How much did it run you to have it done, how long did it take, etc. Any other info. is appreciated.

Thanks!

-E

 

Yep, this info would be appreciated by me as well!
Thanks!

 

I went to my muffler guy and he did it in about a half hour and charged me $60. He does great work!

One guy gave me an estimate for $250!!!

I walked out and went to my muffler guy and he did it for $60. No need for the flex pipe. I had my guy put a flange on it so when I have to take it off for what ever reason, it makes it alot easier.

I love the way it is now and would never go back to that annoying open wastegate.

 

I was going to vent mine back into the exhaust, but I still want to be annoying.

 

Heh. I know, right. I actually kinda like the crappy sound, but they'll never allow us to run at the local autoX with the dB restrictions.

Gotta do it.

Thanks for the input y'all.

-E

 

Just make sure that you don't put the pipe to close to the turbo outlet. Supposedly you can get some turbulence that can decrease performance.

 

You really should put a flex pipe in- the dump tube goes through frequent and large temperature changes when you run up through the gears. I'm not saying you're guaranteed to have it crack if you don't, but it is the recommended way. Also, if possible have them 'Y'-in the dump tube to the dp instead of 'T'-ing it in- less disturbance to the flow.

I think I had mine done for $170, including a flange and flex section.

 

Out of curiosity where did you get the flex pipe? I've been looking for one for a while and havn't had any luck.

Thanks,
Matt

 

What is the benefit of running the wastegate to the DP?

 

Benefit? No noise. The noise is basically like having a 45mm (or however big your wastegate is) hole in your exhaust....

 

No need for the Flex....

Do you see anywhere on the RX7s exhaust that they use flexpipe? No!

The exhaust moves together. A weld is not going to crack if welded correctly.

Mine is Y-ed in too....

 

Ya I like the wastegate noise too... BUUUURRRRRPPPP!!!

 

I'm a little tired of hearing my passengers complain ... it seems it is much louder in the passenger seat! Oh well, I'll get to hear the turbo whine now.

 

People like to ask how my turbo sounds when it spools up. I just say "what?"

 

I hate to burst your bubble on this one but I did the same thing you did 2-3 years ago and while I love the results, I have had problems. The stock manifold has the waste gate built in and its all cast iron, our setup is very different.
The biggest PITA is when you take it apart and try to reassemble it. There is enough positioning play between the manifold, turbo, and down pipe, that you never get them to line up quite right. So now your under the car with a pry bar pushing the down pipe trying to get the bolts for the waste gate started. Or you leave everything loose and wind up hosing the threads on your cast iron waste gate assembly when you try to tighten everything back up, now where having fun! I also recently developed a crack in my Greddy SS manifold.
I am told that those flex pipes are not that flexible so while they can compensate for heat expansion they would not help with the fitment issue. I am told that any type of truly flexible pipe would not withstand the heat. I am still trying to come up with a good solution for this, the most promising idea so far is to use a slip joint.

 

I understand that the flex pipe is only for heat issues, and I'm sure a welded non flex pipe would work, but I have to beleive that there is going to be less stress on joints if there is some (even verry small) ammount of movement in the system.

I am also cautious due to the fact that the manifold is cast (xs-t04e) and the pipes are mild and therefore the diffetent metals will contract/expand at different rates.

I beleive that the HKS t04e kit that comes with the dump pipe routed back into the downpipe uses a flexible section for just this purpose.

Matt

 

my T04E kit does not dump in to the downpipe. dumps to open air.

barrrrrrrrrrrrrrrrrrrrrpppp

 

None, you loose power because of added backpressure. The only reason people do it is because of less noise.

 

Yep. But in fairness, power loss is negligible, unless of course, you're running competitively in an application that requires the xtra hp. And then you probably don't care about the noise anyway.

My autoxing doesn't really require the hp I have, so this won't hurt.

-E

p.s. And less noise *is* a benefit to those of us who have dB limitations within our competition.

 

ok then route your wastegate back to the downpipe.


if you car has too much power for your class then why did you mod your car past what it needs?

why not tune your to the hp you need. becuase im sure you could find a turbo that spools faster for autoxing

granted I dont know much about you or your car or autoxing classes. but seam to me if I was going to compete in a it I would build my car to do what it need for autoxing. a fast spooling turbo or go to NA.


sorry got carried away on that.... but routing the backinto the downpipe will cuase a eddy like effect between the dp between the manifold and where the wastegate goes back into the dp. it interrupts the flow of the gasses

 

Okay. Good chance that I will unless I can muffle the wastegate separately.

Hmmm...an N/A FD. Interesting concept. I could consult jimlab on the V8 project I suppose, but that'd put me over the power limit too. Dude, relax. I'm not worried about my classification in autoX events. I'm gonna be in a class of my own already with all the mods. That wasn't my point. My point was that the minor power gains my open wastegate gives me are of no consequence while autoxing. It's all about handling. Straightline acceleration only gets you so far. You have to be able to drive. And, FWIW, as I waste my breath, I have a very fast spooling turbo, the RX6, which I specifically got for both street and autox applications. I've actually thought this thing through believe it or not. And, again, the wastegate muffle *is* to prepare for autox, as they'll kick me out for running above 95dB.

No biggie. Not to be too much of a dick, but before you get frustrated with my apparent lack of forward-thinking in my modifications, try and ask what setup I have first. Communication is a beautiful thing. Try it.

Also, you're absolutely right about the interruption of the flow of gasses. That's our concern also. That's why we're looking at muffling the wastegate separately. But if we can't do that, we may have to route it through the DP.

paz,

-E

 

RX6 - The wastegate sucks in my opinion. A friend blew his engine when it stuck open. I put a Tial 46mm on mine. To do this use a 1-1/2" to 1-1/4" 304ss SCH10 or 40 pipe reducer and a 1-1/4" 45 degree elbow cut to about 30 degrees. For the connection to the down pipe use 1-1/2" 304ss tubing. Purchase 2 with 90 degree bends and cut 1 of the 90s in half = (2) 45 degree bends then Y it into the down pipe as far down as possible before the mid pipe. Lastly, weld a support to the tube to help support the weight and vibrations of the wastegate. Very basic. When you look at it you will understand. If you do all the cutting and pre-fab first, it will save you a lot of money. I started on mine at midnight on a Saturday and finished by around 3:30. I am a little warped because I should have been out getting FCKED. After you are done, take it to a competent TIG welder. Make sure that he purges all the oxygen out of the air surrounding the welds inside and out. If this is done you will have minimum melt through (the inside) and a very sound and beautiful weld. Welding will cost you around $60 to $120 depending on the person.

If you keep the A'PEXI wastegate (I hope not) just buy 2" 304ss tubing and plumb it as previously stated. Should cost between $40 and $80.

Another option that I did not check out is an HKS which is suppose to be an almost direct bolt on. I saw this posted don't know where do a search. Hope this helps.

 

Thanks man!!

I actually have the HKS already, and I much appreciate the fabrication advice/run-through.

-E

 

The exhaust being free to move relative to the frame doesn't help the dump tube. Since there's a fairly large loop formed when connecting the dump tube back into the exhaust, there may be enough flex in the loop that the welds don't crack. Also depends on how your car is used- I do track event pretty often which is probably a lot harder on the weld than street driving. Again, no guarantee that you'll have a problem. Since it was only an extra $100 or so I wanted it done the right way.

The muffler shop had the flex section.

To minimize the effect of routing the dump tube back into the exhaust, 'y' it back in as far away from the turbo outlet as possible. Mine's 18-24 inches, just in front of the cat.

 

Over here, curcuit racers always route there wastegate back into the DP. Now drifters, street driver, and drag racers usually have open air wastegates.. I was told its not power, but responce, you dont need all that much responce on a track, but you do doing the other types of racing. Also with an open air wastegate, you lose a minor amount of gas milage, but you guys know how curcuit racers are, I wish I didnt have to stop for gas...HAHAHA so they save every drop