popeye Posted January 20, 2010 Share Posted January 20, 2010 Hello to all of you and happy new year ! :D Here is my first question 2010 ... :B I am after informations, photos or documents to explain to me how reinforce my 1500chassis. The 1500 chassis have a weak point at the front due to the recess area to allow the fitting of the exhaust. Where and how some extra welding, reinforcement can be made ? Does anybody have a clue or better: has ever done it? I don't remember where I have ever read the very late chassis were thicker and more rigid: is it true? It might be a silly question :B :X :X ??) but it is done :-/ :-/ MAny thanks for your help. SOmepictures of Le mans spitfure chassis are welcome too ;) Link to comment Share on other sites More sharing options...
thebrookster Posted January 21, 2010 Share Posted January 21, 2010 Not something that I profess to have much knowledge on at all, however if I have read the various posts by some of our esteemed colleagues on this board it would seem that the preferred method is to complete the various box sections. I would maybe suggest reading your way through the section on this forum in regards to Member's Cars and projects, plenty of (varied??) information there. Link to comment Share on other sites More sharing options...
esxefi Posted January 21, 2010 Share Posted January 21, 2010 popeye, from what i have seen on late chassis with the cut out it is seam welded where the flange has been removed and so should be as strong if not stronger than an earlier version. as for the heavier gauge on later chassis i have heard this too but it may only apply to the gt6 i cannot be sure. if you want to add stiffness at the front,you could construct a virtual cage from one outrigger up to the suspension turret then across the front of the engine and then back down via the other turret to the other outrigger,or for maximum effect use the crankcase itself as a stressed member by solidly mounting the engine . being a backbone chassis design there is little stiffness in the periphery of the body so a cage running front to back between doors and seats is quite effective. Link to comment Share on other sites More sharing options...
JohnD Posted January 21, 2010 Share Posted January 21, 2010 There was a long thread here, I think, to which I contributed by posting an artilce by John Thomason, who actaully had a chassis on a - b*gg*r, words gone - 'twist meter' to measure how much deflection occurred and how various mods improved it. Suggest you search. Frommemory, the most flexible part is in the middle, with the two rails close together, NOT at the front. JOhn Link to comment Share on other sites More sharing options...
mattius Posted January 21, 2010 Share Posted January 21, 2010 yeah its the middle at the gearbox which flexes. Link to comment Share on other sites More sharing options...
spitNL Posted January 21, 2010 Share Posted January 21, 2010 Here's the thread: http://www.sideways-technologies.co.uk/forum/Blah.pl?m-1257394628/s-30/ The first post on this page(#3) links to the article John is referring to. Link to comment Share on other sites More sharing options...
popeye Posted January 21, 2010 Author Share Posted January 21, 2010 GREAT GREAT! 8) Thanks a lot for all this help ! ;) I haven't seen this thread :B :B I will have a look tonight when I will be back home. I didn't know the flexe area is in the middle ! Many MAny thanks again : Link to comment Share on other sites More sharing options...
spitNL Posted January 21, 2010 Share Posted January 21, 2010 I haven't seen this thread :B :B Don't worry about it, it was a thread drift, which happens regularly on here. The title isn't alway applicable to the thread. I think it would be a better idea to weld/bolt the suspension towers to the firewall, as some have done. See here: (Photos in reply 34 and 35) http://www.sideways-technologies.co.uk/forum/Blah.pl?m-1252348754/s-39/highlight-tower/#num39 Cheers, Frederick Link to comment Share on other sites More sharing options...
DaveNotSoSideways Posted January 21, 2010 Share Posted January 21, 2010 Heard some 1500 chassis were a tad stiffer also. I used a 1981 chassis on my other car. Was told that by someone who did work for Triumph in various jobs. Link to comment Share on other sites More sharing options...
popeye Posted January 21, 2010 Author Share Posted January 21, 2010 Thanks a lot Fred and Dave. Good news Dave: the car is a late 1500 its first registration is 03/1981, so a very late one. ;) Link to comment Share on other sites More sharing options...
popeye Posted January 22, 2010 Author Share Posted January 22, 2010 Hi, It seems there is a problem to read the document by John Thomason: it doesn'twork. Someone has a copy of the article? MAny thanks by advance Link to comment Share on other sites More sharing options...
SteveA Posted January 22, 2010 Share Posted January 22, 2010 The pdf is working fine for me, can you see images from photobucket as below? Link to comment Share on other sites More sharing options...
SteveA Posted January 22, 2010 Share Posted January 22, 2010 P2 Link to comment Share on other sites More sharing options...
SteveA Posted January 22, 2010 Share Posted January 22, 2010 P3&4 Link to comment Share on other sites More sharing options...
SteveA Posted January 22, 2010 Share Posted January 22, 2010 P5&6 Link to comment Share on other sites More sharing options...
SteveA Posted January 22, 2010 Share Posted January 22, 2010 p7&8 Link to comment Share on other sites More sharing options...
JohnD Posted January 22, 2010 Share Posted January 22, 2010 I think it would be a better idea to weld/bolt the suspension towers to the firewall, as some have done. Frederick Fred, Popeye, I'm sure that Fred will be the first to agree that it's not the firewall that the suspension tower is bolted to. It just gets in the way of transmitting the stress to a properly triangulated point on the roll cage, as shown by those pics. John Link to comment Share on other sites More sharing options...
spitNL Posted January 23, 2010 Share Posted January 23, 2010 Absolutely John. For a road car do you think it would be beneficial to make a brace between the tower and the outrigger, so to only use the lower tube? Frederick edit: PDF works fine here too. Link to comment Share on other sites More sharing options...
JohnD Posted January 23, 2010 Share Posted January 23, 2010 I wouldn't for a road car. But there again I haven't for my race cars. John Link to comment Share on other sites More sharing options...
popeye Posted January 31, 2010 Author Share Posted January 31, 2010 HI, Many many thanks Steve for the pictures. ;) Many thanks John for the comment: yes, I saw the cage inside the car. It would be not easy to build the new crossmember: due to the propshaft, handbrake cables and brackets. The chassis flexes at points where nothing left can be done. In the middle under the body: What do you think about to weld extra plates all along each crossmember. : : Concerning the new crossmember at the rear: I am sure something like the one behind the gearbox in a "U" shape could be made. What is your point of view? Link to comment Share on other sites More sharing options...
JohnD Posted January 31, 2010 Share Posted January 31, 2010 popeye, Is a roll cage out of the question? Stiffness is a property of space! A sheet of cardboard is flexible - make a box out of it, enclose some space, and it is much, much stiffer. Even a very thin box, like a pizza box. Although the cardboard that is made from already encloses space, by being corrugated cardboard. Imagine a piece of corrugated cardboard as thick as a pizza box. Thin skins of card, with corrugations between. If the 'corrugations' are not like the usual in corrugated cardboard, that can flex in one direction, but are made of 'honeycomb' with the corrugations running vertical to the skins, that is as stiff as a piece of wood of the same dimensions! Not as strong as a solid block but as stiff and much lighter. I'm sure that Fred can tell you the mathematics of it, but it works by transmitting the bending forces throughout the piece, so that they are not concentreated at one point or line. A roll cage encloses space. If it is well designed, the struts transmit forces that individual components would otherwise take to throughout the shell, so that the whole thing is stiffer, without making it much heavier. It is often thought that a racer's roll cage is there to protect them. It is, but the frame adds enormously to the stiffness of the shell. The Triumph chassis and body was the last gasp of that now outmoded system, in which the body hardly adds anything to the chassis stiffness, as the body itself is bolted together and ingherentkly flexes, unlike monocoque construction. That was the principal behond Thomason's 'pyramid' (see above), was was intended as a way of imrpoving the sttiffness of a road car. A full roll cage, even if you don't put struts through the fire wall and link the turrets to the cage, adds enormously to the car's stiffness. Ideally, the cage should be attached to the chassis directly, the legs passing through the floor, but the compromise of placing the leg's floor-plates as close to body/chassis mounts as possible produces an excellent effect. What I'm saying is that adding plates and struts to the chassis can have a very limited effect. Nake your stiffening structure much bigger and what you ad is more effective John Link to comment Share on other sites More sharing options...
GHR630 Posted January 31, 2010 Share Posted January 31, 2010 Or you could take the view (like me) that some of the appeal of an uprated 1960's car is the crudity and raw nature? I was brought up on (and still admire) the sports car racers of the '50's and '60's driving vehicles with enormously rediculous power to grip ratios. The C Types and D Types of the 50's drifting at 3 figure speed on cross-plies and the awesome CanAm 1000bhp monsters of the '60's. Maybe I'm an old romantic, but if you want a perfect chassis etc - buy a Focus?? Link to comment Share on other sites More sharing options...
popeye Posted February 4, 2010 Author Share Posted February 4, 2010 Thanks John, George, I can not use a roll cage: the car is a road car. I will use a roll bar similar as the one used by Matt. As the car need a total rebuilt :'(: it is a good time to do extra welding. I am quite like you George: I am an old romantic ... even if the car is no perfect: I like it for her good point and bad point :K). As the chassis is a very late one I guess it should be stiffer: as dave has been told by an ex-TRIUMPH employee Link to comment Share on other sites More sharing options...
JohnD Posted February 4, 2010 Share Posted February 4, 2010 Popeye, A road car can have a roll cage! No probs! In a Herald/Vitesse it makes the rear seat almost unusable, but you have a Spitfire! In the UK, a roll hoop that fits under the soft top is acceptable for racing - you're not racing, but that's the style used here, not the higher USA style. Either could add much stiffness. John Link to comment Share on other sites More sharing options...
popeye Posted February 5, 2010 Author Share Posted February 5, 2010 Hi john, I though to use something like Matt (sorry to have stolen your pic MATT :B but you roll bar is great). What do you think of it? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now