6.1 Exhaust on '09 5.7

[houston_four]

So I have the manifolds but the more I read and the more I think about it I may have a change in heart.

So I would be looking at around 10hp for changing manifolds/mids/cat back to SRT right? But what will I lose in low-end torque? Will it be noticeable. I hate to drop all this money and I want to get it right the first time.

I had an '05 GTO and I went with a Magnaflow X-pipe with chambered mufflers, what could I look to gain on something like that if I kept my stock 5.7 exhaust and changed out all of the above? Would it be close to what I would get by changing to 6.1 exhaust?

And another note, what if I changed out to the 6.1 header/mids and put the Magnaflow X-pipe with chambered mufflers?

Sorry for all the questions. In the end I'm trying to pull the most power out with basic bolt ons. I am not going to do anything to heads/cams until 2019 (when my car comes out of the fleet).

Thanks for the help.

[Hemi31]

With the 6.1 manifolds you shouldn't lose any bottom due to the shortie style header......you will pick up in the midrange.With the 6.1 catback you will have some serious drone with MDS.....just something to keep in mind.

[houston_four]

With the 6.1 manifolds you shouldn't lose any bottom due to the shortie style header......you will pick up in the midrange.With the 6.1 catback you will have some serious drone with MDS.....just something to keep in mind.

It will be disabled via predator so no problem there.

So should I just leave the stock cat-back or is it worth it to get the Magnaflow X-pipe and some chambered mufflers?

[Hemi31]

All the factory stuff is already X-piped......don't go with an aftermarket 6.1 catback as they are too large for a 5.7,then you will lose bottom end.Stick with a stock 6.1 catback.

[houston_four]

All the factory stuff is already X-piped......don't go with an aftermarket 6.1 catback as they are too large for a 5.7,then you will lose bottom end.Stick with a stock 6.1 catback.

Ok, I planned on modding the 6.1 cat back, I saw on here how someone cut the pipes coming off the back of the suitcase because they go down in size, and they put a straight pipe in. I plan on doing something similar. Will my sound improve or will I need to get some mufflers to make her a little louder?

[MuscleMan305]

Ok, I planned on modding the 6.1 cat back, I saw on here how someone cut the pipes coming off the back of the suitcase because they go down in size, and they put a straight pipe in. I plan on doing something similar. Will my sound improve or will I need to get some mufflers to make her a little louder?

6.1 will make your 5.7 sound so much nicer, but you will need a high flow cat or cat-delete to really make a noticeable difference in power. Also go with the 5.7 catback unless your make over 420 crank horses whichisn't easy to do without cam/heads.

[houston_four]

6.1 will make your 5.7 sound so much nicer, but you will need a high flow cat or cat-delete to really make a noticeable difference in power. Also go with the 5.7 catback unless your make over 420 crank horses whichisn't easy to do without cam/heads.

Now I'm really scratching my head....I thought I had to use the 6.1 cat back because the sizing difference...or is that just from header to mids? I was just going to throw the stock 6.1 cat back on too.

[07superbee]

If your getting the whole system for real cheep like under $300 bucks do it and roll with it but if its more then that just get some hi flow cats and delete your rear resonators and you may be better off.

[houston_four]

If your getting the whole system for real cheep like under $300 bucks do it and roll with it but if its more then that just get some hi flow cats and delete your rear resonators and you may be better off.

I paid $200+ shipping for manifolds, and I'll pay another $200+ shipping for mids/cat back so not too bad. I thought about going with hi flow cats but I was worried about the longevity of the cats from various brands and decided against it. I guess I could always upgrade to some hi flow cats for the 6.1 exhaust. I just couldn't get over putting together a full exhaust for under $500 that has the same flow pattern as the JBA shorties.

So now I have another question.....if I got some hi-flow cats for the 6.1 manifolds could I use my stock 5.7 cat back? If that's the case then I'm all over that!

[bandaid]

I have JBA shorties and the 6.1 cat back on my 300C 5.7. I did not loose any bottom end but I sure notice a difference in the mid-range. I did not shut off the MDS and the drone is there but doesn't really bother me.

[concussion]

you'll be fine. You won't loose anything noticeable down low.

I have SRT headers, 6.1 magna flow cats and a 5.7 SLP catback. I just had a local muffler shop weld reducers on the mids. $30... thanks Ernie.

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