Hey everyone, I've been reading up and only found one article referencing port matching the FD turbo housing and manifold for a noticable decrease in spool time. I would love to get a little more detail or ideally photos if anyone has some.
The twin turbo manifold itself looks pretty straight forward, but does anyone have any insight on how much material can be taken out of the turbo housings? I don't want to take too much out and cause a weak spot.
Also since I'm running non sequential, is there any benfit to removing the divider between the pre control gate in the turbo housing? I would think that would help out with flow right? My old turbos had that piece cut out.
Thanks!

 

We experimented with cutting out the absolute maximum amount of material from both the manifold and the body of the twins themselves. Also worked the shape of both so that there were no sharp edges or anything. You know, made the "flow" nice and smooth. It was noted in another thread that there was a substantial amount of material in the wastegate area that could be removed, so we did.

Net result............... don't bother 😒

The video below is about something else but the curves are relevant. We also have a video on our YouTube page where we put a stock car, a perfect modded sequential car and a non sequential head to head. There's some graphs there too but we need to redo that comparison based on community feedback.

 

Tell me you has never plotted shift points with factory gear ratios.

 

Porting the waste gate is worthwhile if you are over boosting with a wide open setup (downpipe/midpipe) - it does help a great deal.

Anything else is not gonna make any sort of measurable difference.

Also the stock twins spool SO damn fast.

Dale

 

The advantages of sequential turbos is at low RPM, so starting dyno pulls at 3,500 & 4,000 rpm really do not show the difference between sequential and non sequential.

 

You mean like this?

 

I think Garfinkle posted about this ages ago.

Also another guy whose name I forget that competed in autox. He had a dyno plot iirc that showed some really nice low rpm torque numbers.

As Full Detail mentioned, the numbers might not reflect any gains so it is a question of doing the work for the sake of fine tuning.

 

The amount of effort with grinding and cutting all that cast iron did not equate to any appreciable result..... period. It feels cool to do all that work thinking you're about to pick up some low end response but then reality hits and LA LA land closes its doors.

We didn't do a direct back to back on the cars but if we did, I don't see any difference being present. That's on a non sequential no "porting" manifold and turbo body vs the one that was.