Road & Track did an article in Dec. '66 on mods done by Kas Kastner to a
TR4A for straight-line speed runs at Bonneville in the F-GT class. He was
manager of Triumph's US competition dept.
Mods included: heavy duty springs, shocks, and axles (all factory
options), and a no-slip diff. All were the same as used on the Sebring
4As. Engine mods were: "F" grind camshaft, 87 mm bore-kit (which
increased displacement to 2182 cc), a pair of 45 DCOE Weber carbs, and a
tuned exhaust. Compression was 12.6:1. Final drive was 3.7:1. Stock
items were: hardtop, steel wheels, IRS, non-OD 4-speed, heater, carpets,
bumpers, etc. (i.e., no body mods were made).
Bottom line was 140 hp @ 5000 rpm, and good on paper for 130 mph at 6000
rpm. In comparison, the sprint-race version had 155-160 hp and, with a
4.55:1 final drive, saw 0-60 mph in 8.9 seconds but with a top-end of only
108 mph.
The "Bonneville" car attained 128.20 mph before mechanical problems
(sheared flywheel bolts and oil pump failure) and strong winds halted the
speed runs. They thought mph 135 was in sight. One run with the SUs hit
127 mph "without strain" and dyno testing had showed little gain with the
Webers.
Rod. '70 TR6 CC55899L
At 13:24 14-10-97 -0700, Steve Witt wrote:
>So, how does one get a TR4 to go 130 mph (in street form, with a Triumph
>engine)? And if one is successful, will the suspension and brakes handle
>this speed?
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