I did a search a while back and had no luck. I have inherited a base model 2005 GMC Sierra with the 4.3L V6. It rides nice, is in great shape, but is almost the slowest vehicle I've ever driven. If I decide to keep it, I'd like to be able to put some more power into it. I'm not asking about means and methods, as I've read all the rules here, I'm just wondering if this 4.3L is a decent platform to start with. I believe the old 4.3 used to be a 350 with two cylinders removed, but I don't know if the 2005 model is the same. Does anyone know if the internals are stout enough to handle boost or would it need a new bottom end? When and if I ever decide to do it I'll figure out which turbo or supercharger to use, as well as the fuel management, I just want to know if anyone knows if this engine can take it without being rebuilt first.

Thanks.

 

Most of the difference between the newer 4.3's has to do with adding the balance shaft and the better heads, as well as the main webbing isn't as thick as an older 4.3. Besides that there great platforms for boost, and if you have a good tune and are careful with the timing and rev limit, they can take boost just like a regular sbc, if i was you i wouldn't try for more than 300whp-350whp or so on a good size turbo (turbo is better than a supercharger with smaller displacements IMHO), as far as fuel management i dont know if the newer 4.3l's have real fuel injectors or spider assemblies, so you might be left with a multiport swap, or fmu device, or maybe extra injectors in the intake path controlled by a aftermarket controller, maybe Megasquirt?

 

Cycle, thanks for the advice...it sounds like a viable project. This one is a TBI unit. Does that make this harder or easier? I would think it would be easier but maybe a less accurate tune.

 

Well, I'm not sure I would turbo that 4.3 for 350rwhp. A bolt on 5.3 or a stock 6.0 can hit 325-350 rwhp. JMO.

 

If its an 05 it doesnt have tbi i know that for sure.. it was only til 95, it more than likely has poppet style injectors... which most of the time get swapped out for real multiport (best) injectors or gets an fmu (bad option for more than 250hp imho) or external injectors in the intake path with an extra injector driver (
ot the worse and has proven to be a good option)... as far as 350hp the block and the internals should take it, and have many times in the past... the key is to have a great tune, and to ensure there's no problem with the motor to begin with, and never rev it high, the crankshafts in these motors are ground on and offset to achieve the true 90* v6, so if you rev to high they can snap with higher hp apps. I'm a firm believer that these motors are good to close to 400 crank hp ( 350 or so rwhp) mark that i have stated, just don't expect it to last with knock off any kind. Now does that mean that you should turn it up until you reach the limit, that's up to you, reliability is one thing you need to consider.. the more you push it the shorter the life span is, this is almost always true for engines. Also no two engines are alike one might take 400hp easily while others might only take 300hp, in the end its up to you.


Go on the s10forum.com and search for 2114 intake manifold swap, thats an edelbrock manifold that people convert to multiport and just tune the stock ecu to run the larger injectors that availible for multiport to support higher hp.

 

As far as fuel management, you have a choice of using a marine intake which allows for switching injectors or modding the 2114 edelbrock(more expensive to do).I run the later on my 4.3 'cause the machining was done for me by a good buddy(freebee)
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https://www.theturboforums.com/smf/index.php?topic=111257.0

 

Thanks to all...that Sunbird is wild. I'll have to study that one a bit more later.

 

must not have searched too hard

https://www.theturboforums.com/smf/index.php?topic=100862.0

search my name you may find more info. its an EXTREMLY simple/mild setup. its very drivable, well over 20mpg without even trying. after the change from a 4.10 to 3.42 gear it was easy to notice have too much cam.