Going Built Motor - Blew engine on track - Suggestions

[pgranberg11]

just from online shopping and doing the work myself vs. letting else someone build a shortblock for me, it's roughly about $1000 difference. And that was taking the cheapest parts for me to build myself. In my opinion I think it's a better investment to let MAPerformance or Full Blown build the short block because for the extra 1000, I KNOW everything will be done right, blue printed, balanced, assembled correctly, and have better internal components. In my opinion, I think that's totally worth the cost difference alone.

I would love to do LS swap, but I don't have any access to fabricate anything, ie machine shop, welder, etc. Plus, if I were to do that, I would like to retain all stock functions/gauge clusters. One can only dream; but as far as I've seen the LS swap isn't100% yet in my eyes.

[pgranberg11]

Originally Posted by solus

im making 435hp on AVO's turbo.

Carrillo rods
CP pistons 12.5:1
Kings Bearings
ARP 1/2" head studs, main
Supertech valves and springs


16psi E85

I have lower boost settings for 91

what made you stick with stock compression ratio just out of curiosity?

[Sportsguy83]

Originally Posted by pgranberg11

what made you stick with stock compression ratio just out of curiosity?

There is no reason to lower compression if you plan on running E85 and under 20 psi. You're just hurting the performance out of boost and while spooling. E85 is incredibly knock resistant (and burn cooler which also helps prevents knock) which is the concern when running pump gas, high boost and high compression.

[solus]

Originally Posted by pgranberg11

what made you stick with stock compression ratio just out of curiosity?

E85 has greater knock protection and additional cooling, to allow better resistance to higher compression. combined that with the exactness of direct injection and there really is no reason to go lower CR. I do run a lower boost setting for 91 though... because sometime E85 isn't available

[pgranberg11]

Originally Posted by Sportsguy83

There is no reason to lower compression if you plan on running E85 and under 20 psi. You're just hurting the performance out of boost and while spooling. E85 is incredibly knock resistant (and burn cooler which also helps prevents knock) which is the concern when running pump gas, high boost and high compression.

I see. I take it when you say spool, it's both applicable to a supercharger and a turbo, correct?

[Fred E]

Originally Posted by pgranberg11

I see. I take it when you say spool, it's both applicable to a supercharger and a turbo, correct?

Kind of, although superchargers don't technically "spool" as the boost they make is entirely dependent on engine RPM. However lowering the compression of the engine while running a supercharger will considerably reduce the power that the engine is able to produce. The only real reason to lower compression with a supercharger build is to increase safety (i.e. reduce the chance of knock) for when you have to use pump gas. If you're certain that you're going to be using E85 (or technically any mixture greater than about 50%?) you'll be perfectly safe keeping the stock compression since the ethanol in the fuel will greatly reduce the chance of knock like @Sportsguy83 mentioned.

The reason people typically lower the compression ratio is because they're not certain they'd be able to use higher levels of ethanol in their fuel 100% of the time. A lot of turbocharger users still lower the compression a bit because they can simply have their tune adjusted to electronically control boost levels dependent on the percentage of ethanol in their fuel. There's no real way to automatically adjust boost levels on a supercharger aside from swapping to a smaller pulley.

[pgranberg11]

Originally Posted by Fred E

Kind of, although superchargers don't technically "spool" as the boost they make is entirely dependent on engine RPM. However lowering the compression of the engine while running a supercharger will considerably reduce the power that the engine is able to produce. The only real reason to lower compression with a supercharger build is to increase safety (i.e. reduce the chance of knock) for when you have to use pump gas. If you're certain that you're going to be using E85 (or technically any mixture greater than about 50%?) you'll be perfectly safe keeping the stock compression since the ethanol in the fuel will greatly reduce the chance of knock like @Sportsguy83 mentioned.

The reason people typically lower the compression ratio is because they're not certain they'd be able to use higher levels of ethanol in their fuel 100% of the time. A lot of turbocharger users still lower the compression a bit because they can simply have their tune adjusted to electronically control boost levels dependent on the percentage of ethanol in their fuel. There's no real way to automatically adjust boost levels on a supercharger aside from swapping to a smaller pulley.

Ok that's what I was thinking when he meant something like that. I figured I just didn't want to miss anything. I suppose I will keep the stock compression. The only time the car will ever see 93 is when it's being stored through winter. So I guess the car will probably see 1-2 full tanks of 93 when it's finished.