boost with 10.5:1 compression?

[Alxsmt]

well im getting kinda tired of my current power level and an idea just hit me today. instead of waiting for my engine to die and going turbo and then having issues of choosing a turbo for auto cross or drag why not just get a supercharger for my current engine!! i do have fogred pistons but there not designed for boost, im assuming they build them with a different meterial for different appliactions (na, boost, nitrous) and i would have to email JE before i bought anything for this project

how much boost could my current engine handle on 92 oct?(sig)
what about meth injection?
i know it would need a tune and maybe even injectors

probly wouldnt do untill winter if i even do it. its just a thought so far

what do you guys think?

[IsaacHayes]

With a good tune I'd guess you could boost probably 8 maybe more. You could always richen it up if need be. 10.5 isn't THAT much higher than stock 9.6/9.8 whatever it is.

What kind of pistons do you have? hyper or forged? Either is ok if you're not knocking. Hypers are more brittle though so they won't survive as easy as forged or so they say. There are stock boosted engines running hypers though.

If you do super charge it, would you go CSC or roots? Either way I would DEFIANTLY intercool it.

If you don't have the AC anymore then try to mount an M90 (preferably gen V) where the AC was, move the radiator forward if needed, install an intercooler, and do that. You might need a GTZ/Z26 front bumper to fit the intercooler.

A roots blower like the m90 will give you off idle boost. It may be TOO much power though unless you modulate the pedal. A CSC builds boost proportional to RPM so the higher the RPM the more power.

Or you could do a "small" turbo that spooled really fast.

.... Lots of things you could do.

[Alxsmt]

i would go with a csc (i acually thought both styles worked like that, gotta lota learning) and it would go where the AC goes, just gotta delete pully there right now. hell, i already have half of my charge pipes routed from my CAI going into the bumper lol

they are forged JE pistons

i wont turbo this engine, i dont wanna take off my headers..

[FallenZ24]

You could deffinately do it with race fuel and make lots of power. With a safe tune and low boost I don't see why you can't do it on 92 octane. Just make sure to cool the charge as much as possible. The CSC would actually work the safest. It builds boost gradually and and is only in "max boost" for a few seconds until you shift or let off. YOu may have to change the cam if you're is too aggressive for FI.

Personally I would just leave the car like it is and spray a 75 shot of (wet) nitrous on it.

-Joseph

[no_doz]

you can boost with 10.5:1 & make loads of power with less boost, just make sure you have a good intercooler setup & a good tune is EXTREMELY important or you could end up breaking something or burning a hole in a piston/etc... the fun stuff :P also from what ive been reading & what ive heard an m90 with a good intercooler setup is right up the 3400's alley considering you are running such high compression & wont require high levels of boost to make your power. with your engine its not as much "how much boost" as it is how good of a tune, hell you could probably crank all the boost you want to it on 92 but without a good tune its pretty much pointless & possibly engine-damaging.

what youll need is: a wideband o2 sensor, boost gauge, & a/f gauge/display-you may also want a higher flowing fuel pump, misc oil lines for the supercharger, intercooler, intake piping, giant hole in your hood, cone air filter, higher flowing exhaust, possibly some sort of additional/new fpr (correct me on this one if im wrong), custom intake or customized intake, and a nice chunk of time

now lets see if you were paying attention, because theres one very big & important piece of info in that list to consider before attempting this (ill give you a hint, it aint the cone filter!!!)

also if you live in ohio-try to shy away from nitrous or keep it hidden well or you may get a ticket/your car impounded because its illegal here!

[ssdurango]

I have a 3.4 with an m90. 10.50:1 compresson, Running hyper pistons on the dyno I broke a ring land on the piston.. . With the new pistons, instructions where included to enlarge to ring endgap. I think the idea was the rings could expand the jam together and put extra stress on the ring lands. But with forged pistons, you should be fine. Do you know your endgap though?

[IsaacHayes]

mars man has a cam and a 3400 with a CSC and he is in the low 12's with a 2nd gen cav.

Go for it!

[Alxsmt]

i didnt even think about gap! i do not rember but im sure my freind does, he choose the gap to go with. how much boost are you running ssdurango?

i really wanna go for it, i think i will this winter at the latest. gotta research

[RedBird]

why don't you go with a remote mounted turbo setup? only differences vs front mount are longer oil and coolant lines, and charge pipes, BUT you don't need an intercooler. And you get to keep your headers

[IsaacHayes]

Yeah but headers are no longer going to be much benefit with a turbo on the end of the exhaust. The turbo will still provide back pressure which will probably negate any scavenging.

[95SleeperAcheiva]

Why does this opportunity keep presenting itself!?

Its one of the oldest jokes in car history!
How much boost?

You turn the blower all the way till the engine blows, then back it off a half turn, and it'll be dead on!

start around 6lbs. if this is street driven i wouldn't try for more then 9lbs.

I agree with everybody above (I like superchargers over turbo, tho). I personally would add an EGT gauge, watch your exh. temps. Watch knock, cool with intercooler, and spray her down with alcohol if she develops knock. Don't forget to retard the timing too.


Who was it that told that guy to port and polish a motor the easy way, "rev it up to 6k rpm and poor sand through the TB?" LMAO

[RedBird]

yes but even poorly designed shorty style headers show good gains over stock manifolds. blasting exhaust pulses down a nice, smooth tube with decent transitions is much better than slamming them into the side of a manifold, going 90*, then tumbling haphazardly down a rough, SMALL flow path :P

headers would definately not be negated with a turbo. if they scavenge good without a turbo they'll work decent enough with a rear mounted turbo, too.

[Alxsmt]

i just dont want a turbo on this engine. a supercharger would be better for what i do anyways

so do i advance the supercharger a few teeth for more boost? or just turn the dial?



thanks guys

[95SleeperAcheiva]

you could always run nitro methane fuel, 100% mix! You'll have tons of power for a few passes......Till your pistons slag anyway.

[IsaacHayes]

Oh yeah headers will still out flow manifolds even if they are not scavenging.