Richmond 6 Speed Overview

T5 World Class Overview

Jaguar Conversion Overview

Many people ask me questions as to what would be a better conversion. The common question is should I go for the 5 speed JT5 or the 6 Speed GTJ? I've been in the standard transmission business for 17 years and feel qualified that information obtained by me is factual and proven.

RICHMOND 6 SPEED OVERVIEW

This 6 speed is the best 6 speed design out there. Since 5th gear is direct and not an overdrive gear you get nice close ratio shifts ( rpm drops less than 25 percent) all the way up 5th. The original concept of the Richmond 6 speed was that it was based on the Richmond 5 Speed ( the old Doug Nash 4+1). That concept was that in the 1960's to early 1970's we didn't mind having 4.11 or 4.56 rear end gears in American muscle cars. We could have a close ratio 4 speed because we could have a 4 speed with a DEAD 1st gear ratio like 2.20 coupled to a rear axle with a 4.88 gear. Since the gas crunch came along we saw conventional autos having the rear axle ratios drop to 3.08. This would not work well with a 2.20 1st gear 4 speed. So they made 4 speeds with 2.88 or 3.42 first gears to make up the difference. The problem was that the 4 speeds being produced became "ultra wide ratio" gearboxes. This wide ratio thing didn't work for the street people since they didn't want 4.11 rear end gears and a close ratio box or 3.08 rear end gears and a wide ratio box. The Doug Nash 4+1 fixed that problem. It gave you the ability to have 3.08 gears in the rear and have a close ratio "5 speed". The 5th gear was direct and first gear ratio was 3.27 to 1. The newer 6 speed adds an overdrive gear to the mix allowing the user to boost axle ratios to 3.90 to 4.11.

BORG WARNER WORLD CLASS T5 5 SPEED OVERVIEW

The World Class T5 has been in automobiles since 1985. Early non World Class 5 speed actually started finding themselves in autos in early 1983. Unlike the 6 speed Richmond Gear transmission this box was never designed around or based on American muscle car needs. The term "World Class" refers to a "World Class standard". What is this standard? Prior to this transmission's design no American car had a gearbox that felt and shifted like European and Japanese 4 and 5 speeds. The Richmond 6 speed is noisy and hard shifting because it uses the same basic synchro rings used in 1957 Borg Warner T-10 4 speeds. The World Class box allowed our muscle cars to shift like BMW's or 300ZX's. The concept was never intended for drag racing but for comfortable road touring. Carbon Fiber synchro rings, tapered bearings, and rollerized gears. Since engines took on fuel injection and lower torque bands they could easily handle the 3.35 or 2.95 1st gear ratios and enjoy the .68 and .73 overdrive. Borg Warner's mistake was that they underestimated American muscle car mentality and before they new it people were trashing these 5 speeds at the drag strip.

Well here we are 13 years later and much has been done to the castings and alloys of the T5 World Class 5 speed. It to most people's surprise has been in Izuzu, Nissan, Panther Cars, AMC Jeep, Korean Ssang, General Motors, Ford Cars, and TVR cars. The new aircraft alloys used in the gears and machining techniques push the smaller gears to higher torque capacities. The 350 horsepower TVR Cebera is getting fantastic reviews and results with this gearbox. It is not uncommon for Mustang owners to pull mid 11 second quarter mile ET's with a good race prepped T5WC. I know, I've done many. I have also seen them break after they have been throttled to death for a full season.

JAGUAR CONVERSION OVERVIEW