Wilwood 16" kit caliper issues

[tigerdog]

What issues specifically?????

The ones described in this thread. Specifically, the 9703 sits about 2mm higher than the 68xx. It's close enough to have fouled the inside of one of my wheels that was cast ever so slightly out of round. Also, the top 1.5mm of the pads sit above the lip of the rotor. See the thread for more detail.

[nitroman]

You sure? The 6808 says it's for a .38" (width) rotor, whilst the other calipers fit a .81" rotor.

I still overwhelmingly recommend the 6811, having experienced 6816, 6811 & 6806 (the latter on someone else's car). There is almost nil pedal travel with the 6811, about equal to newly-bled stock brakes. But where the stock brakes are heavy, and therefore somewhat devoid of tactile feel, the 6811s can be precisely modulated. While the same can be said for the 6816, there is a lot of pedal travel and unless you are careful they can bite too quickly in the rain.

Both the 6806 & 6811 will leave you in good sted for a rear upgrade, but with the 6816 your fluid moving capacity is already maxed-out, so you might have to be overly conservative in you rear-upgrade, leading to the wrong brake-balance.

[theelanman]

IIRC the original design was for the 6806......only somewhere along the line it morphed into 6816....

also IIRC bob browns wilwood rear upgrade needed the 6811 as it was the only one of the three options that provided a correct fron rear balance with the upgraded parts......

the 6816 gave you excellent braking but long oedal travel and changed the overall brake balance with the standard or dorman rear caliper

the 6806 gave you short oedal travel and the correct balance with the std rear/dormen set up

the 6811 gave you long pedal travel and a shift towards front bias with the std rear dorman set up but then gave you the correct balance and a short pedal travel if you upgraded the rear too.....

I also remember the bit where it was said that the 6806 would work with the wilwood rears but you may need to change a master cylinder or upgrade some other part too......

anyone??....

[nitroman]

the 6811 gave you long pedal travel and a shirt towards front bias with the std rear dorman set up but then gave you the correct balance and a short pedal travel if you upgraded the rear too.....

This is incorrect as I have the 6811 with stock rear brakes.

[theelanman]

the 6811 gave you long pedal travel and a shirt towards front bias with the std rear dorman set up but then gave you the correct balance and a short pedal travel if you upgraded the rear too.....

This is incorrect as I have the 6811 with stock rear brakes.

just going off what has been said before.....
amd reading thus it sort of read as basically you have long, medium and short pedal travel for 16, 11 and 06 respectively......
all the calipers work and fit.......
its just a case of brake balance and what the plans for rear upgrades are.....

Ive got new dormans on mine so not planning on the wilwood upgrade (well not just yet)......
but Ive got the 6816 on and have a long pedal travel and I only just meet the MOT criteria for the brake balance.........
so Im thinking....6806...it'll get the pedal travel back and sort the brake balance out too....

[bobbrown]

I do not know where the reference to Wilwood rears came from but the rear upgrade is not Wilwood but Hi-Spec.
As for 6806, 6811, and 6816 calipers these will all fit but the latter two do significantly alter the front to rear bias and will increase the stopping distances not reduce them.
The point at which the wheels lock does not change and the brake size has no impact on this, what so ever, the point of larger brakes in terms performance is to reduce the effect of heat as larger brakes get rid of heat better than small ones.
If you increase size of the fronts and then the line pressure to lock the fronts is significantly reduced as with the 6816's then the rear brakes are not applying the same load to the rear so you lose some of the braking force. Most peoples perception is that the brakes are better because they do not require as much pedal input to stop the car this does not mean the brakes are actually any better as the forces to stop the car do not change and before any one goes on about weight transfer my calculations take weight transfer into account and again the amount of weight transfer does not change as it is a relationship between the weight of the car, the C of G and the distribution of the weight. At the end of the day it is the tyres that stop the car but the road surface has a lot to do with how quickly you stop also wheels that are locked do not exert the same loads as ones that are just at the point of locking but not locked hence ABS, which endeavours to hold the brakes at this point e.g. applying maximum braking without locking the wheels.
If you want to be picky then you want to be at a point of slippage around the 10% mark to get maximum braking any thing above this and the rolling resistance reduces very quickly.
With the Dynalite calipers it is a little unfortunate that Wilwood do not make them with a piston size of 1.5" and my understanding is that the 6806's were a match for the original caliper and do not move the brake bias very much.
FYI front rear with 309mm diameter discs.
6806 72.3% 27.7%
6811 78.2% 21.8%
6816 80.7% 19.3%
As a point of interest to balance a 6816 set up with the standard rear caliper the rear disc would need to be 410mm in diameter that just shows how far out the brake bias is!

Bob

[theelanman]

thanks for that bob.....thats what I thought....although in not quite so much detail

I found at the MOT I was only getting 17% to the rears......it passed but its a bit close....
I can also feel the difference under heavy braking with a twitchy rear.....

[tigerdog]

You sure? The 6808 says it's for a .38" (width) rotor, whilst the other calipers fit a .81" rotor.

Yes, I'm quite sure...
sure that I can mistype a part number as well as anyone on the forum . Of course I meant 6806 - previous post corrected forthwith. Sorry for the confusion!

[theelanman]

You sure? The 6808 says it's for a .38" (width) rotor, whilst the other calipers fit a .81" rotor.

Yes, I'm quite sure...
sure that I can mistype a part number as well as anyone on the forum . Of course I meant 6806 - previous post corrected forthwith. Sorry for the confusion!

how very true......it was a mistyped digit that got us to here.... .......could have been anyone......(and no Im not pointing the finger at anyone at all...just incase what Im typing gets read wrong)
a pure slip of the keyboard.....the numbers should have been completely different so we could have spotted it at the time
6806 or 6816.....should have been 6806, 7806, 8806....we might have spotted it then......ah well.......

[theelanman]

I do not know where the reference to Wilwood rears came from but the rear upgrade is not Wilwood but Hi-Spec.
As for 6806, 6811, and 6816 calipers these will all fit but the latter two do significantly alter the front to rear bias and will increase the stopping distances not reduce them.
The point at which the wheels lock does not change and the brake size has no impact on this, what so ever, the point of larger brakes in terms performance is to reduce the effect of heat as larger brakes get rid of heat better than small ones.
If you increase size of the fronts and then the line pressure to lock the fronts is significantly reduced as with the 6816's then the rear brakes are not applying the same load to the rear so you lose some of the braking force. Most peoples perception is that the brakes are better because they do not require as much pedal input to stop the car this does not mean the brakes are actually any better as the forces to stop the car do not change and before any one goes on about weight transfer my calculations take weight transfer into account and again the amount of weight transfer does not change as it is a relationship between the weight of the car, the C of G and the distribution of the weight. At the end of the day it is the tyres that stop the car but the road surface has a lot to do with how quickly you stop also wheels that are locked do not exert the same loads as ones that are just at the point of locking but not locked hence ABS, which endeavours to hold the brakes at this point e.g. applying maximum braking without locking the wheels.
If you want to be picky then you want to be at a point of slippage around the 10% mark to get maximum braking any thing above this and the rolling resistance reduces very quickly.
With the Dynalite calipers it is a little unfortunate that Wilwood do not make them with a piston size of 1.5" and my understanding is that the 6806's were a match for the original caliper and do not move the brake bias very much.
FYI front rear with 309mm diameter discs.
6806 72.3% 27.7%
6811 78.2% 21.8%
6816 80.7% 19.3%
As a point of interest to balance a 6816 set up with the standard rear caliper the rear disc would need to be 410mm in diameter that just shows how far out the brake bias is!

Bob

ok to that end....what is the brake bias front to rear if I use the 6806 with hi spec rears???
and also what is it if I use 6811 with the hi spec......and we might aswell finish it up with 6816 with the hispecs.....

cheers
G

[bobbrown]

The size of the front discs need to be taken into consideration and the 309mm front disc gives these results all be it the rear disc size is used to get back to a 70 30 split
6806's are a little on the small size and with the smallest disc (240mm dia) give a 68.5% 31.5% split, now it is not uncommon for car makers to bias the brakes slightly more to the front than the ideal figure as this puts it on the safe side of things.
6811's are probably the better option but would still need a 299mm rear disc to get back to a 70/30 split or with a 260mm rear disc give 70.7% 29.3% split which is close.
6816's will need a 340mm rear disc which is not really practical to get to a 70 30 split, closes is around 300mm which would give a 73.1% 26.9% but still front biased so it does go to show how far out these calipers are.

the 275mm front does change things
6806's are to small
6811's with 260mm rears gives 70.7% 29.3%
6816's need a rear disc larger than the front which will not fit .............

All the above assumes that the calipers still clear the wheel spokes which would need to be looked at 240 to 260mm I know is OK but the others require some work but it has been done.

[theelanman]

anyone got the contact details for Lee at Rally Design????
phone number or preferably his email
thanks
G

[a5gcd]

Hi G

I am not sure if Lee is still there but the phone number for Rally Design is 01227 792792 and the Email address is sales@rallydesign.co.uk

Geoff

[awaken101]

Sorry to dredge this topic back up but for awhile now I've been looking in to getting new brakes and rotors to replace the Wilwood parts that were on my car prior to purchase.

Asking in the FB forums someone had mentioned the rotors were 160-12293 and 160-12294 (upgrade from the 160-5844?) and the pads they had purchased were the 150-20-7112K. The pads are a BP-20, I called to speak with Steven B. at WIlwood and he suggested going down to the BP-10's (150-8850K) due to the low dust levels. I'm going in for a complete engine overhaul soon as well as installing the Everest chip so I'm planing to stay with the BP-20's. I've also pre-ordered the above mentioned rotors as well...

I had mentioned the debate about the 6811 and 6808 versions being discussed here and he didn't mention the difference. He only said this in reference to a pic I had sent him of the back of my calipers,

Probably a 120-6816i Dynalite with 1.75 pistons for an .810 rotor but I can’t be sure…
I would measure the thickness of the rotor, it should be .810 or close to it, also see the link below for the kit you may have…
https://mossmiata.com/906-160-cp-front- ... 4&889=2658

Pic of calipers:


Planning on calling him back tomorrow after I measure the thickness (which I'm pretty sure is close to .81. With the last post on this thread being years ago... I'm wondering if this link to the kit is what I currently have or was part of the GB years ago.

Should I be okay with just my current order of the rotors and brakes mentioned at the top of this post? If I did consider going to the 6811's, would I need different rotors/pads? It would also seem that I'd need to adjust the rear brakes to compensate for the change to 6811's, is that correct?

Any advice is greatly appreciated as always!! Cheers!

[Fredjohn]

Might be worth reading this page if you haven't already:

https://web.archive.org/web/20230926060 ... e_upgrades

Hopefully this will confirm your existing knowledge/findings.

FYI I have the 15" Wilwoods on my UK car. I ran with unaltered rears until I fitted a PNM caliper, which is basically a Golf Mk 4 caliper. Don't mess with the proportioning valve, unless you fit an adjustable version as per Dapinky. Thread on that somewhere on here.