Compression for 400bhp????

[marc]

Whats the standard compression of our engines?

And what compression would you run for 400bhp at the fly

thanks marc

 

[campbellju]

8.3:1

errr..... 8.3:1 again

 

[marc]

Ahhh great!!

I was thinking the compression ratio would have to be lowered!!!

 

[marc]

The pistons im looking at are 8:5 ACL forged ones....

Anyone shed some light ?

What pistons do most use? or is it a thicker head gasket ?

 

[nismoboy]

The pistons im looking at are 8:5 ACL forged ones....

Anyone shed some light ?

it depends what turbo u are using to achive 400bhp is u use a small turbo u will have to run more boost (1.6 bar +) but if u use a large turbo 1.3bar on a gt30 would be very close to 400bhp.

so genrally high boost lower the compression, low boost keep the compression standard.

 

[marc]

I plant on buying a gt30 turbo , so the pistons im looking at will not be suitable then ?

 

[nismoboy]

I plant on buying a gt30 turbo , so the pistons im looking at will not be suitable then ?

depends, if u used a 1mm hg to compensate the piston high cr then yes u will be fine, otherwise buy some lower comp pistons.

 

[marc]

When do the standard injectors max out? Im guessing I would need bigger ones? aswell as a maf sensor ?

 

[Mr GTiR]

I've got 87mm JE pistons with a 1.2mm triple layer metal head gasket along with a GT 28/40 turbo.

Injectors are 660cc with a Z32 MAF and Power FC Pro.

All that lot shoudl see 400bhp at 1.4 bar 8)

 

[ashills]

those pistons are for teh 200sx and when used in gtir will give 8.3:1 due to the head on the gtir
400bhp is fine on standard compression on pretty much any boost 500 should be a problem if its mapped spot on

 

[marc]

What head gasket would you reccomend then for that set up , would be a replacment standard one seeing as the comp would be fine i suppose

 

[ashills]

nah just because the compression is the same doesnt mean u can use a standard gasket as cylinder pressure swill be a lot higher than standard if ur gonna run 400bhp
most people go for 1.2 mm gasket from hks etc

 

[jord369!]

id recomend a gearbox to go with the turbo!! they dont like power :lol:

 

[JAMMA]

Marc I have these pistons fitted to my engine along with a 1.2mm head gasket. If your looking for any info gimme a shout.

Jamie