M8 big bore success stories

[98fxstc]

That looks like a WOT run on the base map
Do you have AFR ?
Looks like the timing needs work

[Hossamania]

Seeing that big dip down to 75 ft/lbs does not tell me it "tuned very well." Most M8s hit their torque early and stay there.

[kd]

It appears that bike was not tuned if that's the final (only) sheet.  run #001     

[rigidthumper]

Tune brings out whatever is available. Baffle design and muffler size really influence the curve of the sheet. Here is the same bike (M8 124), first sheet is V&H PCD head pipe, Khromeworks muffler with HP+ baffle. Next sheet is same combo with baffle removed for "sound". Last sheet is with Rinehart  mufflers.

[BigT]

I totally agree with what you're saying. I have the Fuel Moto ac/dc kit with 1" taller element on order. I tried talking my builder into the 64mm tb and intake but he likes the velocity of the 55mm SE extreme flow intake. As far as noise and heat, it runs way cooler and quieter. My fans don't kick on nearly as much or as long👍😎. Thanks

Did you buy this kit directly from Fuel Moto as they could have given you some build advice. I don't recall ever seeing this setup with the 408 cam using the stock throttle body. I had installed the Same FM kit with the SE 64mm throttle body and good flowing exhaust and made 143tq & 152hp.

[riders1.jt]

 I contacted the builder and they're going to do another tune on it at the end of August. They said it would take a full day. I said that's fine as long as they straighten those lines out.  In the meantime I'm going to put the bigger breather on before I head to Sturgis. Thanks for the input  everyone...

[Hossamania]

Have fun, let us know how Sturgis is this year.

[scotman623]

A 64mm TB and a good tune would have that bike running great... Needs more fuel and air...Enjoy Sturgis my friend 😎🤝

[riders1.jt]

So my trip Sturgis was a blast! The bike ran pretty good with the bigger A/C. Still feeling a flat spot if I really rip and get the rpms up over 4K. Think I'm going to get the 64mm Tb  and manifold. Wish the HD tech would've suggested that originally whereas I had to wait forever for the se 55mm extreme flow manifold that isn't working for this setup... I'm getting a day of tuning as well. So I'll let you all know..It's almost like the tech didn't want me to get the full benefit from this kit. He kept comparing the HD 131 stage lV kit. I don't think he's big on fuelmoto and maybe afraid of what numbers are possible with my setup...We shall see...

[Hossamania]

Post up some stories of Sturgis in the Sturgis thread, interested in hearing how it was.
Glad the bike ran well for you.

[riders1.jt]

 Getting the SE 64mm throttle body and manifold and a really  thorough tune. I'll let you know where we end up numbers wise....

[klammer76]

Getting the SE 64mm throttle body and manifold and a really  thorough tune. I'll let you know where we end up numbers wise....

Did you wind up getting the tune?

[riders1.jt]

Not much of a difference😑.  I asked if they got a different map from fuelmoto with the bigger 64mm intake and Tb. They said fuelmoto only gives you one tune per build🙄. So I'm still way below where i thought I'd be. But it's running smoother with better initial throttle response. So idk. Find another tech to tune it? smh

[To The Max]

Hi, if you have the power vision why dont you call fuel moto yourself and get them to send you the correct tune . i have used there tunes before and out of the box they are really close. then if your happy find a good tuner and have him tweek it. Max

[riders1.jt]

 I didn't know that could be done. Thanks Max.  I'll try that.

[Gliding Joe]

riders1, what exhaust are you running with this build. that dip looks to me that your exhaust velocity (some call it back pressure) is the issue. I am guessing Fuel Moto is going to ask that same question and possibly recommend something different. 
Fuel Moto did a exhaust comparison write up showing what different headers and slip ons can do to a tune and slip ons can cause that dip. They do have baffles that can help as well.

[riders1.jt]

 I was wondering about the exhaust. It's the Vance and Hines power duals with eliminator 400....

[riders1.jt]

I sent fuelmoto an email requesting a base map for my setup. I'm hoping to get here eventually.

[riders1.jt]

I just talked to fuelmoto and you were correct in the exhaust theory. I ordered the 6" inserts to hep the dips and shaky lines..Thanks

[riders1.jt]

 Well I got the inserts in. Got the bike dyno tuned AGAIN. This was a 4th gear pull. Was hoping for a little more hp & tq. But it's smooth and stout throughout the gears...

[No Cents]

    I'm sorry and it's none of my business but I don't see how they think your bike is tuned properly with the two graphs you have shown.
    The 1st graph shows only 3 pulls being made, and the last one at least shows six pulls. I'm no tuner but I don't see how they can properly tune a bike with so few pulls.

[Buglet]

   All depends how the runs are saved. I always do my runs 2 or 3 time for checking,  but only save one run so it will show less runs. But the other thing is the time, it looks like he spend 2 1/2 hours from 1 to 6, now if that was for WOT that's a lot of time, but for a full tune that's had to be an easy one to do.   

[BigT]

    I'm sorry and it's none of my business but I don't see how they think your bike is tuned properly with the two graphs you have shown.
    The 1st graph shows only 3 pulls being made, and the last one at least shows six pulls. I'm no tuner but I don't see how they can properly tune a bike with so few pulls.

I just can't get over the low HP output of this build. Most 124" builds with the Woods 408 cam, and larger throttle body are closer to 140 hp. If it was my bike I'd be digging a little deeper for some missing power.

[kd]

Sumping?

[BigT]

Sumping?

I had a built 117" Twin Cam that I thought was running good...had it on a dyno and it was making 100 hp due to sumping.  It made 130+ once it was straightened out.