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Discussion Starter #1
This is a trade off discussion. What I'd like to focus on is what cam profiles would make a car come on boost faster but make less hp, and what profile makes more hp but may spool slower. I know there are more variables like compression, displacement fuel ect.
Let's say methanol fuel, '10 to 1 compression.
 

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First off lets bump the compression to something more realistic like 11-12:1, I am at 11:1 for the last 3 years but going to 11.5:1 on new billet engine. Even if this is all theoretical we need more details to pic cam numbers such as, engine size/make, head details, injector size/type, turbo(s), power goal, 1/8mi or 1/4mi, car weight, etc. Otherwise we have to talk in such general terms it's not going to be very productive.
 

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This is a trade off discussion. What I'd like to focus on is what cam profiles would make a car come on boost faster but make less hp, and what profile makes more hp but may spool slower. I know there are more variables like compression, displacement fuel ect.
Let's say methanol fuel, '10 to 1 compression.
If you deal with the right cam guy you will get a cam that builds boost fast and makes more hp. Doesn't have to be a trade off in my opinion. Thats not to say don't have you conversation here in this thread, I just think that if you enlist the right help, a trade off does not need to exist.
 

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I pick all the cams I use but if I needed cam help my #1 guy would be Mark at Bullet. I primarily use Comp because they have more documentation on their lobe families than anyone else. You can't pick cam lobes without the details, the .050" numbers are only a small part of how the lobe will act.
 

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When you're talking about getting the boost to come in early, it's all about heat. The CFM in the cylinder at a given RPM is going to be about the same, so you need to get the combustion temp up at that RPM to increase the pressure against the turbo.
To do this with the cam, you would use an earlier intake closing point, and also reduce the overlap. Both of these things will hurt the top-end, but they will get the boost up quicker on the bottom end.
 

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Discussion Starter #6
When you're talking about getting the boost to come in early, it's all about heat. The CFM in the cylinder at a given RPM is going to be about the same, so you need to get the combustion temp up at that RPM to increase the pressure against the turbo.
To do this with the cam, you would use an earlier intake closing point, and also reduce the overlap. Both of these things will hurt the top-end, but they will get the boost up quicker on the bottom end.
Thanks. That is the kind of info I was looking for. I just wanted some general info as I know nothing about what makes a cam work in this instance.
 
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