I just finished doing the stage one upgrade on my bike this weekend. I have Rush 2.0 Pipes, an Arlen Ness Big Sucker Stage II (oversized) air filter and the Thundermax tuner with the autotune module and wide band sensors.

The AC upgrade was a piece of cake and the Thundermax installation was also fairly easy once I got an 02 adaptorfrom my local autoparts store.

In my initial map configuration, I selected a 2.75" High flow Air Filter for the AC. They don't have a listing for Rush Pipes so having read some other posts here I chose the KW HP+ Mufflers since those are supposed to be very close. Everything else is the stock 96TC configuration.

While the overall performance seems great, I am getting serious popping on decel. I only have about 100 miles with 6 on/offs so far but this has me concerned. I do not believe I have an exaust leak at this point.

Has anyone else here using Rush pipes experienced backfiring with de-acceleration? Is the KW HP+ muffler selection actually the closest match for Rush pipes?

Also, there seems to be some conflicting information regarding the IAC AutoTune feature. According to my manual, I should run that feature and then manually adjusted the outside ranges per the manual - having read the later manual online..it said it's not necessary to adjust the graph manually.

Now after reading some other posts - I'm told to clear the IAC Autotune settings and simply let it idle to 289 or so without running the IAC Autotune feature at all.

Anyone have experience with this? Any suggestions appreciated.

 

Celtlion,

I can't answer all your questions but I have some input to your post.

First - The IAC autotune is presently correct on-line (don't do it) versus the manual that is per T-Max
(I spoke with them the other day).

Second - I don't have all my notes from talking to T-Max (there at home - I'm at work) but I'll give you my best shot.

I installed my T-Max w/autotune on Memorial Day this year. I only have 1000 miles on the bike total - about 400 of them with the T-Max installed.I still have decel pops from 3rd to 2nd to 1st. Nothing major just sounds like gurgling with slight pops - more if I downshift from a quick speed. Once in a while a slight backfire. I called T-Max the other day to see if they had a newer map out for V&H pipes - They stated that I should still use the Khrome Works map #392.

- He first asked me if the bike ran well on acceleration - Yes it does.
- He then asked me if it idled OK - Yes, a steady 1000RPM.
- He then said it sounds like you just have the decel pop to worry about since the T-Max sounds like it's doing it's job.
- He asked if I was running the factory pipes with my slip-on's - Yes I am.
- He said they have a restrictor piece that you can install between the left slip-on and the factory pipe (about $4 +/-).
What is happening per T-Max is that there is a strong pressure wave on the right side which upon deceleration, the right pipe is
drawing on the cross over and left pipe which is creating the 'decel popping'. Because the slip-on's are so open the restrctor
piece is needed to 'stop the pop'. He stated that this piece will eliminate the decel popping.

I hope this helps. I will post when I receive this piece and install it. I think it's funny that I installed a open stage one air cleaner and less restrictive mufflers just to install a restrictor piece in the system. But it's probably because of the stock pipe design and configuration.

Douce

 

Douce48 is correct in NOT performing the IAC autotune. Download the latest install instructions from Zippers website and you will notice that step is no longer included in loading a base map.

There is "supposed" to be a new firmware update release soon that allows decel enleanment to combat the popping some are having, but if you can't wait, or want to try what one guy suggests in the long thread at V-Twin forums, give it a read. The fellow that seems to have cured decel popping has the screen name ToBeFrank and swears by his method of curing the pop. You could actually start from the back of the thread as his suggestion is near the end of what is currently a lengthy thread.

EDIT: I'm going to cut and paste the fellows info so you do not have to dig for it, but do understand this is to be credited to the guy that actually did all the work on this and his name is ToBeFrank......I am only "borrowing" the exerpt for informative purposes, not for any credit.



A fix for the decel popping [/align]

[hr]



This is a long one, but bear with me (if you don't feel like reading, the solution is in bold below, and I've attached my map so you can look at how I've set it up)...

I have a fix for the decel popping. I've read that it's caused by air being sucked back up the pipe causing the O2 sensor to read lean. I've never really bought that explanation since I can't see air being sucked all the way back up to the port, which is where the O2 sensor is (unless you have an exhaust leak), so I did some research. Doing so, the only place I've seen the above explanation is in the Harley world. In the auto and sport bike world the explanation is different. I'll try to explain.

I think we all agree that deceleration popping is caused by fuel burning in the exhaust header. The following is stolen from another site (and I actually read about it on several different sites):



Quote:[/align]


Ok, so you’re riding along at some given rpm, and suddenly you decide to decelerate, and you reduce the amount of throttle. This causes an “overrun� – that is, the motors rpm is turning faster than the fuel provided can support, so the motor begins to spool down. This causes a couple of things to happen.

First, when you close the throttle, you are also closing the throttle plates. This reduces the air and fuel flowing into the motor, and increases the vacuum (lowers the pressure). This results in less air and fuel in the cylinder during the power stroke, which in turn results in a lower pressure in the combustion chamber. Remember I said earlier, that the A/F mix burns faster in proportion to the pressure applied? Well, when we reduce pressure this way, the mix burns slower.

The lower burning fuel generates less heat, and the cooling effect of the non-burning fuel tends to “quench� the flame front, or slow it down even further. Because the mix is burning much slower, the exhaust valve can open before all the fuel is consumed, and the unburnt fuel is ejected into the exhaust. So, now we end up with unburnt fuel in the exhaust, and burning fuel being ejected into the exhaust, and bang! [/align]
So how do we correct this situation? We can do one of 2 things:

1) Lean the fuel so much during decel that unburnt fuel doesn't end up in the header. This is what the new firmware is supposed to bring us.

2) Richen the mixture enough that the heat of the header is not enough to ignite the mixture in the header.

Since we don't have #1 yet, we need to do #2. I tested this theory, and it does work. So here is what I recommend (and what I did on my bike):

On your AFR vs TPS @ RPM pages, from 1280 RPM all the way to your rev limiter, set TPSs 14 and below rich. I have mine set to 12.5 AFR.

Note that this is not an "immediately eliminate the pops" solution. You then have to take your bike out a

 

Look for a post by cowboy glide He changed the afr to 13.19 in certain rpm ranges. I had the same problem and followed his suggestion and it worked perfect. good luck

 

Responding to UltraKla$$ic's post:

Thank you for that re-post.

My question is:
Why doesn't Zipper's post something like this on their website as a fix to decel popping? Why am I being told to buy a restrictor to install on my left pipe to stop this problem?

It seems that the above explaination as to why it happens is correct. I bought this T-Max so I could enhance the performance with a simple computer fix and forget about it.

I didn't mind doing the research, making a choice and spending the money so as to free up some time and NOT have to have the bike dyno'd or continually adjust the ECM - hence 'Autotune'.

Douce

 

Good information, but there's no substitute for more miles....this is a slow gradual process....I've got over 1200 miles with mine and it gets better everyday....the first 2 weeks I had it installed, I was constantly making small changes based on that days ride....this is a mistake.....let it work on it's on and then make small changes

 

Thanks for the all the good advice, I'll probably call Zippers too. I'll followup once I get it resolved.

 

Talked with tech support at zippers. He suggested clearing all IAC settings, re-initializing and running the temp up to 289 at idle andnot running the IAC auto feature at all.

I'm going to try that and see what happens. He didn't think the restrictor plate is necessary with my setup. He did verify I have the closest map and the KW HP+ Mufflers are the best choice with Rush pipes. I'll let you'all know once I get some miles if this eliminates the popping on decel.

 

Sorry to hi-jack your post but how do you like the pipes? I have been waiting for a set to come in but everyone has them on backorder with the 2" baffle.