DDP Leak Solution Ideas (PICS)

[theKnifeArtist]

Ive had my DDP for almost 3 years now.
I love the wastegate dump noise and without it, it feels like something's missing.

I recently installed my new quiet catback and swapped out my DDP for my spare HKS 3" DP just to enjoy silence for a little while.
I can definetly notice the power difference from one downpipe to the other.
The DDP is definetly going back in, i just thought id take a crack at fixing its quirk.

So the DDP leaks from a poor seal of the exhaust hole and the wastegate hole.
This causes a exhaust leak under normal operation out the dump tube. This also increases drone under cruising and such.
If it could be sealed, it would be golden.
Here's a couple of my ideas.

Not too sure on a good solution here. Was thinking about some kind of exhaust crush sealing material to seal the two sides.

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This was my genious idea, but maybe a little complex.
Y-pipe with a vacuum operated cutout.
A bunch of audi's have this vacuum operated exhaust valve on the rear muffler to make a more aggressive tone when you're on it. I work at an audi shop, so i thought maybe i can score one somehow.
Having a recirc and open WG option at the touch of a switch seems pretty nifty.

This is the valve on an R32. same shit

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[/IMG]

This may be my best solution.
I HAVE an electric cutout right after my downpipe.
Right now i'm running the HKS 3" DP and when the cutout is open, i cant hear the wastegate. I don't like that.

If i use my DDP and lets say its recirculated back into the exhaust about foot or 2 away from the cutout..Will it sound like an open wastegate dump with the cutout open?
If so, thats my perfect solution.

Thoughts, comments, suggestions appreciated.
Discuss.

 

[nick88]

Option a.

 

[Drake69]

Here's mine.....

Ignore the fact that there's no middle "lip" in the pic. We had to weld one on to make it divorced.

Good, throaty sound to it as well.

 

[Mr.PFloyd]

why not cut and re weld?

 

[TurboStreetCar]

Did you buy the downpipe from BIC? Ive herd they seal up pretty well when the exhaust gets hot and expands.

Your not going to hear the waste gate when the cutout is open because its the same sound. The open waste gate is basically just an open exhaust leak, when you open the dump your making a bigger one thats going to drown it out. Doesn't matter how you route it.

You could try to find something that will crush and seal it up, but when it heats up and cools off it will eventually create a leak. Thats just the way it goes.

You could try to weld the flap into the exhaust housing and then use a crush gasket like stock to seal the downpipe flange to the turbine housing. Then the flap that separates the two outlets would would be a part of the housing and just another flat surface to use a custom gasket with.

It would need to be sealed in the same manner as the rest of the gasket surface using a custom gasket.

 

[NashMan]

ddp just gain power form creep that is all

 

[Poodles]

ddp just gain power form creep that is all

Incorrect, and it has nothing to do with the discussion.

Back to the issue, welding to the cast iron turbine housing isn't going to be easy, but the thought has crossed my mind. Honestly I'd go to a recirculated DDP and never look back as the DDP is just a cop call...

 

[grimreaper]

Keep your invoice for the electric cutout for the warranty. I have used several, only one to not leak within a year was corsa ($$$). Sounds like crap when the electric motor loosens up and the flap wont seal 100% against the exhaust flow!

back on topic

 

[toyotanos]

Here's mine.....

Ignore the fact that there's no middle "lip" in the pic. We had to weld one on to make it divorced.

Good, throaty sound to it as well.

why not cut and re weld?

I vote with these guys. My DDP also did not come with a separation plate, so I had to fab one up and weld it.
To do so, I cut out a smaller piece of metal, put ticky-tac around the perimeter, then forced it into place in the CT's exhaust housing where I was welding it. Pull it out and copy that form on a new piece of metal then test fit. Weld onto pipe once a good fit is found.
Mine is recirculated so it didn't matter as much, but this can make a very good seal when done right. It will also help keep the noise down since you're not recirculated.

 

[theKnifeArtist]

why not cut and re weld?

What'chya mean?

Here's mine.....

Good, throaty sound to it as well.

Got a sound clip other than the one idling on the lift?
I know it's recirculated, but can you hear when the wastegate opens?

Did you buy the downpipe from BIC? Ive herd they seal up pretty well when the exhaust gets hot and expands.

Your not going to hear the waste gate when the cutout is open because its the same sound. The open waste gate is basically just an open exhaust leak, when you open the dump your making a bigger one thats going to drown it out. Doesn't matter how you route it.

Yes, authentic BIC.
I don't agree with your statement here. I was running my DDP with a straight pipe exhaust..you definitely knew when the gate is open. I had my cutout on this setup too, and with it open, you can also hear the distinct scream of the wastegate dump.
Now I'm running a regular 3" HKS DP. Right afterward is the e-cutout. With it open and with the wastegate open, there is no wastegate dump scream.
It's not all the same exhaust leak sound.

Incorrect, and it has nothing to do with the discussion.

Back to the issue, welding to the cast iron turbine housing isn't going to be easy, but the thought has crossed my mind. Honestly I'd go to a recirculated DDP and never look back as the DDP is just a cop call...

I think I am going to go with the recirculation of my DDP, not because of the cop attention, but because it seems the be the simplest solution to having the benefits of my DDP without the leaking part. Only bummer here is that i want my wastegate to be loud as shit when its open, its what i'm used to, this may not be the best solution for that.

A soundclip of an open recirculated DDP would be the best way to find out what my solution would sound like

I vote with these guys. My DDP also did not come with a separation plate, so I had to fab one up and weld it.
To do so, I cut out a smaller piece of metal, put ticky-tac around the perimeter, then forced it into place in the CT's exhaust housing where I was welding it. Pull it out and copy that form on a new piece of metal then test fit. Weld onto pipe once a good fit is found.
Mine is recirculated so it didn't matter as much, but this can make a very good seal when done right. It will also help keep the noise down since you're not recirculated.

So youre basically saying to extend the DDP's flap to extrude more and meet up closer to the surface of the turbo. Sounds good yes, i would say some sealing material would be needed to make a complete seal though.

 

[NashMan]

Incorrect, and it has nothing to do with the discussion.

Back to the issue, welding to the cast iron turbine housing isn't going to be easy, but the thought has crossed my mind. Honestly I'd go to a recirculated DDP and never look back as the DDP is just a cop call...

ok think what yae think but i am right and your wroung

 

[theKnifeArtist]

hey no bickering in my thread please stay on topic.

 

[toyotanos]

So youre basically saying to extend the DDP's flap to extrude more and meet up closer to the surface of the turbo. Sounds good yes, i would say some sealing material would be needed to make a complete seal though.

Yep, that's what I'm saying.
Put putty on the edges of your current flap, bolt it on to your turbo (out of car works best) then take it off. Inspect the putty for depth and find where it needs extra sealing metal. Weld it on where it needs it, and grind to perfection.
I don't think a gasket material is really practical in this application since it is exposed to such temperature extremes, and if it got caught in/on the turbo wheel, damage could happen.

edit: I can hear my wastegate open up on my recirculated downpipe, it's more of a personal preference noise rather than blatantly loud. Not easy to hear on videos, though. If you'd like to try to listen for it, check my (same) user name on youtube for the highway pulls.

 

[TurboStreetCar]

Yes, authentic BIC.
I don't agree with your statement here. I was running my DDP with a straight pipe exhaust..you definitely knew when the gate is open. I had my cutout on this setup too, and with it open, you can also hear the distinct scream of the wastegate dump.
Now I'm running a regular 3" HKS DP. Right afterward is the e-cutout. With it open and with the wastegate open, there is no wastegate dump scream.
It's not all the same exhaust leak sound.

Its the same sound, The only difference is pre or post turbo. Its the same engine, One is just usually louder as the waste gate dump is usually never muffled and very short.

I agree with a regular down pipe, the sound of the waste gate is blended more as it is put into the same pipe, Thats how stock is. A DDP with cutout open will drown out most if not all of the sound of the open waste gate.

Of course it will be louder when the gate opens, but nowhere near as noticeable as having a functioning full exhaust with open waste gate dump.

Im running open waste gate, not even a dump tube and on 10psi with a T-70 i cant even really hear the waste gate open unless im next to a car and the sound reflects back into my window. But when that happens its REALLY REALLY loud. :naughty:

Your best bet is to make a flap that contacts the housing in a manner that it can deflect with expansion from heat. like this:

If you give the sides a bend they will flex but still make firm contact with the housing and the expansion should be minimal enough that they will keep there shape and maintain contact.

The innermost edge that seals against the back wall will have the strength of the flange bolted to the housing to keep that in check.

If there are any leaks, they should get crudded up with carbon and seal up for the most part after a little while.

That would be my plan if i had one and had this issue.

 

[toyotanos]

Oh, that's a really good idea ^^

The fundamental problem I see with street-driving an *open* wastegate/dump/DDP is the noise it produces for other people (cops). I would be pulled over before I got out of my cul-de-sac.

 

[NashMan]

the easyiest way to stop cheep is this

go get ring crush gasket cut it bend it to the shape of the tug( may have to flatten the side some) add on some silcone ot keep it on there

then simplly bolt it on. Thats how I did mine when i made my ddp ( witch I toosed cause i did not like creep so i made a mega mouth with divder and i had the best of both dp's

low end and top end with no creep

 

[TurboStreetCar]

Only problem I see with that Nash, is over time the expansion will crush the gasket leaving an inevitable gap. I would be suprised if silicon could withstand the heat of the housing.

Bends in the metal will allow for expansion and when the metal cools the metal should still have enough "spring" to keep as good of a seal as your going to get. Only way to improve woul be to gasket the bent metal where it contacts the housing, though I don't think it would be nessisary.

Welding a divider into the housing would be the best solution though.

 

[D7MSupra]

I could hear that pipe pretty clearly when Drake called me while driving his Supra right after the install. Still waiting to see/hear/feel your new system Drakeman....:evil2:

 

[NashMan]

Only problem I see with that Nash, is over time the expansion will crush the gasket leaving an inevitable gap. I would be suprised if silicon could withstand the heat of the housing.

Bends in the metal will allow for expansion and when the metal cools the metal should still have enough "spring" to keep as good of a seal as your going to get. Only way to improve woul be to gasket the bent metal where it contacts the housing, though I don't think it would be nessisary.

Welding a divider into the housing would be the best solution though.

mine stayed on for about half year befor i pulled it off the sicone is just so it does not fall off during install

so it does work

 

[Supraguy88t]