Street/Strip Build Turbo E85

[Redsta]

I have a 89 auto festiva completely Stock, Wanting to do turbo e85 on the b3 low boost of course what turbo to get bov wastegate and where it fits best, maybe a n/a built b3 if so what cams rods crank pistons maybe a ported intake also wanting to keep it auto if they are strong enough, if not where to get them built or what auto to put in it

[PIKA TM]

I didn't find any rods and pistons for b3 mate, that's a headache, the b6 is easier

[theastronaut]

Just swap in a b6t from a Capri, they're already turbo and built for boost. B3 rods are weak, the crank is single throw so they have harmonic issues at higher rpm at stock power levels, and the chamber design has a hot spot that will torch pistons under boost, there's already a noticeable hot spot on a stock engine that usually has all the carbon burnt off.

Get a junk Capri XR2, use the stronger trans and axles, and you get the harness/ecu to run it. It'l make 180 whp on the stock ecu at about 16 psi. Even if you spent $3k on custom forged pistons and billet rods and custom cam for a B3 you'll still need a XR2 trans and axles, might as well just use the b6t from the Capri.

[theFORDdriver]

The B6T swap advice is spot on - the B3 block has a known single-plane crank harmonic issue and the combustion chamber geometry creates a hot spot that's a real problem under boost, especially on E85 which needs higher compression and more ignition advance to take advantage of its 105+ octane rating. If you're dead set on running the B3, at minimum you'd want forged pistons with a cooler heat range plug, a proper intercooler, and a standalone ECU like a MegaSquirt since the stock computer won't tune for E85 fueling.

[theastronaut]

No need for forged pistons, you can soften the chamber by taking away part of quench pads to eliminate the hot spot.

Still too much work for a b3 that will shake itself apart at higher rpm. I spun mine to 7000 just about every time I drove it and it shook the AC bracket loose, the AC clutch magnet loose, the choke housing loose, and the carb adapter loose. A Kia Rio crank is double counterweighted and drops right in place of the b3 crank and has a rubber damped front pulley that dampens harmonics, that's the best way to make a b3 smoother at higher rpm.

If you look at b6 8V ports you'll never build a b3 though, the ports and valves are huge in comparison and flow roughly 40% more.