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Too touchy at first.. Hill starts are tough. Either I stall or spin-out.. The clutch feel is good, the throttle is too touchy.
I don't know what to do. The pedal is stock. It is rather high up in it's travel for idle, but not beyond it's range. Full throttle isn't to the floor. I can cut more pipe off the accel tube to bring the pedal down more. Would that help the feel be less touchy at first?
How about a variable cam like on nautilus exercise machines on the hexbar linkage?
The issue should not be occuring... I have never needed to go to extremes for something like this. How far before the pedal hits the floor do you run out of travel?
Hey dave......all you have to do is figure a way to extend the center arm on the hex bar that the cable attaches to. This will move the cable away from the centerline and reduce the degrees of travel with the same amount of cable pull.
Looking at the pedal itself, the cam on the back of the pedal that rides the roller starts at about 1/3 for idle and goes to a bit over 2/3 for full open. If I shorten the accelerator tube, I can gain some slack and have the pedal lower, but I'm not sure if the "progression" will change.
What I'm looking for is less carb opening at the lower end of the pedal travel progressing to greater opening as the pedal goes down.
My wife drove the car today for the first time, and that was the big issue for her.
Kudos to you for the for the excellent throttle responce (less than zero bog), but things are a bit hair trigger for drivability for my wife.
mikey373 wrote:Hey dave......all you have to do is figure a way to extend the center arm on the hex bar that the cable attaches to. This will move the cable away from the centerline and reduce the degrees of travel with the same amount of cable pull.
Mike
Gaining some leverage wouldn't be a bad thing. There is more pedal travel available. As far as I can tell, a progressive motion would seem to be the answer, but I don't know how to modify the parts to get that effect.
If I go back to having the throttle arm down, I think I'll get some forward progression (am I getting reverse progression with it up?), but I'll have to relocate where the accelerator tube is coming out of the shroud so it isn't binding.
brianwheelies wrote:you can also shorten the rods that open the throttle plates to change the angle along with making changes to the position of the center arm.
Shortening the threaded linkage rods between the heim joints would seem to me to make it worse as the angle increases, the leverage falls off making the progression backwards. If anything, maybe the steel carburetor linkage arms that mount on the carbs themselves should be longer. I only seem to be using half the pedal travel as it is.
Looking at the threaded linkage rods angle has changed from initial design intent due to adapter having moved the bar about an inch forward. CB Performance does have Heim joint extension either in 2" or 1.125". Part numbers 3396(2") 3395 (1.125"). I've use them on a modified linkage set up on my Notchback with 40 DCNF's to bring the linkage rod to vertical position. http://pg.photos.yahoo.com/ph/stufenhec ... m=3d35.jpg
This helps to eliminate some binding that you are currently experiencing during initial acceleration. Position the center arm so that is as vertical as possible when at half throttle. You may need to short or lenghten the linkage rod and or reposition the center arm.
Your current geometry is what is know as "agressive initial tip in" in the auto inustry. That kind of geometry is usually found on a heavy vehicle with a small engine, and always with an automatic. The vehicle moves briskly from a dead stop and across the intersection in city traffic. This fools the owner into thinking he has a "responsive" vehicle. The real result is two-fold: lousy gas mileage in town (partially offset by a small engine) and near total lack of any acceleration at freeway speeds. You get the general idea.
Change the geometry! Ideally your throttle bar should extend vetrically down from the hex bar at 50% throttle. This would result in a very linear throttle pedal. In your case I would seriously consider adjusting the throttle bar to be very near your doghouse at 100% throttle. Leave a bit of adjustment room because you don't want to bottom out on the doghouse before reaching 100% throttle. That may be the best you can achieve with your geometry. Yes, you will have to relocate the throttle cable through the doghouse. Just call it the price of education. Tell any passersbye the the plug on your old throttle cable hole is supporting your custom designed internal air deflector that makes your engine run cooler. That usually shuts them up in a hurry. When you are done you wil rapidly forget this work as you enjoy your ride. And best of all your wife will also enjoy your ride. That justifies additiional future expenditures. I speak from 40 years of marriage and automobiles. Enjoy the ride.
On my install, I shortened my accelerator tube about 1.5" and set my cable length (using a universal length cable) so the pedal is floored at full throttle pedal and it has the same reverse progressive effect. Probably more than yours because my pedal starts higher on the pedal advance arch than yours. I agree, it's touchy on mine too.
Any additional thoughts on Jakes pedal tweek? Seems easier than messing with the shroud, carbs, etc.
Extending the cable attachment point on the pedal toward the front of the car (in line with the cable) will result in less throttle cable pull per degree of pedal rotation. I don't know if there is room to do this, my car is at the paint shop...
Another option could be to grind the pedal advance arch flat to eliminate the progressive effect from the pedal. Again, could you check this out and see if it makes sense? I'd like to improve my throttle advance on the pedal end...
