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better breathing turbo with catless downpipe


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My turbo wagon ran much better after replacing the cats with straight pipe. It was amazing how much more pep I had above 4000 rpm.

 

If you haven't already, go for the crossover pipe next. As far as EA-82T's go, it seems like exhaust is the biggest power robber.

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Trog, the prototype was a bit of both, both the bender and I worked on the setup.

We made two, one being used for a template for others.

We will no doubt weld up a jig from it depending on interest.

 

The final product is 2.5 " O.D. wrapped in header wrap and comes with bracket for the tranny lower mount and a DOJ heat shield.

I have pictures of it mounted and wrapped.

 

Remember the cat burns unburned hydro carbons and thus becomes very hot,

no cat means much less heat in this area to melt the DOJ

 

I used the same pipe with only a Hi Flow 3 way cat from Jeggs, yes it sounds rodded not riced.

 

 

BTW

I am also working on a crossover pipe, I have Witte's jig and a spare factory X over pipe.

 

if you prefer you can email me direct for details

neper@westol.com

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Was this done on a mandrel bending machine? Or did you use a manual tubing bender?

 

Just curious, as I have been wanting to make this same thing, out of stainless steel, but none of the muffler shops will do it, of course, so I've resinged myself to buying a tubing bender. But I don't have the scratch for a mendrel unit. I'm hoping I can use one of the ones that uses a bottle jack. I don't see why they won't work.

 

RedLance

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RedLance, the bending machine is a mandrel bender, thus having "shoe saddles" on both sides of the pipe when the bend is being made. I have looked at the bottle jack version and wonder what the outer portion will look like with only two pins holding the pipe. Please let us know how it works out. I have wanted to get one of those for another project I'm working on.

 

Caboo, I will send you what I can but the pictures tell the story.

 

Andy, the pictures of the cross over pipes you show indicate that they are very serious about keeping the runners from both heads the same length, I doubt that will happen on the model I am making. Mine will match the port sizes and put mandrel bends in the shape. There is not a lot of room to play with.

 

Hope this helps

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looks cool. the side by pass tube is a great idea. I have a few sugestions if any one wants to make a nice duplicate of that one. I have read that when making a bypass pipe such as the one you have it is a good idea to use a section of flex pipe(on the small pipe) to keep the assembly from cracking due to temp differences. also the crosover or up pipe is designed to be slightly restrictive to keep flow speed fast going into the turbo. I was told not to mess with the size of the up pipe unless going to a larger(wrx?) turbo:banana:

. not speaking from experience as I have yet to make the mods necessary to mount a wrx turbo but when the time comes :burnout: lookout.

 

sorry but those do not look like mandrle bends to me. a true mandrle bender supposedly uses a die on the inside of the pipe while bending. making a multiple bend section without welds such as that not possible. I could be wrong :confused: but this is what I have seen in the past.

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I will attempt to address these issues if I may

 

1) The by pass tube is also wrapped concurrently with the main pipe, I'm sorry I do not think there will be that great of temp diff, they almost touch. Maybe if they were not wrapped you would have a point.

 

2) The X-over pipe is very restrictive right at the exhaust ports ONLY, I can not see how this would speed the flow into the turbo, as it changes to a larger diameter several inches into the pipe. To me this would restrict the exhaust pulse coming out of the head and then cause a slowing of the pulse when it hits the larger pipe.

The reverse entrance of the passenger side pipe into the crossed over pipe is also a confusing design.

I was under the understanding the entrance to the turbo turbine is where the gas acceleration takes place. Please note I said port matching. The size will be the size of the exhaust port.

Question Russ, have you ever seen a crossover pipe off of a car?

 

3) Mandrel bends, this machine does have a "die" on the inside of the pipe when bending. Although some crimping near the turn occurs, the man owning the machine claims it is a mandrel bender? The tight radius may have had something to do with it but as you allude, a true mandrel bend has no crimps.

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yeah skip. I have had the crossovers off a couple of times. the first time I did it I opened up the ports just like you said to provide a smoother transition as I too thought it was restrictive. that crossover later cracked in a bad place to weld. when I changed it out I did not do the same porting as I had done the first time around. it seems to have the same amount of power now as with the ported version. I dont have the luxury of a dyno to tell anything for sure.

I had gone to a muffler shop that does fabrication such as that. he said he would do it for me but I probably would be upset with the performance with out a larger turbo to match the flow with.

 

dont get me wrong I am not tryin to criticize your work I think its great. just trying to sare some info. cheers:headbang:

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hey Skip, i'm interested.. well hell i better not lie... i want one...

 

if i could replace my hole exhaust with 2.5" no cats and a nice flowmaster i'd deffinitely be willin to pay for and pick up the pipes... bet that'd make my 289k soob really run...

 

let us know when you can go into production :headbang::grin:

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