PNM Brake Kits

[Buddsy 1,643]

I have to look into my front brakes sticking. Ive been told lack of use can lead to corrosion on the pistons making them stick.

The solution is so Im told to replace with stainless steel pistons.

Looking around at what else is available I see the PMN ones seem to have a good reputation. Molemot fitted them and said they were good.

I see they have a few different options.

Are the biggest ones just worth going for or do they have much advantage over the smaller ones?

 

310mm FRONT 4 PISTON BRAKE KIT £1078.80

 

286mm 4 PISTON FRONT BRAKE KIT £815.94

 

ESPRIT 266mm WILWOOD 4 PISTON FRONT BRAKE KIT £707.94

 

Stick with what I have

 

Ive been watching Kindgit Customs recently on the tellybox and they always seem to put Wilwood caliper on their hot rods.

 

Cheers chaps

 

buddsy

 

 

[Christian43 21]

I fitted the Wilwood kit to my 84 turbo and they have been good. On my Evora I managed to get the massive AP brakes to fade if I really attacked but tell the truth I just don't drive my Esprit so hard so get away with the Wilwood kit. For spirited road driving the are fine. For regular hard track day work they aren't.

 C43

[ChrisJ 1,490]

@Buddsy - you've answered your question your second sentence

Quote

lack of use

Try to drive the car regularly (2-3 times a month), if you aren't looking at track days, the standard brakes are fine.

[Buddsy 1,643]

4 hours ago, ChrisJ said:

@Buddsy - you've answered your question your second sentence

Try to drive the car regularly (2-3 times a month), if you aren't looking at track days, the standard brakes are fine.

Yes you are correct but as I do need to work on them I still feel it may be time to give her the brakes she needs. 

I was always of the opinion the brakes wernt that bad. I know weve had the discussion about the vacuum issue but Ive had a couple of brown trouser moments regarding the Esprit Braking.

My 2 ton Zafira brakes better to be honest.

Im just wondering if a new shiny set would be worth it?

 

buddsy

[Barrykearley 6,988]

The more surface area you have the better the braking capacity will be - More surface area on the pads - more friction - more braking. Well that’s the theory side.

As for the vacuum - does yours not have a mechanical vacuum pump?? I’m sure I’ve seen some of the earlier turbo cars using engine vacuum and an accumulator - but frankly you should never use an engine vacuum as source on a turbo car as there’s so little of it. It was one of the issues that first came apparent when they turbo’d cars for the first time.

[Buddsy 1,643]

I dont have a mechanical vacuum pump.

I didnt really want to go down that route but maybe its something I will have to do.

 

cheers

 

buddsy

[jonwat 435]

1 hour ago, Barrykearley said:

but frankly you should never use an engine vacuum as source on a turbo car as there’s so little of it. It was one of the issues that first came apparent when they turbo’d cars for the first time.

I'm not disputing this but can anyone explain why this is? 

[Buddsy 1,643]

Cause if your engine stops you got no brakes?

Dunno just guessing.

 

buddsy

[Chillidoggy 4,403]

Because when the engine turbocharger is boosting it pressurises the inlet manifold thus inlet manifold vacuum disappears, as opposed to the negative depression in an N/A engine, which also disappears when the throttles are fully opened up (causing a big hole in the inlet manifold), and vacuum gradually builds as engine revs rise.

There is vacuum from a turbocharged engine inlet manifold because when braking is required, it's usually off throttle with no boost, but vacuum isn't normally as consistent as with an N/A engine. Compression ratio also comes into the equation.

Buddsy - You may wish to consider an electric vacuum pump to assist the engine vacuum if you feel you don't have enough. 

[jonwat 435]

2 minutes ago, Chillidoggy said:

Compression ratio also comes into the equation.

Thanks, that's a fair explanation but I still don't get the above line 

[Chillidoggy 4,403]

Just now, jonwat said:

Thanks, that's a fair explanation but I still don't get the above line 

The higher compression engines tend to suck more..........😀

[jonwat 435]

17 hours ago, Buddsy said:

Are the biggest ones just worth going for or do they have much advantage over the smaller ones?

 

310mm FRONT 4 PISTON BRAKE KIT £1078.80

Buddsy, in your heart you just know you need those big, bad boys with the shiny, red callipers  

[cweeden 191]

You can improve your standard brakes considerably by changing the pads, use braided hoses and a high boiling point fluid. Years ago on my '87 HC Turbo moving to Mintex 1144, braided hoses and Castrol SRF fluid (sadly no longer available) had a huge impact for not a lot of money.

cheers

-Chris

[Buddsy 1,643]

42 minutes ago, jonwat said:

Buddsy, in your heart you just know you need those big, bad boys with the shiny, red callipers  

I know I think I do! We all know shiny new works bester & faster!

 

buddsy

28 minutes ago, cweeden said:

You can improve your standard brakes considerably by changing the pads, use braided hoses and a high boiling point fluid. Years ago on my '87 HC Turbo moving to Mintex 1144, braided hoses and Castrol SRF fluid (sadly no longer available) had a huge impact for not a lot of money.

I do have the green stuff brake pads & braded hoses.

 

buddsy

[jonwat 435]

25 minutes ago, Buddsy said:

I know I think I do! We all know shiny new works bester & faster!

Or slower faster in this case 

[Chillidoggy 4,403]

28 minutes ago, Buddsy said:

I know I think I do! We all know shiny new works bester & faster!

 

buddsy

I do have the green stuff brake pads & braded hoses.

 

buddsy

I agree with Chris, a pad change could be a cheap fix for you.

After trying out quite a few, I plumped for EBC Yellowstuff, but note that’s not a recommendation, just what I felt worked best for my set-up.

There’s quite a few others out there to choose from, so some internet legwork is required. They have internet in Norfolk, right?

[Bibs 11,419]

1 hour ago, Buddsy said:

green stuff brake pads

Developed by EBC for MacDonalds car park style cars, Saxo VTR's and the like. 

Proper pads will be a revelation! 

[Buddsy 1,643]

3 minutes ago, Bibs said:

Proper pads will be a revelation! 

So youre saying go KFC or Pizza Hut? 

 

32 minutes ago, Chillidoggy said:

They have internet in Norfolk, right?

DUH! sure do...during the day time but not at week end obviously! 

 

buddsy

[910Esprit 550]

I seem to recall that a few people have previously expressed slight disappointment with bigger front calipers on early turbos?   Possibly as the standard calipers are not the limiting factor to good braking, especially at low speed pootling about, when it may be more difficult to generate good vacuum.

Think I also recall that some aftermarket calipers, have less in the way of weather seals than standard road calipers, so I wonder if they may be more prone to corrosion in the longer terms or after periods of inactivity?

NB - Parts for Girling calipers are cheap as chips, so you could pretty much treat new pistons/seals as service items.   I'd go for SS pisons and make sure everything else is in good order.  

 

[cweeden 191]

1 hour ago, 910Esprit said:

Think I also recall that some aftermarket calipers, have less in the way of weather seals than standard road calipers, so I wonder if they may be more prone to corrosion in the longer terms or after periods of inactivity?

I'm pretty sure that Wilwood initially and didn't have dust seals but do now. The lack of dust seals in the early days was enough for me to build an instant dislike for the brand, one which I still hold today somewhat unfairly maybe. 😊

[Barrykearley 6,988]

8 hours ago, jonwat said:

Thanks, that's a fair explanation but I still don't get the above line 

Stick a meter on it. 0.25 bar of vacuum at best normally. Typical servo requires 0.4-0.8 to work properly. 

[drdoom 421]

Lots of worthwhile thoughts above to consider. I'm no fan of vacuum boost on the Esprit as the long pedal travel required mucks up my preference for heel/toe efforts at neat downshifts whilst hard on the brakes. As to real-world vacuum assistance levels in the cars it would seem that the limitation comes down to having just one cylinder tapped for the source, rather than the matter of boost pressure. All 4 cylinders contributing should replenish vacuum rather more quickly, not possible in this case as the inlet is an IR system, correct? 

[910Esprit 550]

31 minutes ago, drdoom said:

having just one cylinder tapped for the source

On the early turbos there is a 'damped' common vacuum rail for the servo and accessories that is shared across all 4 cylinders

[Barrykearley 6,988]

And it’s worth measuring. This will show you just how little vacuum there actually is.

There is a reason Lotus fitted a vacuum pump - it’s highly unlikely that lotus would have added heavyness for fun.

[Barrykearley 6,988]

33 minutes ago, 910Esprit said:

On the early turbos there is a 'damped' common vacuum rail for the servo and accessories that is shared across all 4 cylinders

And on the later ones they installed an electric pump just to run the heater flaps as that rail was wholly inadequate