Hi, I am trying to get some pictures of Fabricated T4 Exhaust Manifolds.

I am thinking of making one for my car but need some input, Basicly what makes a good manifold?

I know the basic structure has to be very strong as there is a Huge T4 Turbo swinging around on the end of it. The other thing is the size of the runners? is there a set lenth they have to be or can they modified to suit my car?
I will also be useing an External wastgate i already have a picture of one setup but the wastgate is only conected to one runner?

 

I have some pics on my site of my manifold. I do not recall the sizes since it has been 6 months or so.

 

Typicaly gas flow dynamics question...

Keep flow as smooth as possible...
1) You're limited to the exhaust port exits off the engine, so don't get too stupid with how big they can go.&nbsp The ports on the XS Engineering cast manifold is about the biggest you can go with the stock exhaust port sleeve.
2) Bends should be the largest radius possible.&nbsp Keep in mind a sharp 90-degree bend will decrease flow rate by 1/37th.
3) Y's (for wastegate passages) should be at even angles as main passages and as close to the same vector of flow as he main passages.
4) KEEP PASSAGES DIVIDED - this keeps rotor exhaust pulses as strong as possible, which aids turbo efficiency - of course, this necessitates a divided turbo turbine housing.



-Ted

 

13 INCHES!!!!!!!

 

If i Make it out of quality piping and Dubble but it maybe even a bit of a support to hold some of the Turbos weight will it be more prone to Cracking than the Cast?

Am i right in saying the reason the Fab Manifold cracks is becouse it flexes more with the weight of the Turbo and causes the weakest point of the manifold to stress crack? But saying that i have been told the Cast manifold does'nt like to be heat up and quickly cooled this over time causes Cracking. Also you are limited to the size of your Turbo as Cast manifolds are usaly in the stock position, on a FD there is'nt that much space to play with so people tend to move the Turbo to get better air flow around them and genraly keep under hood temps down hence the Fab manifold.

Does this sound about right or not?

 

STYK33, I have had a look at the pic's of your manifold on your site, Is the two pipes under your manifold the wast gate take offs? do you have a single wastgate?