I was porting an S5 wastegate tonight, and started thinking about how poorly designed this was.
Those who have seen the turbo will understand what I mean.

On the back of the exhaust side is a cover that goes over the wastegate and creates the hole for the downpipe. Between this cover and the turbo is a gasket, and a gasket between this cover and the downpipe.

The wastegate flapper door is limited as to how far it opens by this cover. (and perhaps wastegate actuator arm travel, unsure on that yet). Regardless, the air flow out of the wastegate has to make a complete 90 degree turn before heading out into the downpipe. Doesn't seem to make much sense.



Why do aftermarket downpipes just not remove the cover? It eliminates a gasket, and gives and extra 1/2" of room to play with. Plus, you could make the wastegate flow directly into the exhaust path.

I made some shitty paint jpeg's, but I keep getting error messages trying to post them.

 

i 2nd that opinion.. do some thing like a second pipe off the plate that sites over the wastegate. i'v seen them vent out the quater pannels before. or you could run a duel, y'ed in later down the exhaust that would flow well.

 

It doesn't even need it's own separate pipe. Just have one larger chamber that gathers slowly into a pipe, similar of which is used on WRX's, for example.

I know exactly why this isn't done: It is cheap and easy to make a pipe, and hard and more expensive to make a collector like that.

Money matters over a fantastic product.

It wouldn;t be that hard to make, either.

 

Just like this one for a WRX:



I plan to do this to mine, or I might even do two seperate pipes.
Curing boost creep means improving wastegate flow through the the whole turbo, not just the port. As well as eliminating the twisted path the wastegate flow normally takes, seperating the turbine and wastegate flows significantly reduces turbulance caused by the two flows mixing, which increases flow.
With an S4 turbo a much bigger flap can be used so you can bore the port much bigger. The S5 flap would be much harder to replace but the ports can still be enlarged. Combined with the better downpipe design I think boost can be properly controlled.

 

EXACTLY like that.

The S5 watsgates can be taken to 30mm and 25mm without swapping the flapper door. The only issue is getting the flapper door to open up to 90 degrees.

I'm going to fiddle with some stuff.

Honestly, though, why can't we get a product like that? B/c our manufacturer's are lazy!


SO... I'm on the right track, then, NZ?

 

Hell yeah!

 

Thats the FIRST thing I thought when I put my replacement turbo on.

Hell, I bet even an S4 gate would be controlable with some porting and a seperated wastegate pipe (that could or could not be brought back into the downpipe down the exhuast path)

 

This is a GOOD idea in my opinion, specially if you already have the downpipe.





And here is the thread:

https://www.rx7club.com/forum/showth...hreadid=155100

 

Yes, it's a good idea.&nbsp Are you willing to pay $250+ for it?&nbsp Last time I checked, only a few Japan shops (i.e. KSP?) were offering such a beast.&nbsp A 3" downpipe can be had for a little over $100.


-Ted

 

Hey man,

I believe the downpipe in the pic is a RB one with a custom west gate tube. I believe his total welding cost was like $35. SO that's a heck of downpipe for $160!!

 

Nice!&nbsp You willing to offer this resource to all the members for that price?



-Ted

 

160.00 damn i'll take one ... who do i pay....

 

not worth the time and money to me. cause if you really need to go that far. you're probably also at the stage of wanted a TO4


here's another one that was made

 

This is my set-up : cut a hole in stock TurboII manifold , weld on pipe , buy used Audi 5000 turbo wastegate at junkyard for $25 and install. before I had my TO4E I just closed off the stock internal wastegate on the factory turbo. pics are here BTW works way better than I thought it would.
http://www.hpphoto.com/servlet/LinkPhoto?GUID=444f[img]27da-1452-53ba-2ec4-4ad63a856adc&size=lg[/img]

 

that one looks a little more ghetto. the one above is awesome. (the one with the two pipes) but you have you seperate the wastegate from the turbine obviously, but the whole think looks alotmore professional.

hey knonfs could you give us some more pictures and info about that? and hell, somebody find us someone that will manufacture these things

 

That would be an ideal downpipe for someone with a Hybrid 60-1 compressor inside the stock turbo casing! That might be something to consider for me!

 

KSP made some of these. Comes with an adapter plate that replaces the wastegate cover. It looks similar to the one KNONFS posted. I have one of those KSP pipes but havent installed it since I'm waiting for an S5 turbo I can take some pictures of the DP and adapter plate if anyone wants to see it.

 

J Oliver,

damn that is one trick setup... i gotta pass by your place one day to see what u've got hidden in that garage of yours

 

https://www.rx7club.com/forum/showth...66#post1467666

 

Why would you waste time and money buying one from Japan when they're so easy to custom make? Any decent exhaust builder could do this work. And that'll make boost creep worse, not better...

 

There's a considerable price difference between a compressor upgrade with that downpipe and a full TO4 setup (turbo, manifold, exhaust, wastegate, oil and water lines, etc, etc...)

 

Why would I? I don't even have a running T2 The last sentence on my post was:


And here is the thread:

https://www.rx7club.com/forum/showth...threadid=155100

But I will do mine like that once I get my T2 running, I'm sure it will cost me around $200 bucks, since I'm paying $145 for the RB donwpipe alone.

 

It's not mine

And here is the thread:

https://www.rx7club.com/forum/showth...threadid=155100

 

What happened to this thread?

 

Try this on:

https://www.rx7club.com/forum/showth...hreadid=155100