Downpipe question

[nickygn23]

Quick question. I going to purchase a 3 " downpipe. A few years back I installed a 2 1/2 inch Hooker header exhaust. It came with a test pipe. My question is when I buy my new 3 " downpipe and I have a 2 1/2 inch exhaust ,would the difference in diameter at the test pipe connecting flange cause a choke point?
Do the make a test pipe or dump pipe that goes from 3" to 2 1/2 ?
Thanks

 

[StageII86]

If you are talking about the Hooker catback exhaust system, the flange at the beginning of exhaust will bolt up to the flange on the 3" test pipe (that should come included with your 3" downpipe). Any down pipe you get should include a test pipe, and this should be the missing link you're asking about.

HTH

 

[nickygn23]

This picture might help some

 

[nickygn23]

OH.... I thought the opening in my hooker catback was 2 1/2. You know, where the exhaust meets the test pipe... Where they bolt together.. Your saying that's the opening is three inches?
If that's the case I'm good then.

 

[StageII86]

Yes, it's actually an oval. The rectangular 4-bolt flanges should match.

 

[1984 t-type]

If you get a pipe from RJC or Gbody parts and prob most other vendors the test pipe does not come with the down pipe you have to purchase it

 

[nickygn23]

Sorry about my artwork, If the opening for the y pipe is 2 1/2 and the opening for the dump pipe is 3 inchs wouldn't it cause turbulance?

 

[Reggie West]

A nice smooth bend coming out of the turbo gets rid of a lot of turbulence at the stock elbow. there might be some turbulence at the exhaust but remember you are going from a 3 inch pipe to 2 21/2 inch pipes so they is plenty of flow there. it won't be a problem.

 

[nickygn23]

Thanks guys. I appreciate the info...