speedhoe04

check your air fuel ratio...could be something. your exhaust housing may be a problem....what inlet sizes you have on both sizes? Also the t76 on the cms kit is right there at the engine.....big difference....even if you had slight lag with the t76 in the engine bay you going to have at least double the lag in the back. the bigger the turbo the more flow it gives, also takes a lil more time to spool depending on the trim you have.

if the tune is fine, could be very well the exhaust housing that is limiting you.

F8L Z71

Click on my dyno sheet to see the AFR. It looked really good. A lil lean for a street tune but good for the dyno. We added a bit more fuel to keep me safe with these 105-115deg days coming.

The exhaust housing is most likely hurting me but Garrett wont have one of those available for a couple months. Even then I still think the compressor side is too small for a 6.0L so I want to upgrade now while it's still free

The turbo is basically a 61mm compressor, 68mm exhaust with a .68 A/R. Now I was told the exhaust side is actually higher flowing than the 68mm normally is and it is not like a standard P-Trim 68mm but even so pretty much everyone agrees it is too small.

Like i said though, I am gonna toy around with it for a bit before I do anything drastic. The turbo change is easy since I am not stuck with it if it doesnt work

F8L Z71

Well the new turbo is on the way. Dave at STS sent it out. These guys are awesome at the customer service thing.

The new one is a GT67... 67mm compressor, 96mm exhaust housing and .68 A/R. Maybe be a bit big for now but will work well with my future plans.

speedhoe04

you may have to get a larger converter...like 3200 stall maybe a lil larger.

also how did they get a 67mm wheel when Garret has them on backorder for months now.

unless they had them in stock. lol

lets see the difference when you put that on larger one on.

the gt35 and the gt67 are pretty close....but i believe the gt67 is good for about 80 HP more on the high end.

either way good luck.

F8L Z71

My TT3000 was designed for a regualr stock 5.3L truck so TQ was never above 300rwtq. Now with almost 500rwtq I am stalling closer to 3500rpm.

I talked to Rick about the turbo and he had them on order. Then Dave called and said that one is being shipped out to me. Not sure if they had recieved them or are drop shipping it. Either way I am in no big hurry. I still wanna toy with this GT35.

See the problem we run into is that with so many vairbale with the turbo you can't say for sure what the turbo is capable of. Keep changing this or that and the HP supported changes. I was trying to look at conpressor maps last night and the GT35 looked too small once you start hitting the 60-70lb range which is why I assume CMotoring does the T76 on the 6.0L trucks.

I'm not too worried either way since I can always go back. It's kinda of fun trying to help pioneer these systems and see what works and what doesn't. Plus listening to you and a host of others on different boards makes me think and in doing so I research and learn a ton more about the wonderful world of turbos Thanks man

speedhoe04

hey f8l its a pleasure to work on problems. I am designing a kit currently this is why I am giving my ideas on the whole matter. The T76 is a very large turbo. That requires about a 4000 stall otherwise you going to take time building boost because of an undersized stall converter.

My kit is similar to the STS kit BUT different location, some upgrades, tuning from people who built the 5.3L and 6.0L lol, and its not in the engine bay like CMs'.

These trucks you have 2 ways you can go. Street or Race. Most people prefer street. This is what this application is geared too out the box. With very impressive numbers that will blow any supercharger out the way. The kit I am doing also can go a race version. However, few options must be taken. Upgraded stall converter, higher LB injectors than the one we are supplying with the street kit. new fuel pump and assembly, etc.

you will get any 6000LB truck or even 6300LB for the h2 that is, in the 13-high 10s sec range(h2 will not reach the 10s, however may reach the mid 12s, maybe even low 12s with the race package.

I am almost done. And cant wait to post vids dyno charts etc.

Either way, good luck with the upgrade.

Thanx.

F8L Z71

Sounds like it is gonna be a sweet setup man

I trust you'll post up that stuff when you get it all ready as I am anxious to see it!

One thing to remember though is that you change change the spooling characteristics by going to the smaller A/R but you drop the over HP cabability of the unit which is why I think my GT35 wolnd't go any higher due to the .68 A/R? Not too sure though as I am still learning. Hahaha

MNC5

A 12 second H2 LOL good luck with that one/////