Chassis refurbishment
Discussion
I have noticed several posts describing rebuilds and in particular the chassis. I think it is important to share my discoveries and solutions. Bearing in mind that neither does my car conform to original specification nor do I intend it to, but I note the previous comments on my pimped wedge (450SE).
Firstly, having had all the suspension and brakes sorted, noting the body was not sitting square and the car still suffered from bump steer, I decided to take the body off and dig deep financially. I have used the same engineers who work from basic principles and give a prime allegiance to safety and drivability, but not to authenticity.
These are the points worthy of sharing so far, but not in any particular order:
• The body is attached to the chassis in a way that crushed the fibreglass, used chopped about bolts and odd bits of packing.
• Taking the body off is simple but not straightforward. A frame was constructed to keep the body from bending and even splitting.
• The chassis is constructed from seamed tubing, which is far from ideal. Continuous drawn steel is being used for Replacement tubes.
• The standard of welding is far from ideal. Single welding is used when more than two tubes meet, instead of welding the first two, add the next tube, weld, then the next, with a final weld around the whole joint.
• The existing welds are weak as can be show by standing on an outrigger and seeing the joint open up. On racing cars, a long tube is used as a lever to test the joints.
• An extra tube will be welded right across the foot well to provide mounts for the pedal box and steering column, instead of being attached to the fibreglass.
• Extra tubes will be welded from the outriggers to the centre at the rear, similar to the ones at the front. Extra tubes will be welded alongside the sills but inside the car attached to the new rear and existing supporting tubes.
• I am having a roll bar fitted
• These extra tubes will add considerable stiffness and allow the suspension to be set up and work properly. I am aware that there maybe extra noise from such items as the fuel pumps, but these can be cushioned.
I can write considerably more, but this will do for the time being.
By the way as a throw away line, the seat belts (Mini), would not retract as the existing mounting points leaves too much to roll back into the holder. This will be sorted.
Comments and questions welcome.
Firstly, having had all the suspension and brakes sorted, noting the body was not sitting square and the car still suffered from bump steer, I decided to take the body off and dig deep financially. I have used the same engineers who work from basic principles and give a prime allegiance to safety and drivability, but not to authenticity.
These are the points worthy of sharing so far, but not in any particular order:
• The body is attached to the chassis in a way that crushed the fibreglass, used chopped about bolts and odd bits of packing.
• Taking the body off is simple but not straightforward. A frame was constructed to keep the body from bending and even splitting.
• The chassis is constructed from seamed tubing, which is far from ideal. Continuous drawn steel is being used for Replacement tubes.
• The standard of welding is far from ideal. Single welding is used when more than two tubes meet, instead of welding the first two, add the next tube, weld, then the next, with a final weld around the whole joint.
• The existing welds are weak as can be show by standing on an outrigger and seeing the joint open up. On racing cars, a long tube is used as a lever to test the joints.
• An extra tube will be welded right across the foot well to provide mounts for the pedal box and steering column, instead of being attached to the fibreglass.
• Extra tubes will be welded from the outriggers to the centre at the rear, similar to the ones at the front. Extra tubes will be welded alongside the sills but inside the car attached to the new rear and existing supporting tubes.
• I am having a roll bar fitted
• These extra tubes will add considerable stiffness and allow the suspension to be set up and work properly. I am aware that there maybe extra noise from such items as the fuel pumps, but these can be cushioned.
I can write considerably more, but this will do for the time being.
By the way as a throw away line, the seat belts (Mini), would not retract as the existing mounting points leaves too much to roll back into the holder. This will be sorted.
Comments and questions welcome.
Some of that sounds like overkill but it'd be interesting to see what improvements, if any, it all makes. For a track car I guess stiffness is everything but for a road car... well I suppose it's what you can live with.
The seatbelts usually won't retract properly as they rub on the tube that crosses the car behind the seats and ties the B posts together (early Tasmins don't have that tube, or the problem). TVRs fix was to glue a couple of bits of vinyl to the tube to reduce the friction.. and yes, they are Mini seatbelts.
The seatbelts usually won't retract properly as they rub on the tube that crosses the car behind the seats and ties the B posts together (early Tasmins don't have that tube, or the problem). TVRs fix was to glue a couple of bits of vinyl to the tube to reduce the friction.. and yes, they are Mini seatbelts.
Edited by Wedg1e on Thursday 23 July 00:38
Hi Henry,
Good to meet up with you a couple of weeks ago.
To add my 2p I was impressed enough with these two engineer's work that I'll be booking my body off chassis refurb/rebuild with them.
Essex is also closer than Sheffield and RT.
I believe you were hoping the have the car back real soon.
What's the ETA, or have you, they thought of something else
Phil
420 SEAC
Good to meet up with you a couple of weeks ago.
To add my 2p I was impressed enough with these two engineer's work that I'll be booking my body off chassis refurb/rebuild with them.
Essex is also closer than Sheffield and RT.
I believe you were hoping the have the car back real soon.
What's the ETA, or have you, they thought of something else
Phil
420 SEAC
Here is why you must inspect the chassis from all angles. This could only be seen with the body off and the chassis upside down.
And this is the standard of bolts used to hold the body to the chassis. Notice the shape and misshapen washers. These were the only means of attachment and hence the glass fibre was crushed. I understand this approach is still in use. Not on my car it won't; there will be proper bolt sleeves to support the attachment.
I will gladly answer any questions.
And this is the standard of bolts used to hold the body to the chassis. Notice the shape and misshapen washers. These were the only means of attachment and hence the glass fibre was crushed. I understand this approach is still in use. Not on my car it won't; there will be proper bolt sleeves to support the attachment.
I will gladly answer any questions.
Those welds look sound Henry, the tubes have fractured in the heat-affected zone... granted the welding itself is not pretty but for typical MIG-monkeys it's not bad per se. The Jap motorcycle industry have got away with worse pigeon-sh!t than that for 40 years or more.
Certainly some bracing wouldn't come amiss.
I think there's some misconception that TVR was staffed by engineering degree-qualified physicists, it wasn't. If you think about how the chassis would be welded up it's not hard to see how they ended up as they did: basically you cut a few lengths of tube, line them up in a jig and wherever you see two tubes meet, strike an arc. With no non-destructive testing being carried out (and in all probability no welder tests either - and what about calibration of welding sets, welding rods being preheated etc etc) it's no wonder that mediocrity could be passed. No need for the shop-floor guys to wonder about tensile forces, moment of inertia and all that: just bang the tubes in and bzzzzzt. A goodly number of cars the world over have been built in such a fashion... anyone else remember that car magazine's visit to Lamborghini, where the fabricators would weld up a Countach spaceframe and then twist it straight using 12 foot scaffold poles? Nobody queried what stresses had been set up or relieved in that process...
Certainly some bracing wouldn't come amiss.
I think there's some misconception that TVR was staffed by engineering degree-qualified physicists, it wasn't. If you think about how the chassis would be welded up it's not hard to see how they ended up as they did: basically you cut a few lengths of tube, line them up in a jig and wherever you see two tubes meet, strike an arc. With no non-destructive testing being carried out (and in all probability no welder tests either - and what about calibration of welding sets, welding rods being preheated etc etc) it's no wonder that mediocrity could be passed. No need for the shop-floor guys to wonder about tensile forces, moment of inertia and all that: just bang the tubes in and bzzzzzt. A goodly number of cars the world over have been built in such a fashion... anyone else remember that car magazine's visit to Lamborghini, where the fabricators would weld up a Countach spaceframe and then twist it straight using 12 foot scaffold poles? Nobody queried what stresses had been set up or relieved in that process...
Hi Ian,
An enlightening set of remarks again. Many thanks.
I hope to take this opportunity and have some extra brainpower applied to my car. I am convinced the outcome will be an improvement.
Apart from anything else it is very interesting to learn more about how TVR's were put together. Specifically how the suspension works and interacts with the chassis, whilst having it explained right in front of my eyes.
An enlightening set of remarks again. Many thanks.
I hope to take this opportunity and have some extra brainpower applied to my car. I am convinced the outcome will be an improvement.
Apart from anything else it is very interesting to learn more about how TVR's were put together. Specifically how the suspension works and interacts with the chassis, whilst having it explained right in front of my eyes.
Henry,
You chassis sure looks in need of plenty of TLC .. amazing that it passed an MOT.
THe guys doing the work sound like they know their stuff - which is nice. While they are there - they might as well build a brace between the front struts and another at the chassis weak point arount the bell housing area (boltable - else the gear box will not be able to be removed).
You chassis sure looks in need of plenty of TLC .. amazing that it passed an MOT.
THe guys doing the work sound like they know their stuff - which is nice. While they are there - they might as well build a brace between the front struts and another at the chassis weak point arount the bell housing area (boltable - else the gear box will not be able to be removed).
had the same problem on my car only lifted the body about 6 inch the i found this . the other problem i found is the steel section inside that goes from the top and holds roof and seat belt then bolts throw the chassis at the bottom this has rusted boths sides i will put a pic on soon
Edited by barrington on Friday 31st July 12:39
interesting pictures...and hopefully someones eyes will get opened!!
from my point of view nothing unusual. also nothing unusual is this statement:
"You chassis sure looks in need of plenty of TLC .. amazing that it passed an MOT."
the mot is a waste of time and money, as it proves nothing....i can list plenty of TVR´s and Lotus chassis which have been near to collpase, thanx to the famous britsh invention called "WAXOYL", they all passed the mot!!!
do never ever trust a sales-advert and a sellers statement which refers on the MOT in case of the chassis condition!!!
from my point of view nothing unusual. also nothing unusual is this statement:
"You chassis sure looks in need of plenty of TLC .. amazing that it passed an MOT."
the mot is a waste of time and money, as it proves nothing....i can list plenty of TVR´s and Lotus chassis which have been near to collpase, thanx to the famous britsh invention called "WAXOYL", they all passed the mot!!!
do never ever trust a sales-advert and a sellers statement which refers on the MOT in case of the chassis condition!!!
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