You are correct Spark. The only way the flapper would open sooner is if you had enlarged the wastegate ports increasing the pressure area exerted on the flapper.

Mikey

 

The advantage of the larger diameter WG puck is that it allows you to increase the diameter of the wastegate bypass ports. If you've ever tried to enlarge the size of the exit ports on a stock 10.5 housing then you'll know that there is not much margin for error. The stock puck just has enough overhang to seal.the ports..and that's it.

The puck slides back and forth laterally across the wastegate valve seat. This small amount of horizontal play leaves little room for fudging when you try to enlarge the wastegate bypass ports on a stock 10.5 housing.

I have concluded that it is safer to leave the port exit at the puck seat alone and not even touch it. You can mess with the entrance to the bypass port at the transition from the turbine inlet area to the wastegate bypass port but the exit diameter at the flapper valve seat with a stock flapper valve is best not even touched.

 

I would like to try one of these 11.5 housings on my Red. Will FP even cut this aftermarket housing for the Red's turbine wheel?

 

pressure is force per unit area

P = F/A

rearranging, F = P * A ... work from there

 

Not sure what back round in cars that you are from but if you didnt come from dsm's hop on a old dsm board and ask around. The bigger flappers are good for low boost control. Once you start raising boost pressure and putting more pressure into the exhaust mani/tunrbine they like to blow open with bigger flappers.

 

surely a local engineering shop with a decent lathe would be able to cut it?

 

Like IRA said, F = P * A. Just need a stronger WGA spring to make up for the larger flapper area. Another solution is to weld material around the port opening to reduce the area (A) of the opening. Bigger spring sounds easier though.

 

As far as my experience with internally gated turbos is concerned: I bought a Buick Turbo Regal, new, back in 1987. This was the first turbo car that I owned wherein the turbo had an integral wastegate. Over the years, I installed a few Garrett T04E variants onto that old Buick(TE-60, TE-49, TE-50, etc.).

We would swap out the T04E's stock Garrett turbine housings for the freer flowing Precision(PT&E) housings. There was a .63 Precision housing and a. 82. They both came equipped with a larger than stock diameter wastegate puck.

It was advisable to install a HD Precision wastegate actuator along with their better flowing housing though now that I think about it. So, what MrFred says about a heavier actuator spring sounds right.

I never had a problem keeping the larger diameter WG puck on the seat with those turbos. Of course, as I mentioned, I would fit the HD Precision actuator. Also, I confess toI WORSHIPPING preloading of the Wastegate actuator. In my experience, I have found that in most cases, HEAVY preloading will eliminate any predisposition to premature flapper valve lifting.

Maybe what you say might be true if keeping the same wastegate spring pressure. But, this can be easily remedied by adjusting spring pressure tighter on the stock actuator. Or if the stock actuator is too wimpy then going to a heavier duty after market actuator should solve the problem.

The point that I was originally trying to make was that the stock Mitsu Industries flapper valve on our 16G turbos. is extremely small in relation to the diameter of the bypass port hole.

There is a certain amount of lateral free play of the flapper valve across the face of the machined valve seat due to axial play in the flapper valve's pivot shaft. The valve doesn't overlap the exit hole by very much in this area. So there is not much material that can be removed from the port OD at the exit of the bypass ports when porting the turbine housing, or you'll run into sealing problems and leakage resulting in loss of spoolup.

Anyway, getting back to the case of this new aftermarket 11.5 housing, I imagine that the larger diameter flapper valve must be necessary to cover the proportionally larger bypass port exit area cross section on the 11.5 housing.

I'd like to try one of these puppies on my FP Red.

 

Who cares about wastegate flow?

This is the 4G63 not a little 3S-GTE of B18. You run an internal wastegate turbocharger are hard as you can at all times...

 

I remember reading somewhere that (apparently) Robert's feedback is that he'll cut it, but he won't warranty the turbo if something goes wrong.

 

That is correct, Robert even cut my single scroll housing. We are not sure what the divider wall looks like in this housing and if it is as strong as the stock 10.5 divider wall or not.

Mikey

 

Basically I agree with 03whitegsr. Crank the spring pressure on the actuator down as tight as possible. Maybe 2-3# before your peakboost level. This maximizes spoolup. Tighten preload down to just before where the WG binds. If you get boost creep and overshoot your target boost level....then you deal with that separately by porting the wastegate bypass port in the turbine housing or adding a backup external gate. This maximizes spoolup and torque.

 

Theoretically at least this aftermarket 11.5 housing has the potential to free up a few ponies on the topend. Obviously, turbine backpressure will be reduced. The larger diameter wastegate puck is a plus as well....At least I see it that way. This unit will be especially beneficial on motors over 2.0L.

I would want to put one of these on a larger displacement 2.3L, or 2,4L motor. It will probably show maximum gains when fully ported.

 

What about taking out the divider? If your going for all out power over spool anyways.

 

Mikey, essentially did this. I think that he lost a significant amount of spoolup though...even on a 2.4L block. The loss in spoolup would be even more pronounced on a 2.0L engine.