Due to a discussion on another forum,about an AUM's power,so thought i'd post on here.

Awesomes rollers over-read like a good un. I reckon mine would return 260Bhp on awesomes rollers as its always reads around 240Bhp on cheap rollers.

In fact, at my last rolling road day someone who got 240Bhp at Awesomes rollers got 210Bhp on Dyno Dynamics rollers in shoot-out mode.

Not only that but if you only had a generic upsolute, they dont produce more than 17psi to remain safe, and the N75J will give you another 3psi max, so you'd only be pushing 20psi max, you'd need 23psi to get 220Bhp.

I replied with

So when a std car goes on their rollers and produces what it should ie 150bhp etc...,who's wrong? Awesome or VW?

This was posted

Standard VW's ALWAYS produce more than they are supposed to, in fact the ABF engine was famous for it, constantly showing 160Bhp from most engines.

If yours was an AUM it also had small ports, so it isnt actually possible for it to flow enough air needed for 220Bhp, you're only going to get that from a large port engine such as an AGU.

Regardless, you can trick a rolling road into producing vastly different results just by changing the resistance, thats the idea behind Dyno Dynamics shoot-out mode, whichever DD rollers you use, wherever they are, the road settings will always be the same, so gone are the days of the Dyno Lottery.

If a car produces a figure on DD rollers in shootout mode, then they are accurate numbers.

Any other UK rollers and you're talking resistance, operator differences, cooling etc. So they cant be compared.

I'm not saying your old car wasnt fast, its just that it wasnt AS fast as Awesome would have you believe

Sent this back

there's one quite close to me, you may know it - that really does over-read, eg a mk3 VR with a 'Superchip' putting out 220bhp, and when taken to another place in Chesterfield where it made 183bhp which was the more likely result

I reckon if you're happy with the way the car drives, then all's good

 My Golf 25th Anni diesel went on the rolling road at AMD and the only modification i had done was a green cotton panel air filter. Its supposed to be 150bhp as standard but it came in at 155bhp then after i had my turbo back miltek exhaust fitted it was 158bhp.

the only way to see a fair result would be to try 10's of rolling roads keeping as many of the variances the same and calculating the average from a large pool of runs

Generally speaking, most rolling roads are approximate. They *can* be made to be pretty damned accurate, but only if you compensate for atmospheric pressure, dyno cell temperature and suchlike. And of course, they need to be accurately calibrated, and recalibrated regularly.

Lots of operators don't bother - don't for a minute think that a shiny dyno cell equals scientific measurments.

I pretty much guarantee that you can make the same set of rollers read differently, depending on the process used to take the run, eg, "flash" readings, not letting the car run down to zero after the run to measure transmission losses, that sort of thing.

And of course, in a lot of places a high dyno figure equals a happy punter...

 30bhp extra is a lot though,anyone ran a std car at awesome? What did you get?

Patch:

Not only that but if you only had a generic upsolute, they dont produce more than 17psi to remain safe, and the N75J will give you another 3psi max, so you'd only be pushing 20psi max, you'd need 23psi to get 220Bhp.

23psi to get to 220bhp? Do you realise *if* you managed to hit 23psi it would be merely a spike which would reflect in the torque curve and not the bhp curve.
Max bhp is made around 5500 to 6000rpm, have a guess at boost pressure at that point. Nowhere near 23psi!

Also, I've hit 240hp on many RR but never seen 23psi, not even a spike.

 Awesomes rollers turn out some of the most repeatable and accurate figures I've seen. Jim does not frig the results.

With my car on an ihi vf34 they gave 330hp. It did 327hp at power engineering, 337hp at jbs, 317hp on a dyno dynamics in shootout, 320ish on the old amd's rollers.

With the 18g It did 367hp at superchips, 362hp at chipped UK, and 360hp at awesome.

All within a few hp between rollers, but I know enough to keep the operators honest. 5% between rollers is good accuracy.

Awesome is one set of rollers I know that will give the same realistic results every time.

GaryM:

Patch:

Not only that but if you only had a generic upsolute, they dont produce more than 17psi to remain safe, and the N75J will give you another 3psi max, so you'd only be pushing 20psi max, you'd need 23psi to get 220Bhp.

 

23psi to get to 220bhp? Do you realise *if* you managed to hit 23psi it would be merely a spike which would reflect in the torque curve and not the bhp curve.
Max bhp is made around 5500 to 6000rpm, have a guess at boost pressure at that point. Nowhere near 23psi!

Also, I've hit 240hp on many RR but never seen 23psi, not even a spike.

This is just something someone posted mate,don't quote me.......

Patch:

This is just something someone posted mate,don't quote me.......