rzspyder

As some of you may know, I had an Akra slip-on and link pipe on my Spyder and recently switched to a Kline exhaust (inconel). In this post, I’m going to compare the two from different aspects.
Note that at the moment of writing this review I don’t have a valve controller and I’m just using PSE controller.

Build quality:
Akra using titanium while Kline uses inconel. They both are high end products with exceptional quality. Akra’s link pipe has heat sink while Kline’s doesn’t.
Winner: Akra because of the added heat sink.

Weight:
Kline’s muffler weighs 16.5 lbs
Akra’s muffler weighs 18.9 lbs
Winner: Kline

Sound Volume:
Akra is much much louder than Kline! In fact, Akra with valves closed is a bit louder than Kline with valves open
Winner: It depends! If being loud is your goal, Akra is the winner. If you’re looking for a more civilized loudness, definitely pick Kline

Down shifts:
You can really hear an aggressive downshift sound with Akra, even with valves closed. With Kline the downshifts don’t sound as sexy as they do with Akra. Perhaps if I get a valve controller and keep them always open, Kline’s downshifts will improve.
Winner: Akra

Tone:
Kline produces a higher pitch sound while Akra produces an aggressive sound is somewhat boomy too. The sound of Akra is not like a V8. In my opinion it still has a Porsche character in it but just very aggressive. However, Kline produces the Porsche wail better.

Winner: Kline because of the higher pitch, but Akra’s sound is also beautiful in its own terms.

Valve transition:
There literally is not an audible sound of valve transition between open and close with Akra, while I can definitely hear a sound with Kline. Sometimes it bothers me, but I can live with it.
Winner: Akra

Drone:
With Kline there is a bit of drone around 2K RPM, but it’s totally livable.
With Akra valves closed, there is no drone in lower RPMs but the volume is much louder and the tone of Akra is a bit boomier in general. I’ve experienced a bit of drone with Akra on 5th gear around 4K RPM. If I remember correctly, stock exhaust also had this drone to my ears.

Winner: Can’t really say. It really depends what part of the rev range you can avoid to prevent the drone.

Exhaust tips:
Hands down Akra’s tips look very sexy to me and when I saw OEM tips on Kline I was underwhelmed. I need to look for a replacement.

Sound across the rev range:
Caveat: I don’t yet have a valve controller so I tested with PSE controller for both Akra and Kline
In this section I compare how the sound character changes across the rev range.

First, I start with Akra with valves closed. It has a loud and aggressive sound when the engine starts. It really means business. The sound until 4K RPM is loud but not obnoxious. Then there is a magnificent transition of sound between 4K to 5.5K RPM that the deep sound of lower range is mixed with a high pitch sound of upper range. I can honestly say that even Kline can’t replicate that sound. It truly is a pleasant sound. From 5.5K to 6.5K it gets higher pitched and stays the same tone until you reach 8K. With Akra, you really don’t get a different sound after 6.5K RPM. With valves open, Akra produces the same character but just louder. At some point I ended up never needing to open the valves with Akra. I always drove with PSE off and the sound was loud and pleasant.

Now Kline. Again, I don’t yet have a valve controller and I’m using PSE.
Start thing the engine is underwhelming compared to Akra. Akra is a different beast. Kline is somewhat like OEM when the engine starts. Not very loud but it still has a nice presence.
With valves closed, Kline is very civilized and sounds like OEM until about 4.5K RPM. Then you hear a valve transition sound (sometimes annoying) and then valves open and THEN it starts to sound glorious. With the x-pipe design, it mixes the sound in a way that Akra can never do, and the sound is higher pitched than Akra. In contrast to Akra, Kline gets higher pitched and higher pitched until you reach 8K RPM. So there is always a motivation to get to 8K.
Hovering around 4K and 5.5K you definitely hear the valves open and close (thank you PSE) and sometimes it is annoying. I don’t hear the perfect mixing of lower range and higher range the way Akra could produce. It may get fixed if I get a valve controller and keep the valves always open. Kline with valves open (when PSE decides to open the valves) has the same volume as Akra with valves closed. This actually works pretty nicely for me because I don’t want louder, I want a pleasant tone.

Winner: They are both winners.


Conclusion:

I’m happy with the decision I made to switch to Kline because I wasn’t looking for a very loud exhaust (PSE was off always) and the tone of Kline is more civilized with valves closed and it gets very high pitch up until 8K RPM. I truly enjoyed Akra while I had it. It was just time to try something else. I also think Kline needs a valve controller for sure. So I’m looking forward to installing one and see how the transition from lower range to upper range changes. I wish Kline’s downshifts sounds as good as Akra’s.

If you own Akra and are happy with it and don’t feel the need to try something else, don’t rush to buy Kline just because it has an x-pipe design. Akra is still a very good exhaust.

TRZ06

Wow man, that was fast. How did you get a Kline Inconel system so quickly?

UncleDude

Nice review! What about price?

rzspyder

Eric @SupremePower is the guy to talk to. He was extremely helpful to get these shipped to me quickly. If you’re thinking about a unit, contact him.

UncleDude

I just thought you might want to mention which system was more expensive, not necessarily what you paid.

rzspyder

Ah, Akra is more expensive than Kline

SupremePower

We have inconel aystems in stock ready to ship 🙌🏽

BarryC

Just my $0.02…. I’ve owned both systems (akra on a GT4 and Kline inconel on a Spyder) and I strongly prefer the Kline. The akra has better build quality/fit and finish but the Kline build quality is good and the sounds is hands down better imo. It’s cheaper too. Bought the Kline from Highly Eric at Supreme and highly recommend him!

Thanks,
Barry

Larry Cable

I'm very happy with my Akra slipon + Cargraphic "optimal flow" OAPs ... and the Akra tips are IMO unbeatable for "presence"/appearance

SupremePower

Took us some trial runs but so happy we found the perfect solution for you Larry!!! Smiling ear to ear knowing you are enjoying it!!!

lowbee

Can you describe the sound of the valve transition? Does it sounds like a mechanical click? Or is it just louder and different exhaust note ?

rzspyder

It’s like the transition between a sound that is muffled to a sound that is not muffled. You notice it because the delta between muffled and not muffled is too big, so it sounds like a boom sound. I don’t hear the valve itself.

jmartpr

I'm now the happy owner of RZSPYDER Akra muffler (Thanks!)....will do the install tomorrow and post here the results combined with my Dundon Street Header setup.

dnimi123

Now THIS ^^^ is commitment to the tribe, folks!

Regul8415

Just got the street headers from Dundon installed on my car. So far sound have been great. Interested in how it will sound with the akra and just curious as to why you’re going for more.