KAOS

iTrader: (5)

think that is too high for a turbo set up? running no more than 15psi. and it is completly forged...rods, crank and pistions. will be running stock 6l heads and zo6 cam. let me know what you guys think

bboyferal

iTrader: (9)

Why not lower? What size cubes?

KAOS

iTrader: (5)

stock cubes. its one that w2w has made up and i cant get them to change the pistons at least not yet. waiting to hear back from them. they its callies crank compstar ronds and mahle pistons. compression would be around 9.3-1. this way i wouldnt have to worry about the bottom end anymore. wanting to see what everybody thought about that compression. frcefed98 runs 9.1.

bboyferal

iTrader: (9)

With a VERY low compression (8.5?) on stock cubes (forged), I was told to expect reaching only 700 rwhp or so on pump... I really would like some input on your question so I can start buying parts already for my car...

KAOS

iTrader: (5)

some body will chime in eventually with a good answer. i need to know asap.

Boostaholic

iTrader: (4)

Well its not ideal having that much compression at all, I really like 8.5:1, my current motor is in the 9's but I am planning to replace the pistons and get myself around 8.0:1 this year.

Also, I don't think 8.5 should be considered "very low" for a F/I vehicle, it seems like a good solid number to run at.

KAOS

iTrader: (5)

so really 9.3 is just too high? especially for 15psi?

Smearin

9.3 is good.. Are they using stock pistons.. and 6.0 heads?

KAOS

iTrader: (5)

mahle pistons and stock heads. its in the sponsor sale section. callies crank, callies rods and mahle rings. and with 6l heads kevin said it would be around 9.3 to 1. so can i make it to 15psi on pump gas or not.

bboyferal

iTrader: (9)

Kaos, you're gonna get some answers. So, please don't mind if I start pm'ing you a bit, alright?

Big Geek

iTrader: (2)

Nothing wrong with 9.3:1 so long as you ease into the boost levels while keeping an eye on the O2's and KR. Utilize a dyno with a wideband O2 if possible. Once you find the limit of the psi on pump gas you could always adjust it a pound lower to be on the safe side. Then repeat the process with some high octane fuel or methanol injection for the track setup. I have seen folks with 9.5:1 run 26-28 lbs using a progressive methanol setup and pump gas, but keep in mind that this was done with an EXCELLENT intercooler and ignition as well as a turbo that was properly sized for the C.I.D. Hope this helps.

Jim C.

PS-Very good quench is part of the key to getting away with those compression ratios with a turbo.

Tiago

iTrader: (27)

I run 9.4CR at 700 rwhp on pump gas at 12 psi.

Scalpel

iTrader: (4)

It'll be fine for your duties. You aren't shooting for 700+ RWHP.

RyanJ

For the price of that 347, do it! 9.3:1 will be fine.

bboyferal

iTrader: (9)

Cubes?

Slowhawk

iTrader: (12)

I'm sure you ran past them the boost level? Just make sure that piston/rings is made for the boost. You could also run a different Cam that will bring down the DCR.

Pro Stock John

iTrader: (34)

15psi.. go for it. Run ARP head studs too.

frcefed98

iTrader: (16)

You'd be fine on 9.3 and a great tune at the power levels you want to run, head stud it like PSJ said.

My 9.1 is more like 8.1 due to us being up here a mile above sea level

KAOS

iTrader: (5)

what would be max power on 9.3? with pump gas? without upgrading fuel system at the moment

LSs1Power

iTrader: (5)

Im running 11psi on pump gas with 10.1 C/R Stock motor with no KR with around 13 degrees of timing. I think you might be able to get away with 15psi on pump gas with that C/R, but will most likely run low timing. My car gained 50rwhp by increasing 4-5 degrees of timing (100 mix with pump gas). So you will most likely need Alky to run 15psi on 9.3 C/R and some decent timing to make power. Just be careful when u tune it for the first time and monitor KR and A/F.