Searched but didn't find anything. Does anyone know what the difference is between a S4 and S5 turbo-downpipe gasket? Will there be an exhaust leak if you use a S4 gasket on a S5 turbo or a S5 gasket on a S4 turbo? I'm only asking because the S4 gasket I have on my S5 turbo is leaking and I don't want to spend $60+ for a S5 gasket if it's not going to fix the leak. Any info is much appreciated.

 

As far as I know, they're the same thing. Racingbeat's site even lists just one "87-91" gasket.

 

The s5 gasket is reusable while the s4 is not. Your problem might be caused casue your using an old gasket and have new piping. I would recommend you buy and s5 turbo gasket from your local dealer.

 

RotaryRocket88-They're different.

freemanrx7-I used a brand new OEM S4 gasket.

There are pictures of the 2 different gaskets here: http://www.mazdatrix.com/e6.htm. The S5 gasket looks like a better design.

 

Resurrecting an old thread because I need to know...

I was under the impression I could use my s4 turbo downpipe gasket on my s5 turbo, is it unusable since it's used?

I'd hate to pay 70 bucks for a new one, I'd rather buy a used one thats usable thats made for an s5 turbo.

Also is there any place that sells the stock silicone intercooler hoses and all the hoses that go to the turbo cold side ? Or is there anywhere that has a listing of the sizes I'll need ? I've been searching and can't find anything. I'm trying to replace the hoses on mine that really could use a replacement.

I guess I may have to measure them myself and just go from there, though it'd be much easier if i didn't have to do that.

thanks

 

they are innerchangeable, if the gasket looks allright use it?

if it leaks then replace it.
or u can try adding a very thing layer of ultra copper rtv on both sides can help seal up a used gasket as well.

 

They are constructed differently. The s4 is a layer of metal wrapped around itself and stamped together, like the 87-88 turbo exhaust manifold gasket. The s5 is a 3-ply stack of thinner metal layers. Both are reusable, and both downpipe gaskets fit either turbocharger outlet. Use whatever you have that is in the best condition.

Again, way too much thought for a simple issue.

 

I like to think , I could be the next Einstein but I'd rather be the next Felix Wankel.

 

Nah, you're the next Steve Brule.

 

Nah..before anything you were WTHdidusay EIGHTY ONE..
so you've moved up a notch!
you need many "notches" to be totally Triangular like Our man Felix!
Don Ho tried to be Justin Timberlake..that didn't go well either!..(needs more Uh..Ukelele??)

 

RR has it exactly right,, interchangeble but the s5 unit is layers of metal shim and is much more durable
.. both are re-useable to some extent.. s5 ones are still good 24 yrs down the track .. s4 ones usually not

and FYI .. mazda use NIL gasket between backing plate and turbo.. NADA..
if you cant source a gasket.. it is actually better ( quieter ) to use NONE
.. it will whisper when cold and shut up when hot.. a blown gasket is just loud all the time

 

You talking about the plate over the waste gate? I haven't seen one on any of the turbos I took apart

 

So I guess that makes you the next ik the troll king, you always troll my posts.

 

.. yes exactly my point .. my dump is so large it is welded straight to the wastegate cover plate and the passage opened up to 3 inch .. and i use no gasket . cause there aint one

before going to that extreme,, when i had a standardish dump//
if i lacked a good dump gasket i would fit up without .. the leak is only minor and when cold

 

That must be loud if open and not sent to the back of the exhaust , is it a street driven car or strictly track?

 

do pics make it easier?

 

So you ported the i.d. to 3" ,I'm not sure on the stock size, 2.5" maybe.

I thought you meant that you put a pipe on to dump from the waste gate straight out the exhaust manifold, instead of the down pipe.

 

HE's saying that mazda used no gasket at all between the turbine housing and the back plate, and yet there is never an exhaust leak there. So in theory you could use no gasket between the back plate and the downpipe. However this relies on the back plate outside flange and the downpipe flange both being machined perfectly flat. Aftermarket downpipes (or any aftermarket exhaust component) are not always perfectly flat as you would like to think. Used components also tend to warp over time. The turbo back plate is cast iron and thick enough that it apparently does not warp.

It's possible to modify your back plate for a divorced internal wastegate. You'd weld on a section of pipe with the same ID as the back plate downpipe outlet, that extend over to the turbine housing/wheel outlet, so that those gases go smoothly out the downpipe without interruption. Then you'd cut another hole down at the bottom of the back plate and do the same thing for wastegate gases to escape via their own outlet, and either have that be a curved dump tube open to atmosphere, or join it back into the downpipe at the bottom in a gentle fashion that does not involve the 90 degree angles of a stock wastegate flow path.