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lets here what you guys think
11to1 CR useing e98 fuel and boost? is that to much comp or will it be ok 408ci ls1 motor with a twin turbo set up
 

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What are your goals for the car?
I'm sure you can throw some boost at it, but how much exactly will take some testing.
I would think 12-14psi at least with no trouble assuming a good intercooler, a good tune and cold plugs.
For a dedicated track car with an a/w intercooler, you would be able to turn it up more of course.
FYI, I ran my old 10-1 iron head blow through 355sbc to 12psi with no problems.
 

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I do not see why it would be an issue. We have run up to 43 psi in our non intercooled lsx at 10 to 1 on e98. We went 6.95 at only 35 psi on the cathedral ports.
I plan to run pump gas E85. I am putting a set of 317 heads on a 5.3 out of a running 2003 suburban. Opening up the ring gap to .028, porting the oil pump, and using arp rod bolts. I can either leave the heads alone and I will have around 9.4 compr or I can have them milled slightly to get to 10.1. This is a daily driver that I will thrash every other weekend at the local drag strip. E85 is everywhere around here. I only planned on going around 15-20 psi of boost. My goal is a modest 5.80's in the 1/8. Would you leave the heads alone or mill them a little to up compression. I don't want to kill it driving on the street though.

Thanks. That 63 is wicked!
 

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I would leave them alone and run 9.4:1 as the gains going to 10:1 would be minimal. All upping the compression would do is make your tuning window a bit smaller. If you plan on running a really good intercooler then I would think about running a little more compression.
 

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Like hellbent said..... Beyond a certain point all the extra compression does is narrow the tuning window and limit how much timing you can run. Up to a point its helpful...past that its counterproductive.
 

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Like hellbent said..... Beyond a certain point all the extra compression does is narrow the tuning window and limit how much timing you can run. Up to a point its helpful...past that its counterproductive.
Thanks. Hey I just want to make sure I have this correct. I got the figure 9.4 while searching. A 5.3 block with 317 heads does figure to a 9.4 correct? Someone just mentioned to me it actually drop it down in the 8 compression range. Hmmm can someone set me straight?
 
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