Hi listers-
Through special arrangements with both BPNW and Worldwide Autoparts, I
have the unusual opportunity to "test drive" both a set of rebuild
uprated lever arms and a tube shock conversion following the recent
rebuild of my TR6 front end and rebush of the rear. Following is an
interim report of driving impressions and some measurements. It's long
and I am not terribly qualified, so feel free to delete and move on.
WAY BIG CAVEAT AND WARNING: I AM A TOTAL NOVICE AND HAVE NO BUSINESS
CONDUCTING MUCH LESS REPORTING ON SUCH A COMPARISON OR EXPERIMENT. BUT
WHAT THE HECK. YMMV AND ALL THE OTHER CAVEATS.I AM NOT BEING PAID OR
GETTING ANY DISCOUNTS OR OTHER DEALS OR ANY OTHER FINANCIAL CONNECTION
OR BENEFIT FROM THE TWO VENDORS NOTED ABOVE OTHER THAN A
NO-QUESTIONS-ASKED RIGHT OF RETURN IF THE SHOCKS ARE IN GOOD CONDITION.
THESE VENDORS ARE BEING REALLY NICE ABOUT THIS SO REMEMBER THEM. MY WIFE
ON THE OTHER HAND IS LOSING PATIENCE....
OK, here goes:
My TR6 suspension:
Front: New All-poly bushes on everything except trunions which are nylon
and shock mounts which are rubber , Moss blue mild upgrade springs, Spax
adjustable shocks set at midpoint, anti roll bar that came with the car,
new and stock tie rod ends, rack inner balls and cups,bearings and upper
ball joints. Steering rack and rubber mounts are not new but in decent
shape.
Rear: Poly diff mounts, Nylatron trailing arm bushings, stock springs.
Tires: New 215-65 R15 Coopers on stock rims ( why? because I had them
from another car which got the upgrade. Michelin VR's and Panasports
someday!)
Rear Camber-Nearly neutral
Frame: Less than perfect but serviceable
The products:
Rebuilt Armstrong Lever Arms modified to a moderate firmness
upgrade-stiffer than stock, milder than Apple competition. Worldwide
Autoparts in Madison WI http://www.mailbag.com/users/nosimport
does the rebuilds with warranty including lifetime non-leaks at same
net prices as Apple and offers to customize firmness to your preference.
My guess (not known) is these sound like comparable performing products
to Apple. The fit and finish is good and they come with the usual core
return requirement. I installed with brand new links and Poly link
bushes.
Tube shock conversion kit: This is the kit from British Parts Northwest
( BPNW) http://www.bpnorthwest.com/. It can also be purchased from
Victoria British for more money and is pictured ( upside down) in their
latest catalog. I think BPNW has a picture in the insert to their
catalog. The bracket mounts in the same holes as the stock lever arms
and the skinny end ( see the picture in BPNW or VB catalog) protrudes
with no more height, depth or width than the upper bump stop in the
wheel well. I imagine ( but don't really know) it will not interfere
with wheel and tire arrangements anymore than the bump stop will. It is
quite clear of my 215-65's on stock 6" rims and no contact has occurred
yet while driving or bouncing the car. The brackets are very heavy duty
fashioned from approximately 3/8"thick plate steel with a 90 degree
andiron support welded down the center and appears to be anodized black.
The shocks themselves are "Y2B" brand( or something close to that) gas
pressurized. The shock mounts are rubber.
Observations and measurements:
Holding the levers in my hands and pressing the lever they were very
stiff, stiffer than my existing levers, which were in pretty good
condition but about 10 years old. The tubes really took a lot of
exertion to compress them and of course they push right back out again
from the compressed gas, which the levers do not do. The performance
difference between return vs non return is probably very important but
beyond my ability to discuss. Perhaps someone might discuss this aspect.
Installation: Easy for both. Again, the tubes use the same mounting
point for the bracket and lower extension of the tube as the stock
levers use for the lever body and the link mount.
Axle droop ( lower extreme extension):
The fully extended shock appears to restrict the axle drop angle nearly
exactly the same ( eyesight estimate measurement) as the lever arm bump
stop does when the car is up on the jack.
Upper extreme limit
not measured. I am not planning to pull the spring to do this. A jack
under the trailing arm lifted the car off the stands before either was
even close to their full contraction. In two hours of driving each I did
not "bottom out" either the lever arm or the shocks.
Car height- Identical for each. No effect on height.
Camber-same for each. Right side 1-2 degrees negative. Left side 0-1
degrees positive. ( subjective estimates measured with a carpenters
level)
Bounce- Just using my hands and body weight I bounced the rear end at
the wings up and down. The tubes were very stiff, I could cause hardly
any movement. The lever arms permitted more bounce range which in turn
bounced the front of the car up and down more as a result. ( yep, the
Poly's were squeaking all around)
Bounce and load level measurements:
With my 9 year old daughter as assistant, I performed some comparative
experiments and measured as follows ( my body weight 200lbs (should be
170 lbs-oh well)):
Sat on the lip of the trunk feet off the ground and measure how far the
rear bumper lowered:
Levers 1 3/8"
Tubes 7/8"
Sat in drivers seat and measured how far rear bumper lowered, left and
right sides
Left Levers 3/4"
Tubes 3/8"
Right Levers 3/8"
Tubes 1/8"
Maximum lower bounce drop when I stood in trunk and bounced the car up
and down about 10 times
Levers 2 3/4"
Tubes 1 3/4"
Camber change when I sat in drivers seat on left side was about 1 degree
or less maximum for both.
Driving perceptions:
Since I had at the same time completed the rebush of the rear, I cannot
comment regarding "improvement" over existing suspension as it is
substantially better due to all the improvements, not just the shocks.
I drove over varied terrain, hills, twists, corners, smooth and rough
roads, railroad crossings, and highways up to 75MPH, for about 1 1/2
hours or so on each system, pretty much the same routes on two
consecutive days. The days were sunny and dry and about 65-70 degrees. I
tested the tubes first( I sure wish I could find one solid free day to
do this again but back to back)
Subjectively, and I mean subjectely, by a non-professional driver who
knows only his own TR6 I sensed the following:
The tubes indeed were stiffer, though not harsh. Probably because I have
stock springs. Comp springs in combo might introduce harshness, don't
really know though. (A comparison of levers with comp springs vs tubes
with stock springs would be very interesting)When driving the levers,
the car felt more bouncey in the rear than the levers. Sudden dips in
the road were more pronounced. Keep in mind I mean very minimal here-not
like with old springs). Rear end squat, though minimal, was definitely
visible with the levers and almost imperceptible with the tubes. The car
felt like TR6 _looks_ goining by down the road, with that classic rear
bustle bounce. The tubes felt more like a 55 Chevy with a jacked up rear
looks when you follow it. More jouncey than bouncey. Short jerky
movements on bumps was the feeling rather than the deeper dip I feel in
the gut with the levers. The car felt heavier with levers on curves,
especially quick curves. There seemed to be more body lean with the
levers, which is what I guess makes for the heavy feel.The car felt
lighter and stiffer with the tubes. The levers gave a feeling of
understeer versus a sense of oversteer with the tubes. Both felt
controlled and I guess a driver could adapt style to either. I got the
feeling you could get the car into a four wheel drift faster with the
tubes whereas with the levers, the rear tires felt grippier but I got
the feeling that once they came loose the rear would come around on me
rather than drift.
Cruising around, the levers gave a more supple ride, more of a touring
comfort feel. The tubes gave the car a tension that was always there.
Long distance driving would seem to favor the levers for comfort. Both
were steady through potholes, railroad tracks and rough pavement, though
the tube seemed to have a very slight edge on control in these
situations, I think because they did not have the added dimension of the
bounce effect of the levers on the view down the front fenders. For some
reason, the rattles in my car seemed louder or greater with the levers,
I don't really know why I think this. At highway speeds, while the whole
system with new suspension was operating well, I did find I was feeling
a little more secure and steadied at the high end of the speed range
with the tubes than the levers, but in the lever test there was a whole
lot more traffic, so the nervousness factor may have been unrelated to
handling.
So there it is so far. I am planning another round of driving on each
before deciding for myself. I am undecided at this point and am trying
to be careful not to be seduced by the novelty of the tubes, though I
must admit they do seem to give a more "modern" feel to the driveability
of the car.
If anyone who survived long enough to make it to the end of this
discourse has some ideas for tests or paces I can put these systems
through that will help better evaluate them, let me know and if I can
I'll give it a try and report on it. I will probably run and report
another comparison test by this weekend. I'm in digest mode so be sure
to cc me directly.
Hope this is informative.
Keith Ehrlich
74 TR6 Lever Arms
Keith Ehrlich
74TR6 Tube Shocks
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