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Discussion Starter · #1 ·
Having looked at the numerous posts on this and other forums I'm still confused as to if we need to change the fuelling if replacing the standard exhaust. If so what's the best way to address this?

It would be great if as a group we had a clear/concise/correct veiw.
 

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I think most exhaust manufactures make their slip on mufflers to fit without any mods to the ECU or injection etc. The normally get a bike as a test bed and make the muffler to suit with further testing on their Dyno's to ensure that it works without mods. Their is normally a small increase in HP and torque figures. If you want peak performance then you can tweek it with a PC or similar but I think that on the whole you will be able to slip the new muffler on without any other mods.
I am no expert and will stand corrected if someone knows better though.
 

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I'm pretty sure that if you replace the exhaust on a kawasaki the bike will run too lean which can cause engine damage, Thats why a power commander would be needed (or something similar) to allow the mixture to be adjusted. Though please feel free to correct me if you know different.
 

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Discussion Starter · #4 ·
2 replies and both different. Any thougts on how we get this confirmed one way or the other.
 

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Like I said, I am no expert but when we (Bagman and I) were talking to the guys from Quill Exhausts, They make their exhausst so that you do not need any mods or adjustments and they can be bolted straight on. You might be better talking directly to the manufacturers of the pipe that you are thinking of bolting on.
 

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Every bike i have had with fuel injection that i changed to slip on exhaust there was no need to do anything else.If you change to a full system,headers air filter ect. Then you will need to re-map with a power commander or other type of fule management system.This is just my experience with my bikes in the past and may be different with your's.

keith
 

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I've put a slip-on on every bike I've owned and only put a PC on my TLS which I also did some airbox mods and a high-flow filter. IMHO you will not need a PC just for a slip-on. I've got a Two Bros. on the way and don't plan on getting the PC until I'm ready to pull the flies and get a custom map. That's my $.02 worth.
 

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Full System

Tried to bolt on a full zx14 system. Fitted fine but bracket mounting points were wrong. Also tried the PC from my zx14 but maps were totally wrong
 

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Okay, I'll chime in here not because I'm an expert but because I do know some exhaust experts that have answered this question for me upwards of two months ago. Everyone that has responded to this post has been right but you should figure on getting a PC along with your slip-on. Why? The reason is that most slip-ons cause the GTR engine to run lean in the higher rev range (8000 rpm and above), below this range will most likely be identical to stock. So, it depends on how you will ride the bike (your total performance expectation for your machine). Also, tolerances play a part. Just as with bikes owned by members of this board. Take a group of these bikes allow the same (skilled) rider to put them to the tests ,1/4 mile runs and roll ons from various speeds and you find that however close some of the perfomance values will be greater or lesser for the test performed because of effect of tolerances. Some may say I did a hard break-in or an easy break-in but which ever you did you had to start with your own set of specifc tolerances that you received when taking ownership of that mighty GTR that you chose. Now, Garry your bike afer slip-on installed may not go lean until 9000 rpm. Let's say you spend 98% of your riding time below 9000 rpm. At this point I would ask you; Do you need a PC? Yes if you want to cover the 2% opportunity to be lean up at 9000 rpm and above, no if you are not going to be impersonating Valentino Rossi regularly. On the flip-side, let's say because of my set of tolerances and with slip-on my GTR leans out at 7500 rpm. Well this is a problem if I enjoy and riding that takes me 7500 rpm and above on a regular basis. To help you further slip-ons "typically" create a leam condition somewhere and on rare occasions a rich condition. Pipe manufacturers who say that you don't need a PC are gambling that you are looking for more sound, style, and a handful or so more ponies and thus will not push the bike to lean condition zone regularly enough to do harm. The best thing to do in my opinion is choose you pipe and the specific PC for our GTR. (Fuel Moto is our friend..best maps, knowledge, and prices). Take your Slip-on/PC equipped bike to one of the Dynojet Service Centers near your area. They will show you where your bike is lean ($30 - $50) and dial in your PC to fix the problem for a little more $. The examples I used here are a simplified version of what I learned of this issue. I hope it helps.
 

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I agree that the pipe will lean out the bike, but I don't think it's enough to do any harm. Most bikes come rich from the factory anyway. You will definitely get more out of the upgrade by mapping it and I would recommend getting the PC, but if $ is an issue then I don't think you will harm your bike w/out it.
 

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I agree that the pipe will lean out the bike, but I don't think it's enough to do any harm. Most bikes come rich from the factory anyway. You will definitely get more out of the upgrade by mapping it and I would recommend getting the PC, but if $ is an issue then I don't think you will harm your bike w/out it.
Again, It will depend on the tolerances and the riding style. Some of us may want to know where our motors operate within the spectrum. We all have different riding styles. Main point is that whether harm will occur or not given your riding style, you can know for sure whether a lean/rich condition exists with the dyno/diagnostic and the PC will fix the condition.
 

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Discussion Starter · #12 ·
Followig on from Rocklee's comments can anyone recommend someone who would carry out the work in the UK as he describes in/around London or the South-East area?
 
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