i have a 91 s-10 drag truck. my question is, Can some one give me advice on what size boost tubing to run to the engine trom the turbo. it is going to be a blow thru at the carb. im making a rear mount turbo for my drag truck on the cheap and dont know if 3" or 2.50" would be better. got the exaust run already

 

what motor 2.5 will work up to 1000hp so id amagine its a gasser

 

sorry its a 350ci sbc gasser () it was cheap
drag race only

 

i think the 2.5'' would be fine

 

cool im trying to move foward on this thanks for the advice

 

There's charts out there on the net of such stuff..........do a google search......If not, I've got all that stuff in my notebook in my shop.

Flow to your turbo is gotta be within a certain range......the housing spec's are where your gonna have to tune.....the flow between a 2 1/2" and a 3" is pretty good as far as cfm. At the inlet side of the turbo where the exhause gas is nozzled down is where the funs at.
Get you speed to your turbine too early and you'll cause problems.....too late, turbo lag. Too big.....lazy boost, slow coming on and not enough.....too concentrated......good boost down low but runs out up top........

The kinda stuff you wanna read when your sitting on the toilet with the calculator!

 

well, i was going to get a free turbo of some sort from my cousin, but that went south so still going to try it when i get a turbo, thanks for the advice

 

I'd stick with 2.5. We did the calculations on our SFWD car 3 years ago and you gained very little CFM going to 3 over 2.5 and you lost enough velocity to make it not really worth it for anything short of mega power operations.

 

For a rear mounted turbo, 2.5" would be your best bet, to keep the pressure up. You would REALLY notice the lag with the 3". Mounting the turbo more toward the front of the truck would be your best bet of course, though its not the easiest. You lose so much heat efficiency running the turbo so far from the exhaust gases. Remember that the heat in the exhaust helps spool the turbo quicker.

 

thanks i having to put that project on the back burner for a while, getting a new trans for the dodge (cost most of my dollars)