GT428R

How much boost can this 4.6 handle without problems? And does anyone know where I can find out more information on my 428R? I was wondering if they used the stock GT clutch and is that 4.6 stock other than that roushcharger...I'm thinking it is and I was just curious on how much powerI can add to this car before I have to start worrying about stuff breaking!

eolson

The more conservative folks will say 415-420rwhp or about 480 flywheel. Some say 550 flywheel, or 500rwhp. I believe the Roush charger is pretty much done after 420-425rwhp, I'm not sure what pulley that's with, probably 8lb. Erik

blackS197

It can handle alot if you dont beat on it for 5 mins straight. Heat is your worst enemy. 440 rwhp is about safe.

127shtry127

The ability for a motor to handle boost is highly dependant onthe quality of calibration the car has. If you have to standard Saleen tune your already at risk with stock boost. That's why you'll see many people (even Red Devil himself) go with an aftermarket tune. Beyond that it is dependant on how you drive your car. On a track day a motor may not handle higher boost for longer periods of time where on the street a short blast of accelleration here and there may not hurt-sort of like using NOS. If doing a long term durability cycle to OE standards today the 4.6 is capable of about 440hp. Anything beyond that puts you in the red zone if your driving the car in a track manor.

EricM

He has a 428R (that would be Roush). Do you bother to read the posts you reply to, or just jump at any chance to get a dig in at Saleen?

eolson

As I mentioned before, I saw a post months back, and an experienced roush installer mentioned the roush charger was workable up to about 420-425rwhp, I don't know what pulley gives that on the roush, but that's the number I saw that would still work with the cooling and other items. Erik