Brakes

[imull]

I am about to design a wee modification to my Clan. This should take the power up to about 450bhp/tonne (from 220ish).

Unfortunately, due to the design of the monocoque, I can only carry 13" rims or very low profile tyres and 14" rims. As the car is also to be a rally car and the roads at home arent great, I am not keen to go for 14" rims...

The car will have no problems going places but stopping it will be fun ( ), especially as I car will be geared for about 130mph!

Can anyone recommend a good caliper to use? So far, I have had one person mention using water cooled calipers, but thay aint too cheap.

[avsfan733]

probably better to not do water cooling as its more parts to break. Just feed them a lot of air. Check out Brembos, they are pretty much the best around and they make a lot of different variations

[alfasud]

Inboard brakes maybe? Getting enough air to them could be a problem, but you aren't restricted by rim size.

For outboard brakes, some rims allow bigger brakes than others. Single seaters can have very effective brakes that fit within 13" wheels, so maybe have a look at what's used in F3, F3000 etc.

[Richy_Rich]

Didn't olden days trucks just use windscreen washer pumps connected to the brake light wiring to effect a primitive water cooling?

[zefarelly]

genius idea ! did it also give that un nerving twitch from left to right if one side was wetter than the other!

[imull]

Thanks for the ideas. Think I will pass on spraying water onto the discs.

Plenty of scope for ducting onto brakes but still worried about 20+miles of fast tarmac stages at home. Lots of heavy breaking too...

Will look into Brembo avsfan, cheers.

Inboard brakes are feasible on the rears but not on the front. but will investigate idea anyway.

F3000 brakes - interesting idea but what are pad/disc prices like?

[Tony_Simpson]

F3/F3000 stuff could be very expensive and then you have the problem of getting everything mounted on the imp stub axle.

Try having a word with Tim Duffee at Darrian, as they used the imp parts for a while and used some bigger brakes.

[imull]

cheers tony. Am probably going do design in either double wishbone all round (preferably), or a mix of double wishbone on the front and Astra GTE (for example) front suspension on the rear. That was I can lift and entire front end out of a car and design it into the clan.

[DAVID PATERSON]

Volvo calipers are a popular mod for a substantial improvement at minimal cost. Also, Toyota Hilux calipers are another option.

[Ed_Newman]

Two Clan's were designed and built with larger engines in the back. Both used pug 205 engines complete with g/boxes and suspension. On the front they used double wishbone suspension based on Imp wishbones. It would be worth looking at these two cars, also one of them is for sale on the Clan owners site at reasonable cost. Only one of the them was finished and this was used by Weber for developing fuel injection and is now raced at hillclimbs and sprints in Devon.

The braking system that was used on the racing Davrian's is more than up to the task. My Davrian has ten inch discs alround with large aluminium girling calipers. The only effect the increased power and weight of engine will have is possibly a faster top speed (although an imp engined Clan can be set-up for 130mph) and a greater car weight. One point to consider is that the extra weight and change in position of the engine will upset the design and structure of the car. The majority of imp engined designs that were fitted with larger engines went slower. Examples include the corry cultra versus the davrian, BDA engined spaceframes etc.. Some were succesful but not many.

The three favoured up engining options for these cars at the moment is to either go for a K series bolted to a 5spd skoda box which keeps the weight down and the power up, turbocharge the imp engine (reliable 150hp is easy) or go the bike engined route. One thing to remember is that although the suspension on the Clan appears to be outdated and simple it is very effective. There is very little that can out corner one without the use of wings.

[Lee Janotta]

I don't suppose Baer does business in the UK market? Nope?

Too bad... Good company. They do great brakes for high-performance road use, which can at least hold their own in race and rally situations. Really reasonable prices too, compared to Brembo or other competitors.

[avsfan733]

okay I'm in a good mood so i am gonna get a little crazy here, what would stop you from using two calipers and discs together, maybe smaller than before. this would also provide a backup should the not so good occur on a stage.

not sure the layout of the drivetrain, though if it is two wheel drive you might consider engineering and installing a limited slip differential on the non-driving wheels (probably clutch type set up rather stiff) to effect some antilock ( if anitlock isn't allowed) cooling wise, maybe aim the nozzle of a water system down the cooling vents of the brake rotor (your using vented rotors right?)

I have also heard somewhere, of using angled calipers to allow more force on the rotor and a greater area of contact to prevent heat buildup in a small path and instead use more of the rotor....also if its possible (aka inboard brakes or custom uprights) you might want to mount the calipers horizontal along the bottom of the disc for cg purposes, and if you want to get fancy a selfbleeding system might be good especially in case you have any problems with leaky brakes possibly allowing air in the lines between services or for caliper replacement being quicker

[THR]

i own the clan that Ed talks of, which is currently under a sheet in the garden lol.
i did one sprint in it and run out of money as i had to goto uni!!
this to is geared for over 130 id say, ive had it at 8200rpm in 4th gear and it does about 117mph so i guess 5th would be faster, was still pulling but a corner was coming up rather fast!!

it has solid disc brakes at the front, it stops fine, can lock um up fairly easily, cos it dont really weigh much, they are Front 9” solid Talbot avenger/sunbeam discs, M16 calipers and mintex 171 pads.
the rear has the vented pug 205 front brakes. never locked them up, as bais is quite front wards!

if i wanted to convert a imp clan, id look at wot the westfields use, as they run the same size wheels. can buy some nice aly brakes for them!

mines for sale if you fancy it! pics on my website.
fast car, lots of mods done by me, and needs a good trashing. buot 6k is all i want.
road legal fun

F3 aint man enough for the job, the cars weigh abuot 200-300kg less than a clan does.

more details on the car on my website if you wanna look.

[avsfan733]

solid on the front vented on the rea?

and i thhink his concern was morefor fade resistance and longevity

[THR]

yea, i think its more of just wot was availible and fitted at a reasonable cost.

i didnt think fade was such a problem on rally cars compared to track cars, as they weigh not a great deal, esp a clan, and the speeds arent half as much on average.

[imull]

Have been reading these replies, but not had chance to reply...

Thanks again for all the suggestions.

I doubt you will remember Paul, but I sent you a couple of emails ages ago with qquestions about clans. Small world.

Firstly, I should point out that as far as Clans go I am a bit of a dunce! I wanted something rear wheel drive, different and preferably cheap. Hmmm, 2 out of 3 want bad but the third made up for any gains out of the first two Ultimate impulse buy.

As much as I would like to buy another, I have already sunk an absolute fortune into this one in a full repair and rebuild. It will be an almost brand new car when finished (good ol' student loan lol). So much for thinking I had a good deal!

The three options as far as engine that I was considering was a 1000cc bike engine (though would consider a bigger one depending on final rules of F1000 championship), a 1400cc engine (for BTRDA stuff) or go for a 2ltr 16v Astra engine. I have heard about the turbo imp but never come across anyone who has used it. Anyone know who to talk to about them?

Really haven't made my mind up as I am waiting for judgement from the MSA with regards to the new rules for Category 3 prototype stage rally cars. They are about to start frowning on people altering the engine location and each case will be assessed individually... Though in my case, the driven wheels will be the same and this should work in my favour.

Currently, I have the Fiesta 12" conversion and this should be plenty for the first season as the F1000 is all single venue stuff. It will get plenty of work though going to and from Epynt when at uni though so I will know if they are good enough or not.

The brakes get a heavy workout on Mull and other Tarmac rallies, especially on Epynt. I would rather have slightly over specced brakes and know they work as there are places on Mull, that if you went off you owuld have time to put on a funeral suit before landing again...

Will come back to anythign I missed tomorrow. too tired to think now lol.



ps. does anyone know of any of the following that may be for sale?

Twin Weber 40 DCOE manifold (and throttle linkage)
roll cage
seats and/or harnesses

[Ed_Newman]

For info on turbo imp engines speak to Dave Edge or Nick Cleak on the Imp e-mail list. Both of them have built and run turbo imp engines. Other people to speak to are Martin Jones (runs a turbo Davrian) and Andy Jones (built a turbo Chamois used for hillclimbs, now competes in historic saloons). My brother is starting to assemble the parts for building up a turbo 930 imp engine for his Clan. If you already have a race spec imp engine and g/box then it would probably be best to start with that and see how you get on.

The fiesta brake kit should have plenty of power if not you can upgrade it to bigger calipers and vented discs. The imp rally cars that are raced use the viva disc kit and they don't have any problems. Lower top speed but higher weight.

The best source for combined manifolds is cottage classics (www.ginetta.co.uk) by far the cheapest and good quality. I've got spare Clan bucket seats if you are interested.