Anubis_4_99

bump for a compression answer because im ordering parts tomorrow

zex_cool

i'd go w/ 9.5:1

Anubis_4_99

do you have any experience or heard of any good experiences tuneing at 18psi on 9.5:1 CR though?

im not gonna go as drastic as the 7.8:1 but i've been thinking about 8.5:1 or 9:1 to help keep detenation away

zex_cool

nevermind im an idiot

i just played with some numbers 8.5 seemed good but as a DD it will suck. you wont be like HOTSEX running 21psi daily hahaha
so it will be slow with 12 or w/e psi you drive it daily. so i really dont know, hopefully someone with real experience gets around to this thread.

Anubis_4_99

i probably will run upwards of 18psi daily once the motor is broken in actualy, untill then it'll be 10psi

its not slow now at 12psi so i dont see why it would be so much worse with a CR of 8.5:1

im mostly concerned about detenation and tuneing issues, i'll probably just keep the stock CR unless someone wants to explain why higher or lower would be better

btw i wasnt sayin you were an idiot or anything, lol, was just asking if you'd had any experience, dont like makeing decisions like that without first hand accounts

noboostedEGo

If you're really worried about it, just get 9:1, it's probably the most commonly used cr for a forged dseries piston. Higher compression is good because it'll be more responsive out of boost and will make the same power on lower boost, but it is more prone to detonation (This is only a factor if the tune is bad). Lower compression is just safer, that's the only benefit, you can run more boost with less chance of detonation than high cr. There's no performance gain.

If you're looking into a cheap turbo for 300hp, maybe look into a larger borg warner or a holset perhaps.

raiden571

id say the sleeves are gonna be fin on 300whp. i would suggest 9.5:1. as long as ur tuner isnt an idiot, he shouldnt have to worry about a cr like that and neither should you. id say a small t3/t4 or a super 60 t3 would be good. i had a 48/60 t3 on my d, it spooled hella fast but fell off up top. maybe like a 50 trim with 48 exhaust

Anubis_4_99

im gonna be the tuner....

im just gonna use this as a for instance for a turbo, im not actualy lookin at buying this one, but would one like this be good for my setup?

http://cgi.ebay.com/ebaymotors/T3-T4...QQcmdZViewItem

noboostedEGo

Search xspower and then you tell me. :P

Anubis_4_99

i said as a for instance, im not buying xspower, i was refering to the AR's