Torque..What's possible?

[Darkstang]

83 GS1100E. Dyno'd at 92 rwhp and 64 tlbs torque. It has 4 into 1 kerker headers and that is it unless carbs have been tuned to match. Runs real good but it would be nice to have more more midrange tourque. maybe 5,000 to 7,000.

Not a drag bike but more for back roads and twisties. Looking for a little more flat power curve than peaky.

What can be done besides an all out drag type to increase midrange power?

[TheCafeKid]

83 GS1100E. Dyno'd at 92 rwhp and 64 tlbs torque. It has 4 into 1 kerker headers and that is it unless carbs have been tuned to match. Runs real good but it would be nice to have more more midrange tourque. maybe 5,000 to 7,000.

Not a drag bike but more for back roads and twisties. Looking for a little more flat power curve than peaky.

What can be done besides an all out drag type to increase midrange power?

Well I'm still learning about a this stuff, so hopefully someone who can either explain it better or correct any bad or incorrect info I might give from my limited as of yet understanding will help out. But you can move the powerband around a little bit by degreeing the cams, as well as using a slightly hotter cam. Your low end torque suffers a little when you use a high flow pipe (but the top end performance gains are where the pipe excels generaly speaking). Using a higher lift/longer duration cam will increase torque/hp numbers, depending on how large/long you go. But then you can even take that power and decide where it's maximum gain is placed in the rpm band somewhat by using slotted cam sprockets and degreeing in specific relationship to the stroke/crank/piston position if I understand it all rght.
Obviously an 1166 bore kit is another option as well. And I am currently using GS1150 carbs on my 83-1100 and it really helped wake and otherwise stock motor up. I have a set of GS1150 cams to have degreed as well they are slightly hotter than the stock cams. But you may that even getting a set of slotted sprockets and having your stock cams degrees will put some of that low end punch back. Hopefully Ray or Terry or Bill or someone will chime in soon

[Steve]

Believe it or not, one way to increase mid-range torque is to go back to a stock exhaust (and airbox).

A good 4-into-1 pipe will increase hp in the upper range, but will do it at the expense of mid-range torque.
It won't be a miracle increase, but it will be more than you have now.

The only other way would be like TCK mentioned, degree the cams or change to different cams, then degree them.

.

[trippivot]

mild drop in cam shafts. web will hard face yours if you send them in.


36 flatslide carbs

[posplayr]

Mid range boost:

1166
4:2:1 exhaust
36mm slingshot carbs

[rapidray]

If you want torque, NOTHING will make torque like bigger pistons! I like a GS engine in the range of 1400cc or so. Makes for LOTS of fun! It requires some work to do that though so I would recommend a set of cams in the range of 240-245 degrees of duration @ .050 lift, & a 4 into 2 into 1 exhaust system to begin with. Compression makes torque but you will be limited by the quality of gas you can get. Advancing the timing also adds torque but ask Bill for pictures of what too MUCH advance will do. It ain't pretty!!! Call me at 714-356-7845 if you would like to discuss more in detail & maybe design your engine to do what you are looking for. Ray.

[chef1366]

Not sure if this will help business Ray but here you go



After this you can look forward to building a new motor.

http://s2.photobucket.com/albums/y32/chef1366/1229/

[Darkstang]

Thanks for the reply's. Looks like I need to find a second GS for a guinea pig! My 82 had 36 carbs, 4n1 headers, and a dynojet kit with pods. I liked it but somebody else wanted it more then me! I only had it 3 weeks.

Not quite ready to open this motor up yet as it runs so good. What would carbs and pods realisticaly gain?

Here is my scenario and problem. I ride mainly with a guy that rides a BMW K1200R and a guy that rides a wicked M109R. Coming out of a curve they can pull me till I get back into the revs. Once I get to 7,000rpm I can catch them easily.

If I stay in the upper revs 6-9'000rpms, then the bike is "twitchy"?? It scratches the back tire coming into the curves at times. when I can roll on from 5 grand, then I have more to play with. Problem is that it really comes alive about the time I get to the next curve and then I have to let off. just looking to make it a little flatter.


I currently have 14 tooth front and 45 rear sprockets, so it is lower geared. I just bought the stuff to do the 530 xring chain conversion and got a 50 tooth rear and 16,17, and 18 tooth sprocket to play with gearing.

Would the lower gearing amplify the peakiness of the powerband? Current gearing works out to 3.21.

The 17 front,50 rear will work out to 2.99.

Slipper clutch? That would solve some of the downshift tire scratch problems...

The guy on the M109 just chaps my hide! HUGE bike, INCREDIBLE rider(raced pro class sport bikes at Road Atlanta and Daytona). I simply do not have the balls he does but would be nice to not let him pull me out of the curves when I do catch him....

Ken

[Nessism]

You're going the wrong way on the gearing if you want roll on power.

[Calvin Blackmore]

useful link maybe?

http://www.ajdesigner.com/phphorsepower/horsepower_equation_rotating_torque.php

in keeping with a big bore producing max torque

http://www.vincelewis.net/bigengine.html

so the last engine listed produces torque = 5149019.6078431 pound-foot
at 102 rpm

[UncleMike]

If you're looking to keep up with your friends, I'd suggest some track days rather than engine work.

Speed you take with you, long after the bike is gone.

[Calvin Blackmore]

If you're looking to keep up with your friends, I'd suggest some track days rather than engine work.

Speed you take with you, long after the bike is gone.

gosh I was going to say that as well
I hate to harp on about A Twist of the Wrist II but one segment shows a 7 second per lap improvment just due to throttle control and taking the proper line. oh and overcoming primal self preservation insstincts.

If the other guys have better bikes and track experience then perhaps they would best you if you were on identical bikes.

[davel]

83 GS1100E. Dyno'd at 92 rwhp and 64 ftlbs torque.

These are peak numbers. Can you post the dyno chart - torque vs rpm?

[chef1366]

Upgrade your suspension. There is no way you can't keep up with a 700# bike.

[TheCafeKid]

Upgrade your suspension. There is no way you can't keep up with a 700# bike.

+1
that bike is just getting into the powerband at 6-7K. Keep it there! You should be able to romp all over those guys if you learn to handle the the gears and make your bike stable in the corners. At no time prior to say 120mph should your bike even feel remotely twitchy. Fix the suspension. Get some corner experience. In most real corners I'm usually in second and running high rpms and have mad torque to power out of corners.
Also both those bikes are twins the later being a vtwin which are torqu monsters. But that is no reason to think you can't hang with those guys. A good GS1100E will chew up and spit out most harleys except for maybe the first 50-100 feet in a roll on. Just got to wind it up and let her do her thing. But if you don't have her set up propperly, you're going to end up dead. Tires and suspension, more important than a set of cams or a pistons. If you can carry the speed into and out of the corners, what good is it? (yes Ray, I know you probably disagree. Lmao)