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Twin Turbo 928 fixed and back out there terrorizing the streets!

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Old 10-27-2010 | 08:09 PM
  #436  
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Originally Posted by soupcan
The factory clamps (for mine) are a perfect width, IMO the boot will burst before the clamp will come out of the grove.
The factory clamp width would be fine, but with more boost the factory clamps *cause* the MAF boot to break.

The factory steel clamp expands less than the MAF housing with temperature. With factory clamps, one has two choices. Either leave the clamp a bit loose, which means that it will leak or blow off. Or tighten it really tight, which means that the clamp will cut into the rubber boot every heat cycle. These constant torque clamps deal with this heat expansion problem.

With a groove, I hope the whole package will live happily ever after.
Old 10-27-2010 | 10:11 PM
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Originally Posted by ptuomov
The factory clamp width would be fine, but with more boost the factory clamps *cause* the MAF boot to break.

The factory steel clamp expands less than the MAF housing with temperature. With factory clamps, one has two choices. Either leave the clamp a bit loose, which means that it will leak or blow off. Or tighten it really tight, which means that the clamp will cut into the rubber boot every heat cycle. These constant torque clamps deal with this heat expansion problem.

With a groove, I hope the whole package will live happily ever after.
I always put some electrical tape around rubber gas line before clamping hard it keeps the clamp from cutting into the rubber.Try a 1 or 2 wraps of the electical tape around the rubber of the boot to see if it helps from little slots of a clamp from cutting into it rubber.
Old 10-27-2010 | 10:37 PM
  #438  
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Originally Posted by ptuomov
These constant torque clamps deal with this heat expansion problem.


Interesting. Do you have a measured width of one? I am going to grove my spare maf soon.
Old 11-20-2010 | 12:16 PM
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Originally Posted by soupcan
Interesting. Do you have a measured width of one? I am going to grove my spare maf soon.
CT9472's band width is 9/16.
Old 11-20-2010 | 12:20 PM
  #440  
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Default Quiet exhaust

I've been slowly working on a really quiet turbo exhaust. It's one of those two out of three deals: Out of quiet, high-flowing, and light you can have any two. I am trying to go for quiet and high flowing but compromising on weight.

There's a custom muffler oval midpipe, a couple of 3" magnaflows, and a 4" magnaflow. All laid out on the floor:

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Next, it's time to order the pieces to fill up the gaps.
Old 11-20-2010 | 01:43 PM
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I have looked through this thread, and must be missing it, or it isn't here. But I would love to see pictures of how the system is laid out.

I can't come up with the words to describe what your project does to me. It's a combination of being in the middle of changing engine mounts in my 89 GT, and from having built up a turbo system in 1979.

So I guess that translates to nostalgia combined with the fact that they put cars together now so that one can't even fit their hands into the empty spaces between parts.

I really want to see how this all fits in. Please, please post some photos.
Old 11-20-2010 | 01:58 PM
  #442  
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I too am really really intrigued with the look, and function, of this build.

One thing I would really be sad to see is that if the Y pipe dose not allow full access to the be lower bell housing bolts. When I had the muffler shop build mine, that was a must so that I could slide under and check the drive shaft preload without having to drop the exhaust.

It is a must.

But I really like what you have done so far. More pics please


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Old 11-20-2010 | 04:03 PM
  #443  
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Sorry Brad,

But if that exhaust is on your car you should take it off and throw it away.
From that 1 picture I can tell you that it is going to hurt performance, and caused decreased life of the O2 sensor.
Old 11-20-2010 | 04:29 PM
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Is that a laminate floor?
Old 11-20-2010 | 08:08 PM
  #445  
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Originally Posted by Gregg K
I have looked through this thread, and must be missing it, or it isn't here. But I would love to see pictures of how the system is laid out.
I assume that you are talking about the exhaust that I am building now. This is cat-back exhaust. I have two 3" cats in the car after the turbo downpipes. There's no room for a cross-over before the cats, because installing the down pipes is a contortionist act even when they are not connected in any way. Nothing before the cats is changing.

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The parallel Y of this mid pipe is then connected to the cats with V-band clamps.

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The splayed Y of the mid pipe will go to where the stock resonator boxes usually are. I'll have two oval mufflers there, one on each side.

After the mufflers, I will merge the 3" pipes back into a single 4" pipe and hook them up to the 4" rear muffler.

Originally Posted by bwmac
One thing I would really be sad to see is that if the Y pipe dose not allow full access to the be lower bell housing bolts. When I had the muffler shop build mine, that was a must so that I could slide under and check the drive shaft preload without having to drop the exhaust.
The mid pipe is located much further back, so there's no risk of that.

Originally Posted by Landseer
Is that a laminate floor?
I don't really know what it is.

I bought a nice garage in the spring and it came with a house attached to it. The house has a number of rooms and one of them has a floor like that. It's probably some sort of soft wood.

The rug is an old rug, back from the days when I was a college professor and only could afford to shop furniture at IKEA.
Old 11-20-2010 | 08:47 PM
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Your exhaust system is gorgeous, right on down to the clamps, but my curiosity lies in what is happening at the exhaust manifold end of things. I suppose that's pretty tough to get a picture of.

Overall this is just a very well thought out and implemented project.
Old 11-20-2010 | 11:00 PM
  #447  
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Originally Posted by Gregg K
Your exhaust system is gorgeous, right on down to the clamps, but my curiosity lies in what is happening at the exhaust manifold end of things. I suppose that's pretty tough to get a picture of. Overall this is just a very well thought out and implemented project.
I agree that it's well thought out and implemented, but before I get too carried away let me remind you that I didn't make it, John Kuhn did.

Here's the exhaust manifolding of John's kit:

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Old 11-21-2010 | 09:20 AM
  #448  
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Tuomo let me drive this car at Tass's GTG last month. Thanks Tuomo!
This thing is holy $hit fast, and I have to admit I was scared to get near peak power. The only other thing I can compare it to is a 996TT X50 I drove, and this is quite a bit faster. My .02c

p.s. I have driven a murph '89 5 speed making 470 at the wheels, and a DR '90 GT making 400+ at the wheels, and they were both strong but this 928tt is sort of in another ball park.
I would say that the DR "90 GT was the most drivable and usable (of them) in my opinion.
Old 04-24-2011 | 01:46 AM
  #449  
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Any updates on this?
Old 04-24-2011 | 04:21 AM
  #450  
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I spoke with Tuomo recently and he said that he is swamped with work and it will be months before he can get back to the car work.


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