Lotus Elan

Reconfigured throttle linkage.

PostPost by: sabbot » Sun Jul 25, 2021 1:49 am

While sorting out some fueling issues on my +2 I decided that I didn’t particularly like the feel of the throttle pedal, wasn’t achieving a constant idle position and wasn’t getting full throw with the original cable configuration. A bit of Amazon shopping and welding later the new linkage works really well.
Attachments
A0E2B055-7253-4C71-A215-4B608D0AD6B8.jpeg and
885E2A67-CBEA-49B2-BF29-078BF0614AA4.jpeg and
26EC4F6B-7EE5-4F6A-ACC9-6E8A90C59A84.jpeg and
sabbot
Second Gear
Second Gear
 
Posts: 81
Joined: 18 Nov 2012
Location: San Diego

PostPost by: h20hamelan » Sun Jul 25, 2021 2:18 am

nice work
Born, and brought home from the hospital (no seat belt (wtf)) in a baby!
Find out where the limits are, and start from there
Love your Mother
Earth
User avatar
h20hamelan
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1194
Joined: 25 Sep 2010
Location: RACECAR spelled backward, is——RACECAR!

PostPost by: TBG » Sun Jul 25, 2021 7:08 am

Similar idea but for Webers, lovely smooth action and very simple. D

Throttle linkage Feb 2011.jpg (14).JPG and


Throttle linkage Feb 2011.jpg (7).JPG and


Throttle linkage Feb 2011.jpg (3).JPG and
TBG
Fourth Gear
Fourth Gear
 
Posts: 518
Joined: 21 Apr 2020
Location: Somerset, England

PostPost by: baileyman » Sun Jul 25, 2021 6:18 pm

Those are nice efforts. I had to struggle with mine, too. It was super fast to open nearly full, making part throttle an exercise in micro foot movements. And the standard "race" throttle system could not direct the cable in a linear fashion over the movement angle. So I made this:

IMG_4947.jpeg and
Linear cable pull, Euler curve progression

(Sorry it's upside down!)

Sandwiched inside the rotating bit is an eccentric using an Euler curve. When the cable starts to pull it is pulling on the large diameter end. When it is nearly done, it is pulling the small diameter section. This helps to offset the unbelievably rapid rate of change in throttle area as the valve swings through the arc.

The rod end allows the path of the cable to remain tangent to the eccentric's curve.

It's funny how frequently people become dissatisfied with throttle mechanisms!

John
baileyman
Third Gear
Third Gear
 
Posts: 312
Joined: 17 Aug 2017
Location: Boston

PostPost by: TBG » Sun Jul 25, 2021 9:16 pm

Baileyman - that is a serious bit of kit that makes mine look like something out of a shed! Well it was actually, but it works and is very nicely progressive. Well done you................D
TBG
Fourth Gear
Fourth Gear
 
Posts: 518
Joined: 21 Apr 2020
Location: Somerset, England

PostPost by: Frogelan » Sun Jul 25, 2021 9:38 pm

I have been admiring your handywork gentlemen.

I have started to think through this on this my LHD GTS project. Inspired by the writings of Carroll Smith (1), I have in mind a control cable running in a nice curve behind the dash, but started to run out of ideas for the actuation (I building my own pedals) although I had in mind the idea of running it under the Webers.

The top photo from Sabbot has the sort of rod bearing supports that I had in mind.
The "the rotating bit is...eccentric using an Euler curve" from Baileyman is a very good idea indeed.

This type of detail is very important for making a car easier to drive.

Andrew

(1) "Nuts, bolts, fasteners and plumbing handbook" (I have the 1990 version!)
1965 Lotus Elan S2 26/4022 (originally Dutchess Lotus East, PA and NJ Area, USA)
Frogelan
Fourth Gear
Fourth Gear
 
Posts: 521
Joined: 03 Jul 2017
Location: Paris, France

PostPost by: sabbot » Sun Jul 25, 2021 10:50 pm

I used a Mangoletsi kit on a previous Elan that had twin DHLAs

https://www.burtonpower.com/mangoletsi- ... p4245.html

butt there was nothing similar for Strombergs, hence the fabrication. The only real downside is that I couldn’t find small rod ends with left and right hand threads, which would have made it easier to balance the carbs.
sabbot
Second Gear
Second Gear
 
Posts: 81
Joined: 18 Nov 2012
Location: San Diego

PostPost by: TBG » Mon Jul 26, 2021 7:55 am

I have always thought the Mangoletski all dancing bit of kit hugely over engineered and unnecessary when much simpler and equally effective home made bits of stuff are just as good, and give one quiet satisfaction of a job well done. D
TBG
Fourth Gear
Fourth Gear
 
Posts: 518
Joined: 21 Apr 2020
Location: Somerset, England

Total Online:

Users browsing this forum: p.faurie, SGO 2F and 6 guests