Quote:
|
Originally Posted by tysonK
If the Peak efficiency range on the 1418 is 21psi what does that mean, is that what you would set the boost to peak at at for our car. 21psi is quite a bit of boost right? What kind of boost does can our little four banger handle for sustained periods of time?
I don't really understand teh Max Boost And Peak Effciency Numbers? :?
|
Peak effeciency is the point where you can make the most boost without the heat generated by the turbo greatly effecting the chance of detonation. i.e. that turbo can make 28psi, but it's running so hot that the intake charge's heat promotes detonation, requiring the ECU to pull timing. Basically it's not really beneficial to run over 21 psi.
For comparison, the stock turbo's peak efficiency is around 15 to 15.5psi, but it can make like 18psi if you let it.
What's missing from all these specs are flow numbers. The stock turbo can max out at 18psi, but as the RPMs of the motor get up there, it becomes restrictive to the intake and/or exhaust flows. Ever notice on a stock turbo set to boost at like 16psi that at about 6000 rpm the boost actually backs off, even though the MBC is set for 16?
As far as the EJ20's ability to handle boost. The stock internals are good for like 18 to 20psi IIRC... but you have to prevent detonation. That means plenty of intercooler for that intake charge, and TONS of fuel to keep things from blowing up. The EJ20 block is really a great block... the only one that's better is the EJ22T, which is the basis for motors like I-Speed's 2.4. It's got forged internals and oil squirters that help keep the pistons cool and lubricated. I'll bet you can run almost 2bar (30psi) of boost in a well sorted out EJ22T.
