Rolling Road results

[Firefoot]

Well I finally plucked up the courage to get my baby on the rolling road at Powerstation on Saturday. My older brother (Shaleshifter) also took his on so we could compare.

My results were 270 bhp but I am losing 90 through the transmission

Pete got 277 bhp but he is only losing 70 through the transmission

I was happy with my result (apart from the transmission loss being so high), and the chaps even put my car up on the ramps and did an inspection as they noticed an issue at the passenger rear suspension. All this time I thought I have a faulty diff, it turns out that I have a bent rear shock.
So hopefully that will be a quick fix and no more diff changes :D

Would certainly recommend Powerstation, they have a very professional set up :thumbs:

[pdh 14a]

Good result! But thats a big loss,they are normallyt about 55 loss at that power :confused:

[Butuz]

Not being funny but the flywheel figures are made up. The dyno measures the power at the tyre - and guesses what it equates to at the flywheel.

Only way to figure out accurate transmission loss is to take the engine out :o

Butuz

[George]

Not being funny but the flywheel figures are made up. The dyno measures the power at the tyre - and guesses what it equates to at the flywheel.

Only way to figure out accurate transmission loss is to take the engine out :o

Butuz

It's not a complete stab in the dark though. The rolling road will look at the amount of power required to turn the transmission on run down in gear with the clutch depressed. This gives a fairly good guestimate of transmission losses.

[Butuz]

True - I still think flywheel figures are meaningless - its power being put down between tyre and road that matters but they all seem to want to give flywheel guestimates? :(

Butuz

[George]

True - I still think flywheel figures are meaningless - its power being put down between tyre and road that matters but they all seem to want to give flywheel guestimates? :(

Butuz

True, but it can help highlight excessive losses in your drivetrain, which may be a problem with your gearbox or diff or something.

[VIDAL BABBOON]

Losses are around 25% on the S14

Why are the two results different ? losses should be within 1 or 2 %

What is different on your cars wheel width ?

[blue boy]

I have about 45bhp losses on my S14. Other factors for higher losses can be binding rear brakes and low tyre pressures.

[Mr OCD]

Not being funny but the flywheel figures are made up. The dyno measures the power at the tyre - and guesses what it equates to at the flywheel.

Only way to figure out accurate transmission loss is to take the engine out :o

Butuz

:nod:

Mine made 237bhp at the wheels... thats a genuine 280bhp car :thumbs:

[Firefoot]

Losses are around 25% on the S14

Why are the two results different ? losses should be within 1 or 2 %

What is different on your cars wheel width ?

I have a HKS evc boost controller, Pete has a Profec B (which he turns up a lot higher than I do)
I have a front mounted intercooler, Pete has a standard wmic
I have 18 wheels, 235 front, 255 rear. I think Pete has 17" wheels but not sure of tyre size
We have different induction kits

But I also seem to have a bent rear passenger side suspension near the top mount, once that is fixed my car will feel a bit more stable.

My car went on the rollers first, then when Petes went on they had to adjust the rollers as Petes car was longer. The rolling road guy did comment about that being a bit strange. When I see Pete next I am going to measure the cars to see exactly what the difference is.

Have to admit I didn't check my tyre pressures before putting the car on which possibly didn't help my results

[Papa Lazarou]

Low tyre pressure, slightly binding brakes, tyres size, even suspension alignment will all affect the amount of losses measured.

[VIDAL BABBOON]

The things that will make the difference to Transmission losses are only drive train related.

As Papa has pointed out ;)