so anyone with a full race kit try this yet? I think there is very limited room to do this with the full race mani and where the downpipes are mounted.

 

I thought about doing this as well, I did the same thing on my old miata as well. You lose more than you would expect, unless you merge it back in with a very gradual angle. I had mine flow back into the exhaust about 2 1/2 feet past where the turbine is to minimize hp loss.

 

you shouldnt lose any power i wouldnt think, as the exhaust is still being dumped. PERSONALLY, i hold the ability to scare the hell out of people very dear. i keep something like that for the sheer fact that when that one guy does something belligerant on the open highway you can happily give him an ear full
my $0.02 worth

 

Anyone knows the diameter of the dump tube of the Inline pro's kit? It's off of the 38mm Tial, I'd like to add a flex if I can find the size...

Thanks.

 

I would assume....38mm?

 

The power loss comes from turbulence. The WG is fighting with the rest of the exhaust to get rid of the excess exhaust and because of the turbulance, its harder to do. Hence, why a lot of setups with recirc'd dumps not properly designed creep on the top end and/or lose power in the midrange (like my setup)

 

^2nd that, because of the 'travel the path of least resistance' principle. When bigger-diameter, more flow exhaust has to compete with smaller-diameter less flow WG dump, there will be turbulence. One will try to push the other out.

 

well damn.. if thats the case i'm not trying to spike and what not..

blah..

 

yes i considered that but didnt think it would cause that much resistance i suppose. either way, that definitely makes sense. i am still a firm believer in open wastegate dumps, given you do not inevitably have police trouble like some people...

 

One suggestion,
ask the fabricator / weld shop to make the dump tube as tangential as possible to the downpipe tube.
Avoid the easy 90* weld. Some shops will just make dump tubes that are perpendicular to the gas flow direction in the exhaust stream. Gases don't like right angles!

It will require extra work as you have to cut the pipe at an angle and cut an elliptical hole in the downpipe, but it will flow better as the gases will meet at a smaller angle of incidence as opposed to a 90* angle

here you can see how I did mine (top) for my Subaru. the tube joins the downpipe at a small angle, the bottom pic is what shops like to do as it's easier to cut a pipe in a straight section and make a round hole in the dpipe, then weld.