Rxmfn7

iTrader: (4)

In another post of mine ( Here. ) I showed some pics of what I was doing with my new and old turbos. Basically, I had a S4 TO4B hybrid turbo, and a stock S5 turbo. I just swapped the exhaust housings so I could use the S5 manifold/exhaust housing, with the T04 Compressor that was on the S4 turbo.
Well, I swapped the TO4 compressor onto the S5 exhaust housing...no problems there, everything seems fine. I then put the S5 compressor onto the S4 exhaust housing, and after torqueing down all 6 13mm bolts that hold it on, I can still grab the compressor housing and spin it, and pretty easily.
On the S5 exhaust housing , the part where the brackets and 13mm bolts go seems to be sticking up just a hair, allowing the brackets to tighten down on it. On the S4 it seems to let it sit flush, therefore not really holding it together well. There is no up and down play whatsoever, but I'm pretty damn sure that you shouldnt be able to twist the housings..
I attached a few pics of the turbo in question (S4 exhaust manifold and S5 Compressor. I really could use someones advise on this..I have no idea what the problem could be..

bejbis

i really thought that the exhaust houseings between the 2 turbos wernt interchangeable. you might be able to use some washers or something or grind down the bolts if im reading what your saying correctley. it sounds like the bolts are too long for the houseing, and bottoming out before they tighten down the houseing.

-Daniel

Rxmfn7

iTrader: (4)

Hmm...well I was told before that they were interchangable..so I dunno about that. The problem is not the bolts bottoming out...its the little "lip" that the bolts torque down to seems to be flush with the housing.

Rxmfn7

iTrader: (4)

^

rx7will

iTrader: (6)

On the exhaust housing, between the housing and the bolt is like a cresent like washer that helps the housing to be more evenly torqued town.
From the picture it appears that you are missing it on the compressor side. And the exhaust housings are interchangeable.

Rxmfn7

iTrader: (4)

Alright...thats a start. Thanks! I'll look it over today...maybe that washer was stuck to the other side and I have them doubled up on the Hybrid..

*crosses fingers*

RETed

The parts are interchangable. I would worry about the parts sticking out a bit, as long as everything is tight. The MAIN thing to watch out for is if the wheel contacts the housing - spin the wheel and make sure you get NO scraping sounds!


-Ted

Rxmfn7

iTrader: (4)

Well I dont know what to say. When I put the S4 exhaust housing onto the S5 center section and compressor, the center section sits flush with the housing and doesnt alow the brackets to put enough pressure on it to hold it. I can grab and twist is effortlessly.. The blades arent contacting anything though, they spin freely. When I put it back into the S5 exhaust housing, it sits about 1/8" up, letting the brackets torque it down. I dont know what else to do.... Can anyone else offer any insight please

Rxmfn7

iTrader: (4)

^....

RETed

The CHRA isn't sitting onto the turbine housing properly.
It's a friction fit, and sometimes it takes a little motivation to get them to sit properly.
If the bolts are torqued properly, I wouldn't worry about it.  Corrosion can hinder proper mating of the surfaces.


-Ted

Rxmfn7

iTrader: (4)

So youre saying that even if I can grab the compressor housing, and give it a spin, its not a problem? There doesnt seem to be any up/dowm movement.

RETed

Yes, the main point is that there is NO contact when you spin the shaft.

-Ted

rx7_turbo2

I need to get this straight in my mind.

When you take the hybrid(S4), remove the exhuast housing and replace it with an S5 exhuast housing the center section and wheel does not sit flush into the S5 exhuast housing? That seems very odd.

Is it possible for you Lenny to take a picture of the senario I just mentioned?

Rxmfn7

iTrader: (4)

Yes, exactly. And when the S5 turbo is taken apart, and the S4 exhaust housing is mated to it, the S5 center section seems almost sunken in to the S4 exhaust housing. (maybe not sunken in, but perfectly flush to as where the brackets and 13mm bolts dont do anything to torque it down)

When I put both turbos together as they are(S5 on S5, and S4 on S4), as soon as they are set in place, they get very tight, like its a snug fit. When they are swapped, it seems very loose and able to move all over. Ill try and get some pics up today.

Id really like to use this S5 exhaust housing and manifold on the S4 Hybrid Compressor section, but its making me uneasy being as how they dont seem to be mating properly.

eyecandy

iTrader: (19)

I am having the same problem, the S4 center housing is sticks out about 1/8th of an inch when matted to the s5 exhaust housing, is it possible to us a few washers to get the main clamping brackets flush? Or is that not a good Idea?

Have you thought of adding a ring inside the lip where they meet?

rx7_turbo2

I think I mentioned to Lenny, that if you took the turbo to a good local turbo shop or even a good general machine shop and show them the problem they should be able to grind out or down the small amount of material that seems to be causing the problem.

Rxmfn7

iTrader: (4)

Im thinking of throwing the S5 exhaust housing in the oven at 500* for an hour or so, then seeing if the S4 center section will drop in further. Think this is a good idea or no?

If i will need to take the turbo to get it machined, Ill just sell the S5 turbo and stick with the S4 exhaust housing. All that trouble for the little gains it may have isnt worth it to me..

Just kinda gets to me that so many people say that it should fit fine...and it just doesnt

rx7_turbo2

It really is strange. The turbo see's temp's well above what the oven can produce so I don't see any harm to it. Just don't burn yourself!

Having it machined is no real big deal. It might cost ya $20 or so. If you live in an area without a machine shop then I see how it could be a pain in the ***, but otherwise it would be a pretty quick and easy solution. In the end though you could throw the thing together using the S4 exhuast side and manifold, and run the car. That's the setup I used and it worked just fine and made pretty good power.

eyecandy

iTrader: (19)

Hmmm I have been thinking it over and trying a few things.

You guys are talking about machining down about 1/8 of an inch or so, I thought of that and decided against it and I would try to advise you not to do it either. It may mess up the flow of the turbine, and if they screw up and you then have the same problem you did with the S5 on S4 not tightening down because it is to deep.

I decided to just port the hell out of my S4 wastegate, and maybe in the future I will get the S5 turbo rebuilt or find a excellent condition S5 turbo...

I think it is safe to say that the S4 and S5 tubo housings are NOT interchangeable, with modification.

rx7_turbo2

That's why you get a GOOD shop to do the work. believe me any good machinist would be able to do the job, no problem. That type of work is done to turbo's ALL the time.



You two guy's are the only two I've ever heard of having this problem. A ton of people have swapped the S5 exhuast side onto a S4. Do a search on www.teamfc3s.org/forum I know it's been done by a few members over there. Plus you've had a couple very knowledgable people in this thread say it's been done a million times without modification. I'm not saying you guy's are lying or don't know what your doing, I'm sure the problems your having are very real, but the situation is VERY strange, and without having the turbo in my hands it's really hard to come up with a reason this is happening. The solution of machining the housing is a very easy one and would solve the problem completly I would think. But like I said, port the S4 wastegate VS machine the S5 housing. Six of one half dozen of the other, both will solve the problem and get the turbo in the car.

RETed

I guess the three FC's I've done this to is just a figment of my imagination then...


-Ted