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My 2018 Road King Special with Stage IV

4147 Views 13 Replies 6 Participants Last post by  Jake707SBFMC, 
kkinderen
I purchased the stage iv with the bike but put 2000 miles on the bike while waiting on the parts. During that time I started second guessing whether I even needed the upgrade. It felt that good. But I went ahead and did it anyway.

The result was more tame than I expected. I have very little understanding of how to read the chart but it seems odd that it was checked only between 3400 and 5600 RPM. Shouldn't it have started below 2000 and reach at least 6500?

Seat of the pants, seems like no change up to 3000 RPM and then it feels it could keep pulling until lights peed is reached. I haven't hit 5000 RPM on the road yet.

I have plans to go to another shop just to get another opinion but curious what you might think.

For the parts list and the chart from the catalog see my album.

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WILLIS3251
Hi - one comment I've heard about the new M-8 stage 4 kits is that the cams are very top end, low-mid range is vey much like the stock motor??? The stage IV S.E. cams have to meet EPA standards - so the valve timing is not optimal. I've got the 110 cu stage IV kit in my 2013 softail. I took the 259E cams out - went with a set of the Crane/S&S rocket cams - much better throttle response and low- mid range. top end made more power too. all-around better running. shop the after -market for a different M-8 cam? S&S and Andrews have new grinds. good luck!
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kkinderen
I was hoping for some good advice. Thanks. I'm off to another shop next Thursday to discuss options. Reliability is a concern for me.
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Thermodyne
It all depends on which kit was installed. Not all MoCo stage 4's are equal.

From the looks of your sheet, it's making power right to where the rev limiter grabs it by the balls. But it's also looking like a canned MoCo/EPA approved tune. Mix is 14.5 to 14.7 right through the pull, not going to make huge power starved for fuel. And the MoCo can't supply you with a better map. TC 110 kits with aftermarket tunes make considerably more power than that.
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T
Therm hit the nail square on the head,,, and hard...
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Thermodyne
tall terry said:
Therm hit the nail square on the head,,, and hard...
Click to expand...
No use blowing smoke up his azz, the MoCo already did that.
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T
Therm,,, I agree 110%... I've been known for being brutally honest,,, I don't enjoy it,, it is just the best policy...why lie?
I always called the SE stage kits,, cookie cutter cutter performance
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<G Man>
tall terry said:
Therm,,, I agree 110%... I've been known for being brutally honest,,, I don't enjoy it,, it is just the best policy...why lie?
I always called the SE stage kits,, cookie cutter cutter performance
Click to expand...
OK, that really made me laugh right there. Thanks Terry!
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WILLIS3251
The S.E. kit hardware (pistons, EFI, jugs) are good quality - as Therm said - it 's the MOCO tuning and cam timing. changing the cams and installing a custom tune on my SERT made a huge difference in the way the bike runs. Not just power, but idle, and throttle response at slow speed. the original tune w/the 259E cams had a bad habit of stalling in a hard lurch (almost throw you off the seat!) when leaving a stop if the motor wasn't warmed up!!!:duh2:
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kkinderen
Back from the non-dealer shop. They didn't tell me anything different than you guys told me but I don't think I'm ready to change out the cam yet. I did replace the head pipes as I had previously planned. I also dropped the SE tuner for a TTS MasterTune II. The new run didn't show much of a change (as expected) but I'm getting nowhere near the heat coming up from under the bike. The ride feels great even from a stop but at 3000 RPM it's like a switch is thrown.

I think my next step, before trying to clean up the low RPM curve is to spend some money and effort on bullet proofing. I need to kind of plan things in packages I can afford. I should have that together in a few days.

I asked the dealer about the chart. The high cutoff he said was because of the speed limiter. Not covering the lower RPMs - a mistake. They offered to re-run but I took a pass.

Thanks for the advice.

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<G Man>
kkinderen said:
Back from the non-dealer shop. They didn't tell me anything different than you guys told me but I don't think I'm ready to change out the cam yet. I did replace the head pipes as I had previously planned. I also dropped the SE tuner for a TTS MasterTune II. The new run didn't show much of a change (as expected) but I'm getting nowhere near the heat coming up from under the bike. The ride feels great even from a stop but at 3000 RPM it's like a switch is thrown.

I think my next step, before trying to clean up the low RPM curve is to spend some money and effort on bullet proofing. I need to kind of plan things in packages I can afford. I should have that together in a few days.

I asked the dealer about the chart. The high cutoff he said was because of the speed limiter. Not covering the lower RPMs - a mistake. They offered to re-run but I took a pass.

Thanks for the advice.
Click to expand...
So, you're first chart shows 106/106 and your second chart shows 126/133. If you don't feel any difference then somebody's dyno is way off.

It also seems like a drastic change in the shape of the curve, considering that these charts are from the same motor.

***ETA - ok, now I see that the second run has a different exhaust***
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WILLIS3251
HI - different exhaust on a "modified" motor can be a big change in motor output. I've had a pipe change be good for 18-20 HP!!
and yes - you should feel a serious difference going from 106/106 to 126/133?? I've run a bike at almost exactly both of those sets of numbers - the performance delta is huge. My stg IV 103 was in the 109/109 range and my current 110 cu is running in the 126/130's. Yeah - when you hit the 2500 - 3000 RPM point- it's like you hit the nitrous button!!
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kkinderen
I did 500 miles on Sunday from Brunswick, MD down 340, Ft. Valley Road, 211 (and Cooters for lunch), then south on Skyline and Blue Ridge to Lynchburg and back via 29. The bike rode like an absolute dream and as much as I could expect.

I'm not so good at feeling differences. I thought the HP/TQ differences might actually relate to two different kinds of dynos. I think I've heard that SuperFlow generally reads higher than the same bike on a DynoJet. If you look at the SuperFlow chart, the initial is actually the same setup as the final from the dynojet run on this post.

My only complaints about the original dyno and setup were that the chart started too late and ended too early and that I didn't feel much of a difference over stock (explained by my lack of sensitivity I guess).

I'm keeping the SE cam for a while and looking at projects to bulletproof the engine. Then, maybe later, I might look at some more performance steps. Maybe. I plan to have this bike for a very long time so I want to take things slowly and do them for the right reason.
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J
Maybe I missed it but what do you mean when you say you want to bulletproof the motor? The old twin cam days that meant changing or welding up the crank but Im assuming you are meaning something different with the M8?
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