Rolling Road results

Found a really good rolling road 5 miles from me in Crawley. It's called Austec Racing/AFR tuning and they have the latest MAHA rolling road which the guy assures me is calibrated every 3 months and is 'deadly accurate' . I reckoned that as basically its the same as a decatted A610 running standard boost, it should be around the 260-270 bhp region and low and behold it was 259 bhp. Then I realised it was only running 10 psi boost which is a couple down on a A610 so I'm very pleased as it means the additional mods I've made are probably worth an extra 20 bhp or so Produced a really smooth solid graph with virtually no drop off until 7000 rpm. Torque 253.5 ft/lbs. These figures are well down on what the car made at a bar on other rollers but this did seem a much more reliable and more professional outfit. They said cars rarely make factory figures on their dyno. They seemed a nice bunch and really liked the car. Be interesting to get a standard GTA and A610 on there as a bench mark. I haven't got a scanner but I'll take a picture of the graph and e-mail to Lee who can post it up .

A lb of boost is worth about 10 bhp on these engines so a bar should see it up around the 300 bhp mark as before.

They are up for a dyno shoot out too. How bout a V6 Renault day or even a PRV day.

More to come Tony

When mines done I'm going to put it on the hub dyno at Thor .

Great stuff Tony, really glad you and Lee have been keeping at it!

You are the only guys who are finally getting good reliable results.

Things start to happen when you use good guys who don't talk sh1te.

KEEP IT UP!

Cheers buddy

Good reaults Tony

If you take the 260hp to be correct then forgetting compressor, cooler and other efficiencies for a moment you can assume that power output without boost will be 154hp because at 0.69bar (10psi) you made 260hp (154hp x 1.69bar absolute). If you use that rule of thumb to see what happens at 1 bar of boost it comes out at 308hp. (154hp x 2.0bar absoloute). Ofcourse efficiencies will drop off but it shows that you will certainly make a real 300hp at 1 bar or there abouts.

Chris

It's funny how just working with an engine for a while you learn things and then someone proves you right with the science. I'd always found you got about 10 bhp for every extra psi of boost and Scoff 's formula suggests thats pretty much spot on. That does mean however that a standard GTA turbo doesn't make much over 100 bhp without the turbo on!

[stephendell]

That does mean however that a standard GTA turbo doesn't make much over 100 bhp without the turbo on!

Yes just ask Mr Law!

Mine felt more like 50 bhp when an intercoller pipe fell off.
The car maxed out at 65 mph.