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Discussion Starter · #1 ·
About a month ago I found an Akra 4-2-1 system in really good shape. I pulled the trigger, pieced it all together, and noticed when I’d ride it that it was down on power, naturally. I took it to get it tuned today.

As a baseline when I had the stock exhaust on the bike I had it dyno’d in 2013 and it made 127 horsepower. Today after it was fully tuned, I made 72 horsepower. I’m very disappointed to say the least. It was turned with the DB killer in. I assumed that the DB would eat up some but I never expected to lose over 50 horsepower.

What am I missing with this formula? I had always heard the first gen Z’s did better with full exhausts. I’m very concerned now that if I take it back up to get it tuned without the db in it that I still won’t be happy.
 

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Discussion Starter · #3 ·
The db killers are horsepower killers, but something else is wrong to lose that much.
So I've owned the bike for 13 years. Bought it with 7k on the clock, 30k now. Its always had its services, valve adjustment checks, and I even ride track days on occasion. Its very well maintained and I was pretty acquainted with how it performed prior to the install of this exhaust. Long story short though, yesterday, I did pull out the cork out and wow, even with the shitty DB tune its a noticeable difference. I sure was selling myself short on the sound of it. I also stumbled on a post in the Kawi Concourse forum where a gentleman showed his graphs where he made 83HP with the DB killer in and 142 horsepower with it out. I'm pretty confident now. Personal crisis averted. :LOL:

I'm hoping to get it back on the dyno this week and I'll check back in with the results.
 

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I would like to see a picture of the db killer Dr. Bleed is talking about. It must be huge and restrictive?

My 08 Concours 14 has the stock header with an Ivan ECU reflash. The only other mod is a slip on exhaust. On this bike, the db killer lost 7 hp . The db killer is significant enough to where Ivan offers a different ECU flash for db killer in vs out.
 

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Discussion Starter · #7 ·
Hey Guys,

Update. No word back from the tuner on when next he'll be available. It'll be touch and go with the weather since the near 70 degree weather is on the way out here in Indiana. I've posted some pictures of a few different things to try to pull into perspective. I'll start off by saying even with the shitty 70 horse power tune after riding it a bit there is a noticeable increase in power probably a good 15 or 20, just guessing. There are a few drop outs in higher RPM because he said he had to lean it out so much to get a linear powerband for me with the cork in it so I'd imagine this all goes away once its re-tuned.

The front and rear of the "DB Killer"

Hand Camera lens Finger Lens Thumb


Hand Automotive tire Finger Rim Gas


Stock Exhaust cut down 4" w Stock Header, Open Airbox w K&N, and PCIII Dyno results...
Rectangle Slope Font Line Parallel


After full titanium akra, plus the mods mentioned above...

Rectangle Slope Font Line Parallel


Here are a few pics of my beautiful Z1000 with the new exhaust in all of its current 76 horsepower glory. 🤪

Musical instrument Automotive lighting Automotive tire Bicycle part Fender
Aircraft Automotive tire Automotive exhaust Airplane Motor vehicle


Automotive tire Wheel Motor vehicle Tire Automotive design


The best way I could describe the way it felt when I would throttle through it would hit about 6 or 7 grand and then it was like all power would drop off up top very quickly. The best way I can describe is that it felt like the inside of the exhaust pipes were filling with an immense amount of pressure. Also the headers were much hotter with the cork inside than they were without.
 

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Discussion Starter · #9 · (Edited)
Sounds more like a restrictor than a baffle.
It was a disappointment that's for sure. Thankfully I think I've rid myself of the curse. I'm hoping he finds another time slot before the perma frost arrives and cuts me a deal on the next run since the tune I have now is basically useless.

I actually stumbled on a couple dyno sheets from guys that have Z750's same year as my Z1000 that dyno'd 97 Horsepower with just a slip-on. SMH
 

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Discussion Starter · #11 · (Edited)
That is a massive restriction. Every one I have used allowed more flow than those would . Are they homemade or do they have a name on them?
I'll take a look at it in the morning and see if there is anything etched on it. The thing is, full Akra systems in nearly perfect shape are difficult to track down for first gens these days. I ordered it from a place in Japan that refurbishes exhausts. It is entirely possible that it is a home made piece now that you mention it.

In other news I did talk to the dyno guy today and he said he is actively working on getting me back in the loop so whenever I get the results I'll post them up.

I don't know what I was thinking not taking that out to begin with. My buddy has a Yosh pipe on his CBR1000RR and it sounds pretty beastly with it in so that was the idea I had. I think I thought the bike would be a lot louder with it out but its not any louder than the stock pipes I had that were cut down 4". Lesson leaned. I'm pretty darn excited to get this ironed out.
 

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I've done that same thing. You have a hundred things on your mind when you are in having your bike tested. Plus, you are paying for every second of the testing time. Not wanting to interfere.

If I only had to give up 5% of my performance, I think I would keep the bike quiet.
 

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Discussion Starter · #13 ·
Hey guys,

Today was the day. Talk about a difference. The guy told me if my rev limiter was 500RPM higher he could have netted me another 2HP. Totally exceeded expectations. Here are the dyno results over laid. Green is with that massive DB killer and red is without...

Rectangle Slope Plot Font Parallel


Realistically I went from 126 hp with the original setup to 144.9 with the full Akra and opened airbox on this bike.

About to go enjoy the unseasonably nice weather here in November while I can! Catch ya soon. 😁
 

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I would have never guessed it would be that bad.

The bike had to be VERY quiet with it in?

I've always loved quiet bikes. I learned this when I was a kid illegally riding in the neighborhoods. If your bike was quiet, you could get by with murder and the neighbors would smile.

A 125 two stroke that smoked and damaged eardrums would mean the sheriff showed up. I with we had a way to keep the power as well as the silence and not weigh 50 lbs like the stock zx14 exhaust.
 

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Discussion Starter · #15 ·
I would have never guessed it would be that bad.

The bike had to be VERY quiet with it in?

I've always loved quiet bikes. I learned this when I was a kid illegally riding in the neighborhoods. If your bike was quiet, you could get by with murder and the neighbors would smile.

A 125 two stroke that smoked and damaged eardrums would mean the sheriff showed up. I with we had a way to keep the power as well as the silence and not weigh 50 lbs like the stock zx14 exhaust.
In defense of normal DBkillers I probably would have seen a 10 to 15hp loss. Still quite a bit if you think about it but apparently that piece I had in mine was basically acting as a restrictor plate. It was louder than stock with it in but with it out it was honestly not much louder than the stock pipes I had cut down 4” with baffles left in place

I agree though, I didn’t mind riding it quietly and figured I’d give it a shot but the way it is now, I don’t think I’f have it any other way. 😄
 
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