curls

So I fired up the car this morning and immediately noticed it sounded like a Harley.

When I got home from work I jacked up the car and found the obvious culprit:





So... I need a new flex pipe, that's obvious. Does anyone know the proper size for the upgrade over DC-standard? I believe it's about 1/2" longer than this one... so there's less stress on the braid and thus less chance of the above separation happening.

Any idea on the price to buy one of these and have it installed? I don't want to get ripped and the choices of exhaust shops around here are pretty basic (chain places, and one exhaust specialist that's recommended but a good 45 minute drive from my place each way).

Thanks!
Eric

jlukja

Eric,

I believe you need a 2.25" x 6" flex pilpe. From what I recall they are about $15-$20 plus shipping. My local shop charged me $90 to cut the old flex pipe out and weld the new flex pipe in, all without removing the header.

edit: I think this is the one I used: http://www.performance-curve.com/ind...ROD&ProdID=143

edit2: Disclaimer -- mine is the Topspeed Header which is supposed to be a stainless steel version of the DC header so the dimensions should be the same.

JTso

iTrader: (2)

If the flex pipe didn't crack, then you may not need to replace it. I would pull the separated flange toward the flex pipe and put 2 or 3 witness marks on both the bevel edge on the flange and flex pipe. Then remove the A-pipe and the flange. Take them to a welder and weld them back together from the inside using the witness marks for alignment.

curls

JTso I'm not sure what you mean. By witness marks, that'd be a white grease marker to show where they are to meet when re-welded (by "they" I mean the rear flange pipe and the flex pipe)?

And then the welder would re-weld the existing flex-pipe back onto the existing pipe/flange?

If it isn't too much more I'd probably rather get a double-walled flex pipe, one that's a bit longer, and be done w/ it.

Is the 2"x4" the standard one, and the 2"x6" the longer version to prevent separation like I experienced?

Tx.

JTso

iTrader: (2)

I can't remember but I think it's the 2x6 version. You should get under the car and measure the existing one to make sure.

curls

And add an inch or two to make up for the shortness of the DC-original one... ? I'll have to look tomorrow or Sunday, no time tonight at all.

JTso

iTrader: (2)

I would add 1/4", 1/2" max. Any longer can cause the exhaust pipe to come in contact with the rear swaybar. Keep in mind the exhaust system will extend another 1/4" toward the rear once heated up.

TSXual

my header lasted me once pass down the 1/4.. dc sports is quality ha.....! yaright...

curls

Interesting. So how come in other threads there are lengthy discussions about whether to add a 4" vs a 6" flexpipe? That's a huge difference, and if 1/4-1/2" is the most one should add, I'd think that one of the two options that were discussed would be way outta whack.

I assume adding 1/4" would involve a new small section of pipe and have next to nothing to do with the flex pipe itself?

JTso

iTrader: (2)

I think people are confused with the flex pipe length and the actual overall length. If you read the flex pipe description carefully, you will notice it lists the length of the "flex section" and if it has an extension or not. All replacement flex pipes come with end caps but not all of them come with the extension. Therefore, you need to measure the existing broken flex pipe length and the overall length (including the end caps). Then find one with the exact measurement (flex pipe with end caps) plus the extension. Keep in mind the flex pipe with the extension can be a little too long depends on how much of the original section on the A-pipe the shop is going to cut off. The objective is to only lengthen a small amount to the original A-pipe length.

Tsx536

The entire length of the original DC flex pipe is 6" that includes 4" of mesh and 1" end caps on each side.

The length of the area that you will replace on the DC header is 6". When you buy a flex pipe you want to make sure that the overall length of the part is 6" long. Regardless of whether it has extensions, end caps, etc, it needs to be 6" long to replace the same 6" section on the DC header.

Also inspect that rubber hanger while you're there. I had one go bad on me and rip causing my flex pipe to develop a hole.

curls

Thanks JTso... that makes more sense. So ideally I'd get one with a 4" flex area, and 8" overall length (so I can cut off about 1 1/2" of length between the two ends, effectively lengthening the A-pipe by 1/2".) -- I will consult with the shop doing the work, once I find one to do the work, as to what exactly I want done.

I checked a local place today and the various flex pipe replacement pieces started at $47.00. I'll have to look around some more.

Am I best to look at stainless, or will any replacement one work? Being mild steel but ceramic coated, is there a problem welding stainless to mild steel, or is it trickier causing the shop to jack up the rate?

Tx.

JTso

iTrader: (2)

I would use a stainless flex pipe for added strength. There shouldn't be any problem welding mild steel to stainless. Just grind off the ceramic coating where the joint is and weld the pieces together.

curls

I just verified that on my v1 DC Sports header, the flex pipe is 4" itself and there is a 1" piping section to the welds on each end, so a 6" total length (4" flex). The OD of the header pipe is 2" (6.5" circumfrence / pi (3.14) = 2.07"), so I'd need: 2" ID x 6" total length x 4" flex section as a replacement.

I'll order one tomorrow AM, and hopefully the installer I pick can lengthen the overall length by 3/8" by carefully cutting the old one out.

Thanks to all!

curls

OK, I went a different route for the replacement part.

I ordered a 6" flex pipe, but it's from Vibrant Performance (T304 Stainless) and is about 5.5" of flex pipe, and about 3/8" on each end to weld to. Just enough, meaning what I'll have the shop do is cut out about 5.75" of existing pipe and replace it with this. The end result will be a longer flex pipe than normal which isn't a bad thing (which is also double braided to reduce/eliminate hiss), plus about 3/8" or so of extra length to help this one from getting damaged.

I was unable to find a double-braid stainless 6"x2" w/ 4" flex section anywhere locally -- only alumized which I didn't want. Plus with the way the flex pipe is so close to the flange near the catalytic, having some freedom on where to cut should give the installer some play in where he places it, making his life easier.

I'll get pics of how it looks and tell you how it goes, hopefully tomorrow afternoon/evening.

curls

To follow-up and close this case, the Vibrant flex pipe is the exact same dimensions as the existing DC one (4" flex, 6" overall), even though the tech at Vibrant told me otherwise. So I didn't bother getting it sent back in favour of the 6"/8" overall one, I just had Minute Muffler take the old one out and put the new one in, and do it such that I gained 3/8" of length pre-cat. That was where the exhaust from the cat back sat naturally (as the flex pipe/header wasn't holding it out of natural position even when hot), so it made sense.

The car is fixed, quiet, and the power has returned. Damn it was sluggish with the exhaust not sealed up properly! $30 for the new flex pipe (stainless) and $100 for labour and shop supplies, taxes in. Not too hurtful... I'm happy with the results.

jlukja

Eric, did you buy your flexpipe on-line or in person. Can you post a link to the flex pipe you bought if on-line?

curls

I bought it via a local parts supplier, but the part itself is here (this is the manufacturer site):
http://vibrantperformance.com/catalo...12454abcfc0937

See how the pic looks like there is only about 1/2" one ach end of the flex? Well in reality, the 4256 model (6" flex as per its spec) is 4" of flex, 1" of flange/pipe on each side, totalling 6". It still works 100% and with proper cutting, the length is added no problem.

The Vibrant performance tech suggested getting the biggest flex component that will fit, which in the case of the DC header is probably the 4258 (8" overall, 6" of flex), or the 10" version if they make one. More flex length = less vibration downstream of the flex pipe.

JTso

iTrader: (2)

Please post pics of the repair.

jlukja

I see what you mean about the pics. Looks like they just used a generic pic for the different dimension options. Thanks for the info.

curls

I forgot to bring my camera to the shop but will try to get under the car tonight if the rain doesn't happen (my garage is full of summer stuff like bikes and fishing gear and I don't want to crawl under the car in the rain, or put that stuff in the rain to get the car into the garage, LOL!).

I'd like to see the repair myself, actually.

Tsx536

That's a good part. I'm running Vibrant's TurboFlex, which has an inner linner for Hi Temp/Forced Induction applications:
http://vibrantperformance.com/catalo...12454abcfc0937

I've been very happy with how well that is has held up so far. I know what you mean about the car feeling sluggish with the flex pipe problems.

Tsx536

Here's the same part as Curls got out on Ebay. This is the seller I got my TurboFlex from. Good seller and good price. Wanted to post the link because it can be a little tricky to find. It's listed as a flex coupler.
http://cgi.ebay.com/ebaymotors/2-SS-...9511QQtcZphoto

curls

If I factor in shipping, I got it way cheaper here.

I just saw that Vibrant has Keystone as a wholesaler, and know that many parts sellers locally are contracted with Keystone, so I called them a yup, they got it overnight for under $30. Definitely made me happier than if I'd have done with an alumized POS one from Wagner or an offshore company. And heck, Vibrant is Canadian!

curls

Here's the only pic I got before my camera battery died. I figure its enough.

I'm not sure why the first new weld is there (nearest the O2 sensor) but I figure its where he cut the header to bring it to the bench and get things squared, etc. You'll see he used new hardware to fasten the header to the cat -- I guess they were seized after only 1 year (no surprise in my climate and with the amount of road salt they use here in the winter).

curls

Well well well... the 'new' pipe separated again, same place!!! I noticed a bit of a funky noise when hitting the throttle and sure enough, the Vibrant flex pipe suffered the exact same fate as the original one in the pics way up in this post.

I am heading out of town and didn't have time to get to an exhaust shop this weekend before leaving, so I went the cheap route (hey, $10 vs $150, and it might last as long - 1 year, LOL). I got a tube of your everyday average "Exhaust/Muffler Repair Putty", good to 2000*C, and once I had cut off all of the braided stainless (it was getting gnarled up anyways), just the corrugated/rippled inner liner was left. This is still pretty strong, so I jammed about 1/2 a tube of the putty stuff into the joint where the inner liner separated from its flange (or cap). Started up the engine to heat up the exhaust, and 20 minutes later the stuff was rock hard. It says to let it sit for 24 hours to achieve maximum strength, so I plan to do that.

Worst case scenario would be that the repair doesn't work, and the car is slightly noisier for the family trip on Tuesday, but best case... I saved a lot of money be not having to install yet another flex pipe that will seemingly separate again in 13 months.

So... since the exhaust was previously lengthened, and STILL separated (about a half inch of separation to let it rest naturally, again), I'm thinking there's a chance that my exhaust hangers are stretching and not holding things in line properly. Would this be a valid concern that I have? Has anyone changed their exhaust hangers before and noticed any difference in how the exhaust sits or lines up? I might splurge and get an OEM 'dogbone' hanger for the one in front of the cat (the one in the pics)... maybe.

Are there polyurethane ones available or would the normal rubber be better to isolate the flex pipe from excess vibrations?

Tsx536

I did have a problem where the rubber hanger close to the a-pipe ripped on me. I ended up replacing mine, because it was allowed the header to move too much. I even ending up putting a rubber brace on the new hanger to help further support it.

Also, I went through like 2 flex pipes fairly quickly before going with the Vibrant Turbo Flex with inner liner. I've been running that for over a year now and it's the best one I've had so far. It's still holding up despite many dyno runs. My engine moves quite a bit too. I have to no ETD, auto tranny, and am putting down 265hp/199tq. Hopefully that flex pipe continues to hold up.

curls

I've considered the Turbo Flex flex pipe but the differences seem to be only that the Turbo Flex one has a smooth inner liner, whereas the one I have has a corrugated inner liner. The key thing to note is that both have inner liners for strength and flex, but the Turbo one should simply flow better. It appears upon third glance that my flex pipe is not really listed on their site since their basic line does not have any inner liner, whereas mine does.

The corrugation and/or inner liner doesn't seem to be the problem, however. The problem seems to be that the inner liner is being yanked away from the rearward flange it connects to (inside, can't see these welds from the outside). That's why I think it's a problem with the way the exhaust is hanging and/or interacting with itself, and not necessarily with the flex pipe(s) that I am replacing or repairing.

Was the rip in your hanger noticeable? I checked briefly today and didn't notice anything unusual with the one above the flex pipe. Of note, however, is that the rubber dogbone did NOT sit straight up-and-down from the car hanger to the exhaust hanger. It angled down and to the back at almost a 70* angle (not vertical but definitely not 45*... not THAT severe. Check my last posted picture above - it's slightly worse now but not much). Did or does your rubber hanger sit at an angle? I think that's the problem with mine... its possibly stretched, permanently, and letting the exhaust sit too far back, pulling the inner flex pipe liner from its cap.

Tsx536

Mine, would not separate, but would develop a hole in the area where the rear flange and flex pipe meet on the header. When the engine would move it seems like it would actually push down on the header. Causing the hole to develop there. The holes I would get, would not be visible to the eye, you could not see them, but feel them when the engine was on.

It sounds like your problems may be a little bigger than mine, since you're getting actual separation of the two pieces. My recommendation, is to lengthen the piping and make the header about 1/4"-1/2" inches longer. If you're not doing so already, make sure, that the shop is welding the piece on while they are still on the car. This will provide the best fitment.

I did not see the rip in the hanger until I really looked. It was hard to see. If I were you, I would replace that hanger either way while you're there. It doesn't cost much, and will help add strength to that area and prevent your header from moving soo much. I ended up putting one of the rubber hose clamps, on the hanger to help strengthen mine and prevent it from ripping again. Like I said above, that is what has worked for me the best, even after increasing my boost level.

curls

Thanks a lot for the detail. I had actually brought it in to the same place that did it previously and had them put a new one in. I didn't see whether it was welded on-car or on-bench, but I'm thinking it was the latter, unfortunately.

I had already had them lengthen the header 3/8" last time. I'll check the condition of the hanger next time I can, but regardless, he thought fully that it was due to a bad motor mount and/or too much rocking of the engine, to which he suggested polyurethane mounts (not avail for our car). I suggested the engine torque damper and he thought that might work quite well... hence why I might be looking to buy one now.

Recoil45MM

I just ran into this problem with my POS DC header. Not sure if I should waste more time and money trying and fix it.

Audioserf

It's unfortunate that the DC (and Topspeed, the DC replica) headers run into this issue. Some people have been succesful in remediating it (Tsx536, ljuka) and others apparently have not.

Having used a Topspeed, my advice to DC/Tospeed users is to upgrade to a CT-E header. It's not cheap, but it's an "install and forget it" peace of mind that to me was worth the extra dough.