boost gurus

[Barry Donovan]

I have decided to finish off an old ea82 subaru wagon with an original, first gen 7.7 to 1 shortblock...and it is hefty for reasons I will decipher soon enough. This engine near stripped is the weight of a 1994 loyale EA82 dressed.

the rally record for this engine never saw regular real cams, 1987, and peaked at 192hp and 181 foot pounds.
throwing that out there just for humble reference...
it can go 50hp farther given the facts that it gained through years and tech stuff.

I am swapping heads back to single port, and wanting to try the 2bbl rochester TBI. No multiport for the 2.6 inch stroke, split the bank..get clever with injecton timing. I am thinking somthing like a two stroke..
each bank fires back to back, then off to the other bank , same routine. The stroke length and timing demand is just freakish..like a slowed down formula 1.


I am willing to build a megasquirt custom as the ignition is genius, do not want to bother it at all.
2 bar map, etc

My question is...
boost. ponder a 305 HO cyl head for valve size proportion, old GM like style chamber.. upside down exit single hole for two cyls...7.7 to 1.
1781cc, 3 main bearings. Very hefty flywheel and clutch combo..

is td04 going to be gobbled right up? or perhaps a modified td04 to dish to the 15-20?
part of my joke to humanity is making this look like a subaru oem from the 80s.
(my current carb setup is rather comical in following this vow.)

[Barry Donovan]

I guess I found the answer. Someone was helping me with this.. must be 6 years ago.
It began with the year of the chassis, taling of welds and the dual range..the 12/86 rear end needing positive rake. I took note it was strangely tough, and never seating into new changes.

"missing the foot pounds"

this plan was getting old, glads it is coming together. The turbo plan was simply find the t3/t4 combo, a dime a dozen...make my own round to square flange (welding fun), and buy the one with a wastegate.. flip the turbine to the right angle, worry about waste gate later...

I got answered to my own questions some time back.
the 7.7 to 1 gobbles up all ten to 12psi, todays hybrid cheap turbos can creep a 15. It eats it all due to very low compression.

the single port was to remove lag, aid in crazy slow idle...and aid in a perfect tune, which gives power where we all drive in the cruising rpms. From there, it is part time play with maximum.

the longer lasting version of a subaru misguided. It was not about the 190hp maximum as a goal..forgot about this one. It has been a long time after all.

[dieselgeek]

Putting a turbo on a small subaru would be a blast. But, word of caution attempting TBI with boost, they usually won't have enough injector flowrate for your goals, and they (as far as I can tell) always have distribution problems (different cylinders will receive different fuel or air quantities that cause the engine to misfire and make low power).

Injectors closer to the valve make the whole experience go better - better economy, better startup, etc. So I am just suggesting, with all the fabrication work ahead of you, simplifying to a port system has a better chance of working.

You'd love EFI so much if you tried it - I'm pretty sure about this. The science fair approach to hotrodding (how I learned too) goes well with DIY EFI.

[Barry Donovan]

Putting a turbo on a small subaru would be a blast. But, word of caution attempting TBI with boost, they usually won't have enough injector flowrate for your goals, and they (as far as I can tell) always have distribution problems (different cylinders will receive different fuel or air quantities that cause the engine to misfire and make low power).

Injectors closer to the valve make the whole experience go better - better economy, better startup, etc. So I am just suggesting, with all the fabrication work ahead of you, simplifying to a port system has a better chance of working.

You'd love EFI so much if you tried it - I'm pretty sure about this. The science fair approach to hotrodding (how I learned too) goes well with DIY EFI.

I have a multi port turbo engine on the way...
but not using the multi port intake there. Needs controls, ecm.

will leave it all in tact though. This engine is freakish.. 22 inches hg when timed and tuned. Not much difference to each cylnder through a single port. Always the same shot from a central source..

the mulitport coming is dual port intake, am slapping a carb right in the middle, after bumping compression 2 whole points on another shortblock. let each cylinder suck what it wants. Might see a drop to 18 inches, I am hoping..
but turbo build is on the plans. Will think of getting the multi stuff going.
I have found a subaru ea82 turbo, working with mega squirt. There is a way....

thanks for advice, I have not even gone into a bigger realm in years.. I tend to leave the little engines be what they be. Max what they got is still too humble to mention.