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Been keeping up with the forum for years but never registered till now. Anyway, I'm building a 1975 ford courier with a 4.8ls and twin turbo setup. Looking for input on size for some quick spooling turbos. Any advice is appreciated. Sorry if I put this post in the wrong place.
Last edited by FkinSendit; Nov 25, 2024 at 08:24 PM.
"........4.8ls and twin turbo setup. Looking for input on size for some quick spooling..."
.
Not an expert, but I'd go sorta small-ish on the Turbos.
Maybe ask Viren at VSRacing
or call Precision Turbo ?
"........4.8ls and twin turbo setup. Looking for input on size for some quick spooling..."
.
Not an expert, but I'd go sorta small-ish on the Turbos.
Maybe ask Viren at VSRacing
or call Precision Turbo ?
Yea I've been doing alot of reading on other builds and it seems like somewhere in the high 50s to low 60s is the most common for a twin setup on a 4.8l. Just so many sizes to choose from. I'll give him a call and see what he says. Thanks for responding!
Ridiculously scary is exactly what I'm shooting for lol. I've built nine V8 S10's and they're a piece of cake compared to this. I'm from Texas but recently moved to Southern California where emission laws are crazy strict. But 1975 and older vehicles are exempt. So good ol marketplace landed me this 1975 courier. No smog! So I can put anything under the hood. But a 5hp Briggs and Stratton would've been a tight fight in this thing. Everything is so much tighter than an s10. I bought it as a roller before ever really even researching these trucks. I've found like 2 people on the internet that have ls swapped these. And both cut the cab floor and firewall alot. Them recessed the firewall to allow the motor to sit further back. Nevertheless, it's going to be fun and different.
As for hp goals, I'd be happy with 500-600 boosted. I was looking at those 95 dollar ebay Turbos. Anyone have any working knowledge of how well they hold up? Low boost maybe 6 or 8 psi? Idk. And I've heard the internal waste gates are something to steer clear of? Any thoughts?
I've done 3 setups now with those turbos.
-The first was a 4.8 S10 that made ~600 wheel with a small cam through a T56 and ran mid 10s on ~15 PSI, using the internal gates.
-The 2nd was a 4.8 with 4 of them in a quad turbo setup that was insanely efficient and ran 9s on 9 PSI and made 889 at the wheels on 18 PSI. Also internal gates.
-The 3rd was also a 4.8, but was a street car with no track times. Probably mid-high 10 second potential on 10 PSI, and yes, internal gates.
Zero failures, no blown seals, no burning oil. They're very small and can be made to fit almost anywhere. They spool up very quick with a mild cam.
The only downside to the internal gates is keeping the boost pressure low when used in a twin setup, but you can make adjustments to get them down to ~9 PSI. I wouldn't expect to be able to run any less than that with the internal gates.
I've done 3 setups now with those turbos.
-The first was a 4.8 S10 that made ~600 wheel with a small cam through a T56 and ran mid 10s on ~15 PSI, using the internal gates.
-The 2nd was a 4.8 with 4 of them in a quad turbo setup that was insanely efficient and ran 9s on 9 PSI and made 889 at the wheels on 18 PSI. Also internal gates.
-The 3rd was also a 4.8, but was a street car with no track times. Probably mid-high 10 second potential on 10 PSI, and yes, internal gates.
Zero failures, no blown seals, no burning oil. They're very small and can be made to fit almost anywhere. They spool up very quick with a mild cam.
The only downside to the internal gates is keeping the boost pressure low when used in a twin setup, but you can make adjustments to get them down to ~9 PSI. I wouldn't expect to be able to run any less than that with the internal gates.
You just made my day. Great to hear. This thing really is going to be wild. Looks like I'll be going internal wastegate. Can you post a link to the exact Turbos you ran on a twin setup? I'm also looking at a dual in single out intercooler. Did you plumb your oil lines into the side of the pan? I came across a timing cover with dual AN nipples for a return.
Didn't see your reply about the internal wastegate till after i ordered these. Gt3582. Don't mind the old radiator. Just seeing what's gonna fit. The intercooler is going to be out in front of the grill lol. Cramming 10lbs off **** in a two pound sack. It's tough. I've got two walbro 400lph pumps. Dual in, single out intercooler. Two wastegates, one BOV. Oil feed and return lines. Anything I'm missing?
Idk where I read that the turbo becomes the muffler. But that's a joke. This thing is so fkin loud. I was going to do fender exit but this thing is so loud it will wake the dead. I ordered some 9 inch long resonators. But I don't see that making a difference. Exhaust has been a sore subject from the start of this project. My drivers side manifold is a half inch from the gear box. I'll have to run my exhaust inside the wheel well arch and under the cab outside the frame. Just worried it's going to inhibit me from lowering the front end. Can't wait to try the 2step though. It shoots some pretty good flames lol. If I run the short (like 2" deep) come filters on the turbo inlet, you think it would restrict the airflow too much?
FWIW - Porting of the housing leading into the internal wastegate (on the turbine housing) can help with boost creep. The late great Corky Bell ported one for me a long time ago and it helped.
New to the forum, turbo questions. 
