Supercharger CR ?

Marty64

Hi,

In future, i will put a 2.8" pulley on my astra Z22SE supercharged car with dualpass, ported head, LS4 T/B, ported T/B, ported SC, vxr injectors, 3" exhaust system and maybe some oversized valves. Ecu remap with Odbtuner.
I bought 10 CR Wiseco pistons/con rods to support the hp.
I read 8.9 is better to high boost level PSI, and read also with a good ecu remap the CR 10 is good.
Can i fit 10 CR pistons on my engine project ?
TY

chill

If it's a brand new engine the important thing is the bore
Rather than compression

chill

Higher compression will give more hp

Is your Astra 4 wheel drive

Marty64

Thank's Chill,
I was afraid that poses problem to the block.
My engine is 63.000 miles, bought standard bore 86mm pitons cause i'll ajust the rings to the bore by measuring the gap.
Astra is 2 front wheel drive.

chill

What bore are the Pistons
86.0 are you not rebore the block

chill

Really you want a brand new engine to fit 86mm Pistons
86.5 for a used engine with rebore

Marty64

Wiseco Pistons i bought are 86mm bore (standard bore), so i think i don't need to rebore my used block, just adjust the rings gap or put old rings

dewismotorsport

You need to be very careful with that. What chill is trying to get at is the block cyclinder walls wear so you need a rebore on a older block, otherwise you may put new rings on and they will be straight at the limit of there gap

vocky

I once tried to get a 40k and a 50k mileage blocks honed for standard bore pistons, both had to have a rebore due to bore wear

Marty64

Ok, thank you Vocky for your precision.
And what do you think about 10:1 CR pistons with a 2.8" pulley SC ?
Does detenations will appear and may destroy engine (i'm using 98 octane gasoline) ?

Marty64

Ok guys,
After read some articles on internet and yours too, best choice will the 8.9:1 / 86.5mm overbored size pistons.
Engine will accept more boost without detonation soo more power 🙂
I can change my order but dealer want a short answer, please tell me if it is the good choice:

Part Number Bore mm / Inch Sizes Stroke Comp Height Comp. Ratio Pin

**K583M865 **86.50 / 3.405 0.02 94.6 26.75 20mm 8.9:1 20mm

Will rebore my engine to accept them.

evocarlos

Marty64 said:

Part Number Bore mm / Inch Sizes Stroke Comp Height Comp. Ratio Pin

**K583M865 **86.50 / 3.405 0.02 94.6 26.75 20mm 10:1 20mm

Will rebore my engine to accept them.

that pt number is for 10.0:1

Marty64

evocarlos said:
that pt number is for 10.0:1

Oups :whistle: make an error reporting data, but ref number is good for 8.9:1 ratio :