Just an idiots question...Im not new to RX7's but Im not great with them either. I am currently boost creeping and it is virtually impossible to tune with this situation...

I have eliminated my twin scroll on my S-4 FC. I boost creep up to 16 psi on a stock 91 S-5 Turbo. Should I get my wastegate ported? or should I just put on a newer wastegate? Im looking for the easiest route since money and time are of the essence. If porting is my best bet, what exactly should be done since Ive seen a milion different ways of dioing it?



my mods:

Wolf 3D V.4

3" DP and exhaust

750 cc inj (sec)

street port

3mm seals

and more with little that has to do with my situation

any help would be greatly appreciated



thanks

 

Since you're running a stock S5 turbo, I would try porting it first.



I would use this site as a guide: wastegate port howto

 

[quote name='1988RedT2' date='Jun 2 2005, 12:50 PM']Since you're running a stock S5 turbo, I would try porting it first.



I would use this site as a guide: wastegate port howto


[/quote]



not completely sure about the wastegate I have. But I thought it might still be the Zenki(87)... Either way I found my way to that how-to guide as well. Thanks for the help. It makes it a lot easier looking with those pics.

 

You should take the old wastegate door off, and weld on a larger one. Exhaust valves works great I have heard. Then port the wastegate runner considerably, along with the entrance to the wastegate runner(backcut this area). Then remove material from the backplate to allow the door to open farther.

 

that turbo won't last long at 16psi irregardless if you have the wg ported or not.....

 

If you have a S5 turbo then you should have two wastegate doors. If you have the S4 turbo then you will have one door. Either way you should port the openings and then weld a bigger washer on.

 

thats the problem Im having, how much bigger should they be ported??

as in what size washer should be used? Ive heard many, but the most common sized one I belive was the 34 mm....

And it is an S-5 Turbo, wont it fit on a S-4 wastegate and manifold?

 

[quote name='Infinite' date='Jun 3 2005, 09:49 AM']thats the problem Im having, how much bigger should they be ported??

as in what size washer should be used? Ive heard many, but the most common sized one I belive was the 34 mm....

And it is an S-5 Turbo, wont it fit on a S-4 wastegate and manifold?


[/quote]



Both the S4 and S5 wastegates are integral to the turbo hotside casting. The manifolds are different. An S4 turbo won't bolt to an S5 mani, and vice-versa.



In the discussion at FC3S-Pro, it is pointed out that a properly ported wastegate should be more than adequate for that turbo. I wouldn't go out of my way to make additional work. I ported mine, and even with an upgraded compressor side, I don't have any trouble with boost creep. Just hog it out to where the factory door will just cover the opening.

 

[quote name='1988RedT2' date='Jun 3 2005, 09:30 AM']Both the S4 and S5 wastegates are integral to the turbo hotside casting. The manifolds are different. An S4 turbo won't bolt to an S5 mani, and vice-versa.



In the discussion at FC3S-Pro, it is pointed out that a properly ported wastegate should be more than adequate for that turbo. I wouldn't go out of my way to make additional work. I ported mine, and even with an upgraded compressor side, I don't have any trouble with boost creep. Just hog it out to where the factory door will just cover the opening.


[/quote]



Okay, so I must have an S-5 manifold as well.. So I can still have the S-4 Twin-Scroll B.S. as well right? I dont need to weld a washer onto my flapper? I know it doesnt say so but it also doesnt explain how much it should be ported..

Thanks for the help