4.3 Fanatic

Hello everyone my dad and me were given an s10 by my grandad , it is a 1991 4.3 extended cab 2 wheel drive automatic.

my dad and me we're going to turn it into a track day / autocross truck so we both agree that it could use some performance upgrades but we are not engine swapping.

we have decided that we are going to put vortec heads a mild cam in, and a turbo on.

We need some help with the turbo, we are not sure what size turbo to run we are only going to run between 5-8 psi until we start doing internal work to handle more pressure.

So my question is what size turbo would you fellas recommend?

Also how would i pipe it Into the throttle body.

How would I maintain 5 psi

Thanks for the help everybody I appreciate it I'm pretty knowledgeable when it comes to engines but I really only know inline-6 Jeep engine.

bobfig

first ima say is your probably better off trying to see on s10 sites what they use.

it would be a good idea to look for a marine intake manifold also. or if money allows a 2114 modified with bungs and fuel rails.

as for attaching to the throttle body there are different ways.

just throwing this out there
http://www.sytyperformance.com/index...mart&Itemid=26

05GMC4.8

or try posting in the forced induction section, quite a bit of traffic thru there

Koots

If you're doing this on a budget, finding a junkyard turbocharger with a factory wastegate should hold 5-8PSI perfectly, but can be manually setup to hold more....Just as long as the turbo is in good condition, which means the wastegate isn't rusted shut, there's no shaft wobble at either end, the seals are good and the oil passages are clean. I've pulled 2 turbos apart now to put in "rebuild kits" (which are just reseal kits) just to make sure there are no leaks as soon as it starts spinning.

I'm not well versed on turbo sizing, so I can't recommend anything for you right off hand, but either a GM 6.5TD turbo (search for GM3 turbo's, as they seem to be the best overall) or the 5.9L Cummins turbo's, but they are slightly larger in all dimensions and might put you out of efficient range. If you do go that route, look for the WH1C turbo from the early 90's 5.9L (W-stands for wastegate) or the HX35 from the late 90's-early 00's.

That's about all I can help you with, outside of what was already mentioned regarding marine intakes, etc.

4.3 Fanatic

Thanks guys I appreciate the help.

Koots

BTW, I love 4.3L's after owning a 1998 GMC Sierra RCLB with one. It was used to tow more than it should, always had a snowmobile in the back in the winter (huge work sleds mostly) and was, occasionally in my younger years, used to race local Cavaliers and Sunfires, which it would overtake, unless they had the 2.4L/5-speed and a good driver...and most importantly, It just wouldn't die and consistently got 16+MPG unloaded but was capable of low-20's even with a K1500 in the right conditions.

I'd love to grab another, but a RCSB, turbo it and set it up for optimal handling and balance, plus just to be different

4.3 Fanatic

That's why me and my dad didn't want to v8 swap because everybody said just put 350 in it it will Boltbolt to your transmission and you won't have to change computers but we love that 4.3 it is amazing and it's an exact replica of a 350 small block -2 cylinders.

At first we were just going to put Vortec heads and cam in it and do some internal work, but I convinced my dad to just put a turbo on instead of doing more internal work. I mean the motor only has 91000 miles on it

4.3 Fanatic

Our MPG isn't quite so good because its flooding we are changing the map and the engine temperature sensors on Saturday.

Koots

I wouldn't want to tow with a 4.3L anymore (got a 6.0L 2500HD now for that stuff) but I really put that truck through the wringer, both on and off-road, towing and unloaded, neglected maintenance for months and years at a time and drove it for many winter of -40* and colder without ever plugging it in.

It could have used a new distributor, timing set/harmonic balancer, rear main seal, headgaskets, new spider injectors and a new exhaust, but it was still a fun little truck to drive and still started up perfectly, even before it was given away a few years back.