Not sure if anyone has any ideas, but my mate went on one of those rolling road things in his MY98 standard UK Impreza. To his horror he only managed to produce 190 bhp :eek:. Any ideas why this would be....as least you guys could help put him out of his misey :D

First make sure the tank is full of optimax and maybe some octaine booster as well and do an ECU reset (disconnect the bat over night). Should make a difference.

Has it been serviced on a regular basis?

Ian
Terzo 33

Edited cos I can't spoll

[Edited by ian_sadler - 12/12/2001 10:02:15 AM]

He assures me that its been serviced, but I'll pass on the info and see how he gets on. I thought it best for him to back to the main dealer and get them to sort it out, but he's a bit strapped at the moment :rolleyes:

Cheers

Hi 911,

The reason for the reset is if he has been using ordinary unleaded 95RON. If he has then the engine will wind down the max boost and (IIRC) retard the timing to reduce any detected detting cos of the poorer petrol.

As above a rest & SUL or Optimax & booster will give the engine closer to the 100RON its designed to run on.

The dealer would prob do this first anyway.

Ian

Does that mean that as his is a standard UK car, running on 95 Ron, he will never get the advertised 208bhp or whatever?

Should all Imprezas therefore use the higher super-unleaded?

Sorry about the bad spelling :)

Sounds odd.
I have a MY98 and it put down 232 bhp at well lane it is totally standard and was running BP 95RON fuel.

It was quite a cold day though.

Check out the links to the dyno figures most Std cars seem to get in the 220s-230s.

911,

You'll have to get you mate to read all the SIDC FAQ Page but for the mo. here is the bit on fuel type.

http://www.sidc.co.uk/faq.htm#2.4

ian

Cheers guys....I'll pass on all the info.

One obvious question, was the 190 bhp power at the wheels or estimated power at the flywheel?

Andy

I fail to see why changing fuel would help this guy out, even if he then hits 200+ bhp.

Personally I'd be pissed if my UK spec Impreza only produced 190bhp on 95ron seeing as it's supposed to produce 215bhp.

You might as well tell him to add a bigger turbo cause that will get his figures up too :rolleyes:

Not too sure :confused:.

I'll find out for sure, but I think he said it was at the wheels.

Has it had over boost problems before?

Maybe a restrictor has been put in the pipes around the boost solenoid and it is not the correct size so the car is not boosting correctly.

This happened in my MY98. A new restrictor was put in and it made a BIG difference!

Phil

If it's power at wheels, that's huge power.

190 at the wheels.. I'd be chuffed with that!!!

911,
If it's at the wheels then that is a lot more than the 208bhp because this figure is the power at the flywheel.
Taking into account transmission losses which will be variable depending upon which method the rolling road use to estimate them, the power at the flywheel could be approaching 245-250bhp which is well above standard.

Andy

I've just contacted him....it was'nt at the wheels :rolleyes:. He had around 140 bhp at the wheels.

Depending on the rollers, my transmission losses are around 80 -100bhp.

Which rollers did he use?

Have a look at this (Powerstation): http://dyno.scoobynet.co.uk/psuk/andrew_tang.htm

My power at the wheels on the first run was 142bhp and the second was 138bhp. The car only had breathing modifications at the time (full de-cat exhaust and air inductor)

So 140bhp at the wheels, could show between 220-240bhp at the engine. :confused:

Hi Andy,

I'm not sure about the roller set up, I think it was the first time for him, so I don't know how much he knows either :rolleyes:

I think it was 136bhp at the wheels but only 192 bhp at the flywheel, so he's still a bit down on power :(

Not much else I can say on the matter, but I'll pass on all the info. to him. He may not be so :eek: after reading this thread.

Cheers guys :D

Also Andy,

His car has done a lot of miles ca 90K.........I assume that would make it a bit worse?

:eek: 90k in a MY98.

Not bad 30+ K per year.

Ian

Its a lot, but would this affect the performance?