i have a precision 74. i really like it

 

thanks guys for the imput i think its going to be the GT 91. and can make changes if i dont like it for some reason

 

i'm still learning but what kind of power are you wanting? those are 1000 hp turbo's iirc.

 

A GT91 will murder a PT88. Only reason I went PT88 is because I wanted to stay T4 so I could swap my Tc76 back and forth. If I were going for all out power I would have gone a GT88.

 

stock48 how do u feel the gt88 would compare to the gt91

 

S475, cant beat the price per hp with that monster

 

that s475 looks like it would be a decent turbo for the money. that would be a good turbo to start with and change it out later after the bugs are worked out.

 

So on the street you run the Tc76? How is your downpipe setup so you can just swap turbos?

 

I'm trying to make this same decision... i can't decide whether to stay streetable with something like a PT76 or change my flange to a T6 and go for the S475 or GT88 for all out power. I have 2.5" discharge piping... is that gonna be too small for a large frame turbo like that?
Stock LQ4 for the moment with a 72mm frt mount. Circle D 258mm 2B in a 4L80E. Possibly going to a 408 LSX soon.

 

I am sure his set up is similiar to mine... since KB built both kits

I had KB build me an adapter plate from the T-6 to the T-4 flange - it centers and raises the t-4 turbo to match the center of the down pipe.

He also built an adapter for the down pipe - one adapter goes from the T-6 5" outlet to 4" down pipe and the other adapter goes from T-4 3" outlet to 4" down pipe...

The only other thing is reducing the outlet on turbo from 3" to 2-1/2", not hard at all though.

So its pretty easy to switch from T-6 to T-4... I did this for the intention of using the TC 78 for the street, but after driving around on the GT91, I doubt I will ever put in the TC78