compression

Grinder34

Track Monkey
The compression ratio for OEM pistons is 8.2:1.

and for a compression test i think it should be something like 160 psi, but within 10 psi of eachother.

(not sure which you were asking about)
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
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Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
True.

9.0:1 seems to be the sweet spot. All in all though, (correct me if I'm wrong) 9.5:1 compression would require either e85, race gas or at least 93 oct. + meth injection, unless of course you are planning on running a little bit lower boost.

I figure that when I build my motor, I'm probably going to choose 8.5:1 pistons.

There are others here that understand this topic way more than I. Where's Fuji when we need him?

George? What do you think?
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
Hey Pancho, is this going to remain a daily driver? All I was saying was, I think with boost, 9.5:1 would require an incredible amount
of fuel or race fuel to prevent detonation. If you ran e85, you'd need even more fuel. I suppose if this is a track car, then go for it.
 
Hey Pancho, is this going to remain a daily driver? All I was saying was, I think with boost, 9.5:1 would require an incredible amount
of fuel or race fuel to prevent detonation. If you ran e85, you'd need even more fuel. I suppose if this is a track car, then go for it.

Thats the reason ethanol is even best for a daily driver. The alcohol has as good as or id say even better cooling properties then race gas. Way more stable then pump and meth injection. So there would be no worries of detonation or knock. You need boost or e85 isnt really worth spending the extra hassle of switching. If its not readily available that be ur only limiting factor. The reason u need more fuel is its 1/3 lighter (less dense) then pump gas. So the higher compression pistons you want is perfect for e85. Yea u will burn more then pump or racegas but u make up for it in cost per gallon. Its $.50 per gallon cheaper then 87 octane so thats .70 for us 93 folks :) Just what ive gathered from research and recmmendations before i decided to switch.....im not trying to make it a fuel discussion but i hope to help you take most advantage of the pistons you want.
 

Spamby

Meat Product Toy
At current prices here, I actually spend more per mile for ethanol than I do for pump gas. About .05 more per mile but its really negligible vs. the benefits gained.
I remember when it was nearly 2.00 per gallon cheaper, no more huge subsidies... those days are gone, sigh.
 
At current prices here, I actually spend more per mile for ethanol than I do for pump gas. About .05 more per mile but its really negligible vs. the benefits gained.
I remember when it was nearly 2.00 per gallon cheaper, no more huge subsidies... those days are gone, sigh.

:( but when you buy pump gas, you still have to add the cost of meth....and race gas is just stupid, lol.
 

Spamby

Meat Product Toy
:( but when you buy pump gas, you still have to add the cost of meth....and race gas is just stupid, lol.

Very true. If I had no access to ethanol,I probably would be on a bigger turbo, etc. Doing the math, it would take 10+ years to recoup the cost of going larger turbo and saving a nickels by using pump gas.
Ethanol = win in so many areas.
 

Panchosti208

New member
Ya sounds good i think 9.0:1 is good to i am using it as a daily driver nd idk wat bore size to go with . What the standed bore size
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
Methanol is pretty cheap. For me e85 is more expensive than 93 octane. I fill my 5 gallon methanol tank once a year or maybe even longer in between. Once I went 17 months between meth tank fill ups. I can get a 5 gallon can for about $50. It seems much more cost effective.
 
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Methanol is pretty cheap. For me e85 is more expensive than 93 octane. I fill my 5 gallon methanol tank once a year or maybe even longer in between. Once I went 17 months between meth tank fill ups. I can get a 5 gallon can for about $50. It seems much more cost effective.

:( that sucks how corn is more expensive for you.
 

Batmobile_Engage

Squirrel Meat Aficionado.
Staff member
Maybe it will change someday. I think when I do a motor build in the future, I'll convert for e85 and have a couple different tunes.
 
At current prices here, I actually spend more per mile for ethanol than I do for pump gas. About .05 more per mile but its really negligible vs. the benefits gained.
I remember when it was nearly 2.00 per gallon cheaper, no more huge subsidies... those days are gone, sigh.

the average price spread is 9%. Considering e85 requires 30% more demand. thats adds up to a few hundred $$$ on average in a year...
 
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