Stunned Monkey wrote:David Gentleman wrote:
330bhp was the max ever acheived on the PRV, but this is on race fuel, 8000rpm, sliding throttlebodies, 300+ degree cams with completely reworked heads, valves, ports etc.
Er *cough* - 600bhp on a stroked 93mm 12v at 2 bar boost by Kevin Jones. And the engine is still going.
800bhp from a bespoke-head twin cam odd-fire by the Pug WM LeMans team.
Ref the "smaller wheels" argument. You haven't given me any physics, only "if it were that easy, everyone would do it". I'm sure the gear ratios on top fuel dragsters are optimised so that they can use the traction offered by big wheels.
Are you telling me two identical PRV powered cars will do the same 1/4 mile times if they have a different final drive? And if so, explain to me how?
Martin, *cough* we were talking normally aspirated......
As for the PUG LM, well you just said it, custom twin cam 24v heads. Its no longer a PRV apart from the fact its the original block. All the bad bits of the PRV design have just been replaced!
And even then, 800bhp for 4 bar boost on race fuel isnt really that good...
Martin, don't ask me to write it down, Im not Newton, but in simple terms the one with short gearing will get to say 30mph in top of first for instance, in a shorter time than the longer gear will hit 40 in the top of first, but the difference is it will have also travelled less DISTANCE down the track, whereas the longer gear takes longer to get to the higher speed, but travels further doing so.
Acceration is all about getting to a speed quicker, but you are not actually travelling as far doing so, and this is the thing with drag racing, it it distance related to time, not just time..
If you do a search on the net, you will find a myriad of ET, 1/4 mile calculators etc which are very accurate (this is the same type of system the Racelogic box uses) and not once will it ask what gearing or tyre size is required for the time crossing the line, other than telling you what speed you will be crossing at.
Likewise, as I kept on saying, people would put the shortest gearing and small wheels on their drag cars before anything else if it was so, but they don't.