530 gearing ?

[Guest]

Homework assignment, if the vehicle is experiencing an average of 4 g's of linear acceleration down the track, how fast (ET and top speed) will it do the quarter mile? :-\\\



Hit they don't pull 4 g's down the track. If there is 4 g's it is down force. 1 g is weight and three g's are thrust and aero effects.

Yes the do pull 4 G's down the track 0 to 100 mph in .8 seconds

 

[posplayr]

Yes the do pull 4 G's down the track 0 to 100 mph in .8 seconds

OK I corrected my math error.

 

[Guest]

I'm reading this over again and I have some questions for ya;
1. With all these different combinations, do you have to adjust the chain length? Or do you have enough rear axle adjustment?
2. If you do adjust the chain, do you use spring clip master links? or rivet?
3. Do you run offset counter sprockets to get the chain around the rear tire? If you do, how much offset? And do you use an outer bearing support?
4. In your signature, what is the gearing for those runs?

Thanks,
Kevin

Yes I have to adjust the chain length. I have several different size pieces of chain so I can use any size sprocket and any wheel base my 4" adjustment will alow me to go. I use 2 clip type master link and I use the 1/4" offset countershaft sprocket with no bearing support.
The gearing on my 85 1150 on the 9.72 pass was a 17/47 but that is a nitrous bike and it only uses 4 gears in the 1/4 mile unless I use the No2 then it will use all 5 gears at close to 158 mph.
The 84 GSX mostly stock motor was using a 15/48 gearing. I am using 16/48 now and I can run the 1/4mile in 4 gears or 5 gears it did not make much difference in et or mph. I am going to try 17/50 next and just use 4 gears

 

[jimb12]

I was out on a ride yesterday and realized there's a much easier way to figure this out. I noted that in top gear at 60 mph I was at almost exactly 4,000 RPM.

So if my redline is 10,500 RPM, then my theoretical* top speed is 157 MPH.
Oh, and I'm 17/47 (not 48).**

I want to be in the high 10 second range and I'm guessing 125mph. End of story: I don't think I'll run out of gearing. If anything, I should think about going to a 49 or 50 rear sprocket.***

-Kevin

* - I don't know if my bike has enough power to get there.
*2 - I remember reading about MotoGP bikes in 2005 or so having a wheel speed difference of about 30 mph on the straights. So in order to go 200 mph their theoretical gearing has to be in the 230 mph range.
** - 1150 motor, 530 chain, 17t front, 47t rear, 190/70-17 Dunlop rear tire.
*** - I would do this today, but my axle is adjusted all the way forward. I'd have to buy a new longer chain. (or extend the one I have)

Don't use the speedometer for your calculations, they are full of crap. Use the timing lights on the track.

You can get a pretty good calculation by sitting on your bike, have a buddy mark on the ground where the rear wheel is and wheel reference point, move straight forward ONE revolution and mark it, then measure the distance in feet. Then use formula as follows:

(engine rpm times distance in feet) divided by (gear ratio times primary ratio times sprocket ratio times 88)

Result is speed in mph. Won't be as precise as gathering data with a datalogger but certainly much closer than using the speedometer.

 

[CivilRock]

(engine rpm times distance in feet) divided by (gear ratio times primary ratio times sprocket ratio times 88) Result is speed in mph.

Love it. I'll get all those variables and report back.

I hope you guys aren't tired of seeing my dorky and endless posts and questions.

Another variable I just looked up was the max power RPM, and it's lower than I thought at 8,000 RPM. When I was road racing, I knew the max power RPM and I would try and straddle it with the needle for each gear. I don't even know if that's the best method, I think I just made up the rule for myself.

What RPM should I set my shift light at?

-Kevin

 

[CivilRock]

That is pseudo instantaneously. If it were sustained the 1/4 mile ET would be 2.48 sec at 1304 mph.

I didn't have enough time to figure this out. I did fail 3rd year calculus at UO twice before I realized that I need to stop partying. But I did learn some math along the way, and I do know 1 G is 9.8 m/s^2.

I trust your calculations are correct, and yes, I believe the wikipedia's claim of an average of 4Gs down the track is false.

I would love to see a graph showing the G-force of a top fuel dragster going down the track. I would imagine it was a backwards ski-jump.

 

[CivilRock]

Yes I have to adjust the chain length. I have several different size pieces of chain so I can use any size sprocket and any wheel base my 4" adjustment will alow me to go. I use 2 clip type master link and I use the 1/4" offset countershaft sprocket with no bearing support.
The gearing on my 85 1150 on the 9.72 pass was a 17/47 but that is a nitrous bike and it only uses 4 gears in the 1/4 mile unless I use the No2 then it will use all 5 gears at close to 158 mph.
The 84 GSX mostly stock motor was using a 15/48 gearing. I am using 16/48 now and I can run the 1/4mile in 4 gears or 5 gears it did not make much difference in et or mph. I am going to try 17/50 next and just use 4 gears

Wow, thank you for the info. I had 2 clip type master links fail on my SV650 racebike. That was with safety wire and shoe goo the second time, so I decided to never use them again. Maybe it was the nature of the bike, or user error? but the clips would sure make changes easier as long as they didn't come off!

I find it very interesting that the gearing seems to make little difference. I don't have a quick shift system, so only using 4 gears might help?

In the end, I think we all agree the best way to know is to go out and actually do it. Which is what I need to do.

Thanks for all the info.

So was that 9.72@146 pass in your signature on nitrous?
That build doesn't look too wild, but that time is blistering.

You listed the wheelbase too. Is that just FYI? I went and measured mine just because you listed it, and it's 62-63" depending on the adjustment.

My chain eats the side of my rear tire, so I'm going to shim out the sprocket a hair. I might see if I can reduce the front offset to 1/4" (from 3/8ths) as well. I didn't own my little mini-lathe 9 years ago, and it's come in so handy for these little projects.

 

[posplayr]

I didn't have enough time to figure this out. I did fail 3rd year calculus at UO twice before I realized that I need to stop partying. But I did learn some math along the way, and I do know 1 G is 9.8 m/s^2.

I trust your calculations are correct, and yes, I believe the wikipedia's claim of an average of 4Gs down the track is false.

I would love to see a graph showing the G-force of a top fuel dragster going down the track. I would imagine it was a backwards ski-jump.

I failed algebra I and II in high school, having to retake both in summer school.

I also remember taking about the 3rd test in Cal III and getting 100%. I got straight A's in CAL I,II,III but this one sticks out because I did the test in red pen with no (few) markups.

I only realized after getting the test back, how that must have appeared.


Funny story, while I was working at Raytheon, they had these annual engineering contests. You were given a box or standards parts (wheels, sticks, rubber bands) and you had to design a dragster and the contest was based on fastest ET. Part of the rules were that you were given all the parts and 1 hour to build your dragster on the spot and then the drag heats would start. A combination or team work, cooperation, time pressure and competition.


The mechanical engineers loved this and came up with all kinds of contraptions to drive the wheels with the rubber bands. I think the week of the contest the entire ME department virtually came to a standstill while these guys worked on various contraptions and building the prototypes , practicing for the big day..

I was in systems engineering and my manager said we should also participate. We went and looked at the parts and so we were too busy to protoype, but I did an analysis of the problem recognizing that Tractive effort would be a limitation. So the strategy was to increase TE by spiking the wheels (which locks the wheel to the carpet but easily releases after launch) and then launching the dragster like a rocket using the rubber bands. Basically a slingshot. There was nothing in the rules than said you could not become airborne!!.

It was impressive and how can anything trying to roll down a carpet compete with a sling shot? It cant. Unfortunately our lack of prototyping started to show, the attachment of the rubber band to the axle started to slip and would turn our sling shot launch into a speed brake 2 foot before the finish line. We lost out in the final heat.

I always thought it was unfortunate, that the engineering management did not realize what had been demonstrated and use it as an example of performance based systems engineering for architectural design.

As they say "ignorance is bliss".

 

[Guest]

Wow, thank you for the info. I had 2 clip type master links fail on my SV650 racebike. That was with safety wire and shoe goo the second time, so I decided to never use them again. Maybe it was the nature of the bike, or user error? but the clips would sure make changes easier as long as they didn't come off!

I find it very interesting that the gearing seems to make little difference. I don't have a quick shift system, so only using 4 gears might help?

In the end, I think we all agree the best way to know is to go out and actually do it. Which is what I need to do.

Thanks for all the info.

So was that 9.72@146 pass in your signature on nitrous?
That build doesn't look too wild, but that time is blistering.

You listed the wheelbase too. Is that just FYI? I went and measured mine just because you listed it, and it's 62-63" depending on the adjustment.

My chain eats the side of my rear tire, so I'm going to shim out the sprocket a hair. I might see if I can reduce the front offset to 1/4" (from 3/8ths) as well. I didn't own my little mini-lathe 9 years ago, and it's come in so handy for these little projects.

I have never ever had a clip type master link fail but I don't re use them over and over again either. I buy my master links by the dozen.
The 9.72 pass was on motor only it will run high 8's @ almost 158mph on the nitrous. The 61'' wheel base is stock for the 1150 and the Bandit swingarm and wheel was not done at the time of that pass. The motor build I have is a big head on a little piston. But the build is quite extensive as it has to be to hold a 90hp shot of no2 that is why I went with the 25mm exhaust valves.

 

[jimb12]

Another variable I just looked up was the max power RPM, and it's lower than I thought at 8,000 RPM. When I was road racing, I knew the max power RPM and I would try and straddle it with the needle for each gear. I don't even know if that's the best method, I think I just made up the rule for myself.

Did you look up a magazine test for a stock 1150? You have some mods on the engine so you really should get a dyno graph of your own bike to know where it's happy. When you're there, note the tachometer reading compared to what the dyno pickup says. With the electric tach that you must be using since the mechanical tach doesn't fit the 1150 valve cover, you will probably see more rpm on the tach than it's really doing. This needs to be accounted for if you want to choose your best shift point.

 

[posplayr]

http://en.wikipedia.org/wiki/Top_Fuel

Top fuel dragsters are the fastest sanctioned category of drag racers, with the fastest competitors reaching speeds of 330 miles per hour (530 km/h) and finishing the 1,000 foot (300 m) runs in 3.7 seconds, or the full quarter mile (402 m) in 4.4 seconds.

WHOOPS I screwed up feet for yards

4.4 sec is about 4.15 g's of average acceleration for the 1/4 mile.

I guess they are really using a lot of ground effects At 580 mph there is plenty of energy in the fluid (air)

 

[CivilRock]

I continued my search to find a "G-Force vs. Time" graph on top fuel dragsters for a little time yesterday and came up with nothing. But I did find gobs of interesting information.

After going over all my options, I'm going to just buy a 16t front ($15) and I found another scrap 630 front to use as my spacer. I'm too scared to add a few links using 2 master links. I have visions of the chain coming apart and breaking my engine case. My other option is to buy a new 130 link chain ($140) and go with 16/50 gearing ($60), but I might not even need it.

I'm also going to mill down that spacer on the front to 1/4" (from 3/8ths) and build a spacer for the rear sprocket to try and get the chain off my tire some more.

 

[CivilRock]

There's 6 things that I accomplished in this picture:
1. New 50t rear sprocket (was 47) Ratio - 2.94:1
2. New chain - 124 link.
3. Shimmed sprocket out 3/16" (chain doesn't rub tire now)
4. Discarded tab-locks and drilled nuts for safety-wire.
5. Semi-polished and cleaned cush drive.
6. Gained 1" of wheelbase. (I'm at ~ 60% of adjustment range)

-Kevin

 

[blowerbike]

bandit's used locking shoulder nuts on the rear sprocket..no folding tabs or anything.
nice clean look.

 

[CivilRock]

So I've had 3 master links fail. once on a dirt bike, ironically on a trail called "chain breaker". And twice with my SV650 racebike. The 2nd time with the SV I safety wired and "shoe gooed" the master link. Both were new chains and master links. After that I vowed to forever use riveted master links and haven't had an issue since.

Now I'm in a dilemma, because I want to be able to add and subtract links to accomodate my selection of sprockets. Larry, my bike builder buddy, says in 30 years of drag racing he's never had an issue with clip style links.

Anyway, I'm going with the clip style this time, but adding safety wire and "Goop". Love that stuff. Works great as grip glue too. I paid attention to the sharp and rounded side of the clip (from press manufacturing) and installed this one as best as I know. Even pulling the link plate out just a little so there's slight back pressure on the clip.

Am I paranoid?

-Kevin

 

[posplayr]

So I've had 3 master links fail. once on a dirt bike, ironically on a trail called "chain breaker". And twice with my SV650 racebike. The 2nd time with the SV I safety wired and "shoe gooed" the master link. Both were new chains and master links. After that I vowed to forever use riveted master links and haven't had an issue since.

Now I'm in a dilemma, because I want to be able to add and subtract links to accomodate my selection of sprockets. Larry, my bike builder buddy, says in 30 years of drag racing he's never had an issue with clip style links.

Anyway, I'm going with the clip style this time, but adding safety wire and "Goop". Love that stuff. Works great as grip glue too. I paid attention to the sharp and rounded side of the clip (from press manufacturing) and installed this one as best as I know. Even pulling the link plate out just a little so there's slight back pressure on the clip.

Am I paranoid?

-Kevin

If the wire thickness is less than the plate thickness I would be OK. If not even under wear it can only go down to the plate thickness. You could splash the wire alittle to flatten it, but probably not necessary.

We use Red or black RTV to hold it on not shoe glue.