Search didn't show up anything .....Question is,what's the safest and maximum boost one can run in a low compression S 52 with and without Methanol...
Thanks

Too many variables to give you an answer.

Too many variables to give you an answer.

Like what ?

e,g.....S52--lowered compression to 8.5 using after market headgaskit and a spacer kit,OBD 1 converted,Bigger fuel pump,525 cc injectors,Porsche MAF..

BTW how can one confirm to see what compression the engine is lowered to ?

Maybe 18?

It's not just PSI but CFM...Temperature etc...... +1 on too many variables.

Power is a more important determining factor.

So can some one enlighten me about all these variables ?
Thanks

You could search instead! Everyone wants a free ride these days, sheeesh.

28lbs ... at least! :thumbup:

Yasir, your compression is more like 9.2:1 and you cannot run any more than 15psi. You probably have the old 10mm ARP studs too....I would use the methanol as a bit of insurance instead of trying to make it a power adder....not unless you were on a standalone and can actually monitor how the motor is reacting to added boost.

The limiting point will likely be your rods. Some time ago the accepted safe limit on the stock rods was 17psi. Any more and you risk bending a factory rod. Somewhere above 20psi, even with forged rods, the HG becomes an issue.

With an AA tune, I would run no more than 15psi.

Is there a way of checking what compression ratio the engine is ?

Btw i do not plan on running any thing more then 15 psi...I was just wondering if the car was to be tuned on dyno in real time where you can actually see the AFR,Timing and boost,would you still not tune it for 17/18 psi...

Is there a way of checking what compression ratio the engine is ?
I believe Thomas (M3//M5) made a calculator. Search for his excel thread.

Btw i do not plan on running any thing more then 15 psi...I was just wondering if the car was to be tuned on dyno in real time where you can actually see the AFR,Timing and boost,would you still not tune it for 17/18 psi...
I wouldnt with the stock rods. Maybe tune for 17psi but then only run 16psi daily, but even then having to worry about the condition of your rods all the time wouldnt be worth the extra 1 psi to me.

I would rather have an awesome/rock-solid 16psi tune than a 17/18psi tune which gave me cause for worry whenever I got on the gas.

stock rods good for 600whp ive been told

I believe Thomas (M3//M5) made a calculator. Search for his excel thread.

Killer sig pic!

Your car is HOT, I love Fikse wheels.

Killer sig pic!

Your car is HOT, I love Fikse wheels.
Thanks! Its not as fast as my old 332, but its definitely cleaner :cool

stock rods good for 600whp ive been told
I understand my 17-18psi limit is dependent on some variables, but so is a rwhp figure.

I think one way to check compression would be to do a simple compression test on all of your cylinders. Take the mean and divide it by the standard compression for a stock s52. Multiply the quotient by the compression of a stock s52 which is 10.5:1 (just use the 10.5) and you have the estimated compression of your engine.