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6Cm2 Vs 7Cm2


Brad850

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No matter how hard I push down on the arm, there is play in the circular stopper. I barely have to push on the 19t's arm and the circle feels like it's welded shut. I'm assuming if air was leaking through that would be really bad

Maybe when the turbo heats up it becomes irrelevant? Could be one of those things where my simple logic doesn't apply.

Do you really feel like the looser wastegate can cause any issues?

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Hello all,

Actual inlet size is irrelevant. My S70 came with a 6cm but had the huge inlet as shown on the left in your pics. Where it narrows to flow over the turbine wheel is where the difference lies. 7cm has an angled corner, 6cm is more square overall. I have seen both 6cm and 7cm housings each with the large and small inlets. Think maybe the early units had the smaller inlet?

As for the tabs, my experience is that the 6cm housings have the square tabs. When I was looking for the 7cm 16T that I'm running now, I noticed that all of the 7cm housings had the rounded tabs, and all square tab units ended up being 6cm. So there is seemingly something to that, but consensus has it backward ;).

Hope this helps,

Joe

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19t: 89-13300 6 DCH ... other side says 7D2... no numbers on either side of the inlet flange

18t: 189-13202 7 ... other side says HA32 ....0216 on one side of the inlet flange and 760 on the other side

based on the pretty extensive digging I did several months ago, the markings you posted on the housing fitted to your 18t are the easiest and sure bet identifiers of 7cm... that housing (the "760" as I came to call it) is the "gold standard" in my book. IT IS A 7cm.

All others are a bit of an unknown. Round tab vs square tab, 7 in the numbers vs 6 --- not necessarily indicators of what you have. Again, all based on my extensive digging but otherwise total lack of direct experience.

I had a detailed spreadsheet at one point of all of the various Volvo numbers, MHI numbers, etc. Hours and hours of searching out and compiling data.

Now it seems all I have is a whittled down version with mainly 13t housings, as I became CONVINCED at some point that SOME 13t turbos came with the 7cm --- and they are plentiful and cheap (hence the reason I chopped the list down to 13t only)

I can send it to you if you want it, but now that I am reading here that round vs oval is not necessarily an indicator my chart may be misleading --- I built it based around ebay auctions with visible shots of the opening and various part numbers, with further supporting evidence coming from various manufacturer websites, etc. The primary underlying factor behind my hunting was the fact that I was advised by a reputable and well known tuner that oval vs round is a dead reliable indicator of 7 vs 6.

Now I am really intrigued. I MAY be running a 6cm used housing instead of the brand new 7cm "760" that came on my Volvo 19t (I planned to sell it in new condition in order to recover some costs)

I went so far as to take the housings, remove the clocking pins, and seal off the v band side with plastic wrap and a rubber band... I sealed the manifold flange with clay and clamped on wood, and I filled each with water (and contorted in strange ways to bleed all air without spilling liquid), topped up, dumped out the contents (again contorting to get all liquid out) and did final measurements.

The "760" and the 13t variant with round opening measured up the same. Best method I could come up with without getting too crazy. :)

one final edit: as I recall, I filled them to the point where the wastegate port (wg full open) and turbine hole were covered in liquid. I used a turkey baster to get any excess out. haha. The point is, the post turbine housing volume was taken out of the equation. I took notes, but I can't find them....

edit:

here's the (whittled down) chart I was speaking of:

exhausthousings.jpg

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This is what you're after:

19t: 89-13300 6 DCH ... other side says 7D2... no numbers on either side of the inlet flange

18t: 189-13202 7 ... other side says HA32 ....0216 on one side of the inlet flange and 760 on the other side

The 'other side' numbers don't matter.

I also spent lots of time a few years ago researching turbine housings. There's even a mythical 8cm one going by the books; never seen one so it's bogus AFAIK.

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