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Norbert Sliwinski
(28 posts)

08/11/2012 05:20PM

Main British Car:
1973 MGB GM 2.8 V6

DIY Exhaust
Posted by: NAS1966
Date: December 12, 2018 02:20PM

Hi All,

I am looking for data for a DIY header and exhaust pipes for my 2.8 V6 for my '74 MGB restoration project.
There where a bunch of people who made their own but no one gave pipe sizes i.e. primary and secondary
OD pipe diameters.

According to my calculations the primary ( header ) pipes should be 1 5/8 ID or 1 7/8 OD and the main
exhaust pipes after the collector should be 2 ID or 2 1/16 OD

Also I saw one set-up which had a couple of nice rectangular mufflers - does anyone have data for those?
Can anyone concur with these above pipe sizes or which size pipes should I be using?

Carl Floyd
Kingsport, TN
(3534 posts)

10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: DIY Exhaust
Posted by: MGBV8
Date: December 13, 2018 08:06AM

IMO, your primaries are too large. Except for all out high RPM efforts, smaller is better. I run 1 5/8" primary headers on a 400hp 350 V8.




Scott Costanzo
Columbus, Ohio
(533 posts)

10/25/2007 11:30AM

Main British Car:
1968 MGB GM 5.3 LS4 V8

authors avatar
Re: DIY Exhaust
Posted by: Scott68B
Date: December 13, 2018 04:48PM

I used 1 1/2" primaries on my 3.1 headers with 2 1/4" collectors. I got guidance from Headers by Ed when I sized things.

Rob Ficalora
Willis, TX
(2561 posts)

10/24/2007 02:46PM

Main British Car:
'76 MGB w/CB front, Sebring rear, early metal dash Ford 302

authors avatar
Re: DIY Exhaust
Posted by: rficalora
Date: December 13, 2018 04:54PM

For the mufflers you referred to, check out [spintechmufflers.com].

I use their cruiser series on my car. They are great for clearance, but I wish the sounds was a bit deeper.

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