Turbocharged 5.7 TBI

[Mule89]

Yeah if I have to re do mine (not anytime soon because I only have 14k miles on my current), it’s gonna be a carbed 383, because I’m really at the limit for my fuel mods (which I have all of them), and my computer (chipped/tuned by fastchip) could only handle the cam I have nothing more, so if I want more cam, I have to step up to the fitech or carb it.

sounds like a good plan personally fuel injection has the most benefits.

Allison behind a small block would be a huge let down when you got it to work. 4L80E would be a better dream.
And check out borg warner turbos when you want to get serious. A S475/87 would suprise you.

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The end result of the truck hasn't been decided so the allison is still on the table
for towing and a sequential turbo setup would probably be used. I like axle breaking torque so the more boost at a lower rpm the happier I will be.

 

[RDF1]

sounds like a good plan personally fuel injection has the most benefits.

The end result of the truck hasn't been decided so the allison is still on the table
for towing and a sequential turbo setup would probably be used.

Gotta understand that the Allison is power hog. It's designed for diesels.
4L80E would be your best bet. Plus they are strong and simple.
The right size single turbo setup would be ideal. I've towed alot with a S475/83 turbo on a cammed LQ4 with a 4L80E and it worked awesome, put 200k+ miles on that setup and never had a single issue. Even towing double what the truck was rated for. Staying in boost for 2 and 3 hours at a time. I ran 93 octane and -30* windshield washer fluid in a water/methanol injection system to keep the IATs from getting crazy.

Don't go for cool or complicated. Work toward simplicity and reliability.


I have more experience with LS engines and turbo than I do with older SBC stuff. But alot of boost down low can beat the crap out of your bearings. Plus a turbo setup that's gonna make a ton of torque down is gonna choke up top.



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[Mule89]

Gotta understand that the Allison is power hog. It's designed for diesels.
4L80E would be your best bet. Plus they are strong and simple.
The right size single turbo setup would be ideal. I've towed alot with a S475/83 turbo on a cammed LQ4 with a 4L80E and it worked awesome. Even towing double what the truck was rated for.
Don't go for cool or complicated. Work toward simplicity and reliability.

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You very well have a point on keeping it simple I will gladly take your advice since I have little experience with either transmissions but those are after a biuld the 4 bolt main sbc I'm saving. For this setup I was thinking cheap temporary experiment with a small turbo to get me started and I could transfer all this stuff to another truck or sell as a "kit" when I get the money to build what I really want.

 

[JCribb]

Gotta agree with RDF1, the 4L80E is the best bet, it is the modern electronic version of the turbo 400, except it has overdrive.

 

[Mule89]

Gotta agree with RDF1, the 4L80E is the best bet, it is the modern electronic version of the turbo 400, except it has overdrive.

I know that 700r4 would explode with the kind of power a turbo sbc would put out

 

[RDF1]

When you get around to it, check out what it would cost for you to do a LQ4/4L80E swap and build your own turbo setup for it compared to your future setup your wanting.
In 2008 or 2009 I put down 440hp/540rwtq with stock 6.0/80E and a rear mount Garrett 60mm. It made over 400rwtq at 2500-2600rpms. Towed great. But choked past 5000, Torque was well on its way down and hp too.
I was still learning how to tune it too.

It's hard to beat the stock LS stuff. That same 6.0 has 400k miles on it now with only a top end rebuild from a stock lifter taking out the cam. Bottom end is all original and never been apart. It's even held 30psi+ a couple times on accident... Rev limiter is at 7200 and it's been there alot out playing around.


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[Mule89]

When you get around to it, check out what it would cost for you to do a LQ4/4L80E swap and build your own turbo setup for it compared to your future setup your wanting.
In 2008 or 2009 I put down 440hp/540rwtq with stock 6.0/80E and a rear mount Garrett 60mm. It made over 400rwtq at 2500-2600rpms. Towed great. But choked past 5000, Torque was well on its way down and hp too.
I was still learning how to tune it too.

It's hard to beat the stock LS stuff. That same 6.0 has 400k miles on it now with only a top end rebuild from a stock lifter taking out the cam. Bottom end is all original and never been apart. It's even held 30psi+ a couple times on accident... Rev limiter is at 7200 and it's been there alot out playing around.


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Dang I never realized how much boost you could cram in one like that. Will probably go with a ls or 454 what ever falls in to my hands. I would like to just try the turbo small block just to see what it is like.

 

[RDF1]

Dang I never realized how much boost you could cram in one like that. Will probably go with a ls or 454 what ever falls in to my hands. I would like to just try the turbo small block just to see what it is like.

Well it was a cram alright. I had a couple safetys in the tune to keep it alive incase of over boost. Pulled timing and dumped fuel at 16+psi.
But everyday it was on 7psi for towing and DD and for fun times it was at 15psi.
Great setup that was suprising folks at the the track and towing trailer home. Even out ran a 2002 Camara with heads and cam on interstate while pulling a 12' trailer and street bike on it. 145-150mph he finally put a bumper on me. Trailer tires aren't rated for that kinda speed......


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[Mule89]

So my question is what does it really take to swap in an LS engine?
Looks like I have a lot of reading and research to do.

 

[RDF1]

Depnds on your setup.
But in my '91 2wd I used dirty Dingo adjustable mounts. Bolted it up and in it went. Piece o cake really.

Wiring takes a few hours to sort thru, tune is simple now days. Just mail order a tune.
I test fit with factory truck manifolds and even mocked it up with factory 2500hd y pipe. It all fit really good.

Then I took all that off and bolted on a single turbo setup and had to shim the passenger side mount about 1/2" just to help the manifold clear the control arm mount on the frame.

I'll have all the pics in a thread when I'm through.

I'm cheating on gauges tho. Samsung 8" tablet and a Bluetooth OBDII adapter for all the gages from the PCM. Oil pressure and fuel level will be my only mechanical gauges on the dash.

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