[KD07]

I'm planning on installing my Dinan midpipes soon and looking to bolt them up to the OEM axleback exhaust (not MPE). Anyone know the diameter of the stock exhaust off the top of their head? I know I can always unbolt the exhaust where it meets the downpipe and measure it myself, but wanted to avoid doing that until I went to install everything.

I need to buy a clamp to mate the midpipes to the axleback exhaust after I cut it, and was trying to spend maybe $20-30 for the clamp rather than $80-100+ from BMW or ECS tuning. Just need to know exactly what size to get. 60mm? 80mm? I know the Dinan midpipes are 3.25", which is about 82.5mm. If I had to guess, id say the OEM exhaust is around 2.5" (63.5mm). Maybe 2.25" (~57mm)? Would this mean that I would need a clamp that specifically has a different inlet and outlet size? A clamp is a clamp to me as long as the diameter is the correct size. Here is a link to what I'm looking for, but in hopes of finding something generic much cheaper that will get the job done in an equal fashion.


https://www.ecstuning.com/b-genuine-...FdeLswodU7ECIg

[AlexM240i]

Originally Posted by KD07

I'm planning on installing my Dinan midpipes soon and looking to bolt them up to the OEM axleback exhaust (not MPE). Anyone know the diameter of the stock exhaust off the top of their head? I know I can always unbolt the exhaust where it meets the downpipe and measure it myself, but wanted to avoid doing that until I went to install everything.

I need to buy a clamp to mate the midpipes to the axleback exhaust after I cut it, and was trying to spend maybe $20-30 for the clamp rather than $80-100+ from BMW or ECS tuning. Just need to know exactly what size to get. 60mm? 80mm? I know the Dinan midpipes are 3.25", which is about 82.5mm. If I had to guess, id say the OEM exhaust is around 2.5" (63.5mm). Maybe 2.25" (~57mm)? Would this mean that I would need a clamp that specifically has a different inlet and outlet size? A clamp is a clamp to me as long as the diameter is the correct size. Here is a link to what I'm looking for, but in hopes of finding something generic much cheaper that will get the job done in an equal fashion.


https://www.ecstuning.com/b-genuine-...FdeLswodU7ECIg

Interesting. Subscribing....

[KD07]

So I reached out to Dinan, and they were extremely helpful and prompt with responding and answering all my questions in full. What they informed me on is that the OEM exhaust piping is 80mm. Their midpipes are 3.25" (roughly 82mm and some change). After cutting the OEM exhaust at the dimple, the piping from the OEM axleback will slide into the Dinan midpipes, only requiring a standard 80mm band clamp over top to hold in place. This is good to know, as I think it would be safe to maybe cut an inch or so forward to ensure enough slides into the midpipes. Now when mating the OEM midpipes back up to the OEM axleback, a different clamp will be needed because they will be flush up against each other, being the same diameter. They had recommended a Torca style coupler clamp, which can usually be found for around $20 or so online.

[BASELINE]

Originally Posted by KD07

So I reached out to Dinan, and they were extremely helpful and prompt with responding and answering all my questions in full. What they informed me on is that the OEM exhaust piping is 80mm. Their midpipes are 3.25" (roughly 82mm and some change). After cutting the OEM exhaust at the dimple, the piping from the OEM axleback will slide into the Dinan midpipes, only requiring a standard 80mm band clamp over top to hold in place. This is good to know, as I think it would be safe to maybe cut an inch or so forward to ensure enough slides into the midpipes. Now when mating the OEM midpipes back up to the OEM axleback, a different clamp will be needed because they will be flush up against each other, being the same diameter. They had recommended a Torca style coupler clamp, which can usually be found for around $20 or so online.

This is great info. I was just going to say the OEM piping last time I got the information was slightly larger than a standard 3 inch pipe. Realized this when doing research cutting factory resonator and secondary cat out for straight pipes.

As for installing the Dinan to the OEM, what I would personally do is actually have the shop heat the OEM opened end and take a pipe expander to it. I would shoot for either a flush mate fitment to the Dinan or even have the Dinan slip inside the OEM. The thought of the exhaust flow having that lip of the OEM slid inside the Dinan would drive me nuts lol... i know it's OCD but I like things done right. So I would either have the OEM expanded to accommodate the Dinan or have them butt up evenly against each other with the appropriate clamp. Oh and don't forget to grind out the burr on the inside of the OEM pipe after cutting.

[KD07]

Originally Posted by BASELINE

This is great info. I was just going to say the OEM piping last time I got the information was slightly larger than a standard 3 inch pipe. Realized this when doing research cutting factory resonator and secondary cat out for straight pipes.

As for installing the Dinan to the OEM, what I would personally do is actually have the shop heat the OEM opened end and take a pipe expander to it. I would shoot for either a flush mate fitment to the Dinan or even have the Dinan slip inside the OEM. The thought of the exhaust flow having that lip of the OEM slid inside the Dinan would drive me nuts lol... i know it's OCD but I like things done right. So I would either have the OEM expanded to accommodate the Dinan or have them butt up evenly against each other with the appropriate clamp. Oh and don't forget to grind out the burr on the inside of the OEM pipe after cutting.

Thanks for the insight. Yeah I was shocked that the stock exhaust was over 3" wide. Pretty large if you ask me. My only complication is that my car is leased and I will need to reclamp up the stock midpipes for the lease return. As long as I return the car wth a clean job and the coupler clamp holding it together perfectly I don't expect any problems given to me by BMW. After all, that is what they do if the dealer added the MPE. So heating up the piping to expand it wouldn't be the best idea in my case. However, if I was looking to make this a permanent mod this would definitely be in my, or whoever is doing so's, best interest.

Although, with there only being about ~2mm difference in the 2 pipes, I don't think it will leave much room to shrink or expand either. I'm pretty confident it'll be a perfect slide-in fit and be pretty tight to begin with. And yes, I will definitely be sure to sand down the ends after cutting. Just like you, knowing that's not a smooth ended pipe would drive me nuts as well lol.

I will keep you posted on how it goes after doing so. Just a matter of getting my hands on the tool to cut it. 2 of my buddy's own their own shop so I'm in hopes of pulling one of those strings. Will probably end up doing everything my garage at home though if I can just borrow the tool

[BASELINE]

Originally Posted by KD07

Thanks for the insight. Yeah I was shocked that the stock exhaust was over 3" wide. Pretty large if you ask me. My only complication is that my car is leased and I will need to reclamp up the stock midpipes for the lease return. As long as I return the car wth a clean job and the coupler clamp holding it together perfectly I don't expect any problems given to me by BMW. After all, that is what they do if the dealer added the MPE. So heating up the piping to expand it wouldn't be the best idea in my case. However, if I was looking to make this a permanent mod this would definitely be in my, or whoever is doing so's, best interest.

Although, with there only being about ~2mm difference in the 2 pipes, I don't think it will leave much room to shrink or expand either. I'm pretty confident it'll be a perfect slide-in fit and be pretty tight to begin with. And yes, I will definitely be sure to sand down the ends after cutting. Just like you, knowing that's not a smooth ended pipe would drive me nuts as well lol.

I will keep you posted on how it goes after doing so. Just a matter of getting my hands on the tool to cut it. 2 of my buddy's own their own shop so I'm in hopes of pulling one of those strings. Will probably end up doing everything my garage at home though if I can just borrow the tool

I hear ya... good luck on the install bro.

[SingleturboVert]

So what happened? Hope you got it done okay

[iMinLuv]

Originally Posted by KD07

Thanks for the insight. Yeah I was shocked that the stock exhaust was over 3" wide. Pretty large if you ask me. My only complication is that my car is leased and I will need to reclamp up the stock midpipes for the lease return. As long as I return the car wth a clean job and the coupler clamp holding it together perfectly I don't expect any problems given to me by BMW. After all, that is what they do if the dealer added the MPE. So heating up the piping to expand it wouldn't be the best idea in my case. However, if I was looking to make this a permanent mod this would definitely be in my, or whoever is doing so's, best interest.

Although, with there only being about ~2mm difference in the 2 pipes, I don't think it will leave much room to shrink or expand either. I'm pretty confident it'll be a perfect slide-in fit and be pretty tight to begin with. And yes, I will definitely be sure to sand down the ends after cutting. Just like you, knowing that's not a smooth ended pipe would drive me nuts as well lol.

I will keep you posted on how it goes after doing so. Just a matter of getting my hands on the tool to cut it. 2 of my buddy's own their own shop so I'm in hopes of pulling one of those strings. Will probably end up doing everything my garage at home though if I can just borrow the tool

My dealer said if it's dinan or m performance you can leave it on if anything it helps their cause for resale.

[KD07]

Originally Posted by iMinLuv

My dealer said if it's dinan or m performance you can leave it on if anything it helps their cause for resale.

Thanks for the info. As of right now I'm considering having an exhaust shop make a custom axleback portion and include a performance muffler to bolt up to my Dinan midpipes. Hoping to spend under $2-300 tops. This would give me a full catback and allow me to keep the stock exhaust in 1 piece and remove the midpipes for sale at the end of the lease. I will let everyone know what I end up doing.

[AlexM240i]

Is it possible to build an MPE with Dinan midpipes setup ???

Considering Dinan midpipes are non-resonated, this setup would cause drone ???

[KD07]

Originally Posted by AlexM240i

Is it possible to build an MPE with Dinan midpipes setup ???

Considering Dinan midpipes are non-resonated, this setup would cause drone ???

No one that I've heard of has done it. I'm sure it could be done, considering the Dinan midpipes are nearly identical in width to the OEM exhaust piping. 80mm stock vs. 82.5ish mm dinan. As long as the inlet for the MPE is 80mm it would just slide into the Dinan midpipes as if you were installing them on a stock axleback.

[AlexM240i]

Originally Posted by KD07

No one that I've heard of has done it. I'm sure it could be done, considering the Dinan midpipes are nearly identical in width to the OEM exhaust piping. 80mm stock vs. 82.5ish mm dinan. As long as the inlet for the MPE is 80mm it would just slide into the Dinan midpipes as if you were installing them on a stock axleback.

Could you please send pictures of the setup installed ?? And a video to hear it would be great ! Thanks.

[iMinLuv]

Originally Posted by iMinLuv

My dealer said if it's dinan or m performance you can leave it on if anything it helps their cause for resale.

+1 I had a Dinan exhaust put on and they said I can return it with it or replace the stock. Anything dinan or M performance is fair game.