ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 10-21-2012, 01:56 PM   #31
Bluethumb
Gnarly Adventurer
 
Joined: Aug 2012
Location: Texas Hill Country
Oddometer: 127
Interesting line of reasoning, opinion is more valid then say dyno provided torque and h.p. curves?

I wonder why Cycleworld magazine goes to all the trouble to post figures showing the performance gains for different products in a comparison test when they could just ride the bikes and talk about hw each one "felt".

Take a stock R100 motor, run it on a dyno. Do XYZ, then run it and compare. You will get specific information showing performance gains, or losses, depending on what's done. Doesn't matter if that dyno is at sea level or 6,000 feet or 10% humidity or 60%. The two dyno runs will give comparison figures. A comparison of a stock motor vs that motor with specific mods.

Instead what we get is "real world" opinions? Gimme a break. Why, if real world is so much better, do we get one post saying "my experience is this...." and the next post the person saying "my experience is totally opposite".
Bluethumb is offline   Reply With Quote
Old 10-21-2012, 03:37 PM   #32
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
BT, you really don't understand dyno's if you don't realize the same thing can be done on the same dyno, let alone different ones. Dyno results depend on an endless set of variables. It takes a skilled and experienced operator to reduce them AMAP but, then again, they can be manipulated as well and often are. Why doesn't Cycleworld just report on how they feel? If it's a good test they do just that AND dyno test them. Obviously for the reasons I am trying to make a point of, how they feel and actually work and how they dyno read can be conflicting. Take these obvious IMO short comings of dyno results and throw in different dynos and operators and I will lean towards how they 'feel' versus 'real data'. My dad and I and other people I have worked with have been out pulling too many bikes for too long whose 'real data' said it couldn't be done.

supershaft screwed with this post 10-21-2012 at 03:55 PM
supershaft is offline   Reply With Quote
Old 10-21-2012, 03:42 PM   #33
Uncle Pollo
happy cachiporra
 
Uncle Pollo's Avatar
 
Joined: Jun 2006
Location: Albuquerque, Neue Messico
Oddometer: 47,218
My ass dyno passees or fails mods.

So far so good.
Uncle Pollo is offline   Reply With Quote
Old 10-21-2012, 03:53 PM   #34
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
I was just thinking of another way to put my point across UP. When 'real world' and 'real data' conflict and they VERY often do. I will take 'real world' every time and I will come out ahead for it too!
supershaft is offline   Reply With Quote
Old 10-21-2012, 05:49 PM   #35
Uncle Pollo
happy cachiporra
 
Uncle Pollo's Avatar
 
Joined: Jun 2006
Location: Albuquerque, Neue Messico
Oddometer: 47,218
Quote:
Originally Posted by supershaft View Post
I was just thinking of another way to put my point across UP. When 'real world' and 'real data' conflict and they VERY often do. I will take 'real world' every time and I will come out ahead for it too!
Not all dynos are the same.

But your stopwatch will rarely lie.
Uncle Pollo is offline   Reply With Quote
Old 10-21-2012, 09:26 PM   #36
Voltaire
Beastly Adventurer
 
Voltaire's Avatar
 
Joined: Jun 2011
Location: Auckland,New Zealand
Oddometer: 1,198
We had a race meeting here this weekend, there were 3 BMW's....
#269: 1050, fancy cam, 40mm Dells, re-angled inlet ports ( welded) ,frame bracing, 2.91 FD, Avon race tyres...etc. probably the quickest BMW in New Zealand. He said it its not geared high enough to keep up with the Rob North Triton, the 1000 +cc Guzzi and the 640 Manx Norton.Rider has been racing for some years.
Best Lap- 1:23 ( Triton was 1.18)

#4- Built by the rider of # 269 ( he has an Airhead business and is the local Siebenrock Agent)
apparently over 1050 with Motor Trans Israel bits ( thats what owner wanted he said.)
R80 mono front end, bracing, Avon race tyres....etc
Rider is 70 but former moto cross and speedway rider
Best Lap - 1.28

# 146 Built by me and some mates, 336 cam, 36 mm dells, 1mm off heads, original pistons, valves and so on...no frame bracing, BT45 tyres, rider has 8 months of track experience and is over 50
Best Lap- 1:28

Oh and the Triton has a rider, an owner and a mechanic...the Norton probably has no original engine parts.....The Guzzi is highly modified at huge $$$$$

Conclusion: Super bike School was the best money I spent on my bike and there is lots of room for improvement there too.
I cant red line it in 4th on the hill and I can pass the Harley and Commando on the corners but in the straight line they pull ahead....lots in the Nortons case.
Good fun thought....recommend the California Superbike School for anyone wanting to do this. One thing that works for me is the deep entry into the corners and counter steering to drop the bike in, great technique for keeping high corner speed on low HP machines.

I was going to put the bike on a dyno but can't really see any point in it now as it runs perfectly with no misfires, flat spots or hesitation.
My Butt Dyno would estimate it to have about the same as my old Thruxon which have been widely dyno tested to about 50 to 55 BHP.
Another 10 or so HP would be good on the straights but thats about all.


Voltaire screwed with this post 10-21-2012 at 09:43 PM Reason: adding more BS
Voltaire is offline   Reply With Quote
Old 10-22-2012, 01:47 AM   #37
RGregor
User Awaiting Email Confirmation
 
Joined: Oct 2007
Location: Bavaria
Oddometer: 437
Dyno charts or not

Quote:
Originally Posted by Bluethumb View Post
Interesting line of reasoning, opinion is more valid then say dyno provided torque and h.p. curves?

I wonder why Cycleworld magazine goes to all the trouble to post figures showing the performance gains for different products in a comparison test when they could just ride the bikes and talk about hw each one "felt".

Take a stock R100 motor, run it on a dyno. Do XYZ, then run it and compare. You will get specific information showing performance gains, or losses, depending on what's done. Doesn't matter if that dyno is at sea level or 6,000 feet or 10% humidity or 60%. The two dyno runs will give comparison figures. A comparison of a stock motor vs that motor with specific mods.

Instead what we get is "real world" opinions? Gimme a break. Why, if real world is so much better, do we get one post saying "my experience is this...." and the next post the person saying "my experience is totally opposite".

Now, this discussion is very old and, funny thing, limited to this forum.
Basic argumentation against dyno runs is that there is much room for cheating. Or that comparing numbers taken on two different dynos in different invironmental conditions is nonsense, as they always will differ.

Of course that's right, but to my mind that's still nonsense argumentation.
Cheating would be much simpler by stating "real world" opinions or feelings. At least it's very simple to describe the perfect engine with words, simpler than to generate the perfect torque curve by cheating with the dyno. And what would the benefit of cheating be: having the best virtual engine in a virtual world?

I have ridden quite a few modified beemers.
My experience is, the more self criticism the owner shows ("It's not yet good, I still have to improve this and that and ..."), the better the bike is. So what are personal feelings/opinions good for? Nothing IMO.
How knows what GREAT means? It can mean anything and nothing.

Having a dyno chart at least means to get an idea where a specific engine may have it's strength or maybe weak points. Having multiple dyno charts of similar engines will give you a better impression.
Like in measurement engineering when measuring noisy data, many measurements will decrease uncertainty.

On the other side:
To compare the results of your tuning efforts you would have to document each single step. I can't afford that regarding time and money. It's not my job, just my hobby. And additionally, I never had an unmodified R100 engine. So what would the basis be to refer to?
I already thought to take a friend's bike, an unmodified Monolever R100RT to the same dyno to get a reference baseline. Not for any forum, but just for myself, to be sure.

To the culture of discussion here:
From the main protagonists here I have never seen anything like discussion or even reasoning about the ways others go, just sticking to the own experience and defending it like hell against all threats in form of different experience.
Posting dyno charts here will transfer you into a dogfight faster than you can think. At least if you're not using the holy 336. And never will :-))

In an oilhead forum over here some users seem to work systematically and share their dyno data.
This went to the length that over last christmas holidays one user made a round trip, collected all exhausts and spent holiday on the dyno to find the best combination of headers and mufflers. That is teamwork.
RGregor is offline   Reply With Quote
Old 10-22-2012, 02:13 AM   #38
pommie john
Beastly Adventurer
 
pommie john's Avatar
 
Joined: Apr 2008
Location: Brisvegas, Australia
Oddometer: 1,338
Quote:
Originally Posted by Voltaire View Post
We had a race meeting here this weekend, there were 3 BMW's....
#269: 1050, fancy cam, 40mm Dells, re-angled inlet ports ( welded) ,frame bracing, 2.91 FD, Avon race tyres...etc. probably the quickest BMW in New Zealand. He said it its not geared high enough to keep up with the Rob North Triton, the 1000 +cc Guzzi and the 640 Manx Norton.Rider has been racing for some years.
Best Lap- 1:23 ( Triton was 1.18)

#4- Built by the rider of # 269 ( he has an Airhead business and is the local Siebenrock Agent)
apparently over 1050 with Motor Trans Israel bits ( thats what owner wanted he said.)
R80 mono front end, bracing, Avon race tyres....etc
Rider is 70 but former moto cross and speedway rider
Best Lap - 1.28

# 146 Built by me and some mates, 336 cam, 36 mm dells, 1mm off heads, original pistons, valves and so on...no frame bracing, BT45 tyres, rider has 8 months of track experience and is over 50
Best Lap- 1:28

Oh and the Triton has a rider, an owner and a mechanic...the Norton probably has no original engine parts.....The Guzzi is highly modified at huge $$$$$

Conclusion: Super bike School was the best money I spent on my bike and there is lots of room for improvement there too.
I cant red line it in 4th on the hill and I can pass the Harley and Commando on the corners but in the straight line they pull ahead....lots in the Nortons case.
Good fun thought....recommend the California Superbike School for anyone wanting to do this. One thing that works for me is the deep entry into the corners and counter steering to drop the bike in, great technique for keeping high corner speed on low HP machines.

I was going to put the bike on a dyno but can't really see any point in it now as it runs perfectly with no misfires, flat spots or hesitation.
My Butt Dyno would estimate it to have about the same as my old Thruxon which have been widely dyno tested to about 50 to 55 BHP.
Another 10 or so HP would be good on the straights but thats about all.



Just as a comparison, what lap times does the quick BMW ( #269) get around Pukekohe?

With a 2.91 rear drive you should get 148MPH at 8500 RPM so the others must be flying. With mine I've found it doesn't go any faster with a 2.82 over the 2.91. It revs higher with the 2.91 but achieves the same top speed.

I'd love to go to the Superbike school, but the Aussie one has never answered any e mails and many years ago when the Californian one was the only one, I signed up for a course which they cancelled two weeks out so I ended up wasting an air ticket from London to LA.
__________________
The trouble with the world is that the stupid are cocksure and the intelligent are full of doubt.
Bertrand Russell
pommie john is offline   Reply With Quote
Old 10-22-2012, 11:32 AM   #39
Voltaire
Beastly Adventurer
 
Voltaire's Avatar
 
Joined: Jun 2011
Location: Auckland,New Zealand
Oddometer: 1,198
Quote:
Originally Posted by pommie john View Post
Just as a comparison, what lap times does the quick BMW ( #269) get around Pukekohe?

With a 2.91 rear drive you should get 148MPH at 8500 RPM so the others must be flying. With mine I've found it

doesn't go any faster with a 2.82 over the 2.91. It revs higher with the 2.91 but achieves the same top speed.

I'd love to go to the Superbike school, but the Aussie one has never answered any e mails and many years ago

when the Californian one was the only one, I signed up for a course which they cancelled two weeks out so I

ended up wasting an air ticket from London to LA.
I had to go back to 2009, # 269 was doing 1:11 lap times, he was 5th and the fastest was 1:06 on a 900SS.

I was surprised when he said 2.91 was not tall enough as my 3.0 wont hit redline in 4th on the same bit of the rising track.

I knocked 5 seconds off my previous best time with virtually no mods to the bike, so thats just me improving, I

can see a few more seconds coming that way....I'm pretty slow off the start and the first lap.

I can track the rest of the field on previous races and it would appear you plateau at some point as a rider...?

I did a bit of spectating and observed that nearly all the riders were turning in early on the hairpin...contrary to the

Super Bike school teachings of brake late, deep in, countersteer, throttle on......get on the gas asap.

The pre 89 Jappers are pretty fast in a straight line but some of cornering was pretty slow....I'm no expert but

thats where I think I make up my times on the high HP bikes.

Bummer about Super Bike School as I thinks its really worth while, following others around the track would have

taught me bugger all.

.......of course in the real world I ride an R65 and a Commando and there are cars coming the other way so I

don't worry about HP , butt, dyno, imagined or otherwise...

Did you see on Access Norton where one of the guys got all the Commando heads, flowed them on his bench

and posted up the charts.....showed that my Combat head was the worst.....only made power by the cam and

carbs.
Voltaire is offline   Reply With Quote
Old 10-22-2012, 12:18 PM   #40
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
Your wasting good straight up braking time if you aren't counter steering hard. Nevertheless, it is easy to go too far with our frames. Once you get good at snapping it over you might come to realize that taking just a nano second longer getting the bike to lean (less forceful countersteer) will get you around the entire corner with less buck and weave. Too much counter steer winds up the chassis.

It also really helps to keep on the brakes and let them off AS you lean over. If you let off the brakes before, your forks go back up only to instantly go back down for G forces. It makes your front end pogo right as you enter the turn. NO good. But keeping on the brakes too long is NO good too!

I hope most of you inmates realize that I am not 'against' dyno's. I wish I had one. I use to help my dad tune bikes with one and have worked at two different shops that had one plus a good friend back home has one. Nevertheless, they are not the end all. How the bike feels and performs in the real world is the end all.
supershaft is offline   Reply With Quote
Old 10-22-2012, 12:33 PM   #41
Voltaire
Beastly Adventurer
 
Voltaire's Avatar
 
Joined: Jun 2011
Location: Auckland,New Zealand
Oddometer: 1,198
Quote:
Originally Posted by supershaft View Post
Your wasting good straight up braking time if you aren't counter steering hard. Nevertheless, it is easy to go too far with our frames. Once you get good at snapping it over you might come to realize that taking just a nano second longer getting the bike to lean (less forceful countersteer) will get you around the entire corner with less buck and weave. Too much counter steer winds up the chassis.

It also really helps to keep on the brakes and let them off AS you lean over. If you let off the brakes before, your forks go back up only to instantly go back down for G forces. It makes your front end pogo right as you enter the turn. NO good. But keeping on the brakes too long is NO good too!
.
Well I must be doing something right as I took 5 seconds off my Feb times on the same track.
Average speed was 131 kmph,..81 MPH.....
Maybe you should edit " our frame" to " my frame" as my standard 1983 frame seems rather good.
I have seen Buck and Weave on other bikes and looks to be mainly caused by rider not transitioning at the right time and not bracing against the tank.
If you change position in a turn the bike will react.....all taught at Super Bike school....I wished I had done level 3 and 4 before they pulled the plug

The strange thing is it does not seem that fast on the track.
2.8 km track looks like this with an 8 metre drop in the hairpin....





I grounded the head on the long sweeper....as I have not yet looked at 'hanging off"

Voltaire screwed with this post 10-22-2012 at 12:53 PM
Voltaire is offline   Reply With Quote
Old 10-22-2012, 12:51 PM   #42
supershaft
because I can
 
Joined: Sep 2010
Location: San Francisco Bay area
Oddometer: 8,039
Most frame flex is in the front end but not all of it. Give it some time. You have to work up to it. The right side is usually easier to touch down since it sticks out a little bit more.

I hang off all the time when I am on the move. IMO it makes drifting your tires a lot more manageable since all the moving around isn't right underneath you. Nevertheless, you have to be REALLY smooth at it or you will upset your corner entry! Back up on the bike isn't nearly so critical. Watch the pros on TV or at the races!
supershaft is offline   Reply With Quote
Old 10-22-2012, 12:57 PM   #43
RGregor
User Awaiting Email Confirmation
 
Joined: Oct 2007
Location: Bavaria
Oddometer: 437
Quote:
Originally Posted by supershaft View Post
How the bike feels and performs in the real world is the end all.
But one thing is for sure, two different persons can't compare feelings.

What most of the times is not given is an overall description of the mods made and the result achieved.
Most of the times it's "GREAT", "they like it", ...
Does that help?
After reading a lot of your posts I believe I have a rather good impression about the characteristics of your engine.
But information are spread in many posts and not concentrated. Why?
RGregor is offline   Reply With Quote
Old 10-22-2012, 12:58 PM   #44
Voltaire
Beastly Adventurer
 
Voltaire's Avatar
 
Joined: Jun 2011
Location: Auckland,New Zealand
Oddometer: 1,198
Quote:
I hang off all the time when I am on the move. IMO it makes drifting your tires a lot more manageable since all the moving around isn't right underneath you.


As they say " pictures or it never happened"
Voltaire is offline   Reply With Quote
Old 10-22-2012, 01:01 PM   #45
RGregor
User Awaiting Email Confirmation
 
Joined: Oct 2007
Location: Bavaria
Oddometer: 437
Quote:
Originally Posted by supershaft View Post
Beemers are engines that need to be reved.
Just for curiosity, what's the basis for this statement?
RGregor is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 01:40 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014