bore over on a turbocharged quad?

[chucky797]

i am looking on ordering parts soon for the quad. first i would like to get a 426 bore kit, what do you think that at a 10 to 1? or 11 to 1. i would be running straight race gas. here is what i am looking at. i would like your sugestions.

426 bore at 10 or 11 to 1
hd stud kit
port and polish
forged connecting rod
a +1 sprocket
with my tax return coming i might get a +2 a-arms and a +2 rear axle.

now lets hear some company names where i can get some of this stuff and you sugesstions. the only reason i want to go to a 426 is push more air out the exhaust and spool the turbo faster.

[ImplodedMindZ]

Just qurious what compression ratio you are runnin as of now w/ the turbo setup?

[Ncboost]

What size is the exhaust housing? You could go smaller that way.

[chucky797]

it currently has a low compression. i belive a 8 or 7.2 to one. i don't know the exhause housing at this point.

[ImplodedMindZ]

Originally posted by chucky797
it currently has a low compression. i belive a 8 or 7.2 to one. i don't know the exhause housing at this point.
I would be very carefull when you start messin w/ upping the compression that much in a turbo motor. If you raise the compression ratio that much you are going to have to substatially reduce the amount of Boost you run. Hence why cars that are changed over from N/A to turbo can only run 4-7psi due to the higher comp pistons. Where as cars like eagle talons and SRT4s that come w/ low compression ratio pistons can run 15-25psi on stock internals.

[scruff_mcruff]

Originally posted by ImplodedMindZ
I would be very carefull when you start messin w/ upping the compression that much in a turbo motor. If you raise the compression ratio that much you are going to have to substatially reduce the amount of Boost you run. Hence why cars that are changed over from N/A to turbo can only run 4-7psi due to the higher comp pistons. Where as cars like eagle talons and SRT4s that come w/ low compression ratio pistons can run 15-25psi on stock internals.

huh? we run 15 psi on 10:1 street motors all day. boost is limited in most apps cause the rods cant handle it.

the thing you need to worry about w/ turbo motors is cylinder pressure. if you bore it to a 426 on a stock sleeve and have high comp, its going to crack the sleeve period. get an aftermarket sleeve and keep it a 406-416 then put the good head studs in and you should be ok from there. the extra 10-20ccs of a 426 is not going to spool it much faster, the compression will help spool it quicker than the extra cc's. and it will have more to do with your exhaust housing and what trim wheel.

[ImplodedMindZ]

Originally posted by scruff_mcruff
huh? we run 15 psi on 10:1 street motors all day. boost is limited in most apps cause the rods cant handle it.

the thing you need to worry about w/ turbo motors is cylinder pressure. if you bore it to a 426 on a stock sleeve and have high comp, its going to crack the sleeve period. get an aftermarket sleeve and keep it a 406-416 then put the good head studs in and you should be ok from there. the extra 10-20ccs of a 426 is not going to spool it much faster, the compression will help spool it quicker than the extra cc's. and it will have more to do with your exhaust housing and what trim wheel.

I would imagine all the major auto manufactures & their engineers of turbo engines know nothing about motors since they dont run anything close to 11:1 compression. Im just sayin be careful dont wanna blow your new turbo toy.

I was mierly stating the proper changes need to be made to the turbo setup if he does this and wants a "reliable" motor. and not something that will go like hell for a while and blow apart. Its a fact if the compression ratio gets raised the boost will have to be lowered, and much higher octane fuel will have to be used which he already knows and stated would be used.

I know chucky you said you are gonna be running forged rod, is that what is in it now? or is it still runnin the stock rod?

[scruff_mcruff]

Originally posted by ImplodedMindZ
I would imagine all the major auto manufactures & their engineers of turbo engines know nothing about motors since they dont run anything close to 11:1 compression. Im just sayin be careful dont wanna blow your new turbo toy.

I was mierly stating the proper changes need to be made to the turbo setup if he does this and wants a "reliable" motor. and not something that will go like hell for a while and blow apart. Its a fact if the compression ratio gets raised the boost will have to be lowered, and much higher octane fuel will have to be used which he already knows and stated would be used.

I know chucky you said you are gonna be running forged rod, is that what is in it now? or is it still runnin the stock rod?

you are comparing apples and oranges.he is not putting a stock factory motor w/a warranty in the bike. the fact that your points are what a stock motor is capable of is furhter irrelevant if he isnt using EFI. do you have any blow thru carb experience? do you even have any experience w/ turbo motors at all?

whats abuilt 400 8 or 9:1 motor gonna handle maybe 10psi. ill take a 10.5:1 motor w/7-8psi any day over the low compression setup.

[ImplodedMindZ]

Originally posted by scruff_mcruff
you are comparing apples and oranges.he is not putting a stock factory motor w/a warranty in the bike. the fact that your points are what a stock motor is capable of is furhter irrelevant if he isnt using EFI. do you have any blow thru carb experience? do you even have any experience w/ turbo motors at all?

whats abuilt 400 8 or 9:1 motor gonna handle maybe 10psi. ill take a 10.5:1 motor w/7-8psi any day over the low compression setup.

I do not have any experence w/ blow through carbs, but have a good amount of knowledge w/ turbo motors. I spent alot of time workin, modding, and tuning my own Eclipse GST. Unfortunatly i dont have as much experience as you but i know the basics.
This is a lost cause, good luck chucky hope the build up goes well. Keep us up to date on how it turns out.