Last week I bought an 09' ZX14 that was completely stock. Days afterwards I put on some short slip-ons to replace the obnoxiously huge factory pipes. The slip ons I used have a single acorn-style baffle inside. Here is a before and after video.

https://youtu.be/4BUluJxrFsk

I like the sound, but it is a little loud for me. Additionally I am worried about back pressure. Eventually I intend on running more expensive slip ons, but after looking around a few people have had success installing these drain cups on their mufflers. They can be found at hardware stores.

They seem very similar to factory silencers, and I do not have much room to work with at the outlet before the acorn baffle starts. I figure I can re-drill the holes larger until I get what I want, and at worst I've wasted 6 bucks and a few minutes with the welder.

Anyone tried this before?

* Last updated by: projo198 on 3/13/2017 @ 12:50 PM *

Sorry, no parts from Home Depot on my BBW

My Two Brothers slip-ons offered DB inserts.

I've never tried these, but if not offered by slip-on manufacture I might
take a look at these "DB-DOGS"

http://www.dirtwerkz.com/Pages/products/exhaust/dB_Dawg.html

sounds cool. I guess if you are trying to quiet the slipons down by restricting the exit, you are playing hit or miss with the drain cup. I would wonder about back pressure too. I'd just deal with the noise if you are going to buy quieter slipons. If you do, make sure the slipons you buy are quiet. I doubt you will find any aftermarket exhaust as quiet as OEM.

Well I got them in yesterday evening, Had to chop and weld them back together a bit to get the diameter I needed.

It did quiet things down a little, but not enough to cause me to overlook possible back pressure issues. IT also added a little popping during down-rev that I didn't like, so I pulled them back out.

I got a Power Commander 5 from another user here (thanks!) and am picking up an Autotune Thursday; I may play around with things after I can make adjustments at the fuel/air side of things.

I would not worry much about having too little back pressure. Full systems have no cats at all and people have run them on OEM mapping. You still have the cat in the collector with slipons. That is probably giving you as much back pressure as you need. The stock mufflers gave you more, the slipons opened that up and now the strainer cups would restrict it some....so you are probably have gone some distance in compensating for reduced back pressure of slipons by restricting them with strainers.

The cat in the collector may get burned from using slipons. Also, might interfere with O2 readings.

personally I would buy Wideband 2 instead of Autotune because it's the same thing with a few more features you might use if you get into really advanced tuning. If you are going to self tune with any O2 sensor, you must block or remove the PAIR. That dumps air into your exhaust and it will totally screw your O2 sensor readings. I would not even suggest you try until you disable the PAIR.

Also, you realise how involved it is to actually tune with Autotune? It's a lot of learning. Te principal is simple enough but if you are going to do it on the street, you will be breaking the law over and over to get your fuel trims. It will tune your cruising range automatically as you ride. Any other tuning done with AT must be done methodically like on a dyno or you will be wasting your time.

projo, I never even tried to use AutoTune the way DJ suggests. I figure if Romans felt it was useless to do so, I would not even try.

If Autotune gathers reliable trims just by riding the bike, I should not be getting very large trims after tuning it during repeated runs meticulously monitoring TP and RPM. I believe Autotune is still giving me a trims table that looks like the bike was not tuned at all. Riding on and off throttle often in the cruising range is not the same as doing a tuning run.

sorry no pics at the moment. working on that. Let me know if you need them and I'll get them up.

HOW TO USE AUTOTUNE

Thanks for the informative replies!

The only experience I have with the Autotune is on my friend's Hayabusa. He moves it back and forth from Montana and raves about the way it adjusts the bike for the changing temps and elevation.

As for the mapping I plan on starting with the basic ones provided by DJ and going from there. Other than that I have no experience with these at all so I might be leaning on you in the near future!

Autotune is more than good enough for cruising and would have no problem adjusting for elevation changes (although the Gen2 busa already has this capability without autotune---has stock o2 sensor in pipe). If you can keep a steady rpm without changing throttle position AT will literally tune that map cell your sitting in on the fly in about 2 seconds. Problem is, if you are not cruising, you can't stay in one cell for more than a fraction of a second. The engine spins up faster and faster and AT can only take a very brief sample for every cell it enters on its path to redline. You must hold at a single throttle position from the bottom to redline, let the throttle grip spring closed, decel to a stop at 0 throttle and then accept the trims AT suggested. Now go do that again 2 or 3 times and you should be real close if not dead on.

In short, AT only does what Dj said it does in the cruising range. It is too slow to adjust on the fly for any part of the map where you are accelerating. That requires a lot of human intervention. It's dangerous and pretty time consuming. I like though but I can see how a lot of AT users might be a little disappointed and confused trying to use it to tune the whole map. I'm still learning it too.

If I did not already mention, I'd pay the extra $60 and get Wideband2 instead because it has a couple more features you might as well have available should you ever need them. AT-200 is dumbed down about 3% otherwise exactly the same.

You can see in this video, if you watch the AFR gauge on the laptop when I get into top gear and cruise at 2900 rpm, the AFR bounces up and down until it settles in at very close to 13.5 which was the target AFR. It takes a few seconds to hit it though and if you ever leave that cell, you start all over when you come back to it. AT will not permanently change your map unless you accept the trims. I could have made this point a lot more clear if I would have started with a map that was off by quite a bit more than the one I was running. Say I started with am AFR of 11 at 2900 rpm and cruised there--you would see the AFR bounce back and forth a lot more and settle in at 13.5 after a few seconds.

Works perfect for cruising. Takes a lot of work if you use for racing.

Also pay attention to the Fuel Adj. gauge. You see when I can keep the rpm very steady, the adjustments get smaller and smaller until they reach zero +/-1 at 13.5 AFR. +/-1 is as close to perfect as you can get. If you need that across the powerband, you need to do test and tune runs every couple hours because the atmosphere is always changing.

Whoa man you are making my head hurt lol.

Thanks for the info. I am hoping to get some things done on the bike this weekend and will get my head wrapped around all this. I genuinely appreciate the advice, thank you so much.