I bought a Vortech Supercharger kit (V3 I think but can't remember it might be V1). It was suppose to be a bolt on for stock motors. It keeps blowing head gaskets now. I figure the engine is due for a rebuild anyway. I was thinking about doing a cam and injectors while I had it apart. Is there anything else I should do. What is the ideal CR for this combo, it pushes 8-10psi. Can anyone suggest a cam? I am hoping for right around 400hp. Thanks for the help

 

are you running an fmu?
how are you retarding the timing?
was it ever tuned?
do you have any idea what afr you are running?

if your not running an fmu and you havent upgraded the injectors its no wonder its blowing head gaskets

 

I am running the FMU from the Vortech kit. The injectors are stock right now but I would probably upgrade them when I put in a cam, Im not sure how big I should go though? The computer is a stock Mass Air computer from a later model. I have know idea what the AFR is. The kit came with a timing retard box, it just has stage 1,2,3 so Im not actually sure how much it retards the timing. Its not actually my car I'm just rebuilding the motor. We basically followed the kits instructions since it was supposed to be a bolt on kit for stock basically motors. Superchargers and FI are pretty new to me I like my carbs.

P.S. The car is an 87 mustang GT, 5.0L H.O, 5 speed,converted to mass air, other than that its pretty stock

 

well stock injectors with 10psi is a no no. it needs to be tuned on a dyno with bigger injectors. all the fmu does is keeps the fuel pressure steady. The kits are supposed to include bigger injectors and a chip with a base tune

 

maybe kits for newer cars come with injectors and a chip but not for foxes. all the sc kits come with fmus which dont hold fuel pressure steady, they actually pinch the fuel return line almost shut which causes fuel pressure to go up. a boost line is connected to it and a disc inside it is calibrated to the injectors you have so it keeps the afr safe. its basically a band aid for an insufficient fuel system

 

Anyways, Im not real worried about why it blows gaskets, What I would like to know is, How big of injectors should I go to, if anyone can suggest a good cam, and what a good CR is. Im used to NA motors so Im not really sure what to look for with a supercharger

 

you should be, because if you dont find out why, itll happen again.

anyways, 42# injectors will do the trick. the best cam is a custom cam but since you dont seem to care why your popping head gaskets i doubt your going to go to the trouble of having a custom cam made so just look for a cam that is designed for sc. and cr varies greatly. anything between 8:1 and 11:1 will work depending on the fuel you use, the cam you use and the tune

 

x2
& I wouldn't get on it too much with the stock injectors if you don't know what the car is running like. That's a fast way to destroy an engine.

 

I am going to completely rebuild the engine and go over everything and not a whole lot will be the same so thats why I am not too worried about why it blows gaskets. I realize a custom cam is best but I was hoping there was a good off the shelf cam for superchargers. What is the difference between NA and supercharged cams anyway. I will upgrade to 42# injectors. I have stock cylinder heads (E7TE-AP). It would probably help if I new the max lift for the heads too, if anyone knows. I will run 91 octane. Can I keep the stock 9:1 CR with out any problems. Obviously I will tune it when Im done. I would like a dyno tune but whether or not I can find a dyno tune shop near me is another question. thanks

 

My point was you're at risk of damaging more than just little parts. I was referring to your block, crank, heads, rods, & pistons being at risk. It's amazing what a small damaged piece can do. I have a piston, head, block, & crank that's a pretty good example of that all paperweights now. If you're replacing most of the stuff I wouldn't worry about it then.

Your cam selection will primarily depend on your heads & how much air your flowing. Max lift doesn't always mean it offers the most power. I would go for a dual pattern cam if you're going to be sticking with stock heads for a while due to the poor exhaust port flow. Since you're going to be forcing air into the cylinders you don't want much overlap otherwise you'll be pushing air/fuel out of the exhaust same with duration on the intake side since the air is being forced in; another reason a dual pattern will help.

The biggest i've ran with stock heads & pistons (stock notching) was .542/.542. It was an x303, but since it's a single pattern I wouldn't recommend since you're running e7's & the s/c