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View Poll Results: Whats the best CR to have for 15-22 pounds of boost?
11:1
8
2.87%
10.5:1
4
1.43%
10:1
20
7.17%
9.5:1
59
21.15%
9:1
67
24.01%
8.5:1
95
34.05%
8:1
26
9.32%
Voters: 279. You may not vote on this poll

CR for big boost...

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Old Mar 5, 2008 | 02:10 PM
  #101  
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Originally Posted by rufretic
Lol, I don't know how to else to say it, "race gas" is for racing. If the pole was "what CR for a high boost daily driver" I would agree with the results. Most of the people that vote in these poles don't know why they pick what they pick in the first place, it's just an opinion. Just because a pole shows alot of peoples opinions, it sure doesn't make it the right choice.
So what you are saying is that all the people who didn't vote the way you would, don't really know what they want, and don't know what they are voting for in the first place?

Who said race gas is for racing? The poll doesn't specify either way. It just asks a certain question under the parameters given. It doesn't say for most power as you keep bringing up, or for a track only car, it says whats the best CR for a car with high boost and race gas, period.
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Old Mar 5, 2008 | 02:51 PM
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Originally Posted by CALL911
So what you are saying is that all the people who didn't vote the way you would, don't really know what they want, and don't know what they are voting for in the first place?

Who said race gas is for racing? The poll doesn't specify either way. It just asks a certain question under the parameters given. It doesn't say for most power as you keep bringing up, or for a track only car, it says whats the best CR for a car with high boost and race gas, period.
Your right, 8:5 is the BEST because the pole doesn't lie. Everyone doing a boosted engine should use 8:5.
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Old Mar 5, 2008 | 02:58 PM
  #103  
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Originally Posted by rufretic
Your right, 8:5 is the BEST because the pole doesn't lie. Everyone doing a boosted engine should use 8:5.
Just because we don't agree with your opinion with running risky high CR with high boost for power and un-reliability, doesn't mean we the majority are wrong.

If anything, you should be wondering why is most everyone disagreeing with you.
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Old Mar 5, 2008 | 03:01 PM
  #104  
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LOL @ This thread.

Since when is higher compression automatically "unreliable" ?
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Old Mar 5, 2008 | 03:04 PM
  #105  
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Most people are sheep and I like it that way. I'm done with this post, it's going nowhere.
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Old Mar 5, 2008 | 03:04 PM
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Originally Posted by 1BadAction
LOL @ This thread.

Since when is higher compression automatically "unreliable" ?
That would depend on what your idea of "high compression" actually is. Under high boost, even on race gase you will only be able to go so high before detonation happens. The higher you go, the more dangerous it becomes. Not saying 8.5:1 is the highest you can go by any means, as most of us well know you can go higher, even reliably, however if you get up there to past say 10.5:1 and high boost in the lower 20's to high teens, then you will be looking at a rebuild in your near future, especially if on pump gas.
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Old Mar 5, 2008 | 03:29 PM
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Originally Posted by eb02z06
I know what you mean bro-for example a friend of mine got talked out building his forged 347 at 10.1(they built to be 8.8.1)-then he wondered why he couldn't make the same power as I did cause he couldn't push the blower any further. So he got fed up and swaped over to smaller CC heads and picked up over 50 rwhp with ALOT less timing and fat tune. He's happy now and says the throttle response is sick!
LOL, this thread has me thinking again, LOL

Last night I was scoping out the different style heads and smaller CC volume's to up my CR if needed down the road just like above. If I ever get bored and/or frusterated wth my 8.5, I'll swap to some ported and smaller cc heads to up it to 9-9.2 or so. I think I'll be satisified, well for awhile anyways and want to leave it on pump with meth.

If I do change down the road not only will I pick up over the higher CR but will also make it worth while with some really nice AFR's or ETP heads. Personally 9.5 is the highest I'd go, even on race gas but thats just me. All in all you can't simply argue with the fact that the higher the CR the more efficient and more power you'll make. The only arguable variable is realiability and only few are willing to compromise that which is reasonable since FI isn't cheap. Either way it will make allot of power, the one will just make more.
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Old Mar 5, 2008 | 04:12 PM
  #108  
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It all depends on how you want your engine to run. I would want the highest compression ratio safe for my target boost pressure and power goals. Fortunately for me thats stock CR. Higher CR will spool the turbos quicker and with a low boost street setup thats optimal. Race gas is meant for pushing the limits so more boost and more compression = more power. If youre only running 22psi on a 8.5:1 engine and race gas you will be far from your potential but very safe
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Old Mar 5, 2008 | 10:32 PM
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I personally think 8.5, for our motors I think your better off. It's easy to add boost and little to gain by adding compression. We have head gasket issues as it is.
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Old Mar 5, 2008 | 10:39 PM
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Originally Posted by Johawk
It all depends on how you want your engine to run. I would want the highest compression ratio safe for my target boost pressure and power goals. Fortunately for me thats stock CR. Higher CR will spool the turbos quicker and with a low boost street setup thats optimal. Race gas is meant for pushing the limits so more boost and more compression = more power. If youre only running 22psi on a 8.5:1 engine and race gas you will be far from your potential but very safe
Only 22 lbs= safe, lol. Well at 23 lbs I run 8.20's at 8.9 to 1. Go ahead and ask me how many sets of head gaskets I've installed!
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Old Mar 5, 2008 | 11:48 PM
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Originally Posted by LASTLS1
Only 22 lbs= safe, lol. Well at 23 lbs I run 8.20's at 8.9 to 1. Go ahead and ask me how many sets of head gaskets I've installed!
You bring up another good point on why the higher cr is my choice to go with. Your car obviously makes good power, what do you think it would do with a little higher cr and a little less boost. You would still make about the same power and not have the issues that come with high boost. I personaly don't like changing head gaskets.
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Old Mar 6, 2008 | 08:38 AM
  #112  
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Originally Posted by rufretic
I'm going 10:1 with my 408 but I'm trying to go fast not make a certain amount of boost.
Have a good supply of head gaskets on hand!
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Old Mar 6, 2008 | 08:43 AM
  #113  
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Originally Posted by rufretic
You bring up another good point on why the higher cr is my choice to go with. Your car obviously makes good power, what do you think it would do with a little higher cr and a little less boost. You would still make about the same power and not have the issues that come with high boost. I personaly don't like changing head gaskets.
That's EXACTLY why I say lower compression. Boost is more friendly than compression. If you (don't) like changing head gaskets this is one piece of information you might what to listen to. Btw, I run C16. Then again, you can do it your way and show me how it's done.
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Old Mar 6, 2008 | 08:43 AM
  #114  
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With a centri and running on a 8 rib belt, higher CR is obvious. You'll run into slip before you can push the blower hard enough to make double digit boost numbers.
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Old Mar 6, 2008 | 09:12 AM
  #115  
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Originally Posted by eb02z06
With a centri and running on a 8 rib belt, higher CR is obvious. You'll run into slip before you can push the blower hard enough to make double digit boost numbers.
Not with the right setup. There are tons of guys out there making 20+ psi at 900+ rwhp on a 8 rib drive system. Look into the NMRA Real Street class... they are limited to 8 rib drive, P1SC-2 blower, an NO intercooler. They are going 9.70's with a 2V 4.6.

Here is a video of a car that now makes 30 psi consistantly on an 8 rib belt (the video was before they pullied it up more).

http://www.youtube.com/watch?v=nnPNEJJe0DU
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Old Mar 6, 2008 | 09:15 AM
  #116  
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Originally Posted by LASTLS1
That's EXACTLY why I say lower compression. Boost is more friendly than compression. If you (don't) like changing head gaskets this is one piece of information you might what to listen to. Btw, I run C16. Then again, you can do it your way and show me how it's done.
I always thought it was the added boost that causes them to go because those are the only people I've heard having issues. Plus your turbos run a lot hotter than my procharger will, which I thought I remember making a difference on when you start to blow gaskets. Doesn't the added heat cause detination, causing gaskets to blow? I'm not sure, I'm not a mechanic but I do a lot of research so I can try to make reasonable decissions.
I ran 14psi on a stock block with stock gaskets with no pushing water or having to switch gaskets at all. I think it could of ran a long time like that if my oiling system was keeping up with the high rpms. It hade a good tune and was seeing no kr. 14psi, 682rwhp @ 6800rpm is a lot to ask of the stock 346 and I was taking it up to 7250rpm so most likely more boost and more power, the oiling system didn't keep up and boom. I knew it was a time bomb but I was planning to rebuild so I wanted to see if I could get 9s.
The new build will have a little less compression(10:1), a little more boost(18-20), a lsx 408 with etp heads with the extra mounting holes, race gas and a lot more power and I don't see me having any issues with gaskets. If I followed what eveyone else did, how do I ever improve on it? I want to have something better than the average FI build. All speculation until it's finished but I'm feeling pretty confident so I guess we'll have to wait and see.
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Old Mar 6, 2008 | 09:22 AM
  #117  
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Originally Posted by Ponyhntr
Not with the right setup. There are tons of guys out there making 20+ psi at 900+ rwhp on a 8 rib drive system. Look into the NMRA Real Street class... they are limited to 8 rib drive, P1SC-2 blower, an NO intercooler. They are going 9.70's with a 2V 4.6.

Here is a video of a car that now makes 30 psi consistantly on an 8 rib belt (the video was before they pullied it up more).

http://www.youtube.com/watch?v=nnPNEJJe0DU

This is LS1tech, not NMRAracing board-lol. I know those guys make 30+ but who makes that with the available setups for an LS1-knowone! Look at the size of there cubes too. Believe me I'm a die hard blower guy and EX Pro 5.0, and true street drag racer-pick up some old Muscle Mustang rags and i'm in there-been there done that from Vortech to Novi to Procharger. There is no available drive system to spin our blowers fast enough-period!
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Old Mar 6, 2008 | 09:28 AM
  #118  
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Originally Posted by rufretic
I always thought it was the added boost that causes them to go because those are the only people I've heard having issues. Plus your turbos run a lot hotter than my procharger will, which I thought I remember making a difference on when you start to blow gaskets. Doesn't the added heat cause detination, causing gaskets to blow? I'm not sure, I'm not a mechanic but I do a lot of research so I can try to make reasonable decissions.
I ran 14psi on a stock block with stock gaskets with no pushing water or having to switch gaskets at all. I think it could of ran a long time like that if my oiling system was keeping up with the high rpms. It hade a good tune and was seeing no kr. 14psi, 682rwhp @ 6800rpm is a lot to ask of the stock 346 and I was taking it up to 7250rpm so most likely more boost and more power, the oiling system didn't keep up and boom. I knew it was a time bomb but I was planning to rebuild so I wanted to see if I could get 9s.
The new build will have a little less compression(10:1), a little more boost(18-20), a lsx 408 with etp heads with the extra mounting holes, race gas and a lot more power and I don't see me having any issues with gaskets. If I followed what eveyone else did, how do I ever improve on it? I want to have something better than the average FI build. All speculation until it's finished but I'm feeling pretty confident so I guess we'll have to wait and see.
Did you see my dyno results so far bro? 860 rwhp@5400 rpm or 124mph? the dyno lost signal-got that figured out know so I'll full results on saturday. That's on pump gas and meth, LS2 block 10.1, AFR 225 heads, LS6 intake, stock TB, stock 85mm maf with the "baby" F1A. I should be an 950 by 6500. @5400 that's around 12psi. This is through a locked auto too.
No knock, no pushing water. Just imagine what 950 rwhp would with a good auto, rear and a 3300lb car? And too boot it's on pump!
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Old Mar 6, 2008 | 09:40 AM
  #119  
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Originally Posted by eb02z06
Did you see my dyno results so far bro? 860 rwhp@5400 rpm or 124mph? the dyno lost signal-got that figured out know so I'll full results on saturday. That's on pump gas and meth, LS2 block 10.1, AFR 225 heads, LS6 intake, stock TB, stock 85mm maf with the "baby" F1A. I should be an 950 by 6500. @5400 that's around 12psi. This is through a locked auto too.
No knock, no pushing water. Just imagine what 950 rwhp would with a good auto, rear and a 3300lb car? And too boot it's on pump!
Very nice man! Sounds simular to what I'm looking at doing.
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Old Mar 6, 2008 | 09:53 AM
  #120  
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Originally Posted by eb02z06
This is LS1tech, not NMRAracing board-lol. I know those guys make 30+ but who makes that with the available setups for an LS1-knowone! Look at the size of there cubes too. Believe me I'm a die hard blower guy and EX Pro 5.0, and true street drag racer-pick up some old Muscle Mustang rags and i'm in there-been there done that from Vortech to Novi to Procharger. There is no available drive system to spin our blowers fast enough-period!
I was referring to this comment of yours:

You'll run into slip before you can push the blower hard enough to make double digit boost numbers.
I was just pointing out that your statement isn't 100% accurate. Even on LSx engines.
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