I have an ecotec motor and i would like to run with high amounts of boost. I would need to to do work to my block, like lower the compression ratio. The only only problem is i can't pay for all of that at once.

I'm not sure if i should do my block before or after boost. My question is how much does compression ratio affect power(in this case 10:1 to 8.9:1)? Is it a significant amount of power loss? If so I'll boost first, then do the block.

Also when i do work on the block, what all should i do: bore, stroke, connecting rods, and pistons?

If I were you and I wanted to build a boosted car.... first I would look into getting lower compression oversized .020" forged pistons, like JE or wiseco, then look into eagle rods and a set of oversized clevitte 77 main and rod bearings. ARP Head and Main Studs. The ISC Titan Headgasket from SCE and a nice set of valves and springs and good set of cams. When you have all this aquired, I would stick it in my closet and start building your turbo setup. When you have everything take the engine out and take it to a machine shop. They can bore the engine to the size of the pistons to get the best fit and they can ground the crank to the size of the bearings. Then you have a engine that can easily handle 12 psi and you will have a very nice setup. Total price for it all, around 5 grand assuming you have some mechanic skills. Raising the compression is a bit trickier. If you raise compression to high you will have to run race gas all the time.


96 All motor 5 Speed Z24, Best time 15.97@86MPH

I guess you are saying do the block first. If i do that, i wont run it with boost at first, since ill need to save money. I was wondering how much will a lower compression affect the power n/a?

I saw get a turbo setup, and run it at low boost. That way you won't lose power, and then do the block. after the turbo is in, and fully tuned, working great. etc.

or buy all the parts you need first and tuck them away in a closet like ahitz said. Then save the money to work on your block and when the work on your block is done, put all your parts on.

Quote:

I guess you are saying do the block first. If i do that, i wont run it with boost at first, since ill need to save money. I was wondering how much will a lower compression affect the power n/a?

Do it all at once, you can make a week and a half job out of it putting everything on. Or if you want to build the engine first... depending on the amount of boost you want to run, (Higher boost means lower CR) is how much power you will lose NA.... For example, your car is 9.5:1 stock I think, if you lower it to 8.5:1 then that is a substantial loss in power until you boost it.


96 All motor 5 Speed Z24, Best time 15.97@86MPH

Ok, i guess ill buy the turbo, and wait till i have enough money for the block. I already have the top end of the motor done. Its just really going to suck having a turbo, but its not on the car.

For my other question, what all can i do to the block besides a .02" overbore, lower compression, and connecting rods or is that pretty much all that will help?

Thats all you should need to do to the engine. I would hold off on getting the bearings for it, or at least order stock size bearings. Then you can plexi-gauge them, to make sure your within clearance. I had 50k miles on my 2.4, and only needed stock size bearings. (YOU SHOULDNT NEED OVERSIDES BEARINGS, UNLESS YOU HAVE A MESSED UP CRANK)

I say boost now, build later.....




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