My Car On A Dyno

[Bibbs]

Okay .. I think you all know my car is a bit modded, but with stock turbo and stock internals.

I gave it a run on Saturday, without the Water Injection and at 14 psi ..

So this car :

Produced this plot :

196 @ the wheels - and about 250 at the fly .. now to get the WI on and run it at 17 ..

[Jimlad]

so when people quote their BHP... do they usually quote at the fly ?? For example stock rev1 Turbo is 225BHP.. is this at the fly?

[Dame]

It's usually quoted at the Fly, since this measures the power the engine is producing before it has to go through the transmission, wheels, etc. It's a bit misleading - but once you've driven a few cars, you get to appreciate that 180 - 200bhp at the wheels is a hell of a lot. Of course it's the torque that's the most important measure of performance.

[Titto]

Manufacturers and companies use the fly to big up their power claims. You've got to remember they are only claims and are normally more optimistic than the power really is.

For talking to us guys who feel the power on a day to day basis, use at the wheel - we can all relate to that more!

Brill

[Titto]

Bibbs, whats your thoughts on this other injection, what you hopin for?

[midmotorsteve]

water injection reduces charge temp allowing higher boost with out melting things like pistons.

[Dame]

Bibbs,

Thanks for posting this, it gives us all a bit more of an idea of what to expect.....

[Dame]

Water injection is a great idea, somewhat similar to Water Cooling in PC's. Water is a more efficient cooler than air.

[Jimlad]

so at 15PSI.. I could be running 260BHP ?? ( damn my estimate was wrong... lol )

[Dame]

I reckon you'ld be seeing around that figure, Don't worry about the estimate, crumbs, 260BHP is plenty :)

[Bibbs]

Water/Methanol injection is simple ..

Witha bottle in the boot and a pump you set a little ECU to pump the water into the IC pipes at a preset boost (or can map it via a chip).

This drops intake temps (as you have a water mist in there) .. unfortunately this drops the power ..

You can then up the boost (on a rev1/2 to about 17 psi) and you are back to where you started BHP wise. If you use Methanol you can get more bang out of it.

The hike from 14 -> 17/18 psi will only upp the BHP by about 20/30, as anything over 14 psi is no longer the 10 BHP per PSI.

With the WI I'd be hoping for 270/280 .. but with torque about the same (270/280 ft/lb).

(One rev2 saw a 15 BHP hike just by changing the plugs to new ones).

I've got a load of other specs etc .. so I'll get all the details up at some point. ..

[pizza boy]

Bibbs did they point the fans at your intakes properly on the RR? Im sure you should be producin more bhp@wheels cos I got a readout out of 211BHP and 217BHP@wheels when I was running a bone stock car (bar induction kit sucking plenty hot air in). The 6bhp increase was just from them increasing the fan power as it wasnt cooling my car properly. I was running about 95 degrees in the engine bay and it was a hot day too. They still said it was too hot so I was looking at even more power if they had mobile fans. I should post mine up actually.

Its just that 50bhp is a hell of a lot of power to lose thru the drivetrain etc. You expect that kind of loss on a 4wd car.

[Bibbs]

no fans .. roll it in, strap it down .. and a quick blat ..

[Jimlad]

I assume you would have got better figures if they did have fans ?

[Bibbs]

depends .. it wasn't a hot day .. and fans only effect runs after the IC has heat soak.

So for one run I wouldn't expect much differance .. I'd ecpect my losses to come from big rims and new tyres ..

[Geri]

The big rims and tyres should have been compensated for when they did the run, and shouldn't affect the result, unless the tyres weren't scrubbed in etc and you were getting scrubbing on the drum. The dyno should be measuring your engine RPM as well as the drum speed to figure into it's calculations. My bike gets the same RWHP, within 4bhp with 3 different gearings.

The rolling road dyno only measures power at the wheels, flywheel power is only a guess. The majority of bikers will quote RWHP because that is what is actually measured. If everybody, everywhere quoted RWHP, there would be no speculation and arguments about how much geartrain loss to include etc.

[Bibbs]

and they were compensated for .. someone questioned my high trans losses and this is the only things I can think of.

And yeah .. RW-BHP is the only thing (and I'm actually more of a torque than BHP man).

Ben.

196 BHP @ the wheels.

[John R]

What's rev2 turbo stock, I forgot.?

[Bibbs]

225PS - 220 BHP

[John R]

I suppose that's at the fly then, if not i'f be a bit ****** off that I'd lost power.

[Bibbs]

yeh - so i'm 30 bhp up ..

[John R]

How much did it cost you to get the dyno done then?

[Bibbs]

£20 .. others had a few runs for £20 .. but I couldn't get the WI working ..

[Jimlad]

Bibbs.....

quick question for you mate... I'm actually getting an ERL water injection kit from rogue systems... ( not copying you honest !! They said they had it and I'll buy nearly anything.. lol ).

You mention using water/methanol. From the pics I've seen from Matt it's got a massive bottle.. so what goes in there ? Water/Methanol mixture ??

If you want me to post pics of it, let me know.

Also... I should be able to crank the boost upto 17PSI right ?? The car it was taken from had 18PSI (rev1 !)... so what would you recommend ? 17 or 18PSI ?? I say 17 because that's what you have stated in the post, but like Matt said.. the car it came from was a rev1 running at 18PSI !

cheers mate.

[Bibbs]

I'd suggest getting it tuned to the car .. 17psi is safe, 18 is touch and go .. (it will run <Dr Evil> one million </Dr Evil> psi - but may not last long).

you can either get methanol from a hobby shop and mix it 50/50 with water or just buy Halfords screen wash (cheap at the moment) and use that.

I'll be setting mine to fire at 6 psi ..