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View Full Version : 110 + HP out of 82 c.i.


isiahstites
4th October 2007, 07:23
Got the bike on the dyno for a short time today. We made a real soft first run just to make sure everything was good with the drivetrain and the new motor. All went well and it was clear the bike was on the rich side of things on the main jet. We didn't make any changes as it was more of a shakedown pass then anything. We made two more passes and had some problems with the sniffer/gas analyzer so I couldn't make any changes and then be able to see the affect they had.

So all in all I am happy as I found out that all of the motor/trans work I did held together on the dyno. Checked the hp on the last two passes and both were 110 rwhp @ 7000 rpm with a great power curve that had no dips or spikes in it at all and created power nice and steady all the way to the rev limiter. I have the rev limiter set at 7000 rpm, but may play with it after some research on what will be a safe rpm to rev to without blowing the motor.

We fill that once back on the dyno after it is repaired and some jetting changes, playing with timing a bit and maybe the rev limter we may be able to pull another 10-15 + horse out of the motor.

So for just setting up the motor in my garage by sound and throttle response I am happy to this point with the 110 horse out of the little 82 cubic inch motor.

Scott

CBAS5
4th October 2007, 07:52
Checked the hp on the last two passes and both were 110 rwhp @ 7000 rpm with a great power curve that had no dips or spikes in it at all and created power nice and steady all the way to the rev limiter. I have the rev limiter set at 7000 rpm, but may play with it after some research on what will be a safe rpm to rev to without blowing the motor.

110 hp from 82 ci is nice. As for what rpm. If you are still running the stock stroke, then based off the buells 6400 rpm is safe for SUSTAINED periods of time. However, you can safetly rev it to 6800 rpm for brief periods.

Depending on your pistons and crank you may be able to get away with more. The 2008 buells are able to SUSTAIN 6800 rpm and briefly rev to 7100 rpm.

isiahstites
8th October 2007, 01:55
Ok, I finally got some video of the bike today. I bled the brake today so I thought I would take it out for it's first run.

Video one is 1:37 long and you can really hear how good the bike sounds and video two is 1:50 long and was added because it was kinda hard to see the bike with all the cars parked along the street.

I have'nt done much work to the bike lately as I have kinda been taken a break, however it is almost 100% race ready. I still have to do some small minor stuff to finish along with saftey wiring the bike.

Scott

#1
http://www.youtube.com/watch?v=NWAvkV3TyHM

#2
http://www.youtube.com/watch?v=HqdzIWy6MFU

gwcrim
8th October 2007, 16:48
Great vids!

My 80" made 107 HP but unfortunately it requires race fuel. Can you run pump gas?

rev1970
8th October 2007, 17:00
i have the 88" and it's sick cant keep the front end down and your bike is sweet i like the bars i need to get mine on the dyno soon nice job

jessearias
8th October 2007, 20:57
Scott,

Good job my friend!:banana Please post a copy of your dyno in the reference sticky. This is definetly one for the sticky. :wonderlan

Weo
8th October 2007, 21:03
Nice! :)

isiahstites
19th October 2007, 04:23
I got the air/fuel analyzer working on the dyno and made a few passes this evening. I am still on the rich side but getting closer. I had a nice big dip in power around 6600 rpm and it came back on strong after that so tomorrow I will mess around with that and try and figure it out, I need to read up on my Thunderjet as thinking something may be happening there. After I get the air/fuel right I will move onto the ignition and hopefully be done tomorrow afternoon so I can get ready to go to the race on Sunday.

As we stand now it as at 114 horse at 7300 rpm and if I recall correctly around 90 ft tq give or take and about 12-1 a/f.

If all goes well tomorrow hopefully it will be in the 120's.

Scott

rottenralph
19th October 2007, 04:33
You might need more than one thunderjet. /The dyno guy that tuned my bike has three on his superG drag bike. Setting up the bleed and the thunderjet did not work for me and that is one reason I went for the dyno tune.

NRHS Sales
19th October 2007, 04:35
On Bonneville bikes you are really only worried about wide open throttle so one thunder jet is usually fine. On drag bikes 2 or 3 are needed as you need to make power as you are shifting and working through the rpms.

rottenralph
19th October 2007, 04:41
Good to know. Sounds a little odd to me to have a dip at 6500. No carb transitions there that I am aware of.

isiahstites
19th October 2007, 05:29
Who knows Ralph it could be ignition, but I am leaning towards fuel.

I don't know to much about the bleed so I am going to read up on that as well.

Scott

havi0412c
19th October 2007, 05:43
runnin out of fuel on top end? dunno until I could see the dyno stuff. nice bike though. that thing is awesome!!!

isiahstites
19th October 2007, 05:46
runnin out of fuel on top end? dunno until I could see the dyno stuff. check for a possible factory "rev limiter" aka fuel shutoff at 6500. I know ford computers do it. I dont know too much about the harley stuff though. just a thought. nice bike though. that thing is awesome!!!


Thanks for the post.........a no on the "rev limiter" as I am have total control over that setting on the ignition. However you may have something on the running out of fuel on the top end...........I have heard before that you can run the float bowls dry on these things and that Joker sells a much better bowl.

Scott

lincoln1975
19th October 2007, 05:46
very impressive, also a blast to ride:banana

isiahstites
20th October 2007, 07:13
I got as far as I could this afternoon on the dyno. My final number were 122.7 hp and 95.5 ft tq. I got rid of the dip in power at 6600 rpm by tightening up a loose connection on one of the coils. That was not the only thing that loosened up and had to be tightened......dam Harley's! I got the a/f as close as I could, it is about 13.5 at 4000 rpm and slowly tapers to about 12.5 +/- as it gets to redline at 7500 rpm. I could not get the a/f as good below 4000 rpm because the bigger intermediate jets I ordered are back ordered. I drilled one intermediate out to .041 which helped, but did not completely fix the condition. Good thing is once I am out of first gear the motor should not see to much of 4000 rpm and below. I played with the timing a little bit and got a few extra horsepower out of the motor, however I may have got more if I would of made a few more passes.

I feel there is little bit more hp and tq in the motor if I did some more fine tunning, but it is good for now. I definately feel a good experienced dyno tuner could exceed what I have done as I am just a rookie tuner.
For now I am very happy with the numbers and all that is left to do is race the dam thing!

Scott

Horsepower only
http://i142.photobucket.com/albums/r98/isiahstites/100_1673.jpg

Horsepower and torque........not sure what happened to the dyno/printer with the torque line??
http://i142.photobucket.com/albums/r98/isiahstites/100_1677.jpg

isiahstites
20th October 2007, 07:14
Scott,

Good job my friend!:banana Please post a copy of your dyno in the reference sticky. This is definetly one for the sticky. :wonderlan

Not sure what that is??

hillers03
20th October 2007, 07:50
Great run on the dyno, that engines screams. So how fast do you think it will run down the strip? If you don't mind me asking how much did the dyno runs cost you??:clap

isiahstites
20th October 2007, 08:28
Great run on the dyno, that engines screams. So how fast do you think it will run down the strip? If you don't mind me asking how much did the dyno runs cost you??:clap


Well it did about 140 mph on the dyno in fourth gear so there should be a lot more speed to be gained in fifth. I currently have the bike geared 10% over stock and am confident I should be able to pull the gearing at which point I will go to one tooth down until the bike can not pull the gearing. I am not sure how well the bike will do this weekend as I think I may only get one run, however if all goes well I should get 3-6 runs in November which will allow me to test and tune and get things dialed in.

Dyno did not cost me anything.......I did all of the tuning myself on a fellow friend/racers dyno. He always helps me and I help him where I can.........I repaired the dyno this week after some troubleshooting and saved him a few hundred bucks so I did not feel to guilty this go around like I usually do when he helps me out.

Scott

isiahstites
20th October 2007, 08:29
Great run on the dyno, that engines screams. So how fast do you think it will run down the strip?

Did you mean 1/4 mile strip?

hillers03
20th October 2007, 09:30
Yeah that what I meant.

aswracing
20th October 2007, 16:19
Scott, I'm glad you're happy with the numbers, but I'm not. That motor is capable of well over 130hp, and now that I can see your dyno sheet, I know exactly what it needs to get there.

Take a look at this sheet:

http://www.nrhsperformance.com/images/drdannorlin82revc.gif

This motor is a twin to yours. Same bore, same stroke, same heads, same cams, same carb, etc. There's one big difference, and that's the exhaust system. This bike uses an exhaust system that I designed specifically for this motor and specifically for high rpm power.

The best way to evaluate what an exhaust system is doing is to look at the torque curve. The shape of the torque curve is essentially a map of the cylinder fill. On a motor like this, where exhaust augmentation is a big factor in the cylinder fill because of the overlap in the cams, the torque curve tells you a lot about what the exhaust system is doing.

When you look at your torque curve, you can see that it's filling the cylinder best very early in powerband, and then slowly tapering off as rpm builds. The exhaust system is pulling best at a very low rpm.

Now look at the chart I just posted. The torque is peaking way up high. Doesn't run well down low, in fact it has a pretty big dip in the middle. The exhaust is designed to pull at high rpm.

Remember, horsepower is just torque times rpm. To the extent you can make your torque at higher rpm, horsepower will be higher. In other words, to make more power, you need to move that torque peak to the right on the chart.

Right now, you've got an unhappy marriage between your pipes and your cam. The intake close event timing on your cam is optimized for 6000rpm and up. Your pipe is pulling at something much lower than that. You need to get both of those things onto the same page. That will put you north of 130hp, No doubt in my mind.

I'd be happy to send you dimensions for the pipes.

That hole in the middle of the powerband that these pipes cause is due to reversion. The whole idea of the Thunderjet is to deal with that reversion. It allows you to back down the main to band-aid the reversion, but then replaces the fuel at high rpm where the pipe is working. Thunderjets are basically a crutch for unbaffled drag pipes. But it really doesn't matter much if it goes fat and shoots ducks through the mid range on a Bonneville motor. You pass through that rpm range once in first gear and you never see it again.

aswracing
20th October 2007, 16:32
Scott, the little black bike that my wife rode at Bonneville this year ...

http://www.nrhsperformance.com/pictures/WOS2007/susanwiths1hairblowing.jpg

She went as fast as 166.6 with this bike and set a new BNI record at 165.3.

Well, here's it's dyno sheet:

http://www.nrhsperformance.com/pictures/s1138hp.gif

This ain't the most recent one but close enough, it's in the same range. Depending on the day I dyno it, it's generally 135 to 138hp.

This motor is 82ci like yours, but it's a 3.813 bore x 3.600 stroke. It's a much higher dollar motor than yours, with S&S cases, STD raised oval port heads, etc. It's carb limited, though. Long story. Your motor is quite capable of getting into this range though.

Anyway, you can see that again, by looking at the torque curve, this motor is all about filling the cylinder at high rpm. Filling the cylinder at high rpm means getting the cams and the exhaust onto the same page. Yours are not. You have a great street exhaust system, but it doesn't belong on a land speed bike.

aswracing
20th October 2007, 16:40
By the way, the interruptions in your torque curve are due to the tach pickup not working well. On a Dynojet, the torque is calculated from the horsepower and rpm. Without rpm, it can't do the calculation, so it doesn't show the torque.

isiahstites
20th October 2007, 16:49
Aaron,

Thank you for your post, very informative! I am new to LSR racing as you can tell and really appreciate the info you posted. The more I discuss this the more it starts to come together. I have followed all of NRHS' bikes this year and pleased to be associated with you guys, I feel like I have made new friends and look forward to the day I can meet you, your wife and Dan.

I thank you and Dan again for all that you guys have taught me this year.

Scott

isiahstites
20th October 2007, 16:51
By the way, the interruptions in your torque curve are due to the tach pickup not working well. On a Dynojet, the torque is calculated from the horsepower and rpm. Without rpm, it can't do the calculation, so it doesn't show the torque.


Makes since now as it did not seem to always be working correctly. I will have to try and fix that for them, since them since they let me use their dyno.

Scott

isiahstites
20th October 2007, 17:03
I'd be happy to send you dimensions for the pipes.



I tried to send you a pm, but could not. I would be greatful for that information and would hold it in the highest confidence. I may even be able to have them built before the next meet on the 10th of November.

Scott

NRHS Sales
20th October 2007, 21:12
Scott,
You definately better be planning your vacation so you can attend the Bubs event next year. Aarons getting bored just competing against himself!! ;)

I agree with Aaron. I fully expect that engine to be making well into the 130s with the right state of tune.

isiahstites
20th October 2007, 21:18
Scott,
You definately better be planning your vacation so you can attend the Bubs event next year. Aarons getting bored just competing against himself!! ;)

I agree with Aaron. I fully expect that engine to be making well into the 130s with the right state of tune.


I don't know if I can be Aaron on motor, but maybe, just maybe can get him with the new chassis I am going to build.

Scott

aswracing
20th October 2007, 21:27
Scott, I sent you the gearing spreadsheet. Let me work on the pipe design, I'll try to get it to you later today.

isiahstites
20th October 2007, 21:41
Scott, I sent you the gearing spreadsheet. Let me work on the pipe design, I'll try to get it to you later today.


Thank you!

TommyV
20th March 2008, 00:25
for any possible updates on this Giant Killer!

isiahstites
20th March 2008, 02:47
for any possible updates on this Giant Killer!



Tommy,

Thanks for your interest in my project. Here is the latest thread on the re-build of the bike.

Scott

http://xlforum.net/vbportal/forums/showthread.php?t=154894