I have recently got both a Warpspeed Y-Pipe and a Dynomax Super Turbo muffler installed on my car. Here is the sequence of events:

1. Bought Y-Pipe, went to Rainbow Muffler to get it installed.

2. The guy there says that stock y-pipe bolts had rusted badly, and that it was going to take more effort than he thought to get them off (in other words $60 original installation quote turned into $100 ).

3. I get the Y-Pipe installed, and immediately notice two problems.

There is a rattle around 2.2k rpms under light load
There is a hiss above 4k rpms under heavy load / WOT

4. I go back to the shop so they can take a look at it. They tell me that the rattle was because the Y-Pipe was lighter than the original and that the hiss is coming from a hole in my muffler.

5. I figure out myself that the rattling is coming from the cat's heatshield. I put muffler putty between the cat and the heatshield and the rattle goes away.

6. The muffler really did have a hole in it, so I have a different shop put on a new Dynomax Super Turbo muffler.

7. The hiss doesn't go away after the new muffler is installed.

Here is a quote from Dallas from Warpspeed himself in a different thread that I was involved in:
We have sold over 6,000 Y pipes at last count, typically there is no hissing, but because we use 2.5" tubing which is larger tubing the 2.25" some of the others like stillen and c**man use it may magnify what little exhaust turbulence remains in the lined flex section which is afterall what causes the hissing. The stock Y pipe has a flex section that is not lined but it is 2 inch.

Original post:
http://forums.maxima.org/showpost.ph...8&postcount=35

My main goal now is to figure out the source of the hiss and get rid of it. I'm pretty sure it's related to the flex section of the pipe.

Here are my options as I see them:
1. Try muffler putty that I used on the cat's heatsheild on the flex section of the y-pipe. My logic behind this is that the the muffler putty will dampen the flex section from vibrating if that's what's causing the hiss. Then again, I'm worried that even if I put a little bit of muffler putty on there that the flex section wouldn't be able to flex like it's supposed to.

2. Put header wrap around the flex section of the y-pipe. Unfortunately, if you look at Dallas's post he mentions that header wrap will even cause the stainless flex section to fail.

3. Take the car back to Rainbow Muffler and make them check the welds / bolts, but I would like to give them the benefit of the doubt that they can do something as simple as install a Y-Pipe. Also, I know they don't care about my business since they got the money already. Besides, they didn't even try figure out that it was the cat heatshield that was causing the 2.2k rpm rattle and just gave me a BS response instead (which was probably caused by them trying to brute force the stock y-pipe off, I saw them do it). I really don't want to deal with them again, so I'm considering this my last option.

So, now you know the whole story. Let me know what you guys think.

It seems at this point I'm too **** for aftermarket modifications .

 

Wow warpspeed is full of ****. First of all Cattman is 2.5"

2nd, warpspeed makes ****ty ypipes, i never liked them. You need to replace the flex with a 3ply flex section to get rid of the noise. You can use exhaust wrap but it will cause the flex to rot out more quickly.

 

So, what do you think is causing the hiss? Do you think air is leaking out of the flex section causing the hiss, or do you think the flex section is resonating (vibrating) causing the noise?

 

that pretty much sums it up.

 

Prob both. And their ypipe comes close to the engine which causes the vibration IIRC...

 

Warpspeed does not put a required bend in the pipe going to the Cat converter. By leaving this pipe straight, it puts more stress on the mounts and the flex section, and causes the y-pipe/cat to contact the bottom of the car and/or the metal bracket and causes the vibration/rubbing problems. It can usually be mostly fixed by adjusting the bracket, adding in washers, etc to help adjust it over to where it should be had the pipe been bent correctly, but its still going to cause some issues.

 

About how long do you think the stainless steel flex section would last if I put header wrap on it?

 

I put header wrap on my old warpspeed flex section. Lasted over 2 years before the car was totaled. I pulled it off once about a year in and did not notice any extra wear or corrosion. No salt on the roads here. Your experience may vary.

 

i have the same problem.. im never again buying a warpspeed y pipe... mine leaks and since day 1...

what a POS..... but yea im a little skeptical about putting exhaust rap on it since it will cause the damn thing to rot faster...

 

That is good news, I only plan to have the car another couple of years anyways. I'm in Florida, so I don't have to worry about salt here, but it does rain alot.

 

Well we may have you beat, it rains just a tiny bit here in Seattle. If your really worried, they do sell a spray on coating that is supposed to help protect the wrap and keep crap from soaking into it. I just couldn't live with the hissing, leaking, crappy sound anymore, so I said screw it, if it rusted out, I'd just buy a cattman and call it a day.

 

I like the way you think . I'm assuming the exhaust wrap worked pretty well?

 

For me it did, it dropped the audible noise by about 1/2, which was enough for me. You need to do a good job installing the wrap though, or it will just come off. Don't use those crappy straps that come with the stuff. I used a couple of hose clamps, get it started TIGHT on one side, and then clamp it down. Then work your way around, making sure to get it very VERY tight, wear gloves or that stuff will tear your hands up! I wrapped mine from front to rear, so that the wrap overlapped in a direction such that the wind would not pull up on the layers. Have the other clamp ready, and go slighly past the flex, then clamp it down, again making sure it is all really tight. Soaking the wrap in water can help. I also wear long sleaves when working with it, that stuff will make you itch like crazy. Good luck.