aus73

P130J - A power test is £55 + vat.

We monitor the air/fuel ratio, boost, and inlet temp. We give graphs of bhp vs torque, bhp vs air/fuel, and bhp vs boost pressure. For each car we get 2 runs within 1 bhp - which tells us the numbers are fairly accurate and repeatable. On most turbo cars it takes 1-2 runs to get the combustion temp into the right range, and produce good power before we can get 2 repeatable runs.

The subarus have specially developed software to give accurate flywheel bhp and torque figures - though personally I only like to deal with wheel bhp figures.

We host rolling road days for all the clubs. We do a minimum of 12 cars - and a max of 25, though we have run 28 cars in a day if there are a few extras. Again, each car gets 2 runs to within 1bhp, so its 3 or 4 runs per car. We don't have problems with wheelspin, or inlet temps (even on top mounts), so we get through the cars pretty quickly - as we don't have to wait for temps to stabalise, or repeatedly strapping cars down to prevent wheelspin.
A rolling road day we do for £50 per car (inc vat)

Max power on the rollers is 547 (at the wheels) at the moment - though the norris car ran 543 recently.

Andy - I am trying to find a graph I saw recently from PE on the net. It had max power printed at xxxbhp, where you could see the graph line shoot up at the end. The operator at PE correctly crossed the figure out and wrote a lower power figure where you see the graph start to tail off. I could show you one of ours - but we don't have any

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1800bhp - NO Wheelspin - NO Excuses

5 Type R

I have obviously missed something but how does 1800bhp translate into 547 at the wheels?

aus73

ummmmm

Its a 4-wheel dyno. Rated to do 600bhp at the front wheels - and 1200bhp at the rear wheels. So 1800bhp at all 4 wheels. We can run up to 850bhp at the wheels on a retarder system rated at 600bhp. The numbers sound big and ridiculous, but a dyno of identical construction is used in bhp shootouts all over the world.

have a look at:

http://www.summernats.com.au/results_hpheroes.html

All these figures are at the wheels in the biggest bhp shootout in the world - held in Aus every year. The cars are mostly 2wd - so the rear wheel bed is rated at 1200bhp (at the wheels) and someone has now run 1372bhp (at the wheels).

The most we have seen here is 547 atw - and we're keen to see more.

Cheers,

Chris Davies
Motorsport Engineer
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1800bhp - NO Wheelspin - NO Excuses

Tim W

iTrader: (1)

Maybe I've missed something here, but how do you ensure that there's no wheelspin? I understood that although loading the car with more weight over the slipping wheels helps to improve traction, it also makes the figures unreliable.

I'm going to have to pop in and have a look at the cell, especially as your only 15 minutes from where I live!

aus73

Tim,

This rolling road is the first of its type in the UK. It is state-of-the-art. We have a completely different method of tying the cars down - so we can run 540bhp+ atw cars with just me in the driving seat. We also do at least two runs on each car to verify the numbers are accurate - rather than driving on, doing a run, and driving off - as we've found the turbo cars need at least one run to bring the combustion chamber up to its optimum temperature.
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1800bhp - NO Wheelspin - NO Excuses

5 Type R

I would be up for a dyno day at G Force as its only 15 mins down the road.

Any plans other than the most powerful scooby day you mentioned. Only have around 310 so dont want to waste a place on that day!!!!

P130J

aus73, YHM

Tim W

iTrader: (1)

Chris, I ended up popping in on Sat while you had all the Pug's in...such a quiet rolling road day

Had a peek at the dyno, from what I could see they hard knurled front rollers, but your tie down method was no different to the two other dynos I've used at Power Engineering and Powerstation, who both do at least 2 runs before the actual power run to ensure the car is settled.

To be perfectly honest apart from the environmental chamber and the enormous fan (nice!) I didn't notice anything particularly different about your dyno.

aus73

Tim,

You came all this way - shame I didn't get to talk to you then. The system is specified to run our race cars for power tests and endurance testing. You can run cars up to 350 or so just about anywhere - I agree. When you talk 400+ the situation is a little different. Its in the details.

YHM
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1800bhp - NO Wheelspin - NO Excuses

Tim W

iTrader: (1)

Chris, you were very busy with the pug's, I had a long chat with one of your colleagues in between him shuffling cars, fans and straps

It's not exactly a chore for me to pop in and see you I only live 15 minutes up the road!

YHM(s ) back