oange ss

iTrader: (50)

Going FI on my project, was an 11:1 heads/cam LS1.Now going to home ported #317 heads and a MPT70 with .96 A/R. My question is, the currently installed cam is a Comp XE 228/230 .571/.573 on a 112 LSA. Will a cam swap be absolutely necassary for the turbo ? Hot Rod used the same cam in their 1200 hp 4.8 so it couldnt be too bad.The work wont be a big deal since I will be pulling the heads and front cover anyway, but it will just add more cost. TIA

98Z28CobraKiller

iTrader: (17)

I'd run it.

427

iTrader: (3)

It will be easy to hurt the engine with that combo if you load it early.

Kurt

oange ss

iTrader: (50)

I'm all ears....

bonestock_442

iTrader: (1)

+1 all ears

Professor_speed

iTrader: (8)

I think he was referring to the compression and smallish turbo. the 317s should drop compression down a good amount

427

iTrader: (3)

I think the reason the Hot Rod engine worked was the turbo was to big for the engine. I believe if they pulled off one turbo and left the gate settings alone the engine would have failed fairly quick as one turbo would have made boost low as this one will. The higher compression and small turbo will spool quickly (nice!), but leaves a lot of room for error. It will bend connecting rods/push water if you load it low and make a slight mistake with the timing. It has the potential to be very fun, but will not be forgiving if loaded low or octane is low.

Kurt

VUSS383

I agree with Kirt, this can be made work without a doubt but it will all come down to the tuning as to how long it lives . 1 slight mistake & it will end in tears . Boost & comp work really well together if in the rite hands .

oange ss

iTrader: (50)

Not understanding. Compression shoud be around 9.5:1 with the truck heads. Are you saying that's too much ?

427

iTrader: (3)

The Hot Rod engine would not make early boost because of the turbo size, yours will. When you make the early tq that will be capable of the chance for engine damage goes up in certain situations. If you are using high quality fuel and confident tuning will be used this can work. If the engine will only be run hard on chassis dyno it should also be fine as the load is very low. But if you load the engine early on the street the turbo will come on line very early and can cause 4 digit tq numbers below 3500rpm. This feels great but can buckle rods, break the crank or crack the lower block when the limits are exceeded. The circumstances that can cause disaster need many different things to align and this turbo/engine size/comp can lead both bad and good places depending on intended use.

Kurt

oange ss

iTrader: (50)

10-4, thanx for the advice

Black98s10

Weren't the turbos on the hot rod motor just some cheap ebay turbos?

oange ss

iTrader: (50)

The turbo setup will be goin in my Chevelle. The car weighs about 3100 lbs and has 4.11 gears and a T56 6 speed, so the rpms go pretty quickly. The biggest tire I could fit in the rear is a 255 so those will be my fuseible link so to speak.

Professor_speed

iTrader: (8)

nice car but you don't need 4.11s with a turbo

oange ss

iTrader: (50)

thnax...i realize that, but I'm not swappin em out

427

iTrader: (3)

That tire should keep you very safe, and the car is very cool! The one thing that could get you is wot at 50mph in 6th and letting it climb. As it comes in boost it will make massive tq and can kill parts. This can be protected in the tune if it has aftermarket controller.

Kurt

oange ss

iTrader: (50)

thanx, I appreciate the advice. The PCM is stock GM, using HPTuners to tune, have alot of experience tunning N/A cars,but this will be my first FI venture

oange ss

iTrader: (50)

another question. I have room for a single plane Edelbrock manifold/ TB elbow setup. Would there be any benefit to run that setup or should I just leave the LS6 manifold on ? Thanx for all the advice, I really appreciate it.

Professor_speed

iTrader: (8)

unless you are trying to carry alot of rpm I would not swap it out.

SATAN

iTrader: (2)

The question has been answered, but in an obscure way. They are telling you it is not the best combo but... why?

The specific reason is your turbo...

I would be more worried about the hot side of that turbo than I would be the cam. That turbo is smaller than what I personally run on my little 3.0 liter V6! That is why you will make boost really fast, which as stated is fun, but can be dangerous to the engine at the same time. The cam has some to do with that, but nowhere near as much as that small A/R ratio coupled with a small turbine wheel. If you can, I would try to get the biggest A/R ratio turbine housing as you can for that turbo, Or, just switch turbo's all together to one that will flow more exhaust. If neither of those is an option, then just rock it and take baby steps in the tuning.

Oh, and 9.5:1 compression is great for a turbo engine.

Oh, and with that turbo, you probably will not be turning that high of RPM's coupled with boost. Therefore your current manifold will do fine as was already stated.