Moggy's Darrian T9

[Moggy]

Re: Moggy's Darrian T9

Cheers for that. Darrians normally have fairly 'strong' rear brakes as the car has a heavy mid/rear weight distribution and a very light front end.

My car has Alcon tarmac spec front 4 pots and willwood rear 4 pots.

The front cylinder is .625"
the rear cylinder is .7"

I have always run with a smaller front cylinder on all my cars....but I am open to trying anything if it improves it!

At the moment I have excellent rear brakes and a mega handbrake (which easily locks the wheels at any speed when needed)......but the front seams to have very little feel and not too much power although they will still lock easily and before the rears?

All the pads/discs are bedded in now and get hot. There is no air in the system and the peddle doesn't 'pump up'. However the peddle does seam quite 'long'.

I will check the balance bar/pistion possitions this week....I can't do it on my own as you cant see the cylinders whilst pressing the peddle.....we are having a couple of nights on the car this week so we will have a good look at it.

[Roadsport]

Re: Moggy's Darrian T9

All the pads/discs are bedded in now and get hot. There is no air in the system and the peddle doesn't 'pump up'. However the peddle does seam quite 'long'.

The pedal travel is long because you need to move more fluid to get them bigger pistons moving. Larger cylinder will take care of that. Larger cylindrer moves more fluid with less travel. The pedal feel will improve alot and it easier and more accurate braking. Not lockin the fronts.

[Moggy]

Re: Moggy's Darrian T9

I will be checking it properly later in the week when I get some help.....can't see what's happening with the peddle box properly when sitting in the car pressing the peddle.

With the car stationary, I have noticed that if I put pressure on the rear brakes with the hydraulic handbrake, then the peddle is almost solid and not 'long' at all. If I then release the handbrake and press the peddle it is long again???

[Retromotorsport]

Re: Moggy's Darrian T9

the handbrake has allready moved the pistons, then the footbrake moves a bit and locks, the bias bar is probably jammed against the side, and this means no further fluid is pushed in either cylinders

[Moggy]

Re: Moggy's Darrian T9

OK loads of work on the brakes last night.

As suspected there is no air in the system, leaking or anything loose.

Have actually now read the instructions which came with the Tilton peddle box. Basically our problem was that when depressed the balance bar was not exactly at 90 degree to the piston rods....we had set it at 90 degrees when the peddle is relaxed........so basically it was set the wrong way round.....we reset it and the brakes feel 100% better. Have not tried it yet but I am sure it will now work properly as the peddle is now firm and neither side of the bar is getting locked against the sides at any point along the balance bars adjustment.

However we did discover one rather bad thing.......the amount of flex in the rear Wilwood calipers is huge. The mountings don't move at all....(we checked using a dial point indicator...nothing) but the caliper body flexes across its width.....it's not the joining screws screws which pass though it's body..... its the actual cast body itself....you have to see it to believe it.

The whole body sort of bends and expands as the brakes are pushed.....so the pistons sort of push the body away from the disc rather than the body staying still and pushing the pads towards the disc......(obviously it does push the pads onto the disc as well). You can easily see them flexing.

Now we still have very good rear brakes from them.....but you have to think........"if you buy cheap, you buy twice". Clearly the calipers were flexing more when they got hot the other night.

We checked the front Alcons with the same method......if I absolutely stand on the brakes there is no measurable movement in the caliper body or mounting at all....zero. the only things which move are the pistons and pads.

the difference between the two makes of caliper is shocking...........what is the point in designing a caliper which can bend alowing the pistons to push it away from the disc? surely that just reduces the appiled pressure on the pad/disc.

I feel an eBay listing comming on........

I am going to research some quality rear calipers from AP or Alcon with similar sized pad/pistons to keep my ratios something like.

[Roadsport]

Re: Moggy's Darrian T9

I had the same problem with the Wilwood calibers in the front. Moved them to the rear and they do work there. But escort has a lot lighter rear than Darrian.
Expanded like a ***** when on front.

[Moggy]

Re: Moggy's Darrian T9

Yes I would never have believed it if I hadn't seen it for myself.

[exboyracer]

Re: Moggy's Darrian T9

That's not news unfortunately, that sort of thing has been said about Wilwoods for years.

I keep trying to talk people out of buying them, but often they can't resist the lure of the (relatively) cheap bling factor.

[Retromotorsport]

Re: Moggy's Darrian T9

The older ones did flex a lot , american soggy brakes ... but recently this has been reduced

Moggy, so was the bias bar locking in the tube?

[Moggy]

Re: Moggy's Darrian T9

Moggy, so was the bias bar locking in the tube?

Yes...you were right on the money! cheers.

[Retromotorsport]

Re: Moggy's Darrian T9

99% of the times i've had people say that the rears work and the front dosnt... its a bias tube lock

Glad to help

[cossie matt]

Re: Moggy's Darrian T9

OK loads of work on the brakes last night.

As suspected there is no air in the system, leaking or anything loose.

Have actually now read the instructions which came with the Tilton peddle box. Basically our problem was that when depressed the balance bar was not exactly at 90 degree to the piston rods....we had set it at 90 degrees when the peddle is relaxed........so basically it was set the wrong way round.....we reset it and the brakes feel 100% better. Have not tried it yet but I am sure it will now work properly as the peddle is now firm and neither side of the bar is getting locked against the sides at any point along the balance bars adjustment.

However we did discover one rather bad thing.......the amount of flex in the rear Wilwood calipers is huge. The mountings don't move at all....(we checked using a dial point indicator...nothing) but the caliper body flexes across its width.....it's not the joining screws screws which pass though it's body..... its the actual cast body itself....you have to see it to believe it.

The whole body sort of bends and expands as the brakes are pushed.....so the pistons sort of push the body away from the disc rather than the body staying still and pushing the pads towards the disc......(obviously it does push the pads onto the disc as well). You can easily see them flexing.

Now we still have very good rear brakes from them.....but you have to think........"if you buy cheap, you buy twice". Clearly the calipers were flexing more when they got hot the other night.

We checked the front Alcons with the same method......if I absolutely stand on the brakes there is no measurable movement in the caliper body or mounting at all....zero. the only things which move are the pistons and pads.

the difference between the two makes of caliper is shocking...........what is the point in designing a caliper which can bend alowing the pistons to push it away from the disc? surely that just reduces the appiled pressure on the pad/disc.

I feel an eBay listing comming on........

I am going to research some quality rear calipers from AP or Alcon with similar sized pad/pistons to keep my ratios something like.

This is exactly the reason I got rid of my willwoods pretty rapidly, mine flexed so much they touched on the ends of the split rim bolts which were a good 10mm away, very shocking. Went to Alcon and never looked back, awsome

[muckerbarry]

Re: Moggy's Darrian T9

This is a great thread. What a fantastic car, it’s a credit to you.

Glad I saw the bit about the callipers, I was about to waste some hard earned cash on wilwoods. I couldn’t understand why AP’s or Alcon’s were so much more expensive, you just gave me my answer.

Just as a matter of interest do standard ford sliding calliper flex’s much? Or at all? Is flexing just a problem with cheap alloy callipers?

[Moggy]

Re: Moggy's Darrian T9

This is a great thread. What a fantastic car, it’s a credit to you.

Glad I saw the bit about the callipers, I was about to waste some hard earned cash on wilwoods. I couldn’t understand why AP’s or Alcon’s were so much more expensive, you just gave me my answer.

Just as a matter of interest do standard ford sliding calliper flex’s much? Or at all? Is flexing just a problem with cheap alloy callipers?

Cheers for the support!

I don't know the answer about your sliding Ford calipers...but there is some very knowledgeable people on here, so someone will have the answer.

Reagarding the Willwoods, it's like a said before...."you buy cheap, you buy twice"

[Moggy]

Re: Moggy's Darrian T9

Small update from last night.

We started and completed a few small finishing off jobs.

Made and fitted a tunnel guard which runs along the underside to strengthen the flloor under the ally water pipes (it is single skin kevlar here).....don't you just love riv-nuts!

Made and fitted the bulkhead cover plate over the aperture we use for getting at the cam pulleys......more riv-nuts

rewired the FIA and ignition switches as I was never really happy with them before.

The engineering company next door to me are making me a new gearlever as the one you can see in the photos earlier was only ever temporary....will go and collect it in a bit.

The car is finished now and is ready for competing in.....we want to do a couple fo rallies in comming weeks....but there seams to be a ridiculous shortage of co-drivers arround at the moment.....my last navigator has packed up unfortunately.........so if anyone out there is interested give me a bell/email/pm etc