had my 2002 bug sti on the rollers today and am a little disappointed.

its had a center de-cat , uprated pump and a remap, was looking for around 300-310. 1st run was 284hp and 262lb/ft @4638rpm and the second run was 257hp and 253 lb/ft @4228rpm.

would anyone else be happy with these results ? and do rolling roads vary
much? as 1 car 2 weeks ago reached 250hp today only 220hp on the same rollers.


look forward to your comments thanks

 

how many miles has the car done mate?

 

where do you live bud, i have a 53 plate sti, full decat, k&N panel filter, 330hp

 

would have thought you would need a full decat....

 

hot weather too, not the best.........

 

rolling roads will tell you what you want to hear. very subjective and will vary from road ro road.

 

I'm assuming you're running on good fuel - crappy fuel can make a huge difference. Combined with hot weather and you'd get low figures. Certain rollers are known to be 'low' or 'high' too. Difficult to compare between them. I'd be gutted with 257 - 280 isn't too far off with stated mods, given the variability between rollers.

 

When the car did the second run it was probably still rather warm from the first run. The TMIC was probably still baking hot and combined with it being a very warm day and the crap airflow it gets from the fan on the RR this would have sapped your power.

If you had RR'd in the winter you may well have completely different results.

On the road this is a different matter as well as the TMIC can actually get some air.

A full de-cat and a FMIC would help a lot to increase the power.

 

Rolling roads only give an indication of expected power. on the road, in the real world you will never tell the difference with 23 hp. 100hp yes you will.

i would not worry too much about chasing bhp figures, it about how sharp the car feels on the road. bhp figures are for bragging rights down the pub and not worth the rolling road paper they are printed on. All IMHO of course

 

thanks for all the replys

its done 46,000

Dagenham essex, so a full de-cat does make a big difference then ?

i run it on tesco 99

to be honest i am more than happy with the cars drivability since the re-map , but i am thinking maybe full de-cat or sports cat and poss miltec or similar exhaust , just dont want something really loud

 

what psi/bar is the turbo running at?

 

Who did your remap and where did you get the RR done? Did they have a huge fan directed into the intercooler? (I hope so!)
To be honest, take all Rolling Road results with a pinch of salt, if you're happy with the bum dyno then that's all that matters.

 

very true mate - numbers do not mean anything - the way the car delivers the power, holds boost, low down power etc is what counts

 

^^^^^^did i not just say that about 4 posts ago?

 

What dyno was this on ? (the set ups vary enormously and subsequently the results)

Seems low for the first run possibly from a lack of cooling causing det then made worse on the second run.

Shame cos the car goes really well from my recollection of the mapping.

 

Lots of people get very disappointed with rolling road figures while others go away believing they have more power than they may actually have. One run on its own when you don't know what you are doing and the company conducting the rolling road do not give honest feedback means very little.
A run in isolation is usually a waste of money.
Duncan seems to think the car goes well and for that to be the case it will have a bit more than standard power.
Different rolling roads will give different figures and some rolling roads give different figures and different times on the same rollers so it is worth finding a consistant rolling road and then sticking with it. As an example with a specific car I got 422 bhp on the Thursday at Scooby Clinic on a Dyno Dynamics rolling road followed by 448 bhp on a Dastek rolling road at Northallerton the following Sunday on the same tank of fuel. No modifications. The results from Steve Simpson's Dyno Dynamics which I probably use most often always tie in with the results from Scooby Clinic so I obviously stick with either of these two.
Numerous things can influence the reading from deliberate interference by the operator, ambient temperature, how good the cooling setup is, tyre pressure, fuel in use.
If you go to a rolling road day you can compare the output on your car for your mods against similar cars and that might give an indication of whether you are doing the right thing or not but the important thing is to choose a suitable rolling road, hopefully where the operators will give honest observation and feedback and then stick with it.

 

Agreed.

You an I know, that is not always the case, when you have gullible young boys n girls chasing power figures, the more unscrupulous give a low figure in the hope of getting some tuning work out of the unsuspecting subaru owner. As I have said before a useful tool when tuning but at the end of the day has to be taken in context. I have been sat next to cars on the 1/4 mile with way more power than me yet i have consistantly run better times than them all day. It all can't be down to driver error.

 

Duncan ( top man ) done the re-map and rolling road AMD in lakeside and yes 2 large fans with bonnet open.


Hi Duncan , yep from your recollection the car does go well and i am still happy with it ( for the time being, or until i have more money ) i was just interested in having a bhp figure hence why i got it on the rollers.

i am not 1 one of these people that really cares if it is 250 - 350 or even 450. as some people have said its how the car drives and feels and to me its pretty dam good. Maybe if i can scan the results and mail them to you , would you mind when you get a sec to have a little look for me ? thanks

cheers for all the other replys nice to get some good feedback

 

I notice you say 2 large fans WITH BONNET OPEN are you running a top mount? if so thats the operators mistake> the air will be blowing over the top of it rather that through it to cool it.

With any top mount car the bonnet should be shut with the air from the fans directed into the air scoop to give as near possible road conditions, after all you dont drive around with your bonnet open.

Front mount is a different thing and having the bonnet open has much less impact in the cooling

 

yup top mount , funny you should say that as afterwards 1 of the other guys said the same thing , well from my point of view it is live and learn, i am still new to subaru`s , things were a lot different 18 years ago when i had my escort turbo

so having the bonnet up really didnt do the run any favours then ?

 

Exactly the air will more than likely be blowing over the top of the cooler rather than through it>

The cooling on a top mount is pretty important and an overly hot charge can cause the engine to det which in turn causes the ecu to adjust various paramiters and squash power outputs by some margine

 

Tuffy, i'm from east london mate.
Next time you go to the rr drop me a pm prior, i'll pop down with you if you want so you have a comparison.
My wrx is producing 321/299 tested at Clive Atthowe Tuning's dastek 4wd cell with ambient temps up in the late 20s!!.
You can then have a drive on the road and a drive on the rollers against a car that has been tested on a reliable/competant tuners rr.

 

I agree - when I push the M button on my current car you car really notice the difference, but then it is adding around 107 additional bhp.

I will miss it when it goes

S

 

Thanks nice bit of info for future reference


Thanks nice of you , who and where is Clive Atthowe ?

 

Clive Atthowe is a tuning specialist in Norwich (i know them through my contacts as a bmw tech)
They tuned my WRX for me.
Their cell is very impressive, with a large volume fan system that caters for both top mount and front mount intercoolers, plus an extractor fan system to keep as close to "real life" road conditions.

 

ok sounds expensive lol

by the way what BM dealership do you work at ?

 

Wasn't cheap, but it's fun looking at guys in expensive bmws and mercs, struggling to keep up with my tinny boy racer mobile (been branded by the other guys at work!!)
I'm @ Hexagon BMW in Kentish Town, North London.
Our sales site is in Finchley.