a rev limit on even if for example it's doing 5500rpm? won't go over? might just be the limit of calumsult..

i've got the Sourcecode for it - so i'll see what I can do with it..

[R31Nismoid]

no, once you hit the speed limiter its hardly going to increase in RPM

if you dont have a limiter than thats a different story

Depends where the speed is being taken from too.

I think the ECU should be ok though

[Cubes]

Was the dyno speed calibrated to suit the cars 'real' speed?

Mine used to cut at around 185-190 on the speedo.

Edited August 31, 2005 by Cubes