mopar race exhaust on a gen 4?

[Siciliano15]

Tried doing a search on this but havent really found a definite answer.... The race exhaust advertised for 2003-2006 cars (4510176), will it bolt up to a 2008-2010? I know the car is the same but did the factory exhaust manifolds exit at the same location and were any hanger locations changed? was hoping maybe someone on here has done it... thanks.

 

[MoparMap]

Hmm, I didn't realize they didn't list them for gen 4 as well. I would have thought they would bolt up the same, but if they didn't the only reason I could think of would be the manifold exits. Do you have stock manifolds on your car now or headers? As far as hangers I'm fairly certain they are the same between the gens. The rear hangers on my car were single hole and the race exhaust uses the dual hole isolators instead, but I just used the dual hole hangers that are at the front in the back since you don't use the front ones anymore when the rear cats are removed (which the race exhaust will do). That would just leave the ****** interface to worry about. If you have headers though, that becomes less of an issue as you'd have to adapt the exhaust to your headers anyway and you wouldn't be using the flex pipe section that comes with the race exhaust.

For what it's worth, the parts manuals show basically the same part number for the cat pipe assembly between gen 3 and gen 4 though (goes from AC revision to AF revision, but the number is the same, so that usually means they are interchangeable). Based on that I would like to think the manifold exit is probably in the same location. I wonder if the only reason they don't list fitment for gen 4 is because of tuning? That or the parts just came out so early that they never bothered to update the description to say they worked on both.

 

[Siciliano15]

Yea I have the stock manifolds. Funny I was actually thinking the same thing about how the part numbers on the factory midpipes are basically the same besides the last letter and also was looking at a few aftermarket companies like for example the belanger system that gives you the midpipes and exhaust and for the 2003-2006 the part number is 5625 and for 2008-2010 it's 5625-1 so it must be very cllose....

 

[MoparMap]

The only difference I saw between the pictures in the manifold is the "early" midpipe shows an isolator with a single hole and hanger and the later one shows the dual hole setup. I think they are fully interchangeable if you just swap out the isolator though, so maybe that's why there is a very minor difference. It's not a 100% direct swap, but easily retrofitted kind of deal. Maybe even a running change through the years? I know I had the two hole isolators at the front of my car, but by the parts manual it looks like maybe I shouldn't have, so hard to say. I think it's a pretty safe bet the race exhaust would work on a gen 4 though.

 

[Siciliano15]

I think it would probably work too just hesitant because I haven't seen anyone who's done it before. Maybe I'll just give it a shot.

 

[Siciliano15]

Thanks for all the good info I'll let you know how it goes once I get it and go to install it.

 

[MoparMap]

I would have thought this is what the ACR-X race cars ran for exhaust from the factory, so seems like it would be a natural fit. Granted I think those cars had long tube headers out of the factory as well, so maybe it's not the best comparison.

 

[Siciliano15]

Yea I'm not sure what exhaust the acr-x had but it definitely came with headers and no cats. Was rated at 640hp and 605ft-lbs so a decent gain for only exhaust work and a different pcm probably similar to the Mopar pcm.

 

[Siciliano15]

Just got the Mopar race exhaust in the mail today. System looks great. The system has the hangers in all the right places and the bends and pipe lengths appear to be where they should be.

Only teeny difference is where it mounts to the factory exhaust manifold. The angle of where the manifold goes into the midpipe is like a 45 degree angle instead of a more abrupt transition but it looks like it still ends up at the same size just a more gradual angle. Not sure of how that clamp holds the pipes together but I think it may work.

Another thing I noticed I took a pic of, at the end of the exhaust tip on the inside there is this little **** that gradually reduces the pipe diameter from 3" to 2.25" for about an inch or so and then goes back to 3" right before the pipe's exit... What's that about? Seems like it would be a big restriction. It's only tack welded in there in 2 spots...

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[MoparMap]

Huh, that's odd. I don't think I recall my setup having that end restrictor thing on it. Pretty sure mine was just straight bent pipe for the exit tips. I agree that seems like a pretty odd addition to what is supposed to be a less restrictive exhaust.

 

[Siciliano15]

yea thats what i thought too! 2.25" exit is even smaller than stock. I know they say that if the exhaust exit is slightly smaller than the rest of the system its ok since the gasses have cooled and become more dense but i think taking 3/4 of an inch off seems to be way too much.

 

[MoparMap]

Yeah, I'd be tempted to just cut those out while you're there. I don't think I've ever seen them before. Just seems strange, almost more like a sound restrictor or something to hit a certain volume level for testing or something like that.

 

[Siciliano15]

I've been trying to see if any other Mopar or borla exhausts have that but haven't found anything online or any pictures anywhere. I'll most likely cut them off and save them or maybe start it up with them there and then cut them off and see if the sound changed at all but I didn't spend the money for a smaller exhaust lol so I have a feeling they will definitely be gone soon.

 

[MoparMap]

Yeah, I probably would as well. I still can't figure that one out. I don't think I've ever seen an exhaust tip that looks like that before on any Viper I've ever seen, and I've seen plenty with a race exhaust at track events. Could always potentially make your own tips as well. It's basically just a bent pipe with an angled cut on it, so fairly simple to fabricate if you have the right bend. Could use what you have as a template and go to a custom exhaust shop near you to see if they could make one up.

 

[Siciliano15]

Wish I could contact whoever is designed it and find out what it's true purpose is lol.

 

[MoparMap]

My impression was that the system was made by Borla, but I could be wrong. The "street" system that was sold looked exactly like the Borla aftermarket system they sold (same muffler style), it just had different tips on it. The Borla kit had finished tips with a rolled edge and the Mopar kit was just straight cut. The race exhaust I have at least has identical muffler design (4 perforated tubes in one larger tube), so I assume it might be the same, but I suppose that design might not be unique to Borla.

 

[Siciliano15]

So I ended up just cutting off the restricter pieces because I was painting the tips with flat black spray paint for headers to match the stock look. I didn't want to have them all painted and then scratch them up removing those things. It wasn't too bad just ground off the two tack welds and wiggled them out of there.

I got the drivers side of the exhaust totally installed now just have to do the passenger side. It all bolted up and the connection to the factory header seemed to clamp tight so I'll know for sure when the passenger side is done but I think it will be safe to say the Mopar exhaust works on gen 4s. It's a little tight in some areas with the Mopar muffler tight to the heat shielding but it went in so I guess it's fine.

The hardest part has to be that one nut that is deep inside the body panel that holds the lower body panel to the upper one. That thing is such a pain in the *** to get to its just the worst!

 

[MoparMap]

Yep, that's a pretty infamous fastener. Good to hear that it all went together well. Mine is pretty tight to the shielding as well. I think the muffler is a little different diameter or something. On my old street Borlas you could tell they didn't sit quite in the middle of the side sill from the exhaust tip. It had a little extra swoop and bend in it so the pipes could sit a little off center I think. The race ones are pretty much a straight line down the side of the car, so they fit just a little differently.

 

[Siciliano15]

Yea besides that stupid nut it's been a pretty nice install so far. Not sure why they had to have that nut so close to the edge if it was even a half inch further from the edge u can at least get a ratchet wrench on it without feeling like ur gonna break ur hand off lol.

 

[Siciliano15]

I was able to get the passenger side done yesterday now just need to do some adjustments to line up the tips but was able to briefly start it up and I'm definitely super happy with the sound. At idle it sounds much deeper and it's not much louder than stock which is good so I'm not ******* off the neighbors. It sounds more like a muscle car almost a little like a v8 but definitely way better than before.

I also revved the gas lightly with my hand and it's definitely louder but I don't think it's overkill I've definitely heard louder cars out there. I'll be sure to post up a video when it's all back together but it's official the Mopar Race Exhaust works on the gen 4 cars!

There were a few leaks initially but I tightened up the clamps by the manifold and also coming off the midpipe and they are like 99% gone to the point that you can't hear any leaks and only one connection you have to put your hand right in one little spot to feel a tiny wisp of air coming out but it's so small I think it beats snapping the clamp that holds it to the factory manifold.

 

[Siciliano15]

Also the passenger side wasn't super tight fit like the drivers side for whatever reason.

 

[MoparMap]

Sweet! Glad it all went together well for you. Lining up the tips can be a bit of a pain. It's hard since you kind of have to remove the whole side sill to jiggle things around, but then you need to hold it back up there to see where things are. I think you can adjust the back a little bit with the sides still on though, or at least loosened at the back. I managed to get a ratcheting wrench on the bolts on the rear isolator at the tip so I could adjust it up and down a little bit. If you have the rotation and the angle right that might be all you need.

I agree on the muscle car sound as well. Definitely one of the lower toned exhausts on the market to my ears at least. Curious to see your video when you make it to know what it's like with the factory manifolds.

 

[Siciliano15]

Finally finished putting all the panels back on and tightening everything up and took the car out today. I didnt get to get a good video of me driving around or anything but i did take a quick idle video. Ill try to get another one soon with me revving it and driving it. Driving around at light throttle the car is barely louder than stock. Deeper sound for sure. At moderate throttle its definitely got more volume but again its not really all that loud just sounds great with a much deeper sound than stock. At full throttle its definitely a good amount louder than stock but with a similar sound to the stock sound which is a good thing at the higher rpms.

Ive seen people comment that this exhaust is the loudest exhaust and will vibrate everything and is barely tolerable but I just dont see that to be the case. Im definitely not hard of hearing either lol. I think after driving cammed V8 vehicles, this is pretty mild and should not attract any unwanted attention. Im happy its not too loud I really only wanted the exhaust primarily to cool the side sills down which it does (except for the area right by the tip which is still hot) and also for the power and sound which are just bonuses. Also there arent much gasoline fumes either like what you would experience on a car with a big cam and open exhaust.

Mopar Race Exhaust Idle

 

[MoparMap]

Interestingly enough, I think I had worse exhaust smell with my 2.5" Borlas with no cats than with my 3" Mopar race setup. Maybe the 2.5" just trapped it more with the extra back pressure or something.

I think one reason people think the exhaust is so loud is that the low tone travels really far. I live only a few blocks from my parents, but they can pretty much hear me coming as soon as I leave my garage because the tone just carries so far. It's not a volume thing as much as a damping thing. A high pitched sound will lose energy faster than a low pitched one and doesn't bounce off objects the same way. Either way, glad you like it! Sounds like it ticked all the right boxes for you.

 

[Siciliano15]

Oh wow u noticed the less fumes too. Interesting. Maybe the 4 separate tubes inside the race muffler instead of just one hollow opening in other mufflers are somehow burning off some of the gasses similar to a cat.

Makes sense with the low tone though sounding lower but carrying further. Yea definitely ticked the right boxes and for a surprisingly good price compared to most other viper parts.

 

[Bigwitz]

Good thread and good exhaust set up. I am about to do the Belanger Full headers-exhaust and free flow cats.

 

[Siciliano15]

Nicee. Should sound awesome. Love the green that was the only other color I was looking at when I got mine.

 

[Halsvt1]

I ordered the race exhaust for my gen 4 and going to the instal next week. My question is what did you do with the o2 sensors? I was going to instal the spark plug non foilers to avoid a check engine light

 

[Siciliano15]

Oh nicee. Youre gonna love it. Sounds great. I unplugged the o2 sensors and just put them in a box but I also at the same time got the Mopar PCM part# P5155254AB so theres no issues with engine warning lights or anything. I got it on this dodge dealer website Bamwholesaleparts for around $1,100. I have my own StarScan so if you want to meet up I can program it. I see your in NJ so im sure you're not too far. I hear u can do the non foulers but I never tried that method.

 

[Siciliano15]

I ordered the race exhaust for my gen 4 and going to the instal next week. My question is what did you do with the o2 sensors? I was going to instal the spark plug non foilers to avoid a check engine light

Actually now that I think about it you cant even do the non foulers lol. Theres nowhere to even ***** the rear o2 sensors into so that wouldnt work. I hear on the gen 3 models people would tie the o2s to the frame of the car and leave them out but I dont know if that will work on a gen 4 or not.