So several of us here are playing with the notion of not going with the 8:6 route. Instead a few of us here are going in the 10:5 range.

Now, mind you I am happy with my car. Power is nice for 5 psi but there is always the nagging concern of blowing my motor since it is not forged, and I don't want to make a post with the headline "I blew my motor." So I was thinking, for the sake of reliability, (I AM NOT TRYING TO BRAKE AXLES HERE_ just making a fun tuner car that I've worked on). (Unfortunately, HadesOmega is still in Iraq, so I can't ask him directly).


QUESTION
In terms of heat and what not, won't the egts climb faster? But if they climb higher, can't I just add a tad bit more fuel. I mean, I've notice on my car that once the egt's start climbing (a/f still cycling), then the egts go higher, but when af starts saying rich, my egts go down almost immediately; usually a 100-200 F difference.

I am thinking of going with the 10:5 since I can't find 9:6; I'll run 8-10 psi. It will be a nice reving car to drive everyday and of course get a datalogger, bigger injectors, fmic (or smic).
Anyone know when timing becomes an issue on our cars?

I want to make this a reality; once the hi comp short block is dropped in, I'll, of course, take it easy, run 5 psi, and make sure timing and what not is cool, before going to 8-10.

I've read on here in the archives, and did several searches on google but I keep finding the exact same info from people here. Just info such as, "its harder to tune, detonation more likely, timing issues, etc."

Now, I'm not doing the rebuild till summer but might as well start learning here, and hopefully hades returns so I can ask him... So any more suggestions/thoughts, etc...

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

whenever going with higher compression make sure you get it built correct 1st off... also make sure you got enough fuel and a ignition to retard timing if needed. since your on 91 octane in ca i would not even think about 'trying' to go with higher compression most of all if its a daily car. Most i would go with is stock compression or lower.

Michael
99gs HRC Stage 2000 8-Injector Setup
2004 Honda Accord V6 (240 hp)

Why does the computer advance the timing? Does it advance timing with hi comp for every psi?


-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

computer dosent even see boost. hard part is to make sure the pistons dont smack into the valves cause it is an interfaced engine. i dunno much else.

i would have some custom 9.6:1 (stock) compression pistons made will cost about a 100$ more then the normal price for forged pistons.

if you cant find anyone to make you pistons email me and ill give you 10 places.

je ross cp arias anyone will do.

with stock compression your gonna hit valves if your timing is that far off so there will be no difference between 9.6:1 to 10.5:1 in that aspect.

playing with the map signal will advance or retard timing if the stock computer is stil controlling it.

it advances timing when it leans out especially when your usgin an afc

things you would want would be a msd or crane box that would retard ignition and a megasquirt/e manage/8injectors kit/ dfi 7 to tune fuel with

it could be done if someone was pretty good with a sfmu/chill factory regulator and bleeder valve.


a wideband 02 with some datalogging capabilities would be my first guage.

Originally posted by MotoFool
with stock compression your gonna hit valves if your timing is that far off so there will be no difference between 9.6:1 to 10.5:1 in that aspect.

what about 8.5:1? could those still hit the valves, or is the difference enough to clear them?

Dammit. I'm gonna have to track down that other guy with the 9:5 forged engine...

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

Yeah, anything over 9.6:1 your going to need higher than 91 octane fuel after ~12 psi.

kiku ran 10.5 for a while

i'm as well going that route, i'm pulling my engine out and i'm swapping to my custom ordered JE forged 9.1 pistons. i bought it through this company here in Miami. so atleast i'll have a little more power than i was from the 8:6.1's. i've gotten used to tunning real well, and i always have access with a hookup dyno sessions here also. so i have nothing ot worry about blowing up. just make sure you keep your A/F mixture on tap and you'll have no problems.

I know for a FACT that hades ran 8psi on a high comp internals. He said it was wayyy peppy and extremely rev happy.

To the guys who are going hi comp, when are you all gonna do this?

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

I ran 20psi on 9.5:1 JE's with pump gas. Ignition retard is a must. I was also running 625cc injectors and the DFI. Ran great until a spark plug came apart. :(

how much timing were you pulling?

what did you forsee the limit to be without pulling timing?

So yeah, 99, when did you start pulling? Was it at 12 psi?

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

it really is not that hard to find custom 9-1 or 9,5:1 pistons man
any decent dealer can get them for you.

Yeah. Your right; I'm gonna try to contact VT before the summer starts and tell them about my plans, maybe run 9:5.

-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

cps are nice but your talking more then just an extra 100$ for customs from them. unless the price came down very recently.

if i remember right it takes 6 weeks to have the cps made and deleivered.

vt can tell you whats up either way.

if you gonna do this invest into a ignition and a wideband 02 setup 2 best tools.

Just thought that I would point out that the only time your pistons would hit the valves would be if the cam timing is off. You shouldn't mess with that, buy premade cams from a company if you want to change cam timing. The timing you need to deal with is ignition timing (Which will never cause pistons to hit valves).

Originally posted by Therein10
Just thought that I would point out that the only time your pistons would hit the valves would be if the cam timing is off. You shouldn't mess with that, buy premade cams from a company if you want to change cam timing. The timing you need to deal with is ignition timing (Which will never cause pistons to hit valves).

i think everyone knows that the valves would only hit the pistons if the timing was off. thats not even what we're talking about. i wanted to know if the 8.5:1 pistons would clear the valves or not. for example, if my timing belt broke, would I still bend my valves, even if I had 8.5:1 pistons.

:sigh: no0bs :)

(cough cough)

Copper, just to let you not, Therein isn't exactly a noobie. He runs 28 psi on 9:1 compression. :)


-------jezreel
hrc stage 1, sfmu, ml, prokits, egt, boost gauge, apexi tt, haydans tranny cooler, costum dp, dynotune fp gauge. gst muff, turbo spoiler

nothing like driving with the windows down and the music low: i love hearing the turbo spool, swwwhhhttt!!!!
thanks for www.kaptainmyke.com for the sig hosting :thumbsup

lol, yeah, i didn't really think he was a noob, thats why I put the smiley face there. it was just a goofy sounding post. lol.