Well, my brother has a 2001 Blazer Xtreme. I convinced him to go turbo instead of buying a SC kit for it. I finally got him to listen to me that it would be cheaper to do so. I'd like some help with determining turbo size, piping size, engine managment, exhaust manifolds, etc.... His vortec motor displaces 4.3L. He has a short ram intake and an Hypertech Power Programmer. I already found a place where i can get a fairly priced intercooler (www.johnnyracecar.com) He is looking to run with 6-7lbs daily with a MAX of 10 (due to the bottom end being a 'wet noodle' and having balancing shafts) It wouldn't hurt for the turbo to max out at 15lbs becuase there is no thoughts about upgrading his bottomend in the future. So a fairly small turbo would be good (less boost, more spool) but nothing to choke the V-6. ALL help is appreciated.

 

You could use the Garrett T-25 off of a 2nd gen DSM; they spool quick and don't work too well over 15lbs of boost.

It seems rediculous to me that you convinced him it would be cheaper to run Turbo, when you haven't even really planned out the turbo setup- where are you getting the turbo manifold? Are you using two turbo's, or just one? There are many aftermarket engine management tools, such as the AEM EMS, or the Haltec, but none of them are cheap, and they all require professional programming/tuning.

As most of the work is going to be custom with any turbo setup, (manifolds, piping, etc.) I would guestimate the total bill being about 5-10k. Whereas there is probably a S/C kit for the truck already, priced 3-5k.

-EngineBuilder

 

I would use something larger than a T25 honestly, it wont really be able to feed enough air for 4.3L of engine.

 

why would you use a T- to small ...

i wouldnt use anything small on this truck 60-1, sc60 some thign along those lines you will be able to spool it real easy IMO ....

 

The idea was to use something that the owner would have virtually no chance of blowing his motor on. The T-25 doesn't flow alot of air, but it does reach peak output rather fast. Using a larger turbo on this truck would necessitate using lower compression pistons, forged pistons or both, something that the poster said the owner had no intention of doing.

Personally, I don't see the point in putting a turbocharger on a vehicle if you don't build the engine to handle whatever you throw at it... Its just asking for trouble, no matter what turbo you utilize, because with cast pistons and high compression, your just looking for a meltdown.

Another point: you have made much ado about this being a 4.3ltr motor, making the assumption that because its so big, it will be able to spool a larger turbo, and be able to handle the higher amount of air; one thing you may not have reckoned is the fact that this is a truck, and that because of its transmission and rear-end gearing, will likely never see 5500rpm. I chose the T-25 because it would likely be at full boost before 2000RPM, allowing the truck to make full use of the extra HP during its shorter RPM range.

Believe me, I realize that the T-25 is a small turbo, and one that most ppl wouldn't consider installing on their vehicle; but because the motor isn't being modified, the fact that its a truck, not to mention the price of these turbos, I feel that it would be one of the better turbos for this application.

Keeping with the mitsubishi turbos, you could also get the turbo off of an EVO, known as a "16G" or TD-05. This is a larger turbo, which flows approx 45% more air than the T-25. It would probably reach full boost by 2300RPM. Using this turbo raises the potential for nasty things happening to the stock motor though, which is why I didn't, (and still don't) reccomend it.

-EngineBuilder

 

its not that a larger turbo will just flow more air, you should really look into turbo sizing when talking about this. A T25 at 8psi only flows so much, a T3 at 8psi will flow a lot more, yet at the same boost pressure. On a 4.3l he will have much more air displaced from the larger amount of exhaust gas making it a lot easier to spool a little bit larger turbo like that.

high compression? Not really, they run around a 9:1 ratio, thats not high at all for a low boost setup and cast pistons are perfectly fine for that.

please please please read up more on turbo sizing before recommending something like that again.

no offense to your knowledge, but what you had written above wasn't really correct...

 

thank you

 

If he is only going to run 6-7lbs daily the s/c route may be more cost effective. Is the Hypertech Power Programmer going to be enough to handle the tuning? He may want to look into getting an HP Turner (http://www.hptuners.com). Intercooler wise he could probably find one on e-bay cheaper. The Isuzu truck intercoolers are nice if it will fit.

 

i have heard good reviews on the XS power intercoolers i would check those out

 

throw on a quad supercharger setup and call it a day