Exhaust Flanges & Gaskets

Always hate starting a new thread, but I've spent the last hour searching with little to no info. on this.

Ok, so I have a 3rd gen (keep your murmuring to a minimum), and will be installing a new exhaust setup next week. I am have the new URD y-pipe, Vibrant Ultra-quite 3" Resonator, and Magnaflow muffler (3" in/out) w/ black tip.
I am having the local exhaust shop weld all the custom 3" piping between the y-pipe -> resonator -> muffler -> tip.
So it's pretty much gonna be all new exhaust after the 1st of cats back.

My Question:
The stock exhaust flange on the down pipe side (where it connects to the y-pipe) is currently 2.5" I think??? Anyway, I know it's not 3"... instead of using the stock flange there and welding a 3" pipe onto it, I would like to get a new 3" down pipe flange to connect to the URD y-pipe flange (whose diameter I believe is 2.25").

Would this be the correct flange to get?
http://vibrantperformance.com/catalog/product_info.php?cPath=1527_1532_1122_1153&products_id=144

^^^Is this the same shape & size as the stock two bolt flange?^^^
Looks like it to me, but looks can be deceiving.

Also, assuming that this flange would bolt right up to the URD y-pipe flange (but just have a larger diameter hole), would this gasket work?
http://vibrantperformance.com/catalog/product_info.php?products_id=128

Or do I need to get some kind of donut gasket? Don't know why I would, seeing as how it would all be using aftermarket/custom parts.

Any help would be greatly appreciated. Thank You.

 

If you're going to the expense of getting a custom exhaust, go with v-band, so you don't have to screw around with gaskets and bolt together flanges.

 

Can you use two different diameter flanges with a v-band clamp though? The URD y-pipe is 2.25" and the pipe diameter of the downpipe would be 3"... Not sure how that would work, or if it's even possible

 

If I'm reading the op's question correct, he's trying to change out the flange at the back of the y-pipe. Not sure what he's calling the downpipe. When I hear downpipe I think turbo exhaust. I agree v-band with something like this

http://vibrantperformance.com/catalog/product_info.php?cPath=1528_1211_1320&products_id=1078

be the best option. But if you swap out the spring coupled flange for a rigid mounted flange with a flat gasket or v-band you need to add a flex pipe. That oem flange uses the spring bolts and donut gasket which allow for the exhaust to flex as the motor moves in its mounts.

 

Definitely add a flex coupling, if changing to a v-band.

 

Do y'all think it's worth it to cut the flange off the URD Y-pipe, and add a 4" long flex coupling and v-band to connect it to the muffler pipe?

Keep going back and forth on wether to add the flex coupling & v-band, or leave it as is and just bolt up to stock flange. I know there's some tapering of the URD Y-pipe flange (2.5" down to 2.25" at the flange itself)... Just don't know if the juice is worth the squeeze.

@Torspd I think you have some experience with this maybe??? Worth the $140 in extra parts & whatever the additional labor is gonna cost me?

 

I personally don't think so and I've done exhaust for over 10 years. If you had a bunch of power adders it would be a different story, but as you said the "juice isn't worth the squeeze"

 

What he said.

Do it later on if you really crave the extra power.

We did it to my friend's truck, but his was TRD S/C'd, with additional mods.

 

What does URD recommend to connect their parts to the existing OE parts with?

Seems like they should even be providing those as part of the 'kit'.

 

Their components are designed to bolt up to stock components.

 

They re-use the factory donut. sometimes i think 3rd genners just need to make shit complicated, self engineer everything, and maybe they will magically find another 20hp?

 

For us, I recommended it to him, because the 2nd Gen URD Y-pipe, all 2.25" mandrel bent, bottle necked at that merge collector's outlet. Due to being designed to mate to a factory catback.

His catback was a 3". Well, to keep the flow consistent, that merge's outlet, should be a 3". The necessity to appeal to the broad market means that the merge has to be a ~2.5".

The merge itself, within a few inches of its outlet, is actually a 3", but then tapers down. So we just made the cut there, added a V-band flange, and matched the catback portion as well.

Changed the exhaust tone a little bit, and he said he could feel a slight bump in acceleration.

Then he became a sad panda because 9 psi on the s/c wasn't enough, and went to the dark side. Tuuuuurbooooooo

 

The URD Y pipe is designed to bolt up to the stock or any aftermarket Cat-Back exhaust.

Yes, it does neck down to make that possible. It is also designed so for those that want to eliminate that restriction can very easily slice off the flange and weld 3" pipe directly to it.