MBRP off road H to stock cat back?

[NickSezz]

So...I made a mistake... : /

I got a good deal on an MBRP T409 off road H pipe, but I failed to read in detail about about the products comparability with the stock cat back. The instructions say that is must be used with the MBRP cat back kit, but I would like to use the factory cat back along with my GT500 cans...

MBRP pipe ends with a 3" slot cut joint...unsure about any length issues...

What kind of fabrication am I looking at here to make this work...if feasible?

 

[hightechrdn]

So...I made a mistake... : /

I got a good deal on an MBRP T409 off road H pipe, but I failed to read in detail about about the products comparability with the stock cat back. The instructions say that is must be used with the MBRP cat back kit, but I would like to use the factory cat back along with my GT500 cans...

MBRP pipe ends with a 3" slot cut joint...unsure about any length issues...

What kind of fabrication am I looking at here to make this work...if feasible?

Do you have any intentions of getting their catback or another with 3" over the axle pipes? If so, I would get adapter pieces made at an exhaust shop. They should be 3" ID at the front/H pipe side and then an ID sized to slide over the factory over axle pipes on the other end. Mock things up and determine a good length so that you can trim the factory over axle pipes and have the joint land on smooth tubing. The adapters could even be made long so as to take out the resonators. With this approach it would be more difficult to replace the H pipe with one setup for a factory over the axle pipes later.

Another approach would be to have the adapter made so that you cut the H pipe and leave the factory over the axle pipes alone. Either way an exhaust shop should be able to make adapters easily by expanding a piece of 2.75"OD tubing to 3"OD on one end and 2.75"ID on the other. You could then use any manner of exhaust clamps or welding to hold everything together.

Measure the tubing first as I didn't look under my car to verify, but something along these lines should work and not be very expensive. Would just take some planning to make it easier in the future to upgrade/replace parts.

 

[NickSezz]

I only may be changing over to long tubes in the future. I plan to keep the cutting to the MBRP H pipe when fabing this up. For now I am trying to control the sound of my exhaust note so there is minimal drone while increasing performance by removing the cats; hence keeping the factory over axle pipes and resonators with GT500 cans.

I guess I will take it down to my performance shop and let them help me out. I would not want to do this w/o a lift. That will also give me a chance to make some comparisons on the dyno:

Baseline pull: 2012 GT, manual trans, GT500 mufflers, on 93 octane

After pull: 2012 GT, manual trans, GT 500 mufflers, MBRP o/r H, Steeda CAI, BAMA 93 Race tune

Should be interesting. This will also allow me to data log and see if AM has to do any fine tuning to the e-mail tunes.

 

[Napoleon85]

I only may be chaging over to long tubes in the future. I plan to keep the cutting to the MBRP H pipe when fabing this up. For now I am trying to control the sound of my exhaust note so there is minimal drone while increasing performance by removing the cats; hence keeping the factory over axle pipes and resonators with GT500 cans.

I guess I will take it down to my performance shop and let them help me out. I would not want to do this w/o a lift. That will also give me a chance to make some comparisons on the dyno:

Baseline pull: 2012 GT, manual trans, GT500 mufflers, on 93 octane

After pull: 2012 GT, manual trans, GT 500 mufflers, MBRP o/r H, Steeda CAI, BAMA 93 Race tune

Should be interesting. This will also allow me to data log and see if AM has to do any fine tuning to the e-mail tunes.

Looking forward to those dyno sheets...

 

[NickSezz]

I am having some second thoughts here...

I am thinking about sending the MBRP pipe back and getting the Lethal o/r H or the BBK cat delete pipes like I originally planned...

Or should I just leave to cats in? Some people are telling me I will see gains of 8-10 hp. Some are saying I will lose torque and it is not worth it...

I am doing this for sound and a little bit of performance. Otherwise I would be throwing on long tubes...

What do you think is a better option? I don't want to do anything that makes the car difficult to return to stock (cutting). Lesson learned from when it came time to sell my last Mustang...

 

[2011IngotGt]

I can tell you this. I was running consistant 12.70s @ 113.2, 112.7, 112.9 in spring type air tune only (VMP). I added an o/r x pipe and cold air kit. I then ran solid 12.40s @ 114.9, 114.7. 114.04. The air was almost identical each time out. D.a was around 1800 ish both time.

take that as you will but the combo of cold air intake (steeda) and o/r X pipe (BBR) netted me 3 tenths and about 1.5 mph. This is an Auto launching at idle with a 2.08 sixty being the best all on stock 235 radials.

 

[skwerl]

I put some Pypes cat delete pipes on my stock exhaust a few months ago and I'm extremely happy with it. Not only did I remove about 50 lbs off the front of the car, it sounds totally badass now. I haven't put it on the dyno yet but I'm sure I picked up 10-15 hp minimum.

The Pypes cat deletes were just straight pipe going to the H pipe. I had to measure and cut the stock H pipe and then flare the ends in order to get the cat deletes to fit inside. I then used the nice band style clamps to hold them all together. Did it myself in my carport on jack stands in about 3 hours.

 

[NickSezz]

I put some Pypes cat delete pipes on my stock exhaust a few months ago and I'm extremely happy with it. Not only did I remove about 50 lbs off the front of the car, it sounds totally badass now. I haven't put it on the dyno yet but I'm sure I picked up 10-15 hp minimum.

The Pypes cat deletes were just straight pipe going to the H pipe. I had to measure and cut the stock H pipe and then flare the ends in order to get the cat deletes to fit inside. I then used the nice band style clamps to hold them all together. Did it myself in my carport on jack stands in about 3 hours.

I think BBK has direct bolt on pipes that do the same thing...

http://www.latemodelrestoration.com...parison-shopping&utm_campaign=google-shopping

This may be my plan for now...cheap too.

 

[wbt]

I put some Pypes cat delete pipes on my stock exhaust a few months ago and I'm extremely happy with it. Not only did I remove about 50 lbs off the front of the car, it sounds totally badass now. I haven't put it on the dyno yet but I'm sure I picked up 10-15 hp minimum.

The stock cats don't weigh 50lbs.....also....how do you know how much you picked up? Did you dyno before and if so, do you plan to use the same dyno with the car strapped to the exact same location on the dyno?

 

[skwerl]

They weigh about 20-25 lbs each (guessing), I have them in the shop. And as far as HP gains, I race my car at the local track almost every week and I picked up 2/10 after deleting the cats.

 

[NickSezz]

The stock cats don't weigh 50lbs.....also....how do you know how much you picked up? Did you dyno before and if so, do you plan to use the same dyno with the car strapped to the exact same location on the dyno?

I will take care of this hopefully sometime next week : )

 

[wbt]

They weigh about 20-25 lbs each (guessing), I have them in the shop. And as far as HP gains, I race my car at the local track almost every week and I picked up 2/10 after deleting the cats.

Stock cats weigh 10lbs. each. 20lbs. total for the pair as I just weighed mine.

Remember that track conditions, air conditions, etc. change from day to day, week to week not including driver error, launch etc. Best way to know is to compare timeslips for before and after and correct down to sea level. Given similar 60' times, that will be the best guess on what the gains were. 10-15whp is not unreasonable.

 

[skwerl]

Stock cats weigh 10lbs. each. 20lbs. total for the pair as I just weighed mine.

Remember that track conditions, air conditions, etc. change from day to day, week to week not including driver error, launch etc. Best way to know is to compare timeslips for before and after and correct down to sea level. Given similar 60' times, that will be the best guess on what the gains were. 10-15whp is not unreasonable.

So what's the argument? I said I picked up 10-15 hp minimum and you challenged me, then you turned around and said a person could expect 10-15 hp from deleting the cats. Quit being a fucking dick.

 

[wbt]

So what's the argument? I said I picked up 10-15 hp minimum and you challenged me, then you turned around and said a person could expect 10-15 hp from deleting the cats. Quit being a fucking dick.

You said the cats weighed 50lbs.. Post #7 and #10. Multiple times.

You have no idea what you picked up for gains but "it is 10-15HP minimum.". <---------I gave you a hint on how to check when you stated you had before and after track times but in reality you have no idea nor put forth the effort to figure it out but by God, "it is 10-15HP minimum.". I stated that is not an unreasonable expectation. If you had said 30HP, you would have found out how much of a "dick" I can really be.

You posted incorrect info and get called out for it and call me the dick? Let's not be the community dumbass here.

 

[skwerl]

Fine. You're correct on the cats, I just walked out and picked them up. They aren't as heavy as I remembered. I just remembered taking them off and being surprised at how heavy they were. About 10 lbs each seems correct.

I'm done here, bye.

 

[mbreinin]

I used the Jeg's cat delete pipes into my 3 inch Pypes X pipe. My X-Pipe is welded to the remainder of my exhaust because it is 3 inches all the way. I installed it before I ditched the cats, otherwise I would have gone with a Lethal.

I picked up 3 tenths after ditching the cats and re-tuning. However, I also had a much better launch at the track post cat delete...so I am not sure if it was more power, or a better run. The air was better on the slower run though.

Mike