I just picked my TTR turbo manifold up from my machinist. I had him weld on a V-Band wastegate flange and do some other nice tricks that people here might be interested in.

First off, I'm going to start by saying that in NO WAY am I bashing the quality of the TTR manifold. Off the shelf it is a great piece, with quality welds, nice thick flanges, and a well thought out design. HOWEVER, I'm the type that can't leave well enough alone, and always am looking for ways to improve the performance or function of every piece that I can.

Starting off, the TTR manifold has no provisions for an external wastegate. Seeing as how every setup is different, and in no way could they possibly accommodate every single variance, that's OK with me. I decided on a 38MM V-Band style wastegate, so I had my machinist weld it on for me.



Next, I had him smooth out the transitions from the runners to the turbo flange, eliminating every little ridge, sharp edge, and protrusion. It might not make much of a difference, but every little bit helps.





And lastly, I had him CNC port the flange and runners to match the gasket and my cylinder head. There is nothing wrong with the manifold as is, since the exhaust ports in the manifold and a factory head both look like this.

BUT, the factory exhaust gasket has port holes that look like this.


I don't have a comparison image, but I can say that the difference between the stock port size and the exhaust gasket is phenomenal. There is at least 1/8" bigger port size difference between the two. So now instead of being oval, the manifold ports and runners have been CNC ported to look like this.




And now for the REALLY nice part of it all, and it may interest some of the people on here. As I said before, my machinist CNC ported the runners and flange....

.... AND he saved the CNC program file. So if there is interest, he can now CNC port ALL EcoTec exhaust manifolds, headers, ect!!!

So if there is interest here for CNC porting, let me know. Since my manifold was the prototype for all of the machine work, I have fronted a large chunk of the cost and R&D of getting this done, meaning if someone were to have my machinist do this, it will be reasonably cheap. It would make a world of difference in flow, especially if you already had a ported head. I don't have exact figures, but we figured something in the neighborhood of 20% increased flow over stock port sizing.

Questions, comments, and criticism all appreciated.




Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 3rd quickest Ecotec on the .org - 10.949 @ 131.50 MPH!!!

If only i had an Eco...

Very nice roofy!

awesome, just needs coated, now!



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