M series Front Brake Upgrade

[graham m]

Has anyone got any experience of upgrading the front brakes on a late M series car? Does anyone know where kits are available for vented disks and 4 pot calipers that will fit within a 14" wheel?

[nwarner]

I'm pretty sure Adrian Venn at Exactly TVR (0795 695 6042 ) does a kit with Aluminium 4-pot calipers and vented discs.

Nige

[3154tm]

also, Cambridge Motorsport offer one for the TR6. might fit inside the 14" M wheel.

[Terminator]

I fitted Wilwood 4-pot calipers and vented discs a few months ago, however I have 15" rims so clearance wasn't an issue.

I know of one fellow 3000S owner who fitted vented discs but retained the standard Girling caliper (with a spacer).

If I have the time this weekend, I'll stick a standard 14" rim on the front and see if there is any clearance.

[3154tm]

the Vintage Triumph Register web site has an article about using toyota 4 pot calipers as an upgrade for the tr6.

[solo II]

Take a look at this article. A very inexpensive modification relative to high priced 4 pot calipers and vented rotors. Using the best pad/shoe braking compound for sporting use can make a huge difference and vented rotors really only benefit if one is driving hard for an extended period. A fix for the low pedal mentioned in the thread is a smaller diameter master cylinder piston.
Good luck!!
www.vtr.org/maintain/brake-conversion.html

[graham m]

Gary, thanks for the article on the toyota brake conversion. I will have a look in greater detail at this but it looks interesting.

Has anyone carried out this conversion and if so do you have any comments?

Colin, I would really appreciate it if you could try some 14" wheels on your car and let me know if they are ok. Are you please with the coversion you carried out?

I looked at the Cambridge Motorsport conversion, but they state it is only compatible with 15" wheels. I really want to keep the original 14" split rims on my car. Although I am happy to upgrade the mechanicals for better performance I want to keep the overall car appearance standard.

Graham

[stigproducts]

This looks good, but where to get those Toyota calipers in the UK?

[solo II]

I did this conversion on a Datsun 260z I owned a few years back and ran it with 14" wheels with no problems whatsoever. Coincidentally it is as easy a bolt on for that car as for the M Series. The 240z also uses wheels of the same bolt pattern, offset and backspacing as the TR6 hubs so shouldn't present a problem. I would have done it already for my 2500m but for the fact it would be illegal for SCCA class rules. It will definitely be done to the car if I ever go about putting a real lump in the engine bay. I would think you could obtain the calipers new from a Toyota dealer but not being a resident of Great Britain I hardly speak from firsthand knowledge. They are easily obtained here in the states either new from the dealer or refurbished from any reputable import parts dealer.

[Terminator]

graham m said:

Colin, I would really appreciate it if you could try some 14" wheels on your car and let me know if they are ok. Are you please with the coversion you carried out? I looked at the Cambridge Motorsport conversion, but they state it is only compatible with 15" wheels. Graham

I've only covered 800 miles with the new brakes and most of those were motorway to and from Zolder so it's difficult to say how good they are. They stopped me ok during the 2 laps I managed at Zolder and seemed better than the old system, but when you replace any 25 year old product with a brand new one, something is very wrong if you don't notice an improvement!

From the picture on the website, the Cambridge Motorsport product appears to be the same Wilwood setup as I have fitted, the only difference being the price. (I paid a lot less )

I'll try a 14" wheel this evening and let you know.

[davidy]

Regarding clearance and 14" wheels, watch out for balance weights on the inside of the wheels.

A few years ago, I with a couple of TVR enthusiasts went a slightly different approach and a number of systems were built (4 I believe) with

280mm Cross Drilled and Vented Disc from 93 Nissan Touring Car (35 track miles -testing only) £35 a pair!!! (These things cost over £300 each new!!)

AP 4 Pot motorsport calipers, from an RS200, a batch were being sold off by an ex-RS dealer £250. These were actually designed for a 285mm so we had to space them off slightly from the disc and the very outside part of the pad didn't make contact, but there was so much pad area anyway I'm sure that this wouldn't of had much effect.

We then made some aluminium bells and redrilled the front uprights (using tapered or stepped plugs for the previous holes!). Also had to make some new short brakepipe links.

These would just go behind a 14" wheel, but in my case with no weights. I like Terminator had 15" wheels so clearance wasn't an issue.

The resultant braking was nothing short of stunning!!!

With regard to any brake upgrade you must ask tourself why you are doing it. If its for circuit day use then upograding to 4 pot calipers with a bigger pad area, isn't necessarily a benefit as the disc has less cooling time per rotation, so everything can get hotter. For road use this is less of an issue.

Venting obviously helps with the cooling, and cross-drilling/grooved discs helps with pad glaze, which can happen after repeated hard braking (like a circuit day).

So I would suggest that for lots of track day use, go for cross drilled and vented. If its for the odd circuit day with perhaps hillclimbing/sprinting and fast road use, look at vented discs, and for road use an improvement can be made with just bigger pad areas.

I'm surprised no-ones mentions Princess 4 pot calipers yet, which should just bolt on? and Jaguar 420G calipers also should bolt straight on, a 3 pot caliper with a much bigger pad area.

Hope that helps

davidy

[Terminator]

davidy said:

I'm surprised no-ones mentions Princess 4 pot calipers yet, which should just bolt on? and Jaguar 420G calipers also should bolt straight on, a 3 pot caliper with a much bigger pad area.

I've heard that one type of Diesel Transit (old shape) caliper fits as well (really), but I decided that a kit that bolts straight on was the easiest option.
Don't have time to mess about with the wheels this evening, I'll stick to my original plan for the weekend.

[solo II]

davidy said:

I'm surprised no-ones mentions Princess 4 pot calipers yet, which should just bolt on? and Jaguar 420G calipers also should bolt straight on, a 3 pot caliper with a much bigger pad area.davidy

Ok, I give. What is a Princess (besides the obvious) and what is a Jaguar 420g? And while I'm at it, what is a punter, and what is the difference between an A road and a B road? Oh my God, someone please stop me. I've got a million of them........

[krispy]

solo II said:

davidy said: I'm surprised no-ones mentions Princess 4 pot calipers yet, which should just bolt on? and Jaguar 420G calipers also should bolt straight on, a 3 pot caliper with a much bigger pad area.davidy Ok, I give. What is a Princess (besides the obvious) and what is a Jaguar 420g? And while I'm at it, what is a punter, and what is the difference between an A road and a B road? Oh my God, someone please stop me. I've got a million of them........

Princess: Austin (British Leyland) Princess, 1970s wedgy saloon
Jaguar 420G: very large limousine and, in Daimler guise, often used as a funeral car and, correct me if I'm wrong, by HM the Queen.
Punter: man-in-the street, usually the person about to buy something
A-road: major route but not a motorway
B-road: minor route, smaller than an A-road but still wide enough to get a designation (note that 'wide enough' does not necessarily mean that two cars can pass.......)

Hope that clarifies a few things for you

Keep 'em coming me old china.

Kris..

[davidy]

Terminator

I'm sure you would know about the Diesel Transit, with you being into oil-burners, both of the TVR and pikey pick-up type

davidy

[Terminator]

Ok, just tried a standard 14" M-series wheel on the front and it seems to fit, with about 8mm clearance from the caliper edge to the inside of the rim. Balance weights would certainly be a problem if fitted but are easily relocated.

The calipers are Wilwood Dynalite II, as supplied as part of a full TR6 kit which includes ventilated discs and attachments to bolt to the upright. I got the kit from Rally Design (www.raldes.co.uk) earlier this year and also fitted EBC Greenstuff pads for the Dynalite II calipers.

If anyone wants a couple of pics, just ask me nicely on [e-mail]



Please note. If anyone does fit four-pot calipers, I will NOT be held responsible if they don't fit!

[graham m]

Colin, thanks for trying the wheels. The brakes certainly look promising. I will get a copy of the data sheet off the web site and do some calculations.

Thanks again.