Details on the project:

- 2007 Chevy Silverado LTZ. 5.3L Crew Cab Z71 Package. Fully Loaded

- STS Rear Mount Turbo.

- Specs: Turbo STS 62 (60-1) T4E GT-35 Journal Bearing.

- TURBINE HOUSING STS T4V GT-35 .58 A/R

- Wastegate STS/Turbosmart Ultragate 38mm 3 psi Spring

- No Intercooler or Blow off Valve.

The plan is to install the turbo to try and increase fuel economy. Peak power numbers mean nothing to me as this is only to gain fuel economy. STS thinks it may be possible to pick up as much as 50% on the mileage with the proper tune and the use of AFM ( active fuel management). We shall see.

Please feel free to chime in, good or bad, as I would like to hear everyones opinion. Here is a quick pic of the truck before the turbo install. The turbo should be here in less than a week and will be installed asap. Ill post the dyno graph of the before turbo and after just to show the power difference and how it may affect fuel economy.

 

Oh boy, here we go.....

While I am sure you will love the turbo kit, I don't think it will be for the mileage gain. Ie think a 50% gain is more than a little optimistic. Remember, out of boost, you are restricting your exhaust with that tiny .58 AR turbine side, and in boost, you will be in fuel enrichment, so I don't really understand where the 50% increase in mileage is going to come from, but I have been wrong before.

On a side note,even though you don't think you want a blow-off valve, I would strongly recommend one.

 

50%, I think STS needs to put down the pipe...

 

Like big red said. I dont see how a 50% increase in fuel economy comes into play. When the boost kicks in and the turbo spools up your engine is going to need more fuel for the extra air that is being force fed into the motor.
More air + more fuel = less fuel economy. I've had plenty of turbocharged cars and never once did my economy get better after I installed a turbo.

 

Why don't you just buy a car if you want better MPG? If anything the gains are going to be small. Kinda of a waste of money.

 

I think the number 50 got confused with 15. It happens on the phone quite a bit. I'd be real surprised if someone at STS said five-zero and not one-five percent. Anytime I hear those two numbers, I always make the customer or whomever specify.

15% is believable but not 50%. I think it's entirely possible to get 50% more mileage out of a fullsize truck, but not strictly from a turbo kit alone. Unless you incorporate Smokey Yunicks whole lean burn 26:1 AFR technology.

 

Even if it does get a decent gain in mileage its going to take a looonnnggg time to actually start paying for itself.

 

First of all guys, thanks for all the replies. Ill listen to all of it, good or bad. The 50% was via email, not over the phone fyi. That was best case senario with tuning, turbo etc... Im not expecting 50%, but 20% would be fantastic.

Why would I buy a car, have you seen that truck? Its beautiful. Its a crew cab for taking the kids to home depot with me to pick up material for the house. aka im 35 years old and have 3 kids. This truck is way better than driving a piece of crap car. Its fully loaded with heated leather seats. Great in the snow, which is good for ohio, and for $30,000 plus dollars it should be.

Big RED. to answer your question/statement. The Idea is to tune it with EFILive and control the PE % depending on knock, load etc.. Ill prob have to go SD with the 2 bar Virtual VE table that is stock in the E38 pcm. 3 psi should be able to be reached by 1500-1800 rpm or so WOT. Im guessing I could be around 1 psi at part throttle under moderate load and run just a little richer AFR to compensate. We will be tuning on an All Wheel Load Bearing Dyno to acheive the results we are looking for.

Just to be clear. This is for fun and to see if a turbo really can, or cant help with the fuel mileage and by how much. Keep the replies coming. This is how people learn and im never done learning. Thanks guys.

 

I have always wondered about this. I personally don't believe it is possible, but the guys at genesvettes.com swear that they can do exactly what your saying. I have yet to see any type of independent test prove the results though. I look forward to your conclusion, please try to remain as unbiased as possible though.

 

LMAO.. Agreed!!

LSRacing,
My mileage stayed pretty much where it was at with my front mount 62-1. I wouldn't recommend a turbo for mileage purposes. Just do all the bolt-ons and a good tune.