citylights

Hey everyone!

Found this forum while trying to find info on a dual conversion set up so figured I'd ask you guys for further help. This is doing my head in!

I ran into this thread that THANKFULLY pointed me to rockauto and I was able to find the OTA pipes I need for a true dual conversion. Question: In the thread, the guy says I only need to buy the LEFT pipe and can reuse my stock v6 OTA pipe on the right side, has this been verified to be true?

All I need now is the H-pipe, and it seems to be very elusive. American muscle and other similar websites have an abundance of X pipes made specially for the v6 to complete the conversion, but no H pipes!

I found a few H pipes on amazon marketed for the 05-10 GT but I really don't know if they will fit without some modification and I was wondering if any of you have successfully done this, and if so, which H pipe did you use? If I get pieces that don't fit, it's just going to cause a hue headache and bring my installation price UP.

Local exhaust shop trying to charge me $900 to weld custom H and OTA's and then do the install. I will be cutting this cost in half if I can find the parts myself: Just need that darn H pipe. He quoted me $95/hour labor and said it shouldn't take more than 2 and a half hours, IF my parts go on easily.

Please chime in!

JimC

On the 4.0 (2005-10) the over axle pipes are the same size for the V6 and V8. So yes, you only need the driver side over axle because you already have the passenger side.

The H for a V8 won't fit without modification. The angle, location of the cats, and the size are different. The V6 starts at 2.25" on the down pipes and use a step band to mate up to the larger over axle pipe. You can use the V8 H pipe, you just have to cut and weld it in place.

AMAlexLazarus

Hey City! Welcome to MustangForums! That's a great question and Jim beat me by a mile here! (Listen to this gentleman, he knows a lot and he's building a monster as we speak!)

Being said If you're dead set on doing this I might reccommend taking a look at another shop as this sounds like it's a little "too" expensive!

If there's ever anything I can help out with please don't hesitate to shoot me a PM I'm always around to help out!

Best of luck!

Alex

citylights

Ok, now we are making progress, thank you! That explains why I am having a hell of a time finding that H pipe.

Ok! so the step band part was expected, that won't take the shop any extra time at all, about $20 for the bands. To make it fit, how heavy of a modification are we talking?

ie: Say I brought the exhaust shop As far as additional cutting and welding.. what really will that consist of for him? What does he need to cut? Do the pipes need to be rebent to fit due to angle? (Oh, and I plan on having the entire conversion done via welding as opposed to clamping)

I just want to arm myself with information and understanding of what exactly needs to be done (1) so I am educated on the process, and (2) so I don't get taken advantage of. I don't want him trying to tell me it's going to take an extra hour of "modifying it because it was for a v8" if it's really something that should take no one anymore than an additional 10 minutes.


Thanks Alex!

Sadly I am located in Hawaii and this is the only quality exhaust shop that EVERYONE goes to. I believe it is also the only one to do mandrel bending. Hawaii business are notorious for bumping up prices because they have no competition. I asked him how much it would cost for him to weld me just the H pipe and he wouldn't answer, he just danced around it. He told me the cost of a dual conversion using his material would be $800. I got the impression that when folks bring their cars in for a dual conversion, they pay without questioning but when you itemize it, very little of that price is the actual cost of material. I realized this when I compared the price of their hourly labor rate, with the price of obtaining the materials on my own. I think if he would have told me the price of his custom H and OTA pipes, and I coupled that with 2 hours of quoted labor, there's a lot of money unaccounted for in that $800 quote. I called again about a week or 2 later, and got another quote saying I already owned the mufflers, he said I could bring it by and it would be an additional $700 to complete job. Now we've jumped to $900 lol (yes, same brand of mufflers used in the previous $800 quote.. and he charges MORE for his mufflers in store!). By obtaining the materials myself, I will only be paying $550 for the conversion.

JimC

That H pipe you posted would be easy. All you have to do is remove the Y pipe you have now then get your mufflers and over axle pipes generally in place for measuring. Put your H in place and mark the overlap on your down pipe where you removed the Y. Cut the H to fit and use the step band (or weld it) in place and finish.

It shouldn't take a shop any time at all to do. On my 2006 it took him about a half hour to get it all set up.

JimC

These threads should help you:

https://mustangforums.com/forum/4-0l...rs-w-pics.html

https://mustangforums.com/forum/4-0l...ord-parts.html - uses X pipe but same principal.

And of course you will need to cut the bumper for the driver side muffler
https://mustangforums.com/forum/4-0l...-template.html

Cutting the bumper is easy - nothing you can harm and it can be done with a box cutter.

citylights

Perfect simple explanation. No longer confused. Thanks a ton, it sounds super easy. Unfortunately my driveway is on an incline or i'd be tackling this myself.

citylights

Well I found another exhaust shop who seems a lot more reasonable. He quoted me only $500, but that's with 2.25" OTAs, instead of 2.5"s; and an X pipe instead of an H, it also includes the super 44 mufflers and tips - Great deal if I were going with the X! He said they don't fabricate their own H pipes because he prefers the way the X's flow and feels they are more efficient as far as the mixing of gases go. I took it with a grain of salt, and am pretty dead set against the X, I just do not like their sound on the 4.0 v6 engines.

He also told me that if I went with 2.5" mufflers and 2.5" OTA pipes, that he was concerned about me losing low end torque on the v6. He said he could weld me custom OTA pipes that were 2.25" and it shouldn't sound any different.

Does anyone have any thoughts on this? It makes a lot of sense and I remember coming across some people talking about that on a message board in one of my searches. If I let him weld me the 2.25 OTA's, I can't use the H pipe anymore because its 2.5" (and the shop doesn't fabricate their own). I really don't want to lose low end torque living in a place with a lot of stop and go traffic.

Option #2- What about a divorced set up? Say I let him cut my Y pipes and run a pair of 2.25" mid pipes down to the mufflers... Is this something that could work or do I need to change my headers to do this?


BEGIN RANT
(Side comment: I had to call back and got another guy, he was a complete ******* and sat there arguing with me about how the H pipe on a V6 is raspy and will never be deep, and that the X pipe is deeper. I said I have no need to argue and in my opinion the H pipe has a deeper tone than the X's on mustangs, yes the v6 will never sound like a v8 and that is not what I am trying to do. I am attached to my car and just want a bit more sound out of it. I have no interest in trying to make it sound like something it's not, there is no way a 6 cylinder could sound like an 8 cylinder, or vice verse. How he thinks it's a good idea to argue his personal opinion is beyond me, I nearly hung up had it not been for the initial guy I was speaking to)
END RANT. Had to vent ;D

citylights

Sorry for spamming my own thread but I am unable to edit the above to include this question. Would this be dangerous or beneficial:

The pipes attached to my cats are 2.25" right. Can I do a 2.5" H-pipe next, and then back to 2.25" pipes for the OTAs?

Alternatively, I was able to locate a "universal" 2.25" H-pipe kit, however it is in a lot of pieces and aluminized steel, I don't know if this would jeopardize the quality of this project? Product link here (Click).

BTW this is a 4.0 V6, 2007 mustang.

JimC

The 2.25 to 2.5 to 2.25 would probably disrupt the exhaust flow in my opinion (no science behind that, just my opinion!).

And you can do a completely divorced dual system. I know of a couple of people who have done that. All you need to do is figure out the connection to the over axle pipes.