Hello all!

I am about to go to the DMV to register MY truck in MY name, sometime today or tomorrow - I hope.

Anyway, on the way back I plan on stopping at exhaust shops and see what they say about putting a REAL y-pipe on my V10.

Now the question:

Should I make certain the downpipes are the same length before the Y?

The stock pipe doesn't look like equal lengths, and this probably contributes to the ricer exhaust sound w/overlapping exhaust pulses in the pipe at the same time.

And if I do ensure the downpipes are the same length, how long? Any educated guesses? Or just do whatever fits? I'm not against re-engineering the downpipes all the way out to the cat.

 

well, the install I just got yeaterday was from the manifolds to the flange on the cat. By looking at the piping from the manifolds to the "Y", they are not the same and I believe its a "whatever fits" type of deal. Even the stock pipes were not the same length. Seeing how we have the stock manifolds on there still, length of the exhaust pipes doesn't seem to matter in my opion. With headers, it would be a different situation, header tube lengths need to be the same. But anyhow, for those of you in the So Cal area, D&D Muffler located in Palmdale, CA (Phone: 661 951 3833) can get you a complete new setup (from manifolds to the flange on the cat. which includes new down pipes, new custom y-pipe, and new 02 sensor fittings) for $160 parts and labor. This is the shop who did mine and I am happy camper with BSEG!!! I am also going to ask them if they are going to make this a bolt in assembly people can buy and install themselves. 1999-2004 SD Trucks and Motorhomes of the same year with V10s should all be the same. I'll have to check that out to be positive.

 

Art, I posted in an earlier thread my pipe lengths from manifold to Stan's Y-pipe. I don't think it is possible to make the pipes to the Y equal length since the cat is all the way over on the passenger side. You would have to really snake the pass. side tube to make them equal. I think the flutter is do to poor exhaust manifold design myself.

 

purerockracing,

Just an FYI, The 99 pipe had the 3" triangle flange about 4" from the front of the cat. The 2000 and up, Ford moved it closer to the engine. The exhaust shop would need to make 2 different Y pipes. How did you get away with that in Cali??

 

Art

With a 4x4 you can get fairly creative if you mostly do NOT go rock crawling or other off road trips where under frame Clarence is critical.

But if you need to tuck the exhaust system up out of the way...then the options are very limited on how to mate the two headers to line up with the pass side off center cat and cat back system.

Of course perfectly equal length tubes to the "collector" would be ideal.
Most of the attempts I have seen force the pass side closer to "center" attempting to reduce the long run from the drivers side... BUT...most of the time to do this the angle the "Y" needs to face is back to the pass side and the pass side down tube requires a 240-270 degree bend to line up... my sense is sharp, long radius bends, are more detrimental then a long easy curved section.

The straighter the flows and easier the transition areas the better, as long as the ratios of length are not too wide, the balance will be OK

If you are not adding aftermarket header, look into finding a set of 05 manifolds... exceptionally better design for flow and they will certainly bolt on as long as you are doing a fabed up two to one collector

If you decide headers... I am in the long tube camp for a motor with this stroke length

 

It doesn't alter any of the smog equipment what so ever. As a matter of fact, looking under the truck, it looks like factory equipment. Cat. and 02 sensors are all still there.

 

how did the exhaust sound when you got done? i have been through hell trying to get mine right. im now back to a stock muffler w/ a resonator in front of it. it appears that the sound is actually coming from inside the cat but the muffler guy says the cat is fine and the sound is the motor sound revebing in the cat.

 

art
several of our guys are having big problems with noise after the y pipe mod. hold off! i sent you 2 writeups today about the banks kit seems it's the only way to fly. for 99 to 2004's no noise after it's done .
now if some one would come out with a good cat back for the 05 to 07's. and yes guys the 07 are in production. ford doctor has a few shots posted on his site same out side and looks as ours

 

Which is why I brought up pipe lengths... By just modding the existing setup to remove the restrictions and merge the right-side pipe in better, the pipe lengths seem to be such that the exhaust pulses overlap in a certain way to create bad noises

They look obviously mismatched in length. If both pipes are the same length before the "Y", we'll get a true 72 degree seperation between pulses. With mismatched down pipes, it can be ... weird.

 

seems purerock has the best so far. matching what your talking about art.