question

[97yelstang]

i have a 97 gt
and i was wondering if i should do a pi swap on it, but i want to supercharge it and i don't want to have compression problems.
also i can't decide on a supercharger, stuck between procharger,paxton,and kenne bell.
i want my car for everyday use, so any info would be greatly appreciated

 

[Dark Knight GT]

Swapping cylinder heads isn't going to yield any compression problems. As for which supercharger to chose, its all up to you. Those are some pretty good companies you mentioned. One major difference I believe I can see, is Kenne Bell uses a roots style system supercharger, where as the others are centrifugal design. The difference is one becomes your intake in itself(roots style), while the other forces compressed air into your intake externally. Which is better ? It all depends. Naturally, a centrifugal can make more psi up top, and thus more power. However, a roots style blower is better for more instant power, as it is gearless and doesn't take time to "wind up".

Either way, you'll be fine for every day use as long as you get it tuned properly and don't run too much boost. When I say "too much boost", I mean anything more than 8psi intercooled with the stock bottom end. Even with only 8psi, you're still running the risk of blowing the bottom end. Might want to upgrade to forged internals if you're going to be running boost.

 

[mogs01gt]

The PI head swap will raise your compression a little.I think it raises it to what?10:1? That isnt bad for boost but you will have to run less timing and maybe a few PSI less than a car that had 9:1 or 9.5:1 like the 99-04 cars do.

 

[billfisher]

boost it baby

a recent article in MMFF i think it was showed how C/R is not necessarily a bad thing with boost. better fuel and careful tuning means power. output on any motor is roughly 4 - 4.5 times cylinder pressure(i mean roughly to illustrate point) . lowering C/R to reduce detonation sensitivity is going around the problem. surface temp (reflective) ,hot spots(rounding edges in chamber), plug temps add more to the problem than just C/R alone. good coating, chamber mods to remove edges and focusing on removing heat can help. Also a good high overlap cam say 108 - 109 degree centerline and adequate duration bleed low speed cylinder pressure to help also. I guess what i am trying to say is keep C/R, just put a LOT of money into forgings and proper anti detonation head work.

no need to throw away output. kinda free output (expensive on pocketbook)

 

[mogs01gt]

With forced induction, you want a longer lsa. Like 113+

 

[Dark Knight GT]

To add to the good tech info Billy and Mogs have given you, you might want to do the modular coolant mod to your motor while you've got the cylinder heads off. It will help keep the internal heat down in the cylinder heads and motor, especially while running the boost. Especially in cylinders 7 and 8. I don't know all the specs, but there was an tech article about it over at Modular Depot.

Here are some links to a couple threads:

http://forums.modulardepot.com/showthread.php?s=&threadid=21987&highlight=Cooling

http://forums.modulardepot.com/showthread.php?s=&threadid=17643&highlight=Cooling

http://forums.modulardepot.com/showthread.php?s=&threadid=21728&highlight=Cooling