elias_799

iTrader: (8)

you do not need to change pistons to lower cr. try to see if anybody makes bigger combustion chamber heads for you motor or get a machine shop to open them up, also thicker head gasket will help. this would be much cheaper then removing the motor and replacing pistons.

the only reason why i went with that low of CR is because i wanted a strictly pump gas/ high boost street motor.

ddcarter

iTrader: (14)

Engine is not in yet. I wont be able to supercharge it until later this winter. I was/am hoping to run a high compression engine. Thats is why the low boost. Not ready to go with supercharger only engine
Dustin

obZidian

iTrader: (2)

Well, if the motor is not in then you would need to address it as soon as possible. Since you will be running N/A for a while... you could, potentially, go to a 10.9 CR and still be funky n/a. However, with that CR, you should still be able to hit 700-800rwhp on pump with meth... maybe more... some guys are hitting 740rwhp+ with a stock bottom end LS7.

Good luck!

calongo_SS

iTrader: (7)

You should be pretty safe with 8-10 psi and lots of methanol.

elias_799

iTrader: (8)

^^^ yea, and a very good tune

ddcarter

iTrader: (14)

My only choices right now are stick with what I have, drop to 10.9 or 9.2. I am afraid if I go with the 9.2 it will be to doggy to even drive N/A. I may just have to wait until I can get it all purchased.

elias_799

iTrader: (8)

i would do it the way you actually want it done. that way you will be truly happy with it and do not have to spend time on redoing everything.

Fb0dy0nly

iTrader: (10)

Why dont you just drive the NA engine until you really really want that boosted LSx and do a whole swap? Sell the NA motor and get a built boosted motor that will be ready to handle anything. Dont waste the hassle of having to baby an amazing motor just for a few pounds of boost. Do it right and you will be much more pleased with your results instead of fudging it to get where you want, only to realize a few months later, damn!, I want more boost but cant because my engine will blow if I raise it up...its just the nature of a car junky.....you willl want more.

ddcarter

iTrader: (14)

I ended up buying a D1-SC. I have taken in the advice and am going to reduce my compression. My question now is 10.5 low enough or should it be lower? Thanks, Dustin

95lsxss

Umm D1 on a 427 is a lil small aint it?

Haans249

iTrader: (24)

This is too easy my friend:

Your D1-SC is MUCH too small for your motor, sell it and fund a F1-C/F1-R.

Shoot for the 9.2CR pistons, and mill the heads for ~9.6-9.7CR - run 15-20psi, make 900rwhp if you can hold the heads down. 1,000rwhp is you want to start to break things.

BLNLS1/RX7

iTrader: (2)

Yes you can.

ddcarter

iTrader: (14)

I know what you are thinking. I got a good deal on the D-1. I plan to swap it later for a F1. Baby steps. The car has been stock for the last year. Just want to get something in it.
I would consider a different ratio but I need lightweight pistons. That way I do not have to have it rebalanced.
Does anyone know of 4.130 bore pistons around 430 grams?

Haans249

iTrader: (24)

No matter what, it will have to be rebalanced. Its not just the pistons weight that matters.

ddcarter

iTrader: (14)

If the rings clips and pins all weigh the same shouldn't the balance be the same?

Grr

iTrader: (2)

why dont you just build the fuel system for E85 and run the high compression motor on 8-10psi? It would handle that like nothing, unless its not availible in your area, but in KS i would assume its plentiful. you should be able to max that D1 out on that car in the first pull or 2 and then you will have to replace it anyway. Go F1 or A&A YSi kit and you could do a solid 800whp on E85 with your high compression and not have to spend a dime on your motor

ddcarter

iTrader: (14)

E85 is available here. The problem being is I like to roadtrip. I don't want to be stuck somewhere I can't get fuel. This is a street car. No need to run around with the D1 maxed out. Traction is my biggest problem anyway.