i do apologize for this question, but i need help with a decision. i am building a 2.4l and i have the "secret cam swap", eagle rods, and wiseco 8:5.1 comp. pistons. i am going to put the gm supercharger on and would like to know if it would benefit me to use these pistons or get another comp ratio. again i am debating this and i can't decide if they would work or not, so any help would be appreciated.

With the GM charger i wouldn't go with a lower compression ratio than stock due to the fact it can not produce high boost pressures. I might even consider a higher than stock c/r with the GM s/c.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

Skilz10179 wrote:With the GM charger i wouldn't go with a lower compression ratio than stock due to the fact it can not produce high boost pressures. I might even consider a higher than stock c/r with the GM s/c.

i don't know about higher than stock simply because of how much more heat an eaton produces than a turbo... more compression + higher intake air temp = higher possibility of knock... something worth investigating though....




Arrival Blue 04 LS Sport
Eco
Turbo
Megasquirt
'Nuff said

as some one who actually has the GM supercharger i would say DO NOT go lower compression ... the supercharger can only make 10psi MAX! and thats only good for about 215whp maybe 220whp depending on other mods... as @6psi my buddys dynoed at 205whp.... now lower the compression with out being able to turn up the boost like on a turbo and you will be lucky to push 200hp (depending on elevation as well) as well even with the 2.6" pulley i was getting very very slight knock but nothing more then any other boost car i have seen just you will get a slightly loss in power with heat soak over time.. but all you have to do to over come this is put an alcohol injection set up on your car (very easy to do) and your problems are all fixed and then some... i would just get 2-3 bars of green on my knock gauge with out alcohol and the 2.6" pulley which isn't much and this was with out alcohol injection.... so the heat problem can be solved...

my suggestion would be to get

- P&P head
-Cams
- good cold air intake (i got tones of pictures of how to make a very nice easy custom one)
- good header/ 2.5" exhaust
- alcohol injection (snow performance has a nice kit for GM cars)
- Pulley Boys 2.6" pulley
- and if you feel comfortable enough after you get the GM re-flash done get a HP tuner kit (or a shop/person close by with one) and fix all of GMs screw ups and that right there will probably give you a fairly nice gain



The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno

go with 9.5:1......... Karo has a set of .040"+ in stock.




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

Could turbo tech racing pistons Je 10.1 compression bored .4 over with H beam rods be a good combo with the gm super charger after the obvious oil pump swap and bearing swap. Add a pnp head an upgraded valve train and that would make the gm supercharger a nice componet.

Quote:

Could turbo tech racing pistons Je 10.1 compression bored .4 over with H beam rods be a good combo with the gm super charger

I would say thats your best bet if you want to hit 10 psi . But as stated above you should seriously consider alcohol injection if you do go higher compression.


01 Z24 Turbo /// First Reflashed Turbo AUTO MMMM YUMMY

I was not talking max psi i was thinking combine a n/a motor with a little boost the motors should withstand it. think 10.1 compression add .40 overboar nice n/a motor then add gm supercharger cold air intake and stock sized pully prolly put ya at 250 tuned correctly with the right F/A ratio. Me i like inter coolers i would add one to the front and cool the air even more before it hit the super charger. add a ceramic gaket between the s/c and the block, an evo hood, alky injection, if i could i would tear the super charger down an add water fins to the outside to water cool it on top of every thing then hit 10 psi and say byby axles yes i have atendencey to overdue and overthink

it's 0.040 over. Not 0.400 over.

Also, an "intercooler" before the Sc would be pointless even with CO2 cooling.



Gilles
2.3 Ho

i would personally try going 11:1 compression ratio.... i know a guy in BC is going that way with a twin charged set up like mine @15psi or so.... but then he is tuned for race gas and such... not a street driven car... but on just the GM supercharger kit i would say you could easily get away with 11:1 compression ratio and get the GM re-flash and then finely tune it from there with HP tuners... i am sure you could push 230whp with a 2.6" pulley and a few other things at that comp. ratio



The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno

Boost pressure has nothing to do with anything fro this setup.
The GM 2.4 charger can only move 210-230 hp worth of air on a stock engine.
The only way to make more HP is to either make it easier for the charger to move that air, or make the engine make more power with that air.

Easier to move= cams, headwork, intake, exhaust
Make more power= (mainly) higher compression.


sig not found

protomec wrote:Boost pressure has nothing to do with anything fro this setup.
The GM 2.4 charger can only move 210-230 hp worth of air on a stock engine.
The only way to make more HP is to either make it easier for the charger to move that air, or make the engine make more power with that air.

Easier to move= cams, headwork, intake, exhaust
Make more power= (mainly) higher compression.

and thats exactly what i said... go with 11:1 compression pistons and...........

Josh F wrote:
my suggestion would be to get

- P&P head
-Cams
- good cold air intake (i got tones of pictures of how to make a very nice easy custom one)
- good header/ 2.5" exhaust
- alcohol injection (snow performance has a nice kit for GM cars)
- Pulley Boys 2.6" pulley
- and if you feel comfortable enough after you get the GM re-flash done get a HP tuner kit (or a shop/person close by with one) and fix all of GMs screw ups and that right there will probably give you a fairly nice gain

The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno

....... and retard the timing to combat detonation.........




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

SpeedRacerZ wrote:....... and retard the timing to combat detonation.........

i don't think you would get any with alcohol injection and 94 octane gas.... and proper tuning with a HP tuner kit to fix all GMs Fu#^ ups with their re-flash... in the tune GM gives you it pulls SOO much timing... the kit could produce way more hp if they didn't go so conservative on their tune...



The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno

You're the man Josh F.


- 93 mph in the 1/8 mile
Member of J-Body Of Michigan.

josh when are you going to post more videos of your car and setup again on streetfire