so how long will a 383 with 10.1-.5:1 compression last with a t67 turbo at 7psi. i ask because my 383 kit has pistons with 2cc reliefs. so i can only get the compression down to 10.1-.5:1. i don't really want to buy new pistons. and what size injectors do i need to be looking at? i'm sure 42lbers won't cut it.
also the pistons have to be special made. this kit uses a 6.2" rod for some reason.

looking at the je web site it says .057 head gaskets and 72cc heads it yeilds 10.5:1 and the kit is already balanced so if i get new pistons i have to pay to do that over again too.

 

It'll work just fine. Most will say it's not "ideal", but it will work just fine.
Just be sure to keep the a/f ratio in the low 11's and be sure there is no pinging.
We install chargers on the higher compression LS2's all the time and they aren't as near strong as your forged 383.
If you're only doing 7psi, the LS1 sytle Lucas 48lb injectors with a good pump should be enough; those injectors flow well. If you plan on continuing the mods, 60lb'ers will be needed.

Sounds like a nice project,
allen

 

thanks,
i've heard or read rather, that some injector sizes are harder to tune than others. the 42lbers in my ls1 were easy with hpt. just changed the table and it work. the wastegate spring is 7 psi so i'll stick with that. not sure if the gt67 can go much higher than that. oh and the dcr will be at 8.2:1 i think it was.

 

Ya,the Lucas 42lb'ers are very easy to tune, they are actually a little bigger at 48psi at 58psi.

later,
allen

 

It will run forever and a day. I loved my LQ9 on 7psi. Until I tried 10psi


Just get a good tune and look into a meth injection system if you want more than 7psi.


You can get more out of the 67 too. Oh wait.. Is this front mount or remote?

 

Some say there is more power to be had with a high compression boosted motor over a low compression boosted motor....

 

Keep it cool. You can run a 180 degree thermostat instead of 195, that will help. Use the biggest intercooler you can fit in there. Air-to-air is simplest and maintenance free but if you're up to it an air-to-water will maintain a more steady intake air temperature.
Don't get too greedy with timing initially. As you start to increase boost log knock retard.

 

it will be front mount. i have the turbo and all hardwae but no piping. i was going to do it myself and that fell through lol. so i'm gonna buy the hot and cold parts for a front mount kit. not sure how big the ic is that come with the kit. i had a d-max fmic in my silverado had to cut it down about two inches to fit it. but then it burnt (the truck). so all the stuff i had for the truck is now going to my tahoe.

where can i get a 180 stat? i had a 160 in the truck and it ran 175 all the time after the rad swap along with e-fans. so where should i start my timming? i have hpt so i will probably do a 2bar tune that way i have timming tables in the boost areas. its nice to have all the control over the tune i can.

 

For a front mount the 67 might be done at 7psi then. You can get a 70 front half though and upgrade it a bit.

Wilde is right, for low boost like 7-10psi, higher compression is much better than lower compression, but if you want to run big boost, change those pistons.

 

well what i thought about was doing this and sticking with 7psi then way way later on just buy some 4" psitons and a 6.0 block and then i can go 402. but for now go with this if it will work. may even buy a 5psi spring for the gate for dd then throw in the 7psi spring after i see where its at and for track days.