What would you guys say would be the highest/safest compression I could use (pistons) for a daily driver on pump gas (premium of course). I'm currently running JE SRPs at 10.5:1. I was looking at Type Rs which are 11:1 but I worried they are not forged like the JEs and I want to run nitrous.

If anyone can suggest a particular brand which will have off the shelf pistons without having to bore my block, let me know.

 

A little over 12:1 is the highest I would go. I run a little over 11:1 (ctr slugs) right now with 93 and have no detonation. OEM pistons do not take large doses of nitrous very well (they shatter). OEM pistons can handle some nitrous, but a 100+shot and you'll need forged pistons.


[Modified by Phat_Optimo, 7:17 PM 3/6/2003]

 

13-1 on pump gas 91octane with good tuning, but good luck getting it with a b16 crank.

 

Damn.. please tell me what kind of ecu and who tunes your cars... i tried running CTRs and JEs both were 13.0-1 and i detonated both on 94 octane.... ur the man i need to talk to...

 

Hondata

 

You can't run too much timing advance and you must avoid leaning out, but it can be done.

 

Just a note, ITR's will lower your compression in a B16 and CTR's will give you 10.8:1

 

quote:


Just a note, ITR's will lower your compression in a B16 and CTR's will give you 10.8:1

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This was your response to my question on the highest safe compression on a B16 with stock gas. Thanks for the info - I thought the Type Rs would give me 11:1. Do you know of any off the shelf forged piston that will give me 11:1 - 11:5? I was looking at Arias but they have 12:1 and I'm worried it's too high.

 

i think 11:1 is kool. Dont want to have the early detonation problems most people have when going 12+ compression.

 

12.5

 

im in cali with 91 pump. i would go 11.3-11.5:1. just my .02
remember ctr pistons(pct) in a stock b16 only yield a 10.8:1 compression ratio


[Modified by eghead, 11:02 AM 3/11/2003]

 

ditto.


[Modified by Katman, 11:02 AM 3/11/2003]

 

Which compression calculator is correct?
http://www.c-speedracing.com/howto/c...c/compcalc.php
or
http://www.bojangs.com/calculator/

Kinda funny that the both give different compression ratios when selecting the same parts. I put in B16a block and head with CTR (PCT) slugs OEM (3 layer) headgasket 81mm bore.

C-speed says 10.80:1
Bojangs says 10.99:1
JDMHP told me It would be 11:1 when I bought the pct pistons

I wonder whos is actually correct.

 

This is true, meaning that the only OE pistons that will generate a higher C/R are P30's and PCT's... 10.8:1 isn't all that much and you won't have any problems tuning that out... With 310-370cc injectors and a VAFC you can easily tune out 12.0:1 on 92.... Drop your timing back down to ~12 degrees and you shouldn't detonate at all... I would still recommend Hondata because it really isn't that much more than a VAFC and has a lot more parameters... IGN timing mapping through the rpm band, etc... To achieve ~12.0:1 you're gonna need aftermarket pistons... Look into JE and Endyn.. I like them both....
How did you get 13.0:1 with PCT slugs??? I'm just curious, even in an 81.25mm LSVTEC running a P72 cylinder head you'll still be in the mid to low 12's... (~12.3:1) Was this in a B16?? That would be even harder due to the shorter stroke and the PR3 cylinder heads 1.1cc bigger CC.. Was your head milled or did you have a high compression headgasket... Again I'm just wondering... I can see that C/R with aftermaket pistons... Peace

 

how about we just leave it at a ballpark of 10.8-11.0ish, yeah?
a .3 difference isn't really that noticeable.