http://www.singervehicledesign.com/
Even with GT3 crank, is that for real?

No Way.

375 Ponies absolute Max

Not saying it does it, but with the raw numbers...

If max power (or close) comes around 8000rpm, then it that would be 280lbft of torque. Doesn't sound impossible from a numbers perspective!!! But then armchair tuning is easy

Bert

I think you did not do your homework properly...

That engine costs around £40,000. There are hours spent tuning it and the ECU (Motec M600-M800) alone costs £4,500.

I have less extreme version of that engine in my 911. My car pulls away from a 997 Turbo and GT3 RS on the track.

My car is dynoed at 406HP @7,600 rpm.

Who cares... all dynos are different, different conditions and different fudge factors.

Dynos are only useful to make comparisons on changes/upgrades on the same car.

As I told you my car pulls away from a 997 GT3 RS.

A 997 GT3 RS is 1,375kg and 415HP

A 997 Turbo is 1,440kg and 530HP

My car weighs around 1,200-1,250KG.

You do the math...

Matteo, are you on about your RSR replica or does your 993 also have a 9M built engine? Your RSR replica wieghs about 1050kgs doesn't it?

The torque to power conversion (power=torque*revs/5250) is, I believe, fairly well known. If you need a reference, try Google - there are plenty of places where that formula exists. As for the maximum torque per litre, that's from my experience of race engines. As for the Rennlist article, it doesn't really help in this case but if anything it supports what I've said. BMEP = 150.8 x torque (in lbft)/capacity (in cubic inches) - again, if you want a reference, just Google it, it's hardly arcane knowledge. A 3.82 litre engine has a capacity of 233ci. So BMEP for that engine is torque * 150.8 / 233, which equates to BMEP = torque x 0.64.

Plug in my hypothetical figures, with torque at 344lbft, and that equates to a BMEP of 220. High, undoubtedly, hence my reference to 'a very highly tuned engine'.

Even with a less extreme BMEP figure, 425bhp is still eminently achievable. Let's take a BMEP figure of 200. That would give a maximum torque of 312.5 lbft, or 82 lbft per litre. That is definitely achievable - a well tuned VX/Duratec/K-series can get to 85lbft per litre. That would mean, if maximum torque is produced at the revlimit at 8000rpm, that maximum power is 475bhp. Still well above the figure claimed.

I have a new NA engine for my RSR. 3.82ltr, 720bhp at 8760rpm. Hope to have it ready next week.

Don't spoil my fun....

Depends. Where max torque will be will depend, largely, on the cam profile and timing. There's no reason why it shouldn't be at 8000rpm - plenty of engines out there have maximum power produced at 8000rpm or higher. 3 I've got fitted in my cars, for starters. Equally, I don't know where you've got the max BMEP figure of 180 from, other than thin air. If it's got custom cylinder heads then there's no reason in principle why it shouldn't have a BMEP of 200, although whether it does in fact have a BMEP of 200 I couldn't say.

If max BMEP is 180 and maximum torque is produced at 5300rpm then maximum power will be 283bhp up to 5300rpm, although max power may be greater higher up the rev range even though the torque is lower. However, if the cylinder heads flow well, so maximum BMEP's higher, and if the cam timing is more aggressive, so max torque is produced higher up the rev range, then it could be significantly higher.

The fact is, I don't know and you don't know what this engine will actually produce. However, there is no reason in principle why a 3.82l NA engine should not be capable of producing 425bhp.

EFA...