Thanks but there are many here way more knowledgeable than me on turbos! Billy Mays did do a good setup for a stock looking DD though. Still got great mpg too lol.

 

yea the rear mounts work but when you go front mount you wonder why it took so long..

The turbo that STS sells has a really small turbine housing and it will choke out up top. I ran the 60mm, 76mm and a 67mm rear mount. I like my 75mm front mount much much more!


I sold my rear mount kit to my buddy and he put a 76mm magnum on it. with a 5.3 at 16psi it runs 11.3's@119? We tried more boost and more timing but it didnt go any faster. Its front mount time.

 

Yea rear mounts are OK but nothing compared to front mount. Especially a properly setup front mount

 

You don't need to do anything but swap the wastegate spring...

 

well my turbo can make 15 psi and hold it ... its their upgraded ball bearing turbo, the reason Im asking about heads is that ive got a gen 3 block that I am looking at building up for the boost with 706 heads. Im looking into more options so that I do this right the first time , some guys with the rear mounts have lost power just by changing from stock exhaust manifolds. my first take (before i got the donor 5.3) was to put in forged rods / pistons and then dod delete with ls6 cam and springs arp head studs and just throw all i can at it. while I would like a tq converter for a better launch honestly the only complaint about this rear mount is the oiling system ... im just scared of it blowing my motor if it blows out ... Boost builds up quickly with very little lag at all. I am looking into meth injection also. I would like to lower my compression ratio for easier use of pump gas. In the end I would like to have around 700 hp.

 

The best advise I can give you is read and research. The motor and heads that you have on your truck are better than the ones you are talking about swapping. They probably lost power because the headers are free flowing which dropped the boost a little... just have to crank it back to normal settings. Whats wrong with using pump gas? Whats the point of this thread?

 

If you made 400 rwhp and 560+ rwtq, you are probably out of turbo. When tq is that much higher than the hp that is normally the case. You probably have a t60 turbo. If you up the boost and get little to no increase in hp, then you will need a bigger turbo.

 

The tune was done on the truck with some issues. We stopped tuning at that level due to oil in the intake side from the turbo through all the pipes and intercooler and then over the maf. After cleaning the entire system out we began troubleshooting it. The sts truck kit includes a "snorkel" it's looks like a dryer hose with tar paper instead of plastic. On the inside of the hose it was collapsing on itself but the outside appeared to be perfect. I purchased some three inch mandrel bends and pipe , welded it together and replaced the restrictive snorkel that was not allowing air into te turbo. It appears that the turbo was actually making a vacume that pulled oil into the intake side. On the first test drive on low boost setting the truck went very quickly to 12 lbs and I took my foot out of it. I put a smaller spring back in the wg and low boost is back at 5-6 lbs. to answer alpine stars questions theree is nothing wrong with pump gas, I want to stay with pump gas not e85 or expensive race fuel. I plan on keeping this truck on the road as much as I can. In my town 91 is about as good as it gets. The point of this tread is to discuss with people who may have already experimented with rear mount turbos and identify a good direction to go with on this 5.3. Heads port polished cam suggestions springs tq converter? Looking for input from qualified posters with experience with rear mount turbos.

 

Leave the heads alone for now. A set of dual springs are a must. Turn up the boost and see what it does. If you are not happy with the results, try an ls6 cam or a 212-218 cam. A 3k tq converter would work well, but you may want to consider a 4l80e swap. The 4l60e will not last long once you turn the boost up.

You said there is little lag. This leads me to believe the turbo is smaller than you think. Is your tq converter stock?

 

Have you checked your piping for oil since you replaced the snorkel? Sounds like an oil drain issue or bad seal. I'd listen to quicksilverado.... figure out what turbo you have.