Blowthrough build repeat.

WarWagon

Caustic Cacophony
Joined
Mar 10, 2007
Made the switch to 8AN feed fuel line from the pump to the rail. Now the rail is no longer deadheaded and the regulator is the last stop before fuel return.
I drove the car and it seems alright but I definitely could have hurt it some already but I need to look over a few things. It is very rich on fuel now something happend to the fuel table or somewhere I'll reload the tune on the EFI. I think I may plumb in a PCV I,have never ran one while this engine has been turbocharged.
 

WarWagon

Caustic Cacophony
Joined
Mar 10, 2007
Looked over the engine this morning, I only seen the dip stick had pushed out. Hooked up the laptop to ECU and fired the car up everything looked ok until I noticed the wideband O2 the ECU uses was stuck at 14.7 AFR it didn't matter what I did on the fuel table or learn cells the AFR stayed stuck. It is the original sensor I've been tuning on for 8+ years. Easy fix I have a spare, I put that on the header and fired the car up and looking at the laptop the AFR was stuck at 11.0 AFR in the idle zone but would read right with some throttle opening. I'll pick up a couple spare O2 sensors now but I'll run it with the current one until this engine blows or whatever it's fate may be.
 

WarWagon

Caustic Cacophony
Joined
Mar 10, 2007
Finally got the Buick out this week for a confirmation test. The trans needs to be freshened up, it's been 5 years but the engine is strong. So a pause on this until I can get the trans freshed up, videos of my adventure today:
 

b4black

Well-Known Member
Joined
May 24, 2001
OK, first car is back on the road, and I think I can definitely say I'm going the blow through carb route on the second car.
If you were starting fresh, what carb and intake would you choose?

Some progress finally! Rebuilding an engine was going to take me way too long. I picked up this long block from a friend that upgraded to a stage 2 motor. '85 block, Champion aluminum heads, roller cam. Ran in the 10's.

To that, I bolted on some junk pats to mock it up. '87 Turbo & downpipe. Weiand intake, Champion AC delete bracket and '87 alternator & PS pump. The stock HEI distributor manages to just fit. I think this will work well.

Next is a pick a carb. Looking at a Holley/Demon carb for boost and E85.

And a fuel pump. I wonder if I should go with a in tank pump and hot wire kit like an 87 GN?
 

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ShawnR

Fixer of crap..
Joined
Jan 24, 2011
What kind of fuel pressure can a carb handle? I was going to do that as one of "pre-upgrade" steps, but couldn't find a FPR that would go below 20 psi. I guess I always assumed that anything over 8-9 ish would push past the float valve.
 

WarWagon

Caustic Cacophony
Joined
Mar 10, 2007
The carb's needle/seat can handle any increased fuel pressure but while only in boost, otherwise it floods out quite easily. Carbs see up to and over 40 psi fuel pressure while on boost more in some cases. In the past I had 32psi fuel pressure on a Demon carb, base fuel pressure is 7psi then 1:1 regulator matches boost psi which was 25psi then.
Knowing what I learned and all the issues along the way with a "big" number. Small works here very well, 600cfm MAX ideally 500 cfm is it.
Previously my 800cfm carb is 300cfm too big, it worked but with crutches and deminished drivability.
Any fuel system then handles E85 will be good regardless if it's a pusher in tank pump or an inline pump.
 

b4black

Well-Known Member
Joined
May 24, 2001
Knowing what I learned and all the issues along the way with a "big" number. Small works here very well, 600cfm MAX ideally 500 cfm is it.
Previously my 800cfm carb is 300cfm too big, it worked but with crutches and deminished drivability.
Any fuel system then handles E85 will be good regardless if it's a pusher in tank pump or an inline pump.
Looking at Holley's website, this is the smallest CFM they have for blow through:
 

WarWagon

Caustic Cacophony
Joined
Mar 10, 2007
Everything on the shelf will be calibrated for a v8 for sure. Holley, CSU and others will build you the carb you need, it's easy to do yourself too.
 
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