Header size on 347 with a F1R

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Jan 8, 2007 | 01:19 PM

eb02z06

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From: Waterloo, Ontario

Header size on 347 with a F1R

I'm getting close to adding the finishing touches on this 347/F1R build up on my Z06. One thing I overlooked is header size and midpipe size. Currently I have 1 3/4" headers going into a 2 1/2" intermediate pipes into a GHL catback. Remember this is a Z06 so it is a true dual exhaust. My question is will I get noticeable gains going to a 1 7/8" header into a 3" intermediate pipe? Or maybe a combination of the 2 like a 1 3/4" header and 3" intermediate pipes or 1 7/8" header 2 1/2" intermediate pipe? Remember the car will never run open so it will always go into a 2 1/2 catback int the GHL mufflers which are pretty much straight through.

Thanks!

Jan 8, 2007 | 01:22 PM

eviltwins

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If you're going to choke it all off with a 2.5" catback you'll probably be fine with your 1.75" headers and 2.5" midpipes.

I say run 1 7/8 headers, 3" midpipes, and a 3" catback. You'll see some big gains from the 3" catback on an F1R car.

Jan 8, 2007 | 02:11 PM

eb02z06

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Bro-the mufflers are like a resonater bullet type-it's like a 6" can straight through-here's a pic:

http://www.ghlmotorsports.com/Mercha...tegory_Code=C5

Jan 8, 2007 | 02:43 PM

Got Me SOM

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the 1-7/8 would be a better header to go with cause you will be expelling a lot of exhaust gas from the head so that will be a restriction right there, the rest you can leave the same.

just my opinon. its not really needed but if you're looking for max power that's the way to go.

Jan 8, 2007 | 04:34 PM

HUNTER02SS

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From: Kennesaw, Georgia

I would go with either the 1 7/8 or 1 7/8 stepped to 2in..You are going to need to expell all the exhaust you can to make the #'s.

Jan 8, 2007 | 04:38 PM

JPH

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From: Fort Wayne, IN

1 7/8" would be all you need.

Jan 9, 2007 | 01:30 AM

eviltwins

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Quote:

Originally Posted by Vortech

Bro-the mufflers are like a resonater bullet type-it's like a 6" can straight through-here's a pic:

http://www.ghlmotorsports.com/Mercha...tegory_Code=C5

I saw power gains on my old Novi2K car going from a 2.5" catback to 3", both with dynomax race bullets. I'm talking about 45 RWHP on a 700 RWHP car. Doesn't matter how straight through the muffler is if it's just a 2.5" catback.

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Jan 9, 2007 | 05:22 AM

Inspector12

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From: Pearland

I am a firm believer in over doing the exhaust systems, but I know I am the minority but I thought I'd give you my two cents since you asked for opinions. I belive that the 1 3/4" headers would suit this motor good especially since you are still stock cubes I don't see the need for it until over 380 ci just my theory though. As far as the pipes going back I like a 3" inch personally, but I think you will probably pick up a little low and mid range TQ although you probalby won't need any more LOL! Good luck and remember do what you want and if it doesn't work out how you planned just change it. It is all a learning process there are only theorys until proven on your exact combo. Everyone will be guessing based on there own experiences and not meany run the same exact setup as another etc...