I'm looking to upgrade my exhaust. I'm wondering if I should go with a raceland header or dual outlet manifold with TT down tubes. I'm going 2.25 exhaust with borla xr1. muffler.
It was my understanding that the factory exhaust manifold is pretty good. Spend some time port matching and you should be fine. There are some good header manufacturers but I have always had issues with headers. Either they leak, crack, fit poorly, or something similar.
I made an exhaust system for my wife's 91 Cabriolet. I found an older Mk1 dual port manifold and ported it. I made a 1 7/8" dual long tube head pipe and 2.25" all the way back. I made the resonator and muffler too. It sounds pretty good.
thank Butcher. I haven't really thought about it, but your right. Can't say I've ever had headers that i wasn't changing gaskets on or tightening header bolts. I was just thinking about flow. If the dual outlet manifold with TT down tubes flows as good or better than cheap headers.
This picture shows a stock Mk1 manifold and one that was ported. Porting cast iron is not a fun task. The metal shavings get everywhere and most seem to find a way under the skin. Wearing gloves helps but one they get between the glove and hand, it's even worst.
The dual 1 7/8" down pipe.
The final product.
Not certain it's better than a header, but I'm certain it's better than stock.
Last edited by Butcher; 11-30-2019 at 08:35 AM.
Pain the the rear holding the pipe and tack welding it in place. You can see spots that I just missed. I tig welded them once I got the pipe out of the engine compartment.
My first time and it went well. Learned a lot.
This is my downpipe for the turbo. Separate wastegate exhaust.