hhr, this is a dyno sheet for before and after. the cat delete was no more than 5 horse, the tb was the other 10 hp. its an easy mod. buy a ls4 with adapter plate from zzp, send it to euthanasia to have it ported, polished and blended with the adapter plate then install it and tune. the best part was the boost i picked up from it. i was at 18 with the 2.6 on the lsj tb, switching to the p+p ls4 i went up to 20. amazing how much better a blower works when it doesnt have to fight to pull air through the tb.

 

Ok. Thanks, now I am following. That is why I was inquiring as to your setup as well. This is likely only going to net decent gains when using small pulleys or SC port work. I can tell you it doesn't do jack when using larger pulleys. Maybe I will have an opportunity to swap TBs at the dyno with my 2.7. I bet this mod follows suit with the ported SC. 100% meth noted gains as high as 3psi with a SC port but this was with a 2.6 iirc. I ported mine and gained .9psi on a 3.1. I think if I had a small pulley comparison I would have similar results to his port numbers.

 

your stuck with a big pulley due to a higher compression motor? same problem the na cobalt guys run into? i gotta wonder if its really that hard to just get dished pistons for the 2.4 motor, or to have the dome on the stock pistons reduced with a cnc machine. if mrbelvedere is reading this he would probably know. other than a thicker head gasket there has to be other ways to reduce compression, hell have the combustion chamber on the head opened up a bit as part of a port and polish.

 

Has anyone done a before and after with a small pulley TVs? I keep looking at this mod and going back and forth. My next run through the car ill do it

 

i wouldent be afraid of dropping pullys on a 2.4 because of the higher compression ratio i have ran 10to1 on a m62 2.7 pully with water/meth and i am running the same with my tvs its fun and i have been running the ls4 for a couple of years now

 

Not any more I just finished my rebuild with JE 9.0 pistons and ZZP rods. ZZP offers stock or 9 compression JE pistons. I am dropping down to a 2.7 after I get the engine and clutch broken in. I dropped to 9.0 to make sure I can smaller pulleys without meth.

The JE's are dished:

 

ull still need meth/water mix so you can run a decent amount of timing and to keep the iat2s down

 

I can do comparisons I just got mine a few days ago...it may be a week or to before I do it tho...

 

We will be here