Success with Aaen pipes?

[gixxer6]

Has anyone had "success" running Aaen pipes on a Kawasaki?  I define success as an increase in performance, horse power increase, increase in speed, etc.  Something other than sound and seat of the pants feel. 

[Tory944]

Lol....    NOPE (from "my" experience).  They sound good and shed weight...   that's about it.  I've had them on Interceptors, Invaders and LTD's.  They all came off and stock pipes went back on.  Olav Aaen has been in the business a long time.  He has a wealth of knowledge in a general sense of the sport.  I have found very limited info on porting to match their pipes for Kawasaki.  I've talked with Olav on the phone a number of times trying to get porting specs.  Not much luck.

Aaen performed a dyno on a stock Kawasaki Invader 440 using "stock" cylinders, 38 mm non econo jet Mikunis and a set of their twin pipes...   the results?    69.6 hp.     This info is in one of their books.

[Tory944]

  Looked in their book...   69.6hp @ 8000 rpms.   Same setup...   but with 38mm flatslides ...   72.5 hp @ 8500 (now you will need to re calibrate the clutch).    440 INVADER.

[Boomologist]

Just bolting on equals very limited success unless you do the other things that AAEN recommends.
This includes porting, heads and flyweights. See attached:

[gixxer6]

  Looked in their book...   69.6hp @ 8000 rpms.   Same setup...   but with 38mm flatslides ...   72.5 hp @ 8500 (now you will need to re calibrate the clutch).    440 INVADER.

 

I'm not at all surprised by this.  They are designed to run at 9250. 

[Boomologist]

There is quite a science to expansion chambers. This is especially true with piston ported as opposed to valved engines.

[Tory944]

FYI...   the spec sheet shows tuning for 9250, but Olav told me over the phone that the pipes make their best power at 8800 rpms (not joking).  That's a big difference! Show me a dyno sheet and I'll listen.

By the way, I've had my cyl's ported by Aaen in the past (using their pipes) and I saw little/no performance improvement.  The total bill was almost $1100.  Not worth the $$.  None of their pipes exit the stock location in the pan and these are "trail pipes"...  not full blown race pipes.  Hacking up a belly pan better be worth it!  IMO

[gixxer6]

I have Aaen pipes on my 4/6, it's been ported and has shaved heads.  When I got it, it was clutched to run 8800 RPM.  Yesterday I pulled some weight off from the primary ramps.  It would then run 9000 RPM, it sounded a lot better and was noticeably faster.  I don't have a dyno, but at 8800 RPM it only would run 70MPH, at 9000 it hit 80 with ease (both runs done on a snow covered plowed road).  I'm looking forward to running it at 9250 to see the results. 

[Tory944]

  Just telling you what Olav told me!  Just the messenger.      Aaen do the port work??

[gixxer6]

I don't know who did the port work.  It was ported when I got it.  But I did some measuring while the engine was apart, and its very close to the specs posted above.  Plus the transfer ports have been ported a little.  The port work looked VERY nice. 

Have you run Aaen pipes/porting at 9250? 

[Tory944]

Yes, performance seemed "flat"  sled didn't seem to pull hard above 9000.  Cyl's were ported by Aaen.   If anyone would like to give them a shot...  $125 for the pair (shipped).  Cylinders have minimal run time including a $400 Nicasil job.

[gixxer6]

Along with the pipes on my LTD, I have Aaen pipes for a 440 Invader.  I also have a 440 Invader engine built with NOS cylinders that I had trail ported by Image.  I haven't had time to install it into a sled yet.  I am hopeful that it will make some power... 

I'm surprised that no one has anything good to say about the Aaen pipes. 

[Tory944]

You're gonna chuckle at this one...   guess who does the porting for Image?  LOL  gentleman who used to work for Aaen!  Bob (Image) doesn't know the first thing about porting an engine.  Almost everything that comes through his shop he outsources.

[Tory944]

  I have heard good reviews with Aaen pipe(s) engine combos for other brands such as Yamaha and Polaris.  I just haven't had good luck with their products for Kawis.  This topic was discussed on Vintage Bull in the past...   the post turned into a war in which I was not willing to participate.   The topic turned very negative and started heading South quickly.  Olav Aaen has many followers and he has been a great asset to the sport, but THAT is a "separate topic" and the benefits of using their pipes was quickly lost in the discussion.  Can of worms (bucket).

[gixxer6]

You're gonna chuckle at this one...   guess who does the porting for Image?  LOL  gentleman who used to work for Aaen!  Bob (Image) doesn't know the first thing about porting an engine.  Almost everything that comes through his shop he outsources.

Yes, I knew this when I had the work done.