HarleyTechTalk

Technical Forums => Evo Sportster => Topic started by: xlfan on November 11, 2023, 01:26:17 PM

Title: 4-speed power limitations?
Post by: xlfan on November 11, 2023, 01:26:17 PM
How much power can a 86-90 4-speed transmission take?
Is there 10 sec 4-speeds out there?
Title: Re: 4-speed power limitations?
Post by: jsachs1 on November 11, 2023, 05:01:17 PM
Quote from: xlfan on November 11, 2023, 01:26:17 PMHow much power can a 86-90 4-speed transmission take?
Is there 10 sec 4-speeds out there?
My 86' Sportster has run in the 10.00 second range with the stock 4-speed trans. The weak, frustrating, issue, is the clutch. It doesn't last too long.
John

thumbnail (2).jpg
Title: Re: 4-speed power limitations?
Post by: Mattls6 on November 16, 2023, 05:22:01 PM
A lot of these guys local to me are running 4-speeds. The track is shorter than 1/8" mile but they'd be running 10s if geared and ran in the 1/4 mile. I forget what fuel they're running but I'm figuring they're around 100hp or so.


jsachs1 - I'm trying to get my hands on those pro streets for my street/strip Sportster. Did you run them wide open?



Title: Re: 4-speed power limitations?
Post by: jsachs1 on November 20, 2023, 03:18:34 PM
The person that bought my Sportster in 97', made some changes. Pro Streets, and had me build him a set of wheelie bars. I know the bike is currently for sale. :up:
John