Fitting 18+ MBRP Race catback on 15-17 Premium

[Red65]

A while back I read through a forum post where someone had fit a 2018 factory exhaust on a 15-17 premium, and they just had to open up the black plastic part of the premium valence where the normal exhaust opening is for the quad tips to fit. Seemed easy enough so I decided to go with the 2018+ MBRP catback when I did my header swap. I got it up in the car today to test fit and see where I need to cut, but where it sits now, I’ll have to cut into the painted part of the premium valence. Given that a user here didn’t have to cut into the painted section, I’m wondering if I have something put in wrong. I don’t believe so as everything else fit great and there’s really no wiggle room. Has anyone else had an aftermarket 18+ exhaust on a 15-17 premium fit like this?

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[Liam O]

I found out the same when I fitted a '18 Bullitt catback to my '17. Like yourself I wondered why everyone else managed to work out ok and didn't have to trimmed the painted section. Turns out most either adjusted the hangers or only used the axleback part meaning they had more flexibly over the position of the tips. I'll try and get a picture later. It doesn't look too bad from a distance but I definitely want to get a new valance to finish it off so it looks cleaner.

 

[Red65]

I found out the same when I fitted a '18 Bullitt catback to my '17. Like yourself I wondered why everyone else managed to work out ok and didn't have to trimmed the painted section. Turns out most either adjusted the hangers or only used the axleback part meaning they had more flexibly over the position of the tips. I'll try and get a picture later. It doesn't look too bad from a distance but I definitely want to get a new valance to finish it off so it looks cleaner.

I could see just an axle back having some wiggle room, and admittedly I am unsure about whether or not the post I read before was with an axle or catback. However, I will say that I went back and checked my work and I can't find a single way to adjust it out at all. Especially on the tailpipes; the factory mount leaves them pretty much where they are now. The entire system fits really well with no binding or anything. I just wanted to make sure its actually where its supposed to be sitting before I hack up this valence

 

[17gt_charlotte]

I had the same issue trying to fit my 18+ AWE touring catback on my 17 base GT. I ended up cutting a little bit of the painted part of the valance (probably will get a new one soon anyway) but good to know I wasn’t the only one. So looks like 18+ exhausts won’t fit 15-17 unless you do some work with the hangers and cut the valance.

 

[Red65]

I had the same issue trying to fit my 18+ AWE touring catback on my 17 base GT. I ended up cutting a little bit of the painted part of the valance (probably will get a new one soon anyway) but good to know I wasn’t the only one. So looks like 18+ exhausts won’t fit 15-17 unless you do some work with the hangers and cut the valance.

I’ve been looking at pictures of 18+ cars and where my exhaust is located looks to be identical, it’s just the rear valence on the 18+ has a narrower painted section. I didn’t have to change anything with the exhaust hangers. I think the post I saw was probably a guy just using some quad tips and not specifically an 18+ exhaust

 

[DonnieO]

Try this with it.

https://www.americanmuscle.com/rous...Vo25vBB2T0gYHEAQYASABEgIbfvD_BwE&gclsrc=aw.ds

 

[Liam O]

As promised pictures below. I cut a bit too much away from the outside of the tips, but when i was doing it I kind of made up my mind that it would only be temporary until I decided/found a diffuser I liked hence the edge trim tape that isn't straight! Again, this is a unmodified 2018 Bullitt catback, original hanger locations etc.

 

[Red65]

Try this with it.

https://www.americanmuscle.com/roush-rear-valance-noholes-1516.html?utm_content=Exterior - Rear Diffuser|Roush&T5_Var4=387054&utm_source=google-pla&utm_medium=shopping&T5_Var2=shopping&utm_campaign=AMM+Mustang+Brands+Medium&T5_Var3=blue&intl=0&dialogtech=ppc&gclid=EAIaIQobChMIlrGT2ZS48QIVo25vBB2T0gYHEAQYASABEgIbfvD_BwE&gclsrc=aw.ds

Based on the spacing on the rear lights and markers, that looks perfect!

 

[Red65]

As promised pictures below. I cut a bit too much away from the outside of the tips, but when i was doing it I kind of made up my mind that it would only be temporary until I decided/found a diffuser I liked hence the edge trim tape that isn't straight! Again, this is a unmodified 2018 Bullitt catback, original hanger locations etc.

I really appreciate that! It gives me an idea on how much that I need to cut away. I'll give it a shot for sure. I'll eventually get something like the roush that was suggested here, I'm just tied up for money at the moment

 

[Liam O]

I really appreciate that! It gives me an idea on how much that I need to cut away. I'll give it a shot for sure. I'll eventually get something like the roush that was suggested here, I'm just tied up for money at the moment

No worries, glad I could help! It is a bit tight to the painted part of the valance but theres enough clearance that is doesn't get hot. Ran it like this for about 2/3months and its been fine. I will probably make a thread at some point for 15-17 owners wanting to go quads as the information is dotted around all over the place as has been a right nightmare to find.

As far as I know with running a 18+ catback the options for the rear valance are:

Roush Quad Tip

MP Concepts Quad Tip: https://www.americanmuscle.com/mp-c...iffuser-1517-gt-premium-ecoboost-premium.html

OEM 18+ Valance AND Rear Bumper(Plastic support brackets from 18+ still needed on this I believe)

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