Header tube size?

[cetstang902003]

When should you move from 1 5/8 header tube size to 1 3/4? I know if you go to big with a mild motor you'll actually kill some power so if there is any rule of thumb for choosing between the two I'd greatly appreciate it. Thanks.

 

[86bluecobra]

the 1 5/8's will probably be best for a mild engine. the smaller primary's will allow your motor to make more torque then the 1 and 3/4's. that being said if you plan on upgrading your setup in the future maybe the 1 3/4 would be better. after all the power/torque you lose you will never know about because you haven't swapped between the 2 parts. I have 1 5/8's on my 351w and i am told that my application would prefer 1 3/4's.

 

[Deleted member 87397]

I wouldn't use 1 3/4 unless I was running FI

 

[matm347]

I would say anything more than a typical H/C/I combo would see benifit by going to a larger primary.

 

[cetstang902003]

I am running fuel injection with a cobra intake, GT40X heads, and a B303 cam.( check sig ) Will 1 3/4 header tubes be to much for this set up?

 

[matm347]

A different intake, or intake work would make more of a difference. If you've already got 1-5/8s I would stick with those until you get stroked or blown.

 

[IntenseBlue]

Around 475 flywheel horsepower is when to go 1 3/4 on a street or street/strip car.

 

[04sleeper]

I am running fuel injection with a cobra intake, GT40X heads, and a B303 cam.( check sig ) Will 1 3/4 header tubes be to much for this set up?

I would NOT go with 1 3/4" LT's.

That is too much for your combo.

 

[cetstang902003]

Thanks for the help guys.