[Dinan_Engineering]

Dinan Valved Axle Back Exhaust Systems for the BMW F48 X1 28i & F39 X2 28i

Part Number(s): D660-0088, D660-0088-BLK, D660-0089 & D660-0089-BLK
Applications:

• 2017-2022 F48 X1 sDrive28i (D660-0088 or D660-0088-BLK)
• 2018-2022 F39 X2 sDrive28i (D660-0088 or D660-0088-BLK)
• 2016-2022 F48 X1 xDrive28i (D660-0089 or D660-0089-BLK)
• 2018-2022 F39 X2 xDrive28i (D660-0089 or D660-0089-BLK)

Product Page(s) / Pricing: dinan.info/F48-F39-EXH
Release Date: Available Now!

Description: The F48 X1 and F39 X2 BMW crossovers are, by volume, one of the most successful lines in the BMW brand portfolio. That success capitalizing on those that want the additional cabin space, akin to an SUV, but without the huge sacrifice to fuel economy courtesy of the fuel efficient B48 4-cylinder engine. For a wide swath of the consumers in these vehicles that is enough and all that is desired. However, for a growing segment of the market, there are also those that want even more. Namely performance, and by association, sound, more commonly associated with the sportier B58 6-cylinder engine. From the factory the stock X1/X2 exhaust is largely silent in all modes which is a travesty for any those consumers that fit in the "more" category, but Dinan offers a solution that rights that wrong.

The Dinan exhaust system offers a dramatically improved exhaust note that is not only louder but fuller and deeper as well. 70mm piping, free of hydroforming, is used throughout that allows freer flow to traverse the entirety of the system. The tubing is then fed into a streamlined muffler that is typical of all Dinan exhaust design and utilizes absorption technologies designed to improve exhaust flow and reduce back pressure. The combination results in mildly improved power output at the extreme top end of the power band and a great sporty sound complete with pops for additional aural gratification. Factory valve control is also retained to ensure the perfect blend of civility when not pushing the car and a bit of additional character when in it. Regardless of driving style or conditions the system is purposefully engineered to reduce low-RPM drone, so the cabin of the vehicle remains intimate and not drowned in an excessively loud tone.

While sound is the primary reason for any exhaust purchase the styling and craftsmanship also play an important role for the discerning buyer. The Dinan X1/X2 exhaust has been skillfully crafted entirely out of T304 stainless steel and TIG welded for the best visual appearance and color. The entire system is then brush-finished to further guarantee an immaculate looking system out of the box. The attention to detail is not limited to parts of the system you can't see once the exhaust is installed but is also extended to the exhaust tips themselves. The Dinan exhaust sports enormous, dual 4" (102mm) clamp-on, double-walled, polished and laser engraved exhaust tips. Dinan has retained its signature straight cut tip design, safeguarding its unique and elegant styling position, amongst a marketplace dominated by angle cuts. The tips masterfully fill up and accentuate upon the factory cut-outs showcasing an extremely aggressive, yet refined, styling that will turn heads even before it is heard.

Features/Benefits:

• Maximum gain of +5 HP and +4 ft-lb of torque
• Enjoyably louder, sportier sound
• Dual 4" (102mm) double-walled, polished or black ceramic coated clamp-on tips with laser engraved Dinan logo
• 100% 304 Stainless Steel Construction
• Retains factory valve control
• Bolt-on installation; Includes mounting hardware

[johnjohnxp]

Hello! I was interested in purchasing this and I looked at the install manual and it said I had to cut the factory pipe? Is that the only way to install!? And I wouldn’t be able to go back to stock if I needed too?

[Dinan_Engineering]

Originally Posted by johnjohnxp

Hello! I was interested in purchasing this and I looked at the install manual and it said I had to cut the factory pipe? Is that the only way to install!? And I wouldn’t be able to go back to stock if I needed too?

Yes, it would require cutting of the factory exhaust. All BMW/MINI's (unless there is an exception I am forgetting about) for the past 20 or so years are a one piece exhaust from the cats to the tips so in the case of an axleback exhaust they ALL require cutting. That said, the cut point is at the same location the factory would use for a replacement rear system in the event of an accident. As such, the stock system can be put back on the vehicle with a clamp if the need arises that reverting to stock is required.

[alex2112]

It looks to me from the design that with the valve closed, it routes all exhaust through the muffler and only to the right exhaust tip, and then with the valve open most if not all of the exhaust bypasses the muffler and exits through the left tip. Is this correct?

The factory valve control only allowing exhaust gases to exit from one tip when closed is my biggest pet peeve of the X1/X2 platform. Permanently opening the valve was one of the very first things I did after getting my X1. If this system has most of the exhaust gases bypassing the muffler when the valve is open, might as well do a muffler delete.

[Dinan_Engineering]

Originally Posted by alex2112

It looks to me from the design that with the valve closed, it routes all exhaust through the muffler and only to the right exhaust tip, and then with the valve open most if not all of the exhaust bypasses the muffler and exits through the left tip. Is this correct?

More or less. When the valve is open about 80% of the volume goes the path of least resistance (straight pipe) with the other 20% going through the muffler and the other side.

The factory valve control only allowing exhaust gases to exit from one tip when closed is my biggest pet peeve of the X1/X2 platform. Permanently opening the valve was one of the very first things I did after getting my X1. If this system has most of the exhaust gases bypassing the muffler when the valve is open, might as well do a muffler delete.

Functionally, the routing between the stock and Dinan system's is identical. The primary difference is a drastic reduction in can size and interal pathways within the can that create additional backpressure and sound deadening. With a valved 2 outlet system there is pretty much no way to have both outlets function at all times and be efficient/cost effective. To do so would require copious amounts of additional piping and a price tag that would eliminate 95%+ of the potential market. Would also mean the valve open configuration would be significantly quieter as it would required to go through the muffler. Since the primary purpose of an exhaust is sound the biggest "get" beyond changing general tone for a valved exhaust is a significant delta from closed to open. Going fully open and being essentially a straight pipe guarantees the maximum volume change between modes. This has proven to be a very successful formula for not only ourselves but BMW M performance for many years.

[TakeOne]

Okay Dinan,
Got around to putting the newly released Exhaust for the X1/X2 yesterday.
Cliff Notes:
- Incredibly well packaged! The box arrived in a somewhat questionable condition. (from shipping I'm sure) But EVERYTHING was extremely protected by form fitted foam.
- Build Quality: TOP NOTCH (except for one piece I'll mention later)
- Sound: Just right. A little drone if you're at low speed in a high gear. Specifically 1,300-1,400rpm's, but everywhere else is great. In fact, the higher you go, the more glorious it sounds!

Okay, the not so good…
Instructions, gonna unfortunately have to give an "F". For one, there were none. Atypical from Dinan as they always had a paper copy included when I bought their piggyback and their intake. Okay, no big deal. We'll just go to their website and download instructions. After finding the model number of the exhaust and specifying X-Drive, we noticed something VERY off from their cutting measurements. I mean VERY off. Before taking the blade to the exhaust we just kept re-reading and re-reading. Eventually, we noticed that even though we clicked the link for X-Drive, the link actually re-directed us to the S-Drive PDF. We thought, oh, maybe they accidentally flip flopped the PDF instructions, so we went to the S-Drive instructions. But nope, S-Drive instructions were S-Drive, and the X-Drive link took us to S-Drive.
I ended up calling Dinan, but unfortunately they don't have technical people or engineers working on Saturday. Only sales and returns people were manning the phones. So we had to use a specific exhaust mounting point that both the OEM had, and the new Dinan pipe had, and work are way backwards to ESTIMATE a cutting point.
Short story, it worked, but it took measuring, and measuring, and measuring to make sure we would cut correctly.

Last part: There is a bracket that attaches which is for mounting the actuator flap. After spending more time than we should have, we noticed that the bracket did NOT have the necessary bend that it was suppose to an order to line up with the screw holes. It appears that from your CAD drawing, and Parts photos, it should have had an approximate 30 degree bend so the holes could line up. Mine was completely straight. This left almost a 1" gap.
(see photos attached)
So at this point, we had to figure an on-the-spot solutions, as the stock exhaust was already cut. We ended up using a vice, and in multiple steps, used a vice to bend the bracket in, eventually to where the two screw holes would line up and be flush.

Please don't take this as a bash to the product. It seems like everything else they nailed. I just want Dinan to take this as an opportunity to make these two simple corrections. UPDATE your website with correct links, and double check/or revise that bracket. (and no, i don't believe this was damaged from shipping as i would have noticed a "previous crease" where there should have been.

As always, i've recorded everything from unboxing, instal (issues we ran into) and driving review. Video will be coming in the next several days.

[Dinan_Engineering]

Originally Posted by TakeOne

Okay Dinan,
Got around to putting the newly released Exhaust for the X1/X2 yesterday.
Cliff Notes:
- Incredibly well packaged! The box arrived in a somewhat questionable condition. (from shipping I'm sure) But EVERYTHING was extremely protected by form fitted foam.
- Build Quality: TOP NOTCH (except for one piece I'll mention later)
- Sound: Just right. A little drone if you're at low speed in a high gear. Specifically 1,300-1,400rpm's, but everywhere else is great. In fact, the higher you go, the more glorious it sounds!

Okay, the not so good…
Instructions, gonna unfortunately have to give an "F". For one, there were none. Atypical from Dinan as they always had a paper copy included when I bought their piggyback and their intake. Okay, no big deal. We'll just go to their website and download instructions. After finding the model number of the exhaust and specifying X-Drive, we noticed something VERY off from their cutting measurements. I mean VERY off. Before taking the blade to the exhaust we just kept re-reading and re-reading. Eventually, we noticed that even though we clicked the link for X-Drive, the link actually re-directed us to the S-Drive PDF. We thought, oh, maybe they accidentally flip flopped the PDF instructions, so we went to the S-Drive instructions. But nope, S-Drive instructions were S-Drive, and the X-Drive link took us to S-Drive.
I ended up calling Dinan, but unfortunately they don't have technical people or engineers working on Saturday. Only sales and returns people were manning the phones. So we had to use a specific exhaust mounting point that both the OEM had, and the new Dinan pipe had, and work are way backwards to ESTIMATE a cutting point.
Short story, it worked, but it took measuring, and measuring, and measuring to make sure we would cut correctly.

Last part: There is a bracket that attaches which is for mounting the actuator flap. After spending more time than we should have, we noticed that the bracket did NOT have the necessary bend that it was suppose to an order to line up with the screw holes. It appears that from your CAD drawing, and Parts photos, it should have had an approximate 30 degree bend so the holes could line up. Mine was completely straight. This left almost a 1" gap.
(see photos attached)
So at this point, we had to figure an on-the-spot solutions, as the stock exhaust was already cut. We ended up using a vice, and in multiple steps, used a vice to bend the bracket in, eventually to where the two screw holes would line up and be flush.

Please don't take this as a bash to the product. It seems like everything else they nailed. I just want Dinan to take this as an opportunity to make these two simple corrections. UPDATE your website with correct links, and double check/or revise that bracket. (and no, i don't believe this was damaged from shipping as i would have noticed a "previous crease" where there should have been.

As always, i've recorded everything from unboxing, instal (issues we ran into) and driving review. Video will be coming in the next several days.

Oi, sorry you had a less than ideal experience. Suprised this was only caught now with a number of systems sold prior but alas...

Website links have been "fixed" (D660-0089 was the only SKU linking wrong) but the xDrive instructions still need to be updated as the initial step one cut point is for the sDrive and not xDrive. I could make an educated guess based on Figure 7 of the instructions on where the cut point mark actually is for xDrive cars (appears to be at the factory cut point/dimple) but I will defer to engineering to actually tell me the real number when they come in this morning. Once they update the instructions with the correct measurement for that step I will get the website instructions fully updated.

The bracket is odd but not unheard of. The non-kinked bracket has made an appearance 3-4 times across different exhausts over the last 2 years. No idea how they are getting into the mix though -- they are flagged for 100% inspection when they come in and everytime we check our raw bin when this comes up they are always correct in there as well. Seem to appear randomly. Infuriating on both ends I can assure you.

Regardless, glad you are at least enjoying the exhaust.

UPDATE: See below for a sweet MS paint diagram but essentially the 2 3/4" measurement is correct but it would be from the rear most cut dimple on the xDrive variant.

Will update the instructions on the website once I get the revised version from engineering.

[TakeOne]

As promised, full review/install video up now:
https://f48.bimmerpost.com/forums/sh...00&postcount=1