Bill Wood wrote:
>
> ate: Mon, 13 Oct 1997 17:58:20 -0700
> From: bugeye59@kingsnet.com
> Subject: Re: 302ci TR8
>
> The inherent chassis flex that the TR7 suffers would most likely make
> this an impossible swap. Heck, even stock TR7s had their doors fly open
> under hard cornering! Call John's Cars in Dallas, TX and inquire about
> a 3.8 Buick V6 conversion. That engine did wonders for my Bugeye
> Sprite, and I'd gladly put it up against any 5.0 Mustang!
> - --
> Harris
> '59 Bugeye Sprite -- Buick V6 powered!
> '60 TR3A -- TS67621 L
>
> I have seen this comment about TR7/8 chassis flex twice on this list.
> While I am certainly no expert, I do know that Wedges had the most
> torsional stiffness of any Triumph mass manufactured. The unibody is
> quite stiff, even in convertible guise. I have _NEVER_ heard any Wedge
> owner complain of this problem and I have _NEVER_NEVER_ seen a Wedge car
> doors fly open, ever.
>
> I am cross posting this to the TR7/8 list to solicit their comments on
> this matter. Maybe I'll learn something. I know Woody Cooper has built
> some monster motors and has never mentioned this and Ted Schumacher did
> and does race these cars and I would love to hear his comments.
>
> Bill Wood
> TR7/8 Vehicle Consultant
> 1973 TR6
> 1979 TR8 Coupe
> 1980 TR8 Coupe
> 1981 TR8 F.I.
> Greensboro, N.C.
bill, sorry for the delay in reponding but i promised you a response.
. you are right, the car is fairly stiff and much better in convt. form
than many cars. my son was went to GMI, mechanical engineering, and he
co-op'd at ASC. ASC makes concept cars and also production runs for the
automotive industry such as the Buick Reatta convt., the top design for
new camaro/firebird "F" body cars, etc. anyhow, one of the first
projects he worked on was the Nissan Infiniti convt. this car did not
want to be topless and would sag in the middle once the structural
integrity of the roof was gone. they finally had to use a sliding rod
that would automatically extend into the B pillar when the door was
closed to give the needed strength. the wedges are much better than
this. the wedge convt. does have an additional latch on the B pillar
that is not present on the coupe. this helps transfer the load from
the door into the rear of the unibody. even though the coupe is
stronger, we always added this latch to our coupes for extra rigidity.
the cars can become flexible from stress and age. in 1984 the coupe we
were racing was almost 1 1/2 seconds slower at the last race at mid-ohio
than it had been in the spring. this was all from the car starting to
flex. we built a new coupe for the scca run-offs from a body-in-white
(in about a 3 week period since the mid-ohio race was in early sept. and
the run-offs were in early october) and the handling difference was very
evident. as the car had slowly gotten flexible, i didn't notice it and
compensated by altering driving techniques such as early turn-in or a
slightly different line through a corner. with the new body the turn-in
points had to be altered since the car would now respond in a different
time sequence due to no flex. these cars, scca showroom stock A, were
only allowed bolt-in roll cages. the weld in cage is stiffer since
there is no possible movement (flex) on the attachment points. to
eliminate as much flex as possible we put the empty body tub on 4 jack
stands that were located at the corners of the main body tub wher the
floor met the front and rear bulkheads. a bar was made to go across
the bumper mounts on the body tub and bolted to the bumper mounts at the
front and rear of the tub. we then hung weight, engine blocks, tractor
wheel weights, etc. to the bars. the tub sat for a few days with this
weight trying to bend the car. the roll cage was then bolted into the
car with the weights still attached. the rear hoop of the cage was
mounted to the floor, then we used a porta-power to push the front hoop
of the cage forward a tiny amount and the holes were drilled and the
front part of the cage was bolted in thus allowing the cage to become a
stressed chassis member. this process put most of the chassis flex into
the car at one time and we could then align the car around the "warp" we
created. the integrity of this setup was great. in later cars where we
were allowed to weld in the cage, we used 3/4" x 2 1/2" rectangular
steel tubing inside the rocker panel tube. this was "stitched" to the
inner sill panel and the cage then welded to the floor and also to this
tube, creating a "tube frame" unibody. that's how it works. hope this
answers or at least informs. ted
--
Ted Schumacher
TS Imported Automotive
404 Basinger Rd.
Pandora, Ohio, USA 45877
Ph. 800/543-6648 (sorry, USA only)
Ph. 419/384-3022 - tech./general information
FAX 419/384-3272 - 24 hrs
New-Used-Rebuilt-NOS-Performance British car parts.
We also have used sports cars for sale.
Always 200 - 300 cars for parts in our British-only
salvage yard.
For the finest in British car apparel, accessories and
regalia, be sure to check with our MotoringXtras store.
We also have an extensive line of Black & White
checkered race-theme apparel. Same address and phones.
Check it out!!!
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