i'm going to be ordering the STS kit for my car this week. it's only a bolt-on car (mods in sig) but i'm adding this to it:

918 springs
comp TI retainers
comp chromoly PR
42# inj
racetronix fuel pump
sts kit at 6psi
dyno tuning by sts dealer

I'm aiming for 425rwhp (for now)
with no IC (maybe in a year or so when my wallet recovers)
my car is a daily driver so i want to stay on the safe side of the lower end and rear ends' power limits. should i get the gt67?
I've heard that the spool time is a bit longer (~4k) vs the base turbo (~3k) but that the base turbo falls off after 5k rpm. i'd like to have something that spools quickly (DD) but with my valvetrain/fuel upgrades could i raise the rev limiter and take it to 6600rpm? would this mean i should get the gt67?
Sorry for asking what seems a common question. I've searched, but every post is talking about going for BIG numbers and with different circumstances then mine.
Thanks!

 

I've got the first LS2GTO STS kit (pre-release...ready to install and get tuned within the next 1-2 weeks...) and am using the GT67 + I/C...also methanol injection, injectors, fuel pump mods. The updgrade is not only bigger, but it is a better quality turbo as well. I have not heard of much difference in spool up...and these engines have pretty good low end as they sit, anyway.

The best bang for the buck would be to add a methanol kit. There are several out there, and I am trying a kit that hasn't been used on a GTO yet. For $300-400, you can run more boost and timing => more HP. Also, you've got good valvetrain upgrades...if you feel like doing the work, getting CompCams or Ed Curtis to custom grind you a mild turbo cam, you'd love it!

Although I am using the STS intercooler, I would bet you could get a custom spearco or other that would cost a bit less. And I realize that this add'l stuff is "down the road".

 

The base turbo does fall off above about 5200 rpm on my car. I would say if you plan on turning the boost up, it makes sense to get the upgraded turbo now, even though the base turbo will work fine at 6 psi. By the way, my intercooler was only $300 off Ebay. Not much $$ to be able to run 8 psi.

 

wow $300 for an intercooler? does that include the piping? (if so do you have a list of the parts/bends needed?) thanks! i plan to maybe go 7 or 8 after i get an intercooler in like a year or two. I don't know how much more than that the stock bottom end can take so i'm not looking for huge amounts of boost. but i don't want the car to fall on its face above 5000 but want the boost to kick in below 4000rpm too.

 

Oops sorry, that doesn't include the piping. It cost me $400 to have a shop custom fab the piping for me. Sorry, I should have mentioned that before. If your compression ration is stock, you should be fine with 8 psi. Matter of fact, you'll be in good shape because of the valvetrain upgrades. I had to turn my boost down because I was getting a lot of valve float at 8 psi. But, once I uprgrade that, I'm ready for 8 psi.

By the way, if your planning on turning the boost up, you may want to consider going with 60# injectors from the get go. I have the 42's, and they were reaching there limits at 8 psi.

 

i went from a t60 to gt67 turbo also and it made a big diffrence on my truck and would recommend it...also billy at trtturbo has 200$ intercoolers.i even saw where he has the 4" inlet coolers...they work very good

 

cool thanks for the info guys, guess i'll be getting the gt67!

 

about what rpm's are you seeing full boost at w/ the upgraded turbo versus the one that comes w/ the kit?

 

Your maxing out your 42# injectors... on 8lbs of Boost?

 

I maxxed out my 42lb injectors on 10 psi. 110% duty cycle with a 11.0:1 a/f. Go bigger on the injectors. I now have 60's and only run them at 65% duty on 13 psi

 

Would one of these OBX IC work on the GTO?

 

There are other intercoolers at lower prices than what STS gets for our goats. However, you will have to fabricate end tanks, bend the tubing, and figure out your mounts. Today as I was preparing for my install, I realized that the intercooler actually requires 5 different pipes + hoses to replace the '7' pipe that comes stock.

 

I would like to see the Dyno Numbers for the GT67 vs the GT60... anyone have them?

 

yeah i'd like to see some dyno sheets between the two, preferably at 5-8psi!