21-05-2012, 10:31 AM
Marelli IAW 1AP can't understand boost without significant modification... The only way the supercharged guys get away with it is because their chargers are just proportional to rpm... The volumetric efficiency increases as rpms do, so you just adjust the fuel map to suit...
You can't really apply a vnt to a petrol, exhaust gas temps are far too high and because you've got the option of high rpms, you just rev it to get the boost... There have been attempts, it does work, but the reliability of a vnt turbo on a petrol just isn't going to happen unless you're looking at one of the porker 997 borgwarner ceramic jobbies which from memory are well over 1700 quid a piece and are only a 60 or 62mm compressor...
A MODERN wastegate turbo will do everything and more, take a look at some cars with a Precision 6262 turbo o, you'll find people slating Precision, but they are darned good! Stupid quick spool and its a 400-500hp capable turbo... The problem lies when people put on a 'cossie t3 hybrid' and wonder why its a piece of shit!
You can't really apply a vnt to a petrol, exhaust gas temps are far too high and because you've got the option of high rpms, you just rev it to get the boost... There have been attempts, it does work, but the reliability of a vnt turbo on a petrol just isn't going to happen unless you're looking at one of the porker 997 borgwarner ceramic jobbies which from memory are well over 1700 quid a piece and are only a 60 or 62mm compressor...
A MODERN wastegate turbo will do everything and more, take a look at some cars with a Precision 6262 turbo o, you'll find people slating Precision, but they are darned good! Stupid quick spool and its a 400-500hp capable turbo... The problem lies when people put on a 'cossie t3 hybrid' and wonder why its a piece of shit!
