compression question

[ONR]

Is 9 to 1 compression really really high for a 91 gsx...i think thats pretty high, id be too afriad to boost on that motor...i woudl rather see somethign in the 8s for aftermarket stuff...what's all of your input...thanks

 

[candela]

my opinion....only a wussy woudl say something like that =)

In all reality if you think its to high it prolly is to high (for you that is). You may be better of running lower compression as it is much more friendly when it comes to tuning in most cases. On the other hand I just love my 9:1 pistons and feel it is such a wonderful daily driver compared to stock 6 bolt compression.

 

[91 NT Eclipse]

9:1 gives better off-boost acceleration but allows you to boost less on the top end. So its all about what's important to you.

 

[ONR]

thanks for your input, i think ill not worry about the 9 to 1 compression then...just not boost on it alot until i get more tuning abilities as in gadgest and gismos hey Candela how much boost do you run with yours?...Oh yea because someone is selling a car around here with this motor built like these is the reason i asked bout the compression...thanks

 

[NickSimcheck]

candela, thanks for letting me know I'm not the only goon that is putting 9 to 1's in a daily driver. What mods do you have? And what rpm do you build full boost? I don't have a mod list but I guess I'll make one right now...

Bottom end:

ARP head studs and Mitsu steel head gasket
ROSS pistons, 9 to 1 compression, .30 over
1G Rods, reconditioned, beamed, shot peened, ARP bolts, the works
Balanced shafts removed (what killed the old engine), full rotating assembly balanced, a lot more machine work that I'm to lazy to type so I'll end it there...

Other then Crower stage 2's the top end is stock and the rest is in suspension and other junk...

Long story short the block is at the machine shop, I'm having them match the bore to each piston but after that is done it goes back into the car and will be fired up and I'll see how I like it... I thought 9 to 1 was good because the steel head gasket is 1.7MM thick so that lowers my compression down a bit so since I'm to lazy to figure out the compression or static compression I'm just going to say it's in the 8.7-8.8 range and for static, no clue. Back to why I chose 9 to 1's is because I'm not planning on boosting it without more then enough fuel to support it and I don't plan on dicking with the car more then I already have and so with stock boost (what like 11 or 11.5?) I should be more then ok on 92/93 octane. I'll get better gas mileage, have more power off and on boost, faster spool up, etc. In my opinion, if your going with aftermaket go with a higher compression then 8.5 to 1.