Conner, I haven't changed the stock 8.9:1 compression ratio other than the slight (0.50mm/.020") overbore and head/deck surfacing when I did the engine rebuild. It's just right for modest boost and the 3.0L ignition curve under acceleration seems to beg for a blower - advance drops to 15* BTDC under load. If the boost shows ~10psi (and it might), I won't mind since I "think" I have enough leeway with fuel pressure and injectors to tune it.

I'm not trying to build a race engine - just trying to gain some mid-upper range carry on the hills in O/D and 3rd with 32" tires without lugging.... should be doable.... the off-idle "right now" power Kevin referred to is the kicker that I'll hopefully get to enjoy daily as I leave the stoplights. <img src="/forums/images/graemlins/wink.gif" alt="" />

Kevin, I've allowed for an aftercooler, but probably won't install it unless/until I need it. If I get any detonation - or if boost is above 8psi - I'll install it. It's just a matter of cutting another S/C mounting plate with an extended flange to accept the heat extractor/exchanger, adding a coolant pump and installing a remote heat exchanger under the front skid plate. The compressor maps show ~80F(dT) above ambient at max, so 180-220F should be peak, with the lower value at modest boost and short duty cycles (ooops - looked again at the Eaton chart supplied by Magnacharger and it shows 180F(dT), but a Magnacharger rep says they see 220F discharge temps on the MP62 ... I "thought".. before cooling... I need to check that again). As you know, the trade off in cooling is air flow restriction... I'd like to run it first without the aftercooler to see what happens.

This is the first forced induction engine package I've built, so I'm taking it one step at a time. If this one works, I might go all out on the next one - this one I want to be very street-friendly with no drivability issues - and I want it to be as simple and reliable as possible.

Frank