Sr22Det pistons

[thurman548]

I ordered my 90mm pistons and rods from Enjuku but told him to hold off on shipping the order. I been having a few thoughts about comperssion. Right now I am thinking about going 9:1 instead of 8:5 to spool the Gt35 turbo faster on the twin scroll manifold by fullrace. I am not sure anymore if I want to go 9:1 or 8:5. Anyone have any suggestions or know anyone who has built there bottom end with 90MM pistons and 9:1 compression ratio? Anybody with a list of pros and cons would greatly help me decide on which way to go. I will also drive the car alot on the streets also. Thanks

[GSXRJJordan]

9:1 - pros: better performance off boost
cons: max boost is lower at the same max cylinder pressure

8.5:1 - pros: more boost
cons: worse performance off boost

I don't understand what's so hard? Tell Enjuku or the shop that's building the motor what kind of power and powerband you're looking for, and they'll tell you what you need. For reference, bored/stroked SR's at ~ 18psi are putting down mid 400's to the wheels on smaller turbos, with GREAT powerbands (Rossta S15 for instance). With 9:1 and 18psi, you're looking at around 500hp with decent performance off-boost... going to a GT30xx would help even more, but you probably know that.

[screaminfast]

Go with the 9:1 pistons. It should help spooling and as Jordan said above, it'll help performance off boost.

[fliprayzin240sx]

Well the problem is running higher comp is that you wont be running that high of a boost, is it gonna be high enough to get into the efficiency range of the turbo?

[screaminfast]

Well the problem is running higher comp is that you wont be running that high of a boost, is it gonna be high enough to get into the efficiency range of the turbo?
I suppose you could run more boost, but it would require better fuel haha :)

[Teambadrun]

well
it depends on fuel
and your tuner

but why not go custom order cp and mix it up and get 8.8 compression?? it might not even be worth it

with a GT35 you want big boost so just get 8.5's and you will be done .. because you need 1.5bar to make the GT35.40 to work properly.. you should see 400-450rwhp at those boost levels with high lift high duration camshafts

GL HF

[s15specR]

I'm doing the same setup, BC Crank and CP pistons (haven't ordered the psitons yet either) and from what I understand you'll want to be in the efficiency range of the turbo or get a turbo that you will be better suited if the pistons prevents or vice versa

[thurman548]

I am going with the 8:5 the bore and twinscroll should help out with the lag. Flipray you might not remember me but this car was orginally your boy's s14 that sold it to me when I PCS'd from Kadena. The white one.

[fliprayzin240sx]

I am going with the 8:5 the bore and twinscroll should help out with the lag. Flipray you might not remember me but this car was orginally your boy's s14 that sold it to me when I PCS'd from Kadena. The white one.

Jesus' car?!?! That shits been ages ago...like 5 yrs ago hasnt it? Well he can thank you later cuz he used that money to build his 280Z and stuff it with an RB25det...I hope its in a better shape now compared to when you first got it....:p

So wait...90mm, what sleeves are you going with and how much is it gonna cost you to get the block machined?!?!

[thurman548]

Yup. I could not remeber his name for the life of me. Most likely Darton sleeves not sure yet about the block. The car is sitting in storage until I PCS back to the states this Jan. He do you know my boy Vance over there? He drives a red flared miata and works at the comm sq by schilling center oh the good old days lliving in Marek Park by gate 1. Hope you are having a ball out there. Tell Jesus I said whats up and want to see the 280z. I just picked up a z32 tranny for my car.

[Zerolift Autolab]

It all depends on what power levels you are trying to achieve.
Aswell as the purpose of the vehicle, race use, street use ... etc

[fliprayzin240sx]

Yup. I could not remeber his name for the life of me. Most likely Darton sleeves not sure yet about the block. The car is sitting in storage until I PCS back to the states this Jan. He do you know my boy Vance over there? He drives a red flared miata and works at the comm sq by schilling center oh the good old days lliving in Marek Park by gate 1. Hope you are having a ball out there. Tell Jesus I said whats up and want to see the 280z. I just picked up a z32 tranny for my car.

Thats funny, I work CS...but I havent seen any red miata running around here, atleast not for the CS. Hell, I even live in Marek Park. Where you at right now?

Anyways, small world...good luck with the build. Just curious, what else has been done to the car since you got it.

[thurman548]

I at Ramstein AB, Germany. For the car, I picked up some Tomei Cams 260 pro cams, jun surge tank (from vaughn gittin s14), supertech dual valve springs and valves, cp pistons, rods, full-race twinscroll manifold and aem ecu with wideband. I am pretty sure he has the miata still. Do you work near the terminal or where the command staff sits. Vance works on GCCS across from the tech control room. Man I really miss the dragon cheap food. what do you done to you car. They still drifting at the dock and draging on 58? It is a small world.

[fliprayzin240sx]

Nah, I work up on the hill by Chili's, where the golf balls are at, maintaining terminals for the weather satellites out here. Driftings pretty much dead out in Aja, dragging has been bust too. I just go on touge drives nowadays...