Educate me on Turbo's....
 

Ive always been a "nitrous guy", i suppose because its significantly cheaper than a good turbo setup, and im still a "poor college student". After seeing a few friends turbo setups (ABEASST on here specifically, and one our shop did) i am truly considering changing setups. Im new with the real technical turbo stuff, so i have a few questions.


My motor is a 347 forged and balanced (LS6 block and stock crank), stock(ish) compression, T-rex cam (242/248). th400, 5k stall, transbrake. suspension, etc.

I know my compression isnt ideal for a FI setup, so how much boost am i going to be able to safely run realistically? If i end up going turbo, the turbo is going to be big. Upwards of 80mm. The car is not a daily driver by any means (th400 w/ 3.73's), so Im not worried about gas mileage or any of that. its mainly a "weekend and track" car.

Am i more than likely going to need to lower the compression to make that kind of power safely? I would assume so, but like i said, I'm new to this FI stuff.

I realize i would also need to change the cam, what is an ideal(ish) cam size for a boosted setup? Single duration? split duration with more intake?

The car has 36lb injectors now, so to make the type of power I am looking at, what size am i going to need? What do you turbo guys run? Ill be looking for upwards of 750whp through a th400. im guessing in the 60lb range? bigger?

You guys who have had your kits built by smaller shops or single people, whats a good going rate for a good turbo kit? Id rather stay away from a "pre made" kit such as PTK for cost issues, as well as i would like thge kit built specifically for my car. There are a few people in the area i would consider have build the kit for me, but what would be a good LSx turbo kit price?

Im sure ill have some more questions here eventually, but theres a start.

Also, what about fuel systems? what are you high horsepower guys running? Im currently stock system with the exception of the injectors and 255 pump. im assuming all the lines will need to be upgraded, and possibly go to a dual pump setup?

I hope you live somewhere up north...because most traditional turbo kits will cost you your Air Conditioning...

Definetely get rid of the HUGE freaking CAM your running. Most guys stick with a stock cam for either the LS1 or LS6 or go with something that has little to no overlap i guess. There's one guy on there that is putting down over 500 with a custom TRT cam at only 5.5psi. That's pretty impressive IMO.

Might as well go 96# injectors just incase you feel like upgrading in the future. Racetronix I believe with their boost-a-pump and in-line fuel pump + in the tank fuel pump (something like that) is good for the kind of power you're trying to make I would think.

With lower compression pistons or simply the lower compression heads (6 liter truck heads I think), plus maybe some Meth or H2O/alky injection, I could see 700+rwhp with what...maybe 14 PSI??

I am by no means an expert...I'm simply relaying info to you that I have collected across the forums.

To give you an idea here’s my old setup, I did basically what you're doing...

Forged 346ci( diamond pistons w/ 2cc valve reliefs)
TEA Stage 1.5 heads
MS3 cam
Fast 90/NW90
And about 300 worth of bottle on a wet shot.
Fuel system was racetronix pump and 30lb SVO red top injectors.
Static compression was around 10.8

Car was making right around 700HP/800TW to the wheels.

The new setup I’m in the middle of building is a 408ci iron block w/ a GT47-88

The only thing I’m using from the old motor is the rods.

Complete new fuel system A1000 external pump, -10 feed -8 return, regulator, sumped tank, 96lb injectors w/ driver box

317 cast heads

Static compression will be 8.5.


It all depends on how much safe power you want to make. You’ll want lower static compression so you can run more boost w/ 93 oct and not have to worry about detonation.

Use the search button, read a lot of threads, ask questions, talk to reputable shops how have done high HP FI applications.

your basically gonna have to start alll over from the set up you have besides the transmission, goo thing is you can sell alot of the stuff off of your car and make some cash to pay for the new stuff,
look into some 60lb injectors,fuel rails, im running the Speed Inc. TU1 for a cam, add another 255 pump into the mix, along with a bigger feed line and return, dont forget the boost referenced FPR, gauges, shit just keeps adding up

depending on the turbo kit whether its log style or header would determine whether it would be a split duration or single. like TINKRD said read the stickys plenty of useful information.
bte you have an awefully nice set up for being a "poor college student", lol

I save my pennies, and look around for deals ;)


Thanks for the help guys, im gonna go read up now haha

A decent fuel system with two walbros will run you around $1400 for parts. Get a fuel pressure gauge, wideband and a boost gauge / controller.

750 through a stick is about the max of 60lbs, the RC 75s should be enough depending on hp and converter loss. A injector box with 96lbs would be the next option.

you can run 75's with factory ecu?

i got you on that one. thanx, you dont need a monster cam to get power

who makes a good dual pump setup?

lonnies performance but its expensive. Also racetronix.

what are you running?

RC engineering makes a set of hi z for the stock computer.

custom dual intank setup. Not that hard to do really. Just modify the bucket to fit 2 pumps, splice together wiring, and install a bulkhead in the top for the feed.

o reallythat's good to know.

taht lonnies shit is bad ass
the lonnies set up is racetronix, at least i thought

ill get with you on HPJ about that...

they are not cheap though....ive got a set waiting for my car