The Triumph Dolomite Club - Discussion Forum

Hi - I am new to the Dolomite forum - I need some help to get my 1972 1850 sorted for road rally / autostests.
The car has a sprint rear axle & poly bushed with gas dampers. It has 1850 std springs. The front is more or less completely std apart from the brakes. Body roll is excessive! also has a tendancy to bump steer.
Ideally I would like to keep the front ride height as now and lower the rear as it sits up at the back.
Can anyone recommend suitable springs front and rear - name a stockist of same?
Also there's lots of droop / long travel on the unloaded wheel - I guess this is controlled by the damper length or ??

I have put solid rack mounts on, the steering feels OK although there is too many turns lock to lock - and the full lock angle is too sharp - good for u turns but not nice for competion use.

ANY ADVICE WELCOMED !

Thanks

Hi Pete, welcome to the board!

My advice is going to be somewhat limited due my car being a curcuit racer and I'm not sure the same ride heights, spring rates are that transferable.

I think Adam knows someone who rallies a Dolomite Sprint and he has taken a few pics of them in action. Could be worth looking at just as rough reference of what they are running or maybe get in touch with them.

One of our American board users Autotested his Sprint with great success and maybe he can offer advice.

Have you looked through the old boards archive yet?

I would suggest coilover shock absorbers would be a good starting point. Avo are very popular among those that race or track their cars. I would think your standard springs are responsible for the roly-poly nature. My race car is going to be stored reasonably close to Chelmsford soon so you are welcome to come over and have a gander when it arrives.

Regards,

Scott

Hello and welcome!

You can change the pinion afaik to build your own 'quickrack'......which one was it again? You can also buy quickracks still which (if memory serves me right) are 2.5 turns lock to lock instead of 3.5.

I was demonstrating the chronic understeer/snap oversteer quite nicely in the 1500 yesterday, need to do something about that! Better rubber, 210lb fronts and 180lb rears may be arranged soon, along with 2" off the ride height.....might just use standard new dampers for the meantime or a set of, as mentioned, AVOs from Jigsaw or someplace.

Certainly you need some uprated springs but for rallying I am not sure what would be the best configuration.

I rang up to get mine sorted from South yorkshire springs. Ace company who actually manufacture rather than buy in. Quoted me under £120 for the 1500, any Rate, any length, 4 Coils including VAT and delivery. Would take about ten days to have them made.

He had good suggestions on what to use so may be worth ringing up and asking him?

Its where MC Rallying used to buy from before they went all Maxy pants bodykits

Phone number is : 01709 375375

Also worth getting in touch with http://www.coilsprings.co.uk/ - they prefer the classic stuff

Thanks for the info - Dolly is tucked up in her garage until Xmas so ther wont be any updates(clutch slipping) - our original plan was to run the car on all the club events but we have agreed the the trusty MK1 Fiesta supersport and the newly joined ( but very well rallied) Golf GTi Mk2 will front the winter events.

My brother auto tested his 1850 last week. It has full polly bushes, spax coilovers with 175 lb springs on the front and standard on the rear, solid mount steering rack, and yokohama A021R tyres on the front, goodyear eagles on the back. He also thought that it had to many turns lock to lock and needs much better brakes and that a sprint engine would be nice.

Hi Neil,
I heard of a cheap way to really boost the brakes - apparently it's possibel to fit a second set of calipers onto the uprights on the bolt fixings that are used to mount the disc stone gaurds, which would have to be removed obviously. I guess some kind of larger bore master cylinder should be used - I was talking to a guy at the Chelmsford Motor Club who rallied a Dolly back in the 70's. I cant do this mod on my car for HRCR and keep within the rules unless I can prove that theworks cars did this. I was also told that Austin Princess discs and 4 pot calipers could be fitted.

I have to say though that until the handling is sorted on my car the brakes with DS11 pads have been just about OK - I have not had any issues with fade - when I can be a little more confident with the higher speed handling I guess that fade will arrive!

I've deffinatly had brake fade on my 1850! The two caliper plan to me looks like a sure fire way to get instant brake fade The way they are the brakes can't get rid of heat quick enough if driven enthusiastically, I've even boiled old brake fluid with my car

Apparently you can put another caliper on, but the amount of extra heat generated on that poor disc...

If your're limited to what you can & can't use then there is the ST brake set up. I've heard many times of the Princess calipers leaking but have never had them myself. If, like me, you can fit whatever you want, then the Sierra brake conversion is a very worthwhile choice, cheap & effective and proven.

_________________
Sprintless for the first time in 35+ years. ... Still Sprintless.

Engines, Gearboxes, Overdrives etc. rebuilt. PM me.


1997 TVR Chimaera 450

I've said it before and I'll say it again

You cannot put more heat into the disk by adding a 2nd caliper.

Remember conservation of energy from school? Heat energy comes from kinetic energy. You can vary the rate at which energy goes into the disk and you can vary the rate at which heat can escape by changing the brakes. Only by driving faster, increasing your cars kinetic energy, can increase the heat energy that goes into the disk.

There's a brief look at the various impacts of this mod all from 1st principles in the archive.

Tinweevil

_________________
1978 Pageant Sprint - the rustomite, 1972 Spitfire IV - sprintfire project, 1968 Valencia GT6 II - little Blue, 1980 Vermillion 1500HL - resting. 1974 Sienna 1500TC, Mrs Weevils big brown.

Bare with this old 'un a minute. I can hardly remember school let alone what I did there.

Does not friction cause heat? If you put on 2 calipers (4 pads) does this not then equate to twice as much friction (for extra stopping power) and therefore twice as much heat being generated?

_________________
Sprintless for the first time in 35+ years. ... Still Sprintless.

Engines, Gearboxes, Overdrives etc. rebuilt. PM me.


1997 TVR Chimaera 450

Putting it simplistically - If the tyres could cope with twice the stopping force then theortically you could produce the same heat over twice the area but the car would stop twice as fast so you'd only produce heat for half as long, result is same heat in the disks.

Conservation of energy

Tinweevil

_________________
1978 Pageant Sprint - the rustomite, 1972 Spitfire IV - sprintfire project, 1968 Valencia GT6 II - little Blue, 1980 Vermillion 1500HL - resting. 1974 Sienna 1500TC, Mrs Weevils big brown.

My opinion of the effects is in this thread

The bit I forgot to mention was the possible effect of raised disk temperature on bearings, it would not be positive.

Thing to remember is that standard sprint brakes are capable of locking up the tyres. Therefore any change you make to the brakes can not improve your maximum rate of retardation. All you can really do is improve cooling to prevent fluid boiling and increase bearing life, reduce mass to improve handling or play with pad contact, master, caliper and piston areas to improve brake control.

Stick soft tyres on and it's a whole new game

Tinweevil

_________________
1978 Pageant Sprint - the rustomite, 1972 Spitfire IV - sprintfire project, 1968 Valencia GT6 II - little Blue, 1980 Vermillion 1500HL - resting. 1974 Sienna 1500TC, Mrs Weevils big brown.

since we know that the brakes can lock the wheels at least once, there is already enough braking power. What we have is too much braking power for the disc, which is unable to dissapate the heat properly, and which then causes the system to overheat.

standard discs - crap by modern standards unless you drive like a nun, even then, still crap, but if you stamp on them hard enough you can lock the wheels on 185 tyres. go to the gym, wimps... leg press, feel the burn, rraaaaa!

drilled grooved discs - marked improvement, fine for modern road, ok for light track use too i would have thought

vented discs and 4 pots - yum, but personally cant be arsed, and itd be nice to have a finished car to put them on...

It seems the discusion went from suspension to brakes.
Most people go to Poliurithane busches and thats it.
I think these yellow and nowedays blu busches are an improvement, over original, but the real hard rubber competition busches are stiffer.
Next to that the front trailing arm busches are the worst solution you can think of, we solved this problem with special made rose joint and made the arm lengt adjusteble, never had to renew these rose jounts in many jears of racing.
The 2 top busches per side can be renewed by iether nylon made busches or also smal pherifaeral bearings (this is an od sise you have to order special)
An other improvement is reenforce the 2 sub subframes who suport the front wish bone as subscribed in the RAC homologation forms.
An other weak pount are the lower swivels, using 9" wide slicks did put so much force on them that mostly after 3/4 of every race you could feel they start to give in, many times replaced them even after practice, running 2 cars is quite some swivels on a year base.
When they started to dry up we disided to make our own and placed top quality pherifaeral bearings inside, and they last now alredy for over 25 races, no play at all.
Also a good and adjusteble roll bar is essentional, we used a modified bar from a Siera in solid mountings, the original type is crap.
For a start I would use adjusteble Spax although they don't last long, with 2.5" springs, rate is a very personal mather and depend on your skils also. We do have many many sorts of springs for sale, for this type of lengt shock absorber.
A set of good Koni's are also a good start, but than you have to use spacers to adjust the hight.
(We use now special made for us short shock absorbers from Intrax with seperated cilinders)

Brakes, on our normal road cars I use calipers from a 2500 becouse of the same distanse of the connecting lugs, including modified new 2500 disk which are considereble thicker, If you use an original Sprint wheel the caliper have to be grinded a bit to give the spokes the nessesary cleearens.

For real serious braking all this upraded road material is not good enoufg,
again the homologation forms show what the works cars used, proper AP stuff, vent disk 11.5" wide, 4 pot biased caliper (F3) yes in a 13" Compomotive wheel.

We use depends on rain or dry 2 types of Ferodo pads, again 9" slicks real on temperature do stick enorm, but at top speed every time you atach the brakes you must be carfull not to lock up.
Good brakes give CONFIDENCE (outbraking that litle bit faster fukking Escort every lap at the end of the straight is wath I mean)
Upgrading your brakes with a litle spring behind the piston prevent that the pads are of the disk at the moment you start to brake and you have to use up alredy some travel of the pedal befor the pads reach the disk.
becouse the stubaxle is so week it always bend in every corner, and by doing so it puches the pad even furter back and an extra "deep" pedal is the result.

Last part on this side of the car wath need atention are the front bearings, for a start far to small and now almost having a heat shock by all the heat bild up in the brakes.
Normal grease just melts and even start to burn if you unlucky, the best we found till now is a red silicon based stuf, what can stand the heat.

To adjust the the bearing play correct the plate between the nut and the bearing must be without a wornout groove for a start.
We prepare this plate/washer by drilling 2 litle 5 mm holes almost on the side, so now with a simple tool with 2 pins the plate can be prevent to turn with the nut and finaly get solid with the acle thrath.
If you want to do it real proper a spacer (cone) between the 2 inner bearing race have to be made and hardened, than grinded to sise.
Now the inner race wont turn over the stub axle.

Good luck

Hans