TG02Z71

iTrader: (2)

Anyone here with the GT67 upgrade have the base turbo first? What kind of difference did you notice? Spool up, overall power, off the line power.
Tell me what you experience was.
Also anyone with the GT67 tell me what you think of that turbo even if you had it from the start. I'm very interesed in knowing the performance gains or losses from the Turbo upgrade.
Thanks guys.

BeefTip

what psi are you running right now? Im not real sure on the output differences on the two, my brother has an unistalled 67 sts kit for his SS...However, i imagine that if not going much over 9-10 psi on the 5.3, the base would be ideal because i would think that it would spool up much quicker. I know that F8TL had both on his 5.3 z71, Im not sure if he is still around here though.

Wilde Racing

iTrader: (26)

Well I didn't have the base 6.0, but I had the upgraded 5.3 60-1. and went to the 67.The spool time was very close with the two the 60-1 spooled faster but not by much. The main differents for me was my IAT's and air moved. with the 60-1 it would move around 40 pound/min and the gt would move around 48pound/min. Plus the IAT would stay cooler longer with the GT.

TG02Z71

iTrader: (2)

I'm running 5psi low and 8.5psi high right now but wil be at 10psi when I finally get my in-line pump put in.
Know anything about the base kits vs the GT67's output at either of the two psi ranges?

TG02Z71

iTrader: (2)

That's interesting Wilde, your IATs stayed cooler longer.
I wonder why?
Could it be the smaller turbo is less efficient or more efficient in some way causing the temp rise?
More air or volume pushed into a defined space would mean more heat correct?
Yet the bigger turbo would ultimately push more air than the smaller one. Maybe the velocity is higher with the smaller turbo thus creating more turbulence and more heat?
I may be talking out my *** on that one.

BeefTip

I know that Weedo on there a while back had an AWD denali yukon with the 6.0 which is basically the same setup as my brothers SS, I believe that at 9lbs w/ meth he made 485 awhp and like 525 awtq or something close to those numbers. I dont see why the gt 67 wouldnt push a 6.0 to around 15lbs or so but i have no hard numbers to show this except for the fact that the 35 is also the base kit on the 6.0 SSs i believe. I think that F8TL was running from 12-14 lbs(cant remember) on his 5.3 w/6.0 ltr heads. I cant remember his hp numbers

quicksilverado

iTrader: (8)

A larger turbo can move more air and it will not get as hot as a smaller turbo trying to move the same amount of air.

F8L Z71

I started off with a GT35 and the thing spooled very fast but there was a noticible bit of lag but totally livable. The last part of my video where I take off in the tunnel is the GT35. I was only making 430 something rwhp at that point on 13psi and meth.

I then switched to the GT67 AND stuck an intercooler on it. Between those 2 things lag went through the roof if I tried to floor it from a dead stop without boosting. If I went WOT at anything over 30mph though, boost came on fast and hard and would often spin the tires if I didnt have it in 4wd. I ran a max of 14-15psi on this setup and if you do the math for 110mph trap speeds and 5250lb raceweight it comes out to 550rwhp, give or take since TQ and aerodynamics are not figured in.

So in all I can say that on my 5.3L the GT67 increased quit a bit of lag BUT I was using a .96 A/R exhaust housing at the time. When I did the intercooler I switched to the .81 A/R housing and lag stayed the same, I'm assuming because I added the IC.

If you want crazy midrange and top end then the GT67 kicks major butt over the smaller turbos. If you want part throttle and quick boost then the small turbo works fine. On a 2wd truck I think having that lag from a dead stop helps out with wheelspin issues. Just dont be suprised if you end up kicking out sideways as soon as you hit about 30mph and hit full boost LOL

hemifever

A couple of my buddies with the hemi have the GT67 upgrade and they have 60' troubles over what I've seen with the base turbo. All on 4x4 QC's so they are much heavier than your standard shortbox. I would imagine this upgrade would also be more noticeable with off the line performance the heavier you are.

F8L Z71

Yeah, with the GT67 you defiantely have to preboost before launching or else your 60' goes to hell. I would run 2.1 60's without boosting more than 5psi but if I boost 6-7psi I would hit 1.80-1.85 60's depending on if you tranny would slip or not.