MR2 turbo rolling road results - shows huge variation in different dynos

[Lee H]

As some of you will know or remember I brought this car to the North West rolling road day at Minisport last year and some people with XE's got some interesting (flattering) results from this dyno lol My MR2 made 265bhp @ 0.9 bar on that day with 220 ft/lb of torque.

This weekend I got the car remapped after fitting a new fuel pump and a metal head gasket. The rollers this weekend were Dyno Dynamics rollers. We ran it at 0.9 bar same as Minisport before adjusting the map at all and made 200bhp. Obviously 65bhp is a massive variance and is not linked to just swapping a headgasket and fuel pump as no changes had been made to the fuel pressure regulator.

Had the car remapped to 1.2 bar and made 260bhp at the fly, 218bhp at the wheels with about 260ft/lb of torque. Previously it had been mapped to 1.1 bar but was never ran on the other rollers at this pressure. So according to these results i'm 5bhp down running an extra 0.3 bar of boost, total rubbish I think lol

Car feels so much quicker than it did before at 1.1 bar so the power is definitely higher. People on the MR2 forum are claiming to have made 300bhp on the same spec but none on the same make of rollers.

Someone has also said the gear the run was done in can make a difference to power figures as well, someone basically ran the car back to back and made 20bhp more running in 3rd than 4th? Anyone else got any thoughts on this? Stuart maybe?

Graphs below for anyone interested. (don't know why PB won't rotate them)

http://i192.photobucket.com/albums/z163/Lee_H25/138805e5.jpg

http://i192.photobucket.com/albums/z163/Lee_H25/65440ff4.jpg

Certainly makes me feel better about my 1/4 mile times if i'm as down on power as much as these results suggest :d

[Calamity Josh]

i've always used a local rollers that my dads friend has in his shed, simple gauge cable tied to the wall! i got 45bhp from a rebuilt 12nz with k&n and a bike exhaust. which is about what they have as standard so i'd say thats a pretty true reading! Baring in mind this is used in a autograss class where only specific modifications are allowed (which mine is built to) someone said he had 80bhp...

[Bubba]

had you removed any "rip speed" stickers or bolt on spoilers? they cause massive power loss when removed once installed lol

my bet is on one of the rollers being faulty.

[Calamity Josh]

my bet is on one of the rollers being faulty.

faulty? is that what they call it? :wtf:

[Angus Closier]

I belive the problem is more down to the set up, you can get funny power readings in diffwgears due to the rolling road being set up to calculate transmission loss etc on whater ratio the rollers are calibrated to...so normally 1:1 normaly found in 4th gear. Also depends on other input data aswell such as air temp and altitude. I suspect most of the time its lazy peole not setting the rollers up rather thank "broken" rolling roads.
In the case.of your mr2 it seems very out, however i remember at college we tested my car using six power runs and after 3 changed the air temp and managed to gain an extra 10bhp.....
Please corect me if im wrong. (May well be)

[Jack]

we tested my car using six power runs and after 3 changed the air temp and managed to gain an extra 10bhp.....
Its not uncommon for dodgy RRs to input a duff air temp so it over calculates power.

Lee, I'd have thought it should be getting more than 200bhp at 0.9, the rev3 3SGTE makes 239-250 on that as standard.

[Mazz]

...Minisport last year and some people with XE's got some interesting (flattering) results from this dyno lol

Adam's 190bhp nearly standard XE maybe! Mine made 168 there iirc

[Spudly]

My vectra estate made 200.5 bhp on the same rollers as Lee's did on the same day, it had previously been on the rollers at Z-cars, where it made 184.3 lol



http://i8.photobucket.com/albums/a36/spudly01/Events%20Piccies/DSC04129.jpg


http://i8.photobucket.com/albums/a36/spudly01/Events%20Piccies/DSC04136.jpg

[Lee H]

Its not uncommon for dodgy RRs to input a duff air temp so it over calculates power.

Lee, I'd have thought it should be getting more than 200bhp at 0.9, the rev3 3SGTE makes 239-250 on that as standard.

After the mapping work I got 230bhp at 0.9 bar but running the old map only made 200bhp. Sounds about right as the rev 2 head and cams aren't as good as the rev 3 stuff?!

[Lee H]

Adam's 190bhp nearly standard XE maybe! Mine made 168 there iirc

Riggy made 164bhp and his car was using more oil than petrol!

[Adam]

That Minisports rollers were a joke tbh.

Sounds like you latest figures are about right and the Minisport readout was 20%+ up on what it should lol