Akrapovic X-Pipe Adapters (RKP Style) Remake Group Buy

[GORDON.M3]

So after years of searching and finally acquiring my Akrapovic EVO Titanium X-Pipe, I’ve come to realize and discover why the Akrapovic Titanium Xpipe is still one of the best x-pipe choices for this platform. The workmanship and quality are second to none.

The weight of it is very impressive for something that still retains secondary cats. The Akrapovic Evo is the balance between being a full-on race car and having a street/OEM+ car. The weight savings alone can be felt immediately and the characteristics of how the car drives is incomparable to any other style x-pipes I have tried.

However, there was one downfall with this masterpiece. You were forced to use their rear exhaust system as the piping was not adaptable to the traditional ball-fitting flanges that were found in most standardized rear sections for the E9x M3.

RKP was the first to introduce a solution several years back, their adapters allowed you to mate the Akrapovic x-pipe to any brand rear section. Meaning you could mate the titanium x-pipe to a stainless steel rear section which offered a very unique sounding combination. In recent years these adapters are impossible to find. IND no longer sells them and has listed them as a discontinued product.



I’ve tried searching everywhere for these adapters, and they were nowhere to be found. The only way is if you ever get lucky enough to get them used by another forum member. Over these past few years only a few have ever come up for sale in the classifieds, and many sellers force you to buy the whole system from them. Rarely were the RKP adapters ever parted out from an x-pipe.

There is a good reason why many sellers also refuse to part out the adapters, the adapters from RKP were so tight and seized on the x-pipe that it made it impossible to remove without butchering them. RKP decided to use titanium for the piping which mimicked the finish on the Akrapovic system but the ball fitting flange from the two-piece design was made out of aluminum. Over time with heat, the aluminum ball flange shrunk and eventually corroded/galled with the titanium piping on the x-pipe.

Fast forward to today. I was able to reach out to a machine shop that is willing to take on the task of remaking these adapters so they can be available for the masses that have been unable to get their hands on a set of the RKP ones. That being said, the machine shop that I have spoken with specializes in Titanium alloys, and they can remake the adapters for us, also addressing the removal issues with RKP’s original design.

For those wondering, these are not the same thing as the adapters that are being sold on CarID. Those ones are smaller and fit on the Akra rear section of the exhaust with clamps to use the OEM ball flanged x-pipe. You cannot simply make a ball fitting and use the Akrapovic® P-EXT002 – Adapter. It will not work, ask me how I know…

This will be a limited run and not something they will be producing regularly. Titanium pricing has increased 20-30% as a commodity over the past few years, so the pricing that the machine shop had told me is to ballpark around $400 - $450 shipped within North America depending on how many people we get signed on this group buy. The majority of the cost will be for the mold/jig they will be making for the adapters and titanium piping for such a small batch order.
With enough interest, the machine shop is able to send out a sample unit to me for testing as soon as next week!

For those who are interested, please add your name to the list so we can get this going! The adapters will work with both the Akrapovic Evolution x-pipe and GT4 x-pipe.

[GORDON.M3]

Feel free to add your name here:

1.) GORDON.M3
2.) warddrew
3.) OverDrive
4.) e9x_chucky
5.) irokwrx
6.)
7.)
8.)
9.)
10.)


***[04/06/2021 Update:]***

The Test-fitting sample from the machine shop has arrived!
Finish and quality are second-to-none. OE Akrapovic style Titanium with micro polish surface treatment, and SS304 Machined Rings.

Really impressed with the outcome! Akrapovic owners rejoyce!

In the photos, RKP adapters on the left and the machine shop's sample on the right.

[amrazM]

Good luck with this, after recently getting an akrapovic setup I realized it is the best out there.

[TapOut]

Why wouldn't you guys just buy 2 of these? Secondly, why are you looking to use titanium? These adapters are so small and light as is, what's the benefit of spending 5x the money to go with titanium?

https://www.amazon.com/dp/B00J9KMZN2...ing=UTF8&psc=1

[GORDON.M3]

Originally Posted by TapOut

Why wouldn't you guys just buy 2 of these? Secondly, why are you looking to use titanium? These adapters are so small and light as is, what's the benefit of spending 5x the money to go with titanium?

https://www.amazon.com/dp/B00J9KMZN2...ing=UTF8&psc=1

These universal slip-on adapters are never perfect and tend to have gaps larger than 3-5mm which will add rattling and improper seal to your rear section, affecting the overall tone and performance.
There are also too many screws/nuts that could potentially get seized/rusted out.

Not to mention the weight savings from Titanium. For those buying a Titanium that's usually the main point.

Originally Posted by amrazM

Good luck with this, after recently getting an akrapovic setup I realized it is the best out there.

Agreed! Thanks!

[msan]

Originally Posted by GORDON.M3

Reserved the next post for updates.

FYI I have an Akra muffler (one side) and Akra test pipe (one side) that maybe you can use the titanium plus the piping might make the machine shops job easier...I believe the muffler pipe slips over the xpipe... If it works PM me and we can work something out.

[GORDON.M3]

Originally Posted by msan

FYI I have an Akra muffler (one side) and Akra test pipe (one side) that maybe you can use the titanium plus the piping might make the machine shops job easier...I believe the muffler pipe slips over the xpipe... If it works PM me and we can work something out.

The machine shop already has my Akra X-Pipe and dimensions and is working on it already, we just need to get more interest so costs go lower.

Thanks for reaching out!

[SAMM3Y]

I kind of agree with the other poster. Why not make them out of 304? It'll be 1/4 of the price and most the other aftermarket mufflers with an OE style ball flange will be SS anyways. I have thought about changing my akra rear out for a valved setup but go back and forth as I think the cars the perfect volume as is.

[GORDON.M3]

Originally Posted by SAMM3Y

I kind of agree with the other poster. Why not make them out of 304? It'll be 1/4 of the price and most the other aftermarket mufflers with an OE style ball flange will be SS anyways. I have thought about changing my akra rear out for a valved setup but go back and forth as I think the cars the perfect volume as is.

Many titanium rear sections for this platform still have OE ball flanges. Select few only have straight through slip-on/clamp application.

Making it fully out of SS is an option but the Titanium piping holds up from corrosion and galling much better and won't rust onto the OEM clamps.

I spoke to the machine shop the other day and they said that ring coupling on the two-piece design will be made out of SS304 so it is stronger than the original design RKP made in aluminum. This way it can ensure that when it's being clamped down with the OE clamps it won't get crushed/warped.

[tbuck]

What is happening with this? I may be interested in a set, but $400 seems a bit high for the temp need I have for it. Just want to use my akra x-pipe on other rear sections without a hack job. No chance to do it out of SS for less money? I can't imagine there would be much corrosion on SS. Interested either way.

[GORDON.M3]

Originally Posted by tbuck

What is happening with this? I may be interested in a set, but $400 seems a bit high for the temp need I have for it. Just want to use my akra x-pipe on other rear sections without a hack job. No chance to do it out of SS for less money? I can't imagine there would be much corrosion on SS. Interested either way.

Well if you live in a city like me, where salt and brine are used on the road during winter/spring months the SS piping will create a serious layer of surface rust that will potentially gall to the Titanium on the Akra x-pipe.
Fusing the adapters on. The clearance of these adapters is so tight, that even a little sand could potentially cause issues when removing.

The machine shop said titanium will hold up from rusting or any kind of corrosion for a much longer time. They see it as a long-term thing since most people don't switch exhaust systems every couple of months.

The original RKP adapters were also priced at $400, or more if I recall...
https://www.atomic-shop.eu/part/253193-RKP-ADPT/
Atomic Shop EU has them on their site and its listed for 415€.
So depending on the interest we have, it could be potentially more or less.

You hit the nail on the word, "hackjob". Out of all the solutions I've encountered and tried, the two-piece design is really the best solution when fitting the Akra X-pipe to a OEM style rear without being a hackjob.

I should be receiving a test fitting unit this week, will keep you guys informed.

Feel free to add yourself to the list in a post if you are confirmed interested, that way we can get this going, even if its a small batch!

[tbuck]

Yeah, put me down for a set. Thanks!

[GORDON.M3]

Originally Posted by tbuck

Yeah, put me down for a set. Thanks!

Added to the GB list.

[GORDON.M3]

***[04/06/2021 Update:]***

The Test-fitting sample from the machine shop has arrived!
Finish and quality are second-to-none. OE Akrapovic style Titanium with micro polish surface treatment, and SS304 Machined Rings.

Really impressed with the outcome! Akrapovic owners rejoyce!

In the photos, RKP adapters on the left and the machine shop's sample on the right.

[tbuck]

Wow, that looks great! My main goal here is to use these until I can get the Akra rear section in a couple months, so I am hoping they will come off without issue later. I am guessing the marks on the x-pipe are from the RKP units?

[GORDON.M3]

Originally Posted by tbuck

Wow, that looks great! My main goal here is to use these until I can get the Akra rear section in a couple months, so I am hoping they will come off without issue later. I am guessing the marks on the x-pipe are from the RKP units?

Yes, the marks on the x-pipe that you can see were from the corrosion/galling of the RKP aluminum rings being seized on the Akra x-pipe. The x-pipe was in very good condition also but the adapters had to be sacrificed to make the new ones with the machine shop as they could not be removed. I guess you could say, my x-pipe had to "take one for the team".

[tbuck]

Any idea yet when these might be available?

[GORDON.M3]

Originally Posted by tbuck

Any idea yet when these might be available?

They said they'll have a small batch ready by end of next week.

[The-Traveler]

I'm in the market for an exhaust but not sure what to get. Do you guys think the MPE would sound nice with this adapter and an akra xpipe?

I want something exotic sounding and like the MPE, but hear that test pipes make it too loud. I'm looking to retain secondary cats so the car doesn't smell too much.

Thanks.

[tbuck]

All that I had read and all of the people I have talked with have said that the MPE does not play well with other than the stock x-pipe. Not sure why this is but I decided to sell my MPE and go with a full akra. I totally loved the sound of the MPE on my car, but with an SC coming I needed to get rid of the primary cats and went with the akra evo x-pipe, and so the MPE had to go. YMMV

[GORDON.M3]

Originally Posted by The-Traveler

I'm in the market for an exhaust but not sure what to get. Do you guys think the MPE would sound nice with this adapter and an akra xpipe?

I want something exotic sounding and like the MPE, but hear that test pipes make it too loud. I'm looking to retain secondary cats so the car doesn't smell too much.

Thanks.

The MPE is a great pair-up with test pipes even though you are getting rid of the front primary cats. It wasn't enough. Down low there was virtually no sound in the cabin. When it got to higher RPMs that's when it started screaming. I switched over to a Valved titanium style exhaust so I can have it loud or quiet whenever I want. Which sounds a hell of a lot more exotic even though the MPE had a great tone. The MPE has similar characteristics to Titanium since it is Inconel (a thin version of SS).

[The-Traveler]

Originally Posted by GORDON.M3

The MPE is a great pair-up with test pipes even though you are getting rid of the front primary cats. It wasn't enough. Down low there was virtually no sound in the cabin. When it got to higher RPMs that's when it started screaming. I switched over to a Valved titanium style exhaust so I can have it loud or quiet whenever I want. Which sounds a hell of a lot more exotic even though the MPE had a great tone. The MPE has similar characteristics to Titanium since it is Inconel (a thin version of SS).

Who makes valved titanium exhausts?