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[leoniru]

Ok, I'm very new to this forum but have quickly succumbed to the many positive reviews given exhaust, cam,  and engine management upgrades on the 110" SERK.
My bike has now only about 140 total miles on it, but already I'm noticeing UNsmooth low (1000-2000) rpm behavior. Now before you start admonishing me about lugging the engine let me add that I do not make a habit of running around in this rpm range. I am following engine break-in guidelines, but on occasion, when rolling along easily and letting things slow down with a light throttle, it's very apparent that she's not running smooth. Seems to surge. Clears right up from about 2000 rpm up. Makes me long for a Thundermax with autotune.
But I also want a set of true duals for esthetics, performance, and sound.
This is how I currently (maybe?) see things being done.

1. Probably should wait to accrue more miles and have at least the first service or two done.

2. Purchase the Thundermax/autotune and easier breathing A/C first as this would allow me to tweak the bike (even with everything else stock this should give me  more smooth, tractable behavior right?) without being enslaved to my dealer and his dyno/service rates.
Does it seem crazy to use this autotune ecm primarily for smoothness/tractability/engine health rather than just power gains?

3. Purchase the true duals --leaning towards the Rineharts despite the fitment issues discussed in the several threads in this forum-- and install them. The Autotune ECM should 'adapt' to this mod, again saving me dyno/tuning time.

4. If for some reason I'm not satisfied with the likely meager gains in power output, I could then pursue a cam, etc. change.

OR

Find a skilled tuner ---any recommendations in the Noreast Pennsylvania area?, or who would the closest be to me? ---to tweak my stock bike.

I'm concerned that my bike is not set up as best it could be at present (maybe lean?). Yeah, it's in warranty, but I might consider switching the stock ecm (and probably void my warranty) if I knew that I'd likely be preventing major engine problems down the road.

I really like the idea of being able to modify my engines management programming at will, and monitoring the many engine/performance parameters available with the Thundermax.

I realize that the cost of the exhaust and ecm changes could buy quite a bit of dyno/tuning time, but then again I'd still be tethered to my dealer or some tuner.

Is it realistic to think that someone like me--with a more-than-passing amount of mechanical skill and aptitude but by no means a pro -- and my SERK could live happily with the Thundermax/autotune module?
I've read through the Thundermax's install manual on Zipper's website and  don't feel the least intimidated by the computer related aspects of this mod.

Am I missing anything here?

Any input ( assurances/encouragement/discouragement/insight/suggestions/etc.) would be greatly appreciated.

Thanx,

leoniru

[Twolanerider]

Opinions will be like weeds; they'll be many and they'll flourish.  Here's my weed.

I've been pleased with the T-Max and autotune system so far.  That response has been almost universal among those I remember commenting.  It'll make any other modifications you do later cheaper and easier as you'll avoid tuning time and scheduling time to get that tuning done.

If losing the factory ECM (with all liabilities that implies from a potentially bitchy dealership) doesn't worry you, and if the install doesn't seem cumbersome, it has been a good system on my bike.  As for exhaust or not being done at the same time; might as well knock out as much as you can as early as you can to get the bike running well.

[Hoist!]

Leon, you basically answered your own question in the beginning. Anything under 2000 RPM under load is lugging the engine. I wouldn't take it below 2000 RPM in any gear but first. Any of the mods you mention are fine. Discuss them with your tuner and go with his recommendations and your own comfort level/requirements. But your initial issue is easily resolved by bringing your RPM up a little. Hoist!

[Twolanerider]

Leon, you basically answered your own question in the beginning. Anything under 2000 RPM under load is lugging the engine. I wouldn't take it below 2000 RPM in any gear but first. Any of the mods you mention are fine. Discuss them with your tuner and go with his recommendations and your own comfort level/requirements. But your initial issue is easily resolved by bringing your RPM up a little. Hoist!

But Howie, he's wanting to spend money on the bike.  Remember the Site Member's Credo:

Thou shal't help a man spend his money on his bike.  Thou shal't not suggest basic changes when hairy involved mods are an option.  Thou shal't drink a man's beer while he works on his bike.  So say one, so say we all.

[leoniru]

TLR;

How many miles have you logged with the Tmax ecm, and do you run in open or closed loop mainly? Not quite sure I fully understand the open vs. closed loop and all the implications.

[Twolanerider]

TLR;

How many miles have you logged with the Tmax ecm, and do you run in open or closed loop mainly? Not quite sure I fully understand the open vs. closed loop and all the implications.

Leon, open vs. closed loop is (in my opinion) the single most important advantage of the system.  Rather than the stock system that monitors and adjusts itself to its environment in only a very few and very specific circumstances the autotune system simply does it all the time.  It also does it offering a wider range of "answers."  The sensors on the stock system provide yes/no data.  The autotune setup provides an operating range.  The stock system has some limited ability to adapt; very limited.  The autotune has an almost unlimited ability to do so.  Granted, it's not state of the art for the automotive world generally; but it certainly is for the Harley's.  Much advanced from what the stock system will do on your bike.

[Hoist!]

But Howie, he's wanting to spend money on the bike.  Remember the Site Member's Credo:

Thou shal't help a man spend his money on his bike.  Thou shal't not suggest basic changes when hairy involved mods are an option.  Thou shal't drink a man's beer while he works on his bike.  So say one, so say we all.

Hey Don, I'm not preventing him, or us from helping him, to spend his money. He listed a bunch of mods he's considering. They make sense and we can start discussing options. But I was addressing his issue of the roughness bet. 1000 & 2000 RPM. No mod will correct that, as you should not be riding there anyway. Cams will make that range even worse, not better. OK, now that we've established how to correct his roughness, we are now free to help Leon spend his hard earned cash! Hoist!

[Twolanerider]

Hey Don, I'm not preventing him, or us from helping him, to spend his money. He listed a bunch of mods he's considering. They make sense and we can start discussing options. But I was addressing his issue of the roughness bet. 1000 & 2000 RPM. No mod will correct that, as you should not be riding there anyway. Cams will make that range even worse, not better. OK, now that we've established how to correct his roughness, we are now free to help Leon spend his hard earned cash! Hoist!

Yeah Howie, I was just yanking your chain.  Since he'd addressed the RPM range a little bit in his first post I was going to let that lie; that's all.  You're right of course, it's never going to feel right at that RPM range.  They just don't run there.  Was just giving the benefit of the doubt that he understood that since he'd at least mentioned it a little up above.  We should still drink his beers.

[leoniru]

Hoist;
Back to the 1000-2000 rpm thing. You said that you wouldn't take it below 2000 rs in any gear EXCEPT 1st. Well, that's my point. Maybe I didn't express myself clearly enough earlier. Let's say we're puttin' around a parking lot, or stuck in some stop and go situation. Shouldn't the bike move smoothly, at least in first? Is one expected to just pull the clutch lever in at 2000 rs? I don't think I pull away from a full stop at 2000 rpm. Probably closer to 1200 or 1400. Beginning to think that maybe I should have bought an old John Deere tractor!
I seem to recall my 1970 Sporty would lumber away without so much as a hiccup, and it sure seems like a lot of newer Hog owners pass by (say in a low speed area such as a parking scenario at an event) doing that. I realize that this SERK isn't my old Sporty, but dang, is it geared that tall or tuned such that one can't smoothly drop down into this zone in first without surging and carrying on? Or is this a querk of EFI?
Oh, BTW, I've been known to pull on a brewski now and then but most folks around these parts are into making --and drinking--wine. So if ya ever get to this neck of the woods, bring your sleeping bag cause we vint for maximum ETOH content.

[SPIDERMAN]

I have SERTs in both bikes. If I had it to do over again I have T-Max with autotune in both. Why ? Because dyno tuning has gone from something like $150 to almost $400 a pop.

B B

[Hoist!]

Hoist;
Back to the 1000-2000 rpm thing. You said that you wouldn't take it below 2000 rs in any gear EXCEPT 1st. Well, that's my point. Maybe I didn't express myself clearly enough earlier. Let's say we're puttin' around a parking lot, or stuck in some stop and go situation. Shouldn't the bike move smoothly, at least in first? Is one expected to just pull the clutch lever in at 2000 rs? I don't think I pull away from a full stop at 2000 rpm. Probably closer to 1200 or 1400. Beginning to think that maybe I should have bought an old John Deere tractor!
I seem to recall my 1970 Sporty would lumber away without so much as a hiccup, and it sure seems like a lot of newer Hog owners pass by (say in a low speed area such as a parking scenario at an event) doing that. I realize that this SERK isn't my old Sporty, but dang, is it geared that tall or tuned such that one can't smoothly drop down into this zone in first without surging and carrying on? Or is this a querk of EFI?
Oh, BTW, I've been known to pull on a brewski now and then but most folks around these parts are into making --and drinking--wine. So if ya ever get to this neck of the woods, bring your sleeping bag cause we vint for maximum ETOH content.

The only time you're at those RPM's in 1st is when you have to be. It's still lugging, but the gearing gets you out of it quickly. 2000 RPM is really the minimum RPM. It doesn't really smooth out until 2K RPM. Don't get hung up on it, just try not to ride below it. Hoist!

[SPIDERMAN]

The only time you're at those RPM's in 1st is when you have to be. It's still lugging, but the gearing gets you out of it quickly. 2000 RPM is really the minimum RPM. It doesn't really smooth out until 2K RPM. Don't get hung up on it, just try not to ride below it. Hoist!

Meaningless post 

You had that one coming to you Howie   hahahahahahahahahahahahahahahahah

B B

[Serkcus]

Agree with you Hoist. On my mechanics advise, I also had never run my old 88 inch EG Classic below the 2K mark or it would lug always kept  it between 2200 and 3000 around town, and always dowshifted to keep the revs in the 2 to 3 area. These Serk , including the 96 inchers seem to br more critical in this need for a little more RPM than the previous motors. I find that once I got it moving in 1st, to do parking lot speeds you need to do a lot of clutch work, even true of the previous motors. Is a tribute to these engines that they survive so much abuse as most owners that a I know tend to lug thier motors continuosly as  I believe they like the pulsing exhaust note better that way. To each his own, but I believe that the newer stroked engine will not tolerate the lugging as well or for so long.

[Tros]

I don't usually lug my 96 too much but it will put put around a slow corner without surging or bucking, even with a passenger.  The more it gets broken in the less inclined I am to do any serious mods.*





*subject to change without notice, YMMV