compression set up, opinions, thoughts?

[isaiahgs]

my set up now as it looks is a ported big16g turbo w/a 34mm flapper, rre custom fmic, 2.5 inch piping, 3inch turboback, 2g mas and plan on setting that up with a safc, greddy profec b, 550's, porting the head, 264/272's now that is my projected plan on the car, ive been readin on compression ratio's for 1g's 7.8-1 , 2g's 8.5-1. now buying 2g pistons with rings isnt that much cheaper than just buying ross pistons at turbogarage.com for 390. im just not sure what compression ratio to pick with the pistons like a 8.5-1 or a 9.0-1?

 

[DSM90AWD]

On Pistons:
IMO.. save the piston upgrade till you really need it. The money is better spent now on mods that will make more performance for the $.

[over-simplification]Lower compression allows more boost at the cost of spoolup. Higher Compression gives you slightly quicker spoolup at the expense of boost capability [/over-simplification]

BTW.. Your stock 1G Piston/Rods combo have held upward of 450HP

On Turbo:
The EVOIII 16G costs about the same as the Big16G (on groupbuy even less) supports ~20 more HP and is of a better design.

Even with the 34mm flapper mod and ported turbine there is a definite possibility you will creep since you are looking at a 3" Turbo-Back system. IMO.. to save you this hassle instead get a decent 2.5" DP and 3" Cat + CatBack.

The 2.5" section will have little/no impact on a 16Gs performance potential. And to me.. not worrying about creep / melting piston tops is well worth it

 

[isaiahgs]

ok with the setup i mentioned above how does a 02 housing dump tube sound? better performance ? no more no less more noise? i found this on at http://www.punishmentracing.com/frameset.html
150 shipped? anyone got it?

 

[DSM90AWD]

Being from CA this'll definitely get you in trouble with the emissions police. When the W/G opens your are basically running open exhaust thru the dump.. so will be loud.

Some like this sound.. but many have thought the noise, risk of ticket..etc was not worth the small gains in performance.

I say "small".. as running an EVOIII or 122performance.com tubular EVO-O2 and a decent DP, 3" exhaust will make the gain of an O2 dump not that much (i.e. the dump makes up for an otherwise restrictive exhaust).

My setup (which hopefully will be here this week ) is a VP O2housing 38mm TIAL and dump which I'm plumbing back into my DP (for the street) and to ATM for the track (or when I want to further p/o my neighbors )

 

[dsm1kenobe]

Originally posted by isaiahgs
my set up now as it looks is a ported big16g turbo w/a 34mm flapper, rre custom fmic, 2.5 inch piping, 3inch turboback, 2g mas and plan on setting that up with a safc, greddy profec b, 550's, porting the head, 264/272's now that is my projected plan on the car, ive been readin on compression ratio's for 1g's 7.8-1 , 2g's 8.5-1. now buying 2g pistons with rings isnt that much cheaper than just buying ross pistons at turbogarage.com for 390. im just not sure what compression ratio to pick with the pistons like a 8.5-1 or a 9.0-1?

IMO, get 8.5:1 CR pistons for a larger tuning window, especially if you plan on running 91 octane on a regular basis.