Power loss?

[AndybS3]

Yesterday a few of my mates were going to a Vauxhall rolling road day at Dastek (Dalgety Bay). At the last moment a few dropped out so I got the chance to put the S3 on. After a few attempts trying to get an accurate reading because of the Haldex shifting power I finally diconnected the controller, much to the amazement of the Vauxhall boys the car was now FWD. Anyway we ran it up in FWD and the figures were 246bhp/264lb/ft on APR Optimax setting which I thought was low so he ran it up again as he thought the wheels may have been spinning but got the same figures. I then asked if he would run it up in standard setting which he did and we got 210bhp on the button which is correct for my car. Does anyone have any idea why I am not seeing the gains other APR users seem to be enjoying or is this just the product of an accurate dyno and I've spent just short of a grand for 36bhp /ubbthreads/images/graemlins/burningmad.gif

p.s. cheers to the Vauxhall Club and the boys at Dastek for going out their way to help, Top Blokes best £20 I've spent in a while

 

[Khufu]

Sorry to hear about that. Are you coming up north for the rolling road session at the end of the month? Maybe get a second opinion /ubbthreads/images/graemlins/wink.gif Hopefully there is something simple wrong like a split hose or dodgy DV.

 

[Paul-RS6]

look around for a spare haldex if you pulled the fuse for 2wd.

i know of a couple of people that have had to have haldexs replaced and all of them at some point run 2wd on a RR.

whilst the S3 is part time 4x4 the rear wheels are always turning, This doesnt happen if you run FWD on a RR.

I would never, (and have) refused to run 2WD for this very reason.

 

[AndybS3]

I'm hoping it's something like that Ewan but the standard power would also be down unless it was more than 210 to start with

I didn't pull the fuse Paul I unplugged the controller. With respect why would Audi put a fuse in to protect the Haldex if every time it blew it knackered the thing? also when certain sensors or controllers malfunction the car will usually default to FWD which seems to have no adverse affects when the sensors are replaced, looking at the mechanics in the Haldex I can't see how running in FWD would bother it. Saying that I've got a spare in the garage /ubbthreads/images/graemlins/smile.gif

 

[DavidR]

Andy, the figures are not far off the numbers for an otherwise standard car with a stage 1 upgrade. Dastek seem to produce realistic figures, rather at odds to some of the over inflated and often talked about 270bhp stage 1 conversions.

Running 2wd can affect the interpretation of the numbers though..

Can you post your graph up, does it show boost figures?

David

 

[Paul-RS6]

running 2wd on the road is not a problem Andy,
after all the S3 is part time 4x4 anyway,
But the rear wheels are always turning as the same speed to the driven ones.... more or less.

what does seem to cause problems is when you run 2wd on a RR, where the fronts are doing XXX mph and the rears are static.

Its not set in stone that it WILL damage it, but the two people i know that have needed haldexes both have run 2wd on a RR before hand.

 

[DavidR]

[ QUOTE ]
PaulS3 said:
look around for a spare haldex if you pulled the fuse for 2wd.


[/ QUOTE ]

I think that andy has not pulled the fuse (one possible way to disable haldex) but rather has disconnected the ABS / ESP loom under the bonnet, which means the haldex is still working, but that the ECU doesn't shift power rear when front traction is lost.

 

[Ess_Three]

[ QUOTE ]
David R said:

I think that andy has not pulled the fuse (one possible way to disable haldex) but rather has disconnected the ABS / ESP loom under the bonnet, which means the haldex is still working, but that the ECU doesn't shift power rear when front traction is lost.

[/ QUOTE ]

Sounds like it...

for the record, have completed dyno runs that total approx 50 in the last 3 1/2 years...I have run 4WD, 2WD with the fuse pulled and with the Haldex plug pulled but all 4 wheels turning...and never had a single problem.

Just to confirm...pulling the connector under the bonnet does have all 4 wheels turning...but your corrected figures will be a bit off due to incorrect driveline losses being generated.

But, bweing honest, approx 245-250 BHP genuine, is about right for an APR stage 1 re-map.
Mine started off at 209 standard and went to about 250 with the APR re-map - I have the dyno plot to prove it.

Since then, ever step of development has produced a gain of some sort...

The sad thing is that APRs 250 ish BHP / 27-280 lb-ft is just as strong, on the road, as certain other tuning companies 275BHP/300 lb-ft. Go figure.
Strange that these mythical gains as produced by other companies rolling roads are never re-produced on the dyno days I attend!

As long as it goes well, who really cares what the pie-in-the-sky figures say?

 

[AndybS3]

Sadly David the boost was not logged. I agree about the accuracy of Dasteks rollers there were a lot of new standard cars there that all made 0-2 bhp from their documented standard figures

I wondered if FWD would affect the figures but the standard setting getting 210 would suggest it doesn't
the question is now do I start looking for a fault that may not be there?

This sort of puts Glens/your /ubbthreads/images/graemlins/confused.gif figures into perspective, after all the mods, tweaks, de-restrictions and maxed out fuelling the difference between the almost identical cars from stock seems about right

 

[AndybS3]

Torque