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Boss Noss'n Muscle
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162 Posts
Discussion Starter #1
Hey guys,
A lot of us are having problems with the 4-6K sputters with our quality Thundermax units. I just got done riding about 200 miles. Riding between 65-75, the thing sputters, misses, and runs like shit if you apply any load to the bike. If you're going downhill or aren't trying hard to accelerate, it doesn't sputter as bad.

But, my question is, are we hurting our bikes by riding it when it's sitting there running like shit? Most of us, I would assume, cruise within this RPM range. I wonder what's making the bikes run like crap. Is it too lean of an AFR?

I'd appreciate any insight to this. I'm getting fed up with the Thundermax. I've been fighting it for over a year and hear the same "it's your bike" excuse everyone else is.

Thanks,
Tom
 

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TURBONATOR
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1,366 Posts
I don't have the sputter that a few of you have so not sure what is really going on but why dont some of you that have the sputter put a laptop on and run the monitor log and see what is actually going on in that range? Thats the only way your going to find out.
 

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Boss Noss'n Muscle
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162 Posts
Discussion Starter #3
I actually have hooked the laptop up and strapped on a backpack and logged. The log just spits out a text file of garble. I've sent these files to James and he won't tell me anything. Any idea what to do with them?

Thanks,
Tom
 

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TURBONATOR
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1,366 Posts
You have to have your monitor function on when you replay....it has all info, injector dutycycle, afr,speed,rpm, etc. all your data.
Go to post 93 under "new 1250 map" and the data window you see is what you want to have activated.
 

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Registered
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976 Posts
I have no such issue with my Tmax .I have run it for about 1.5k now .

Are you using the new map ?
 

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Boss Noss'n Muscle
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162 Posts
Discussion Starter #7
You have to have your monitor function on when you replay....it has all info, injector dutycycle, afr,speed,rpm, etc. all your data.
Go to post 93 under "new 1250 map" and the data window you see is what you want to have activated.
Ok, so it just needs to be linked to the bike and then you can play it back? Do you use the file and open to open the text file monitor log?

Thanks,
Tom
 

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TURBONATOR
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You don't have to b hooked up to replay. But I suggest you have your monitor function on when you do the test run. Then when your done testing go into "monitor" log file that is next to your configure button and clik on file that has the date you loged. There will b 2 files but only one will play all your data back.
If you need more help pm me for cell # much easier to explain than texting on this phone.
 

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Registered
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Hey guys,
A lot of us are having problems with the 4-6K sputters with our quality Thundermax units. I just got done riding about 200 miles. Riding between 65-75, the thing sputters, misses, and runs like shit if you apply any load to the bike. If you're going downhill or aren't trying hard to accelerate, it doesn't sputter as bad.
Did someone set up a list of mods that were done on the bikes having the problem? Maybe the problem is related to something like the exhaust and the TM can't do much about it? For instance I ran across http://www.nightrider.com/biketech/exhaust.htm: the dyno graph isn't for a VROD but I suppose that such a problem may arise on any bike.. :2cents:
 

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(.)(.)Modster(.)(.)
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Did someone set up a list of mods that were done on the bikes having the problem? Maybe the problem is related to something like the exhaust and the TM can't do much about it? For instance I ran across http://www.nightrider.com/biketech/exhaust.htm: the dyno graph isn't for a VROD but I suppose that such a problem may arise on any bike.. :2cents:
It is possible it's the exhaust fault, I have a vmodded powerline with a lolliwasher. The weird thing is it runs with NO 4-6k hesitation when I load in a fresh map, but it slowly degrades as the Tmax autotunes. So yes it can very well be the pipe is giving the Tmax feedback it doesn't know what to do with. But if this is the case then the Tmax is flawed because it's sold with the expectation that it will be used for aftermarket pipes.

This is kind of the same issue I had with the garbage Daytona system. I could never get a very good tune because of reversion, and sure enough Chris over at Daytona said if you had an open pipe you would get crappy results with his unit, which I never understood at that point the rationale to sell the unit as the vast majority of aftermarket pipes are open.
 

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TURBONATOR
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1,366 Posts
Doc
You have mentioned degrading before. When this happens are you riding easy for awhile then one day you ride it hard and it does not have the bite it used to? If so I have had simular experience. Wife rode w/me for several rides then went on a ride solo all day and at first it didn't have the pull like it did until I started riding alittle harder blowing the cobs out of it and started running like it should but it took it most of the day to get there. IMO if you ride like Granny it will tune for Granny and vice versa. JMHO
 

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SpeedoDocter
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2,364 Posts
If i would have these problems for already a year i would be pissed too... My 1130 runs good with 'open' pipes. Meaning stock headers and 3rd volume,only stock looking mufflers have 2 x 2" pipe with a anti ticket 'sound'valve in the middle normaly set full open. I know it's not 1250 but why would the same technology not work the same with 120cc more. Maybee there is somone who can loan you a different pipe to try?

Oh... If i ride with my granny airheadbuds all day long and WOT it it happens i imagine i feel a small sputter from the engine saying'... here weeeeeeee gooooooooooo..:D..'
 

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Premium Member
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533 Posts
I have no such issue with my Tmax .I have run it for about 1.5k now .

Are you using the new map ?
Same here, just a few months shy of 2 years on the box with ~5,000 miles on the bike. I have really not done much other than install it and forget it. I am running a 26t pulley so I am in the 4k ~ 6k range all the time and have not noticed any issues.
 

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Posting From The Pub
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7,850 Posts
It is possible it's the exhaust fault, I have a vmodded powerline with a lolliwasher. The weird thing is it runs with NO 4-6k hesitation when I load in a fresh map, but it slowly degrades as the Tmax autotunes. So yes it can very well be the pipe is giving the Tmax feedback it doesn't know what to do with. But if this is the case then the Tmax is flawed because it's sold with the expectation that it will be used for aftermarket pipes.

This is kind of the same issue I had with the garbage Daytona system. I could never get a very good tune because of reversion, and sure enough Chris over at Daytona said if you had an open pipe you would get crappy results with his unit, which I never understood at that point the rationale to sell the unit as the vast majority of aftermarket pipes are open.
Chris appears to have strong personal views on pipes. I find using his diagnostic system (forget the name) and plugging the numbers, modified by common sense, into a PC3, has given me a powerful, frugal, effective tune.

That's on an open D&D. Possibly the length solves the reversion issues, but then that should apply to the V-Mod too...
 

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RIP Jerry
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956 Posts
If i would have these problems for already a year i would be pissed too... My 1130 runs good with 'open' pipes. Meaning stock headers and 3rd volume,only stock looking mufflers have 2 x 2" pipe with a anti ticket 'sound'valve in the middle normaly set full open. I know it's not 1250 but why would the same technology not work the same with 120cc more. Maybee there is somone who can loan you a different pipe to try?

Oh... If i ride with my granny airheadbuds all day long and WOT it it happens i imagine i feel a small sputter from the engine saying'... here weeeeeeee gooooooooooo..:D..'
:them: have an 05' and installed tm and haven't done a thing to it. Went from dyno tuned pc3 to tm and got a noticeable amount of low end power and maybe more top end too. Just doesn't make sense why some have all these prob?? Ride it hard or slow bike always runs gwad!
 

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(.)(.)Modster(.)(.)
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Chris appears to have strong personal views on pipes. I find using his diagnostic system (forget the name) and plugging the numbers, modified by common sense, into a PC3, has given me a powerful, frugal, effective tune.

That's on an open D&D. Possibly the length solves the reversion issues, but then that should apply to the V-Mod too...
I tried for a couple of years on both a thunderheader and my powerline, and while I could make myself a decent map I just could never ever get rid of the decel pops. The Daytona system was just not able to handle the reversion and Chris didn't seem to care at all. Maybe calling the Daytona system "junk" was a bit harsh, as it did the job at a basic level, but it wasn't a great system, or even good IMO.

The Tmax, while I complain a lot and put my problems on the forums, still runs MUCH better than any Daytona map I put together (does it still have that silly limited memory where you have to stop every 10 minutes to record your log?!?), and it's a better map than I could dial into my SEPST even with a tuner working on it.

Most importantly to me the Tmax COMPLETELY got rid of any decel pops, every single last one of them, and that's NOT running in decel fuel cut off mode. Really the only issues I had were the idle issues, which seem 99% solved with the latest tweak posted here, and the very slight 4-6k surge which is fading the more I ride it.
 

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(.)(.)Modster(.)(.)
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Doc
You have mentioned degrading before. When this happens are you riding easy for awhile then one day you ride it hard and it does not have the bite it used to? If so I have had simular experience. Wife rode w/me for several rides then went on a ride solo all day and at first it didn't have the pull like it did until I started riding alittle harder blowing the cobs out of it and started running like it should but it took it most of the day to get there. IMO if you ride like Granny it will tune for Granny and vice versa. JMHO
I took it out for a nice hard run the other day, lots of WOT's and just beat on the bike. The surging is definitely getting better. The idle continues to be nice and smooth, it hasn't dogged on me at all since I tweaked it.
 

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I just came across this introduction to the exhaust magic here.

According to this doc, the 'lolliwasher' arbitrarily set at 1 inch from the exit of the exhaust whatever the engine type/pipe length used is difficult to understand, maybe it was the correct setup for a particular combination but it can't be applied systematically to every bike out there.

I would get rid of this washer and run with the TM for a while to see if the situation changes.
 

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TURBONATOR
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I took it out for a nice hard run the other day, lots of WOT's and just beat on the bike. The surging is definitely getting better. The idle continues to be nice and smooth, it hasn't dogged on me at all since I tweaked it.
Good to see it's working so far.
 

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(.)(.)Modster(.)(.)
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I just came across this introduction to the exhaust magic here.

According to this doc, the 'lolliwasher' arbitrarily set at 1 inch from the exit of the exhaust whatever the engine type/pipe length used is difficult to understand, maybe it was the correct setup for a particular combination but it can't be applied systematically to every bike out there.

I would get rid of this washer and run with the TM for a while to see if the situation changes.
I tried it for years without the lolliwasher, and using the lolliwasher is actually what helped me with the Daytona system. I'm tempted to get rid of it on my Tmax system, but I really do notice an increase in low end power by leaving it in, it's convenient in that if I ever want to play with it I can just rotate it to simulate it being out of the exhaust stream. It really helps with reversion on having such an open pipe. I understand it's a trade off of mid to high end in exchange for low end and no decel pops, but that's how I ride my bike mostly.

I'll tell you one thing, I HIGHLY doubt aftermarket exhaust makers take very much of the great science in that article into consideration when designing a pipe. The vast majority of them are just open tubes of varying lengths and widths anyhow.

"This makes it difficult to tune an exhaust system to take advantage of reversion waves which is why there are various anti-reversion devices designed to improve performance. These anti-reversion devices are designed to weaken and disrupt the detrimental reversion waves (when the wave's higher-pressure node impedes scavenging and intake draw-through). Specifically designed performance baffles can be extremely effective, as well as heads with D shaped ports."

It may be a moot point as once again the exhaust gods have been pushing me to change my exhaust, ahh the sickness.
 
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