F8L Z71

I am working on getting #s out of the STS kit and everytime I talk to anyone it seems they agree the turbo is too small for the motor. I originally only had plans for 450rwhp or so and I have come pretty damned close to that but it wasn't as quick feeling as I wanted so I am searching for my weak link.

STS and numerous other people feel if I wanna be in the 500+rwhp range that I need to get into a T70-T76 turbo (if I get the 6.0L for sure). I will eventually do that once I get a size nailed down and know how long it will be before I can afford the 6.0L.

I just feel pretty good knowing I made this much power and torque on a small 61mm turbo I even dyno'd unlocked and with the filter and prefilter bag on. With the knowledge of running too small of a turbo I am gonna consider this system a success.

I'll keep you guys posted as to when i get the bigger turbo and what kind of #s I pull out of it. In the mean time I am gonna race this small turbo and have some fun

Deckhand

iTrader: (1)

yea dude, its a learning experience... thats the way I look at it everytime I screw up.. lol.

seriously though, you are making good power, and just have fun with it until you're ready for the next stage.

Good luck!

trtturbo

iTrader: (25)

I think its too small also. What made you go with the GT35 instead of the 60-1? Truck sounds great though.

F8L Z71

Billy,

Rick and I originally talked and he thought that would be the best setup to get me to 450-500rwhp. I got real close but it is taking way too much boost IMO to do so. The truck runs great otherwise so no complaints. Dave is gonna send me out a GT67 maybe with a 98mm eexhaust housing pretty soon so I can get more power out of this thing and really turn some heads

I think all of us are learning with these rear mount things. It's fun though and really makes you learn alot about turbos and how they work.

BTW, I was told I actually should be running a T70-T76 \. Especially if I went to the 6.0L. But I am gonna trust Ricks judgement and try the GT67

Hit Man X

Very cool! Are you plotting to convert this from a hot air to a intercooled turbo?

F8L Z71

When money permits and I have my new tranny installed I will be having a custom intercooler made up. Just Air/Air is all I need. Something to get the IATs down into the 110range BEFORE the methanol. Then when I spray the meth it will drop it down hopefully into the 75-80deg range but it's mostly for the added fuel and octane.

Plus with the bigger turbo I wont be running such hot air. I htink I am super heating the air with this smaller turbo and getting out of it's efficiency range.

speedhoe04

the 61mm wheel is fine. the housing and AR is the problem. You need a gt61 or maybe a gt67. not much of a difference from the two just high end power.
did you change the fuel pump? or upgrade it. if you pushing 436 rwhp...personally you may need to change the pump...it may be negatively affecting the overall fuel aspect. also the tune seems to me it may be conservative. that gt35 (ball bearing?) if it is it spools fast and is generally more efficient then most..its the new hybrid. either way i would check the tune again. that gt35 is good for 680 FWHP which is pretty up there.

food for thought.

thanx.

F8L Z71

The tune is conservative to an extent but not at the point of sacrificing a bunch of HP. I have more than enough fuel right now. Udty cycle looked good and the AFR was perfect. There was just nothing else to be had or else the tuner would have pushed it. He street tuned it, then dyno tuned it then rechecked it for the street and that was all she wrote. I have a 255lph pusher pump and will be adding a Racetronics intank pump when money permits.


We are running 18deg of timing and fuel pressure stays around 58-62psi. PLus the extra fuel from the Alk kit helps to make up for any weak spots in the fuel system for right now.

I was originally gonna stay with the 61mm compressor and change out the exhaust housing but since I will eventually end up with a 6.0L I'd rather jump right into the 67mm compressor and a larger exhaust housing and see where it takes me on the 5.3L. If I get some lag no big deal. If I get a lot of lag but make great power then I'll simply buy another exhaust housing for daily driving and swap it out for race days. No biggy

The CMotoring kit comes with aT76 unit and it doesn't seem to laggy on Parish's truck so a T67 shouldn't be too big for my setup. If it is it's an easy fix because one of my buddies is buying an STS kit for his Trans Am and is gonna use the T67 so if it doesn't work on mine I'll just hand it to him as part of his kit

Black Blown 02

Hey F8L....Just curious, what MAF #'s did your tuner see? Did he say?

F8L Z71

No he didn't say but I remember asking him once about it and that it wasn't maxed. Since I've only had the truck back for 2 hours I didn't get a chance to check anything else. I'm gonna do some more data logging this weekend when I get the truck back though.