Looking for improved low-end torque and faster spooling for autocross. Thinking of the EFR6258 twinscroll with Boport twinscroll header. There was mention in another thread about boost coming on too early causing detonation. Is this an issue using E85?
Currently have: 2.1 Boport Stage 3 2.4l stroker Stock intercooler (will switch to FMIC) 3” elbow and downpipe Boport E6 ported Manual boost controller (16 psi) E85 (52# injectors, stock PE ECU, adjustable FPR)
Also still have original PIMP and 82# injectors still on the shelf, never installed
Cylinder pressure is the same regardless of the fuel type. It's the same reason you can't spray nitrous much below 3000rpm, cyl pressure is too high and parts get hurt. With that said, E85 is very detonation resistant so it will certainly help keep it from detonating (if timing is right) but it won't lower cyl pressure.
Having a stock ECU with a timing table that doesn't know you've got boost earlier than stock doesn't help things at all.
Using the PiMP with an electronic boost controller and tuning it so max boost at low RPM is limited and then allowing it to ramp higher with RPM to keep cylinder pressure reasonable would be beneficial. Flat shift may help as well as it helps to hold boost between shifts (it's what causes all the popping and banging rally cars make when shifting). With that said, a PiMPx does all of these things better than a PiMP.
...With that said, a PiMPx does all of these things better than a PiMP.
Can you clarify "better" please? Is "better" worth selling my still-in-the-box PIMP at used pricing for the PIMPx? Is the base PIMP "do-able" or am I risking/giving up performance, reliability, and/or ease of use?
It depends on if you're wanting to do all of the things I listed or only some.
Flat shift is about the same for both versions.
Your PiMP has no ability to do boost by gear/speed so it's much harder to limit boost in the lower gears or at lower RPM. With a PiMPx and a stock VSS or a wheel speed sensor of some sort it can do these things.
Reliability and performance is the same.
Ease of use is similar, main thing that's easier with the new one is adding additional features/options through the expansion connector as we offer all the pieces to do so.