1/8 mile drag Commando performance?
- Thread starter Jagbruno
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OK so blind freddy could come up with some of the quotes here. !
But a sample of 1 is not going to be terribly instructive now, is it.
Averages and meaningful results and all that.
I've been out the drags, more than a few times. Spectator though.
Some tracks also record 1/8th mile times for 1/4 mile sprints.
But a sample of 1 is not going to be terribly instructive now, is it.
Averages and meaningful results and all that.
I've been out the drags, more than a few times. Spectator though.
Some tracks also record 1/8th mile times for 1/4 mile sprints.
Interested to hear if you find anything.
This subject has been discussed here before.
"best run et-7.617 " Combat with 19t sprocket. Fighting wheelstands.
need-some-drag-racing-tips-t641.html
Couple of acceleration graph types to consider.
Time vs mph, and time vs 1/4 mile run.
Juggling that mix gives the real world...
The steeper the clime, the better the time
This subject has been discussed here before.
"best run et-7.617 " Combat with 19t sprocket. Fighting wheelstands.
need-some-drag-racing-tips-t641.html
Couple of acceleration graph types to consider.
Time vs mph, and time vs 1/4 mile run.
Juggling that mix gives the real world...
The steeper the clime, the better the time
If you watch the amateur drag race guys, they about sit on the tank to 'get the weight distro right'.
That was the technique the NV factory guys used on that hotrod 850 back in the 70s.
And also the Combats etc when they were doing sub 12 sec times.
The top fuel guys have wheelie bars, having sooo much hp they couldn't possibly hold the front down.
A lot of serious sports bikes these days have a switch in the gearbox, that limits the hp in 1st, 2nd and even 3rd,
so the bike doesn't loop if you open the throttle hard.
No one has commented on that low time that earlier Combat poster did for the 1/8th.
Thats more like it ?
That was the technique the NV factory guys used on that hotrod 850 back in the 70s.
And also the Combats etc when they were doing sub 12 sec times.
The top fuel guys have wheelie bars, having sooo much hp they couldn't possibly hold the front down.
A lot of serious sports bikes these days have a switch in the gearbox, that limits the hp in 1st, 2nd and even 3rd,
so the bike doesn't loop if you open the throttle hard.
No one has commented on that low time that earlier Combat poster did for the 1/8th.
Thats more like it ?
- Joined
- Sep 15, 2005
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- 175
Hi,
Good topic,
Back in the day, ( ~ 1975 ) I ran an 11.78 at New England Drag Way, 1/4 mile.
It was in Epping N.H.. with my 1971 Norton daily rider, with a Dunstal 810 kit, Dunstal big valve head , full cam, Dunstal 2 into one into 2 exhaust.
The rest of the bike was stock, normal tires Etc. Sorry, I do not have the timing slip any more.
? What do the new Norton's do the 1/4 mile in now?
Bruce MacGregor
Good topic,
Back in the day, ( ~ 1975 ) I ran an 11.78 at New England Drag Way, 1/4 mile.
It was in Epping N.H.. with my 1971 Norton daily rider, with a Dunstal 810 kit, Dunstal big valve head , full cam, Dunstal 2 into one into 2 exhaust.
The rest of the bike was stock, normal tires Etc. Sorry, I do not have the timing slip any more.
? What do the new Norton's do the 1/4 mile in now?
Bruce MacGregor
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Back in the 70s, most two-strokes would wheelie very easily - the guys who allowed that to happen always seemed to be slower coming out of corners. Also I once rode a standard Triumph Trident which wheelied very easily, however did not seem very fast. Surely the quickest you can accelerate is when the back wheel is just losing traction, while the front wheel is just becoming airborne ? So if the weight is on the front and the rear tyre gains traction through heating - that should be faster. Or am I missing something ?
Bruce,Bruce MacGregor said:
Thanks for sharing that – it’s great! Do you recall how your bike was geared for the endeavor?
In past posts reference has been made to a Cycle World article chronicling “an 11-second terror anyone can build”, so thought it would be fun to post it here since it dovetails nicely with your information. Hope it's legible as the on-line copy of the article was pretty grainy.
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Really nice article. The illustrations look identical to those found in one of the aftermarket (Haynes) manuals in the back pages. What catches my attention is the comparative flow values of the heads selected. The Norton head is notorious for exceptional flow and maybe extraordinary flow with a little work.
Thanks for sharing.
The 850 Hop Up title reminded me of some good discussions on Brit Iron years back when someone asked what it was. One person suggested something like it being a method for vertically challenged carnies to mount an 850 Commando...you can use your imagination as to where that thread went.
Thanks for sharing.
The 850 Hop Up title reminded me of some good discussions on Brit Iron years back when someone asked what it was. One person suggested something like it being a method for vertically challenged carnies to mount an 850 Commando...you can use your imagination as to where that thread went.
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- 175
Hi,
That was with a 19 tooth sprocket
Bruce
That was with a 19 tooth sprocket
Bruce
The article shown above is based pretty much entirely on the FACTORY 850 Tuning Guides 1 & 2
that were released back then - as they note - and shown in other threads here.
Diagrams too, without checking them individually...
BTW, this is a more sophisticated (?) 1/8 mile to 1/4 mile time convertor, and vice versa.
Takes note of time AND speed.
http://vexer.com/automotive-tools/quart ... calculator
Explains below what formula it uses, and it does note
"This is less of a calculator and more of a wild assumptions generator"
So use at your own peril.... !
that were released back then - as they note - and shown in other threads here.
Diagrams too, without checking them individually...
BTW, this is a more sophisticated (?) 1/8 mile to 1/4 mile time convertor, and vice versa.
Takes note of time AND speed.
http://vexer.com/automotive-tools/quart ... calculator
Explains below what formula it uses, and it does note
"This is less of a calculator and more of a wild assumptions generator"
So use at your own peril.... !
Added for the benefit of the great unwashed amongst the community. ?
I know where he is coming from....
Actually, looking at the VERY large disparity of the few times posted here as examples,
perhaps some measure needs to to be taken to allow for the phases of the moon.
Or the stickiness / dew factor of the road surface.
Or the tire compound ?
I know where he is coming from....
Actually, looking at the VERY large disparity of the few times posted here as examples,
perhaps some measure needs to to be taken to allow for the phases of the moon.
Or the stickiness / dew factor of the road surface.
Or the tire compound ?
yves norton seeley
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Hi There, yves here,
About my tme on 1/8 mile
A very important thing: I weight 180 pounds, that will not help to break records
My TTI 5 speed gearbox is not a racing close ratio, but the road version, but even in this case, the first gear is more longer than on a normal Codo box
Some racing close ratio have a first gear going 50% ot the top speed: if you put a gearing to have 120 M/H at top gear, you first gear will reach 60 M/H
I was using my normal road gearing 23 x 36 and the only changes I make for the sprint was to replace my K & N air filters witk belt mouts and also I take the stator out
Another important thing: on drag racing, you dont decide when the chrono is starting, you have to watch the christmas tree and you can only start when the lights are green so even if you anticipate the start you will have a reaction time between 2.0 and 3.0 of a second.
I am wondering if the times from the magasines are set on a real drag track where the christmas tree decide when you can start and not when the rider decide to cross the fotocells
I remember that I did a run with a 1.100 Susuki, and the rider take an advantage of 30 feets half way the 1/8 mile, but when I put the second and third gear I finish, 30 feets in front of him
Here Belgium we don't have 1/4 mile drag track, but one day I will go to Holland or to the UK to try 1/4 mile
But the most important: It was a very funy day
Yves
About my tme on 1/8 mile
A very important thing: I weight 180 pounds, that will not help to break records
My TTI 5 speed gearbox is not a racing close ratio, but the road version, but even in this case, the first gear is more longer than on a normal Codo box
Some racing close ratio have a first gear going 50% ot the top speed: if you put a gearing to have 120 M/H at top gear, you first gear will reach 60 M/H
I was using my normal road gearing 23 x 36 and the only changes I make for the sprint was to replace my K & N air filters witk belt mouts and also I take the stator out
Another important thing: on drag racing, you dont decide when the chrono is starting, you have to watch the christmas tree and you can only start when the lights are green so even if you anticipate the start you will have a reaction time between 2.0 and 3.0 of a second.
I am wondering if the times from the magasines are set on a real drag track where the christmas tree decide when you can start and not when the rider decide to cross the fotocells
I remember that I did a run with a 1.100 Susuki, and the rider take an advantage of 30 feets half way the 1/8 mile, but when I put the second and third gear I finish, 30 feets in front of him
Here Belgium we don't have 1/4 mile drag track, but one day I will go to Holland or to the UK to try 1/4 mile
But the most important: It was a very funy day
Yves
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