hey guys im building my motor again and have my old 9:1 cp pistons, but got a set of 11:1 cp pistons too, i was woundering if i should do high comp with less boost since im uesing a 6262 with a 82ar, the block is bing sleeved from erl so i would appreciate u guys inputs would like to get the most power out of the setup

 

whats your definition of "the most power of the setup"?

whats the power goal, what is the car going to be used for? DD, season drag? planning on having the car reliable? Pump gas? race gas?

11.1 compression with a turbocharger is a ticking time bomb, especially if its going to be Daily Driven on pump gas. thats why you dont see many people turbocharging a stock type r engine ( i say not many, because there are a couple builds here on HT like that ).

thats why everyone opts to lower compression for the ability to bring up boost pressures. As shawn church told me, it makes tuning a little easier, because the higher the compression, the less room for error there is.

but it all depends on your goal for the car. for "the most power" the 11.1 is going to make "more power" than the 9.1 counterpart at the same boost levels, but its also going to have higher cylinder pressures.



TheShodan should be here soon enough to clear it all up. Youre going to have to provide more details though

whats the whole setup? supporting mods?

 

should be gettin tuned in a few weeks will let you know how my 12.5:1 does with a 6265(q16 only)

 

I would like to know what this ends up putting down at full boost.

 

Thanks for info but the car is for the track only the set up is a Full gsr,the head has skunk2 valve train with Mazworx turbo cam, the block is being sleeved at erl for 81mm stock bore, the crack has all color coded bearing from Honda,turbo 6262 82ar top mount 44 mvr wastegate, fuel is a 255 intank and a 044 inline 8am freed and 6am return with 1600 injectors automotive fuel regulator Aem fuel rail, the car is on Aem and has boost by gear, already made 550 on 20psi but wanted more power so I took the block to get sleeved, want to get like 650 or more

 

should of went with a 84mm bore.

 

run the 11:1 and dont back off the boost.

Just treat it like any other engine. Unless you are building a street gas car, its not going to be a ticking time bomb and will perform just fine at even 30+ psi

 

The car made 550 on 20 psi when it was on 9:1 comp on stock sleeves

 

Thanks for the help guys im gonna just run the 11:1 but what kind head gasket should I use or what kind of head studs

 

stock and golden eagle? Golden eagle also modified stock gaskets to fit other bore sizes.

 

I'd want something right between 9 and 11:1 if your ever going to run pump. If strictly race maybe go 11:1 if more likely always pump go 9.

Both will be a compromise to some extent. Sell both sets of pistons and buy 1 suitable set.

 

we have a car thats tuned for 500 on 93 octane and 700 on race gas....11.1:1 comp and it runs just fine.

if you can switch the tunes around with a laptop then youll be fine.

 

The car is only for the track and always gonna be on race gas

 

11:1 will be fine. It won't be a ticking time bomb unless your running a fmu lol. You should be able the 650 without an issue

 

Run the 11:1... your on race gas and AEM, no reason not to.

 

i take that back its 11.5:1 i must have misheard what my engine builder said. here you go 30-31psi mustang dyno

http://www.youtube.com/watch?v=SUL-s...layer_embedded