98 in the Quarter

[FXDRYDR]

Congrats on some great times! We're running similar set ups, but you're a tenth quicker.

[claydbal]

chop, you wanna max out the air in the shock. you want to stop the rear tire from moving upward and unloading----this is what happens when you rip the tire off and get crooked, like my dyna.

[pwmorris]

Originally Posted by GPO03FatBoy

I data log every run, and the clutch isn't slipping. It's a Bandit Sportsman with a 3/3 mix of red and gray springs. It holds the nominal 105-110 HP that my motor is putting out, but lets it give just a little when I powershift it, so all the impact isn't on the drivetrain. I've tried shifting higher but it's both out of my power band and doesn't let the motor recover to near the peak TQ area. 5800 is just where the HP starts to nose over. It's not peaked there, but the rate of increase starts dropping off right about there. Also, while I get good TQ right from 2k, my peak TQ is right around 4k rpm. Shifting at 5800 lets it drop down near the peak TQ, to let it pull strong after the shift. The motor is balanced and I've tried shifts up to 6800, but higher than 5800 and I'm out of the motors' strongest range.

Until I go to a different build, or a different rear wheel/tire, I think the rest of my improvement will have to come from getting the 60' down. We'll see...

Love your clutch! Haven't seen many guys runnin' Bandit stuff on the street. I run a Bandit with lockup on my racebike.
Hey, is your front tire coming of the ground yet like the dresser in the above photo? What RPM do you launch at?
I suspect you aren't leaving at a high enough RPM.
When you get to 11.4, don't think you are going to be satisfied!
The same drive and dedication that got you this far is going to want to push you farther-till you get into the 10 Second Zone!

[pwmorris]

Originally Posted by TXCHOP

GPO. congrats! Nice job running that bike out.


Dennis or Pw, better to launch on solid rears righ? If i let my air out all the way, wheel to the moon like your pic. Air up, burns tire. 1 inch or so travel has been good to me. Of course all bets are off at the track, i am talking street.

As Dennis said, stiff, stiff, and stiffer! The energy of that motor unloading at launch (on the street treet or track) has to go somewhere. You don't want the rear squatting too much and then unloading the tire. If you can get the rear suspension stiff, have enough of a soft tire and the right tire pressure to grab the ground, have enough HP (You have plenty Chop!), have a stout enough clutch that wont slip, and leave a stoplight at a healthy enough RPM, The energy is going to transfer to the front of the bike and BAM!-Wheelie. There is nothing that blows peoples minds on the street more than a Big Bike with it's front tire in the air. I don't do it anymore but people still talk about a wheelie I pulled in
2nd gear racing a guy on the streets of downtown late at night a few years ago. It came up so hard and so high that a guy standing on the street said he could see the other guy on his bike from UNDER my front tire. I remember coming down from that wheelie real hard and guys behind us said sparks flew when I came down (frame or pipe?). Only time on the street I thought I might go all the way over!

[Totenkopf]

pwmorris, we also run the Bandit with lockup in a pro mod and a pro gas bike, we firmly believe it is the best clutch made. We also use Energy One ceramic compound friction discs and get great, controllable, repeatable performance.

For GPO..... just for comparison, a few years ago we campaigned a #1 plate pro eliminator bike that was a '99 Dyna that was stock frame except the rear shocks were replaced with CrMo struts and we ran a set of wheelie bars with a 5" M/T slick on a stock spoked wheel. The motor was a carbed 103" Twinkie and we had a Pingel air/electric shift to a stock trans with a Bandit Sportsman clutch. When setup for a best pass, as opposed to running the 10.90 PE index, it would run 10.50's, in the 120's and 60' was in the high 1.3's to 1.4's with considerable wheel spin yet. If you took off the wheelie bars and hooked up a headlight, it could have been riden on the street. From memory, that 103 made 127hp and 123 tq on the dyno. So, the point of all of this is to relate to what you are doing and to shed light on the way forward, should you ever get bored with 11.5 seconds. I think pwmorris is on track talking about the 10 sec zone.

all the best!

[vafatboy]

Originally Posted by GPO03FatBoy

Thanks. I don't have much experience at this, so I'm pretty happy with where I am. The tuning has all been on the street with a Twinscan, so dyno time might help, but it's a real rideable bike, so I guess now I just need practice! Need more HD's on the track though. We just went to an event where there were about 785 sport bikes, and 15 HDs. Worse yet, there were only about 6 street-ridden HDs there. Would be nice to see more Harley's racing around here...

Felt a bit out of place didn't we? Maybe we could talk Jason into something for Street HD's. Waiting for a run with 8 second bikes all around was a bit strange. I was watching GPO's backside all day. My best run was one of my first too. The more I tried to improve the 60' the worse it got. No tach, shift light etc.

Greg, had a great time.


04 FatBoy
95 FT
37B
BigBoyz heads
Stock gearing and clutch with SE spring. I could get the hook up, but lacked clutch, throttle technique for a smooth roll out.

R/T .031
60' 1.883
330' 5.271
1/8 8.147
mph 84.98
1000' 10.709
1/4 12.912
mph 101.65

[GPO03FatBoy]

Originally Posted by FXDRYDR

Congrats on some great times! We're running similar set ups, but you're a tenth quicker.

Thanks! The Bandit clutch is great.

It's all for fun. At least until I can build a 124 with a 180 rear tire...

[RidingJerry]

Sounds like ya'll had a great time.
Glad you ran so well!!!!!!!!!!!

Fun is what it is all about!!

[GPO03FatBoy]

Originally Posted by GPO03FatBoy

So, I'm still trying to figure out the launch, but here is where my 98 is at the moment in the quarter mile.

R/T = .141
60' = 1.751
330 = 4.757
1/8 = 7.296
MPH = 95.21
1000= 9.591
1/4 = 11.554
MPH =114.18

I cut a better light and quicker 60' (1.709) in later runs, but I was playing with the tune and didn't get any faster than this. My rear tire is just a worn out Dunlop K591, so when I get a better tire on I'm thinking I'll get my 60' into the 1.6 range and quarter mile down into the 1.4's.

The bike is an EFI 03 Fatboy with Revperf 98 jugs, Redshift 577 cams, a bored OEM TB, and a V&H Propipe - hauling close to 210 lbs of dressed out rider down the track. Oh and I'll have to agree now, the change from 3.15 to 3.37 makes a big difference. It seems to have dropped my 60' time almost .15 sec.

So, I wondered how the bike would perform with a Tmax. I swapped out the SERT tuned HD ECM for a Tmax, and loaded a close map. The AFR is set to 13.0 at WOT and the timing is taken from my SERT tuning. The fuelflow was tuned in for 93 pump gas, but I was trying 103 race gas today, the temp was low, and I hadn't adjusted the Tmax tuning temp range lower so the fuelflow was not fully readjusted. So, the run on the left below was from a month ago with the SERT tuned HD ECM, and the run on the right is with the roughed in Tmax:

SERT/HD ECM .................... TMAX
R/T = .141 ..................... .213
60' = 1.751 ..................... 1.792
330 = 4.757 ..................... 4.804
1/8 = 7.296 ..................... 7.371
MPH = 95.21 ..................... 94.81
1000= 9.591 ..................... 9.646
1/4 = 11.554 ..................... 11.620
MPH =114.18 ..................... 113.26


I'm just posting this info for rough comparison. Overall I was not launching well today. Sometimes I would lift the front wheel, and sometimes I would stall. I did have several 114.5 mph runs, but the ETs were not any faster. My feeling is that if I was launching better, I played with the timing a bit, and I adjusted the AFR plus or minus a tenth or two and let the fuelflows fully retune, the bike would easily be in the 11.4s with the Tmax. I guess I'll have to wait until the spring to find out...

[Hillsidecycle.com]

At what rpms are you at 20 to 25 ft., before the first cones?
If geared correctly, your shift light should be on at that point.
Agree with the Bandit clutch as we tried 'em all when we raced.
Once you catch the 10's, it be a very big effort to motor on down to the nines.
Still remember the day we ran our first 10 sec pull with a 101" Shovel. 10.81. Lebenon Valley, Nausau, N.Y. Tom Quayle, Tony Mattioli, Vito Sabbato, and us, were all test/tune that day.
That Shovel ended going 10.14 best(105") with a 200 lbs. rider.
Then we put STD Evo 5 bolt heads/pistons, upped it to 108" with cylinders from the King, Evo valve gear on it,etc,etc, and came off the trailer, next spring, lighter rider, with a 9.24. Marched it down, with our dual carb set-up, to a best of 8.88/148.85, with a stinkin' 4 speed gear box!! It would have ripped a tenth or better with a 5 speed. Over a decade ago, and then some. Absolutely lived for that bike.
Scott

[GPO03FatBoy]

Originally Posted by Hillsidecycle.com

At what rpms are you at 20 to 25 ft., before the first cones?
If geared correctly, your shift light should be on at that point.
Agree with the Bandit clutch as we tried 'em all when we raced.
Once you catch the 10's, it be a very big effort to motor on down to the nines.
Still remember the day we ran our first 10 sec pull with a 101" Shovel. 10.81. Lebenon Valley, Nausau, N.Y. Tom Quayle, Tony Mattioli, Vito Sabbato, and us, were all test/tune that day.
That Shovel ended going 10.14 best(105") with a 200 lbs. rider.
Then we put STD Evo 5 bolt heads/pistons, upped it to 108" with cylinders from the King, Evo valve gear on it,etc,etc, and came off the trailer, next spring, lighter rider, with a 9.24. Marched it down, with our dual carb set-up, to a best of 8.88/148.85, with a stinkin' 4 speed gear box!! It would have ripped a tenth or better with a 5 speed. Over a decade ago, and then some. Absolutely lived for that bike.
Scott

Scott - you are right. I keep wanting to go faster. I'm starting to look to the 10's, but this is still my street bike so I'm not looking to go extreme.

I'll have to start tracking my rpm at the 25' mark. Right now I'm launching at 3500 rpm, and shifting at 5800. That puts me across the line at 5000 rpm in 5th at about 114 mph. Except for my change to 3.37, I've still got stock gearing and the 150 rear tire.

Launching at 4000 rpm lifts my front tire, which generally gives me a red light. 3500 seems to work well without bogging or spinning excessively. I think I may try retarding my cam timing 4 deg and shifting at 6200 rpm to see if staying in gear a little longer will provide any advantage.

If nothing else, maybe I'll look for a few more cubes to move 680 lbs of bike and 215 lbs of rider down the track...

[YankeeBob]

Are you launching in 2nd or 1st?

[GPO03FatBoy]

Originally Posted by YankeeBob

Are you launching in 2nd or 1st?

Launching in 1st YB. Haven't tried a 2nd gear launch with the 3.37, but I went to 3.37 since the 3.15 wasn't doing much for my 60' times. 2nd gear with the 3.15 was too tame. It launches pretty well in 1st with the 3.37. No bogging. Just have to slip the 2nd half of the clutch release a bit to keep from raising the front wheel.

[Hillsidecycle.com]

Originally Posted by GPO03FatBoy

Scott - you are right. I keep wanting to go faster. I'm starting to look to the 10's, but this is still my street bike so I'm not looking to go extreme.

I'll have to start tracking my rpm at the 25' mark. Right now I'm launching at 3500 rpm, and shifting at 5800. That puts me across the line at 5000 rpm in 5th at about 114 mph. Except for my change to 3.37, I've still got stock gearing and the 150 rear tire.

Launching at 4000 rpm lifts my front tire, which generally gives me a red light. 3500 seems to work well without bogging or spinning excessively. I think I may try retarding my cam timing 4 deg and shifting at 6200 rpm to see if staying in gear a little longer will provide any advantage.

If nothing else, maybe I'll look for a few more cubes to move 680 lbs of bike and 215 lbs of rider down the track...

If your rolling thru at 5000, and hp peak is 5800,then you'll have to step on the gearing to get that 800 rpms on the tach.