supercharged 4.0 question

[06s197]

A question to all the s/c 4.0 . I have the 06 coupe model and I was curious did any of you that installed a s/c change your compression from the stock 9.7 : 1 to a 9.0 : 1 or running the 380 to 400 hp with that engine ? cause i was told that it would be wise to do that so you dont blow heads and how much boost are running to get that kind of hp ? Are you still using the 7.5 rear end that you built up ? thanks

 

[JimC12]

I have the Xcharger Xtreme on my car - put the supercharger on with 90,000 on the engine and now have 167,000 miles; I pulled the nitrous that I had been running on the car when I put the Xcharger on. Still on the stock bottom and top on the engine, haven't changed anything on it. Runs strong still and took me to 12.6 this last fall.

I broke the 7.5 that I built up launching on drag radials and before nitrous or the supercharger - ended up it cost me more to build the 7.5 than the 8.8 swap cost me. Building the 7.5 was the worst modding decision I ever made.

 

[boss 245]

Go with Jim's advice. I have a charge cooled vortech v2 at 16psi on mine, no issues, I also am the only one still using the 7.5 that can run 11's, although with a girdle, auburn diff, 4:10's and 3" wheel studs, it is best to go with the 8.8 swap, it will cost less in the long run.

 

[NicePony]

The 4.0 actually responds well to FI with the stock 9.7 compression. I run an X-Charger with stock internals and have 107,000 miles on it and 137,000 miles on the engine with no issues at all. There have been a few guys that went with lower compression and FI and actually lost power. If planning anything at all with the gears definitely just go 8.8.