I have been trying to get an answer to my question on the specification of the Ford brake proportioning valve that is fitted to Speed 6 TVRs as standard.
When I posted this in October it looked good – Ford had acknowledged my request for information and it had been passed to their technical team.
However, when the letter arrived I was disappointed. It basically said that they couldn’t provide any information on the brake proportioning concern as the vehicle was not a Ford and that I should contact the manufacturer.
Via e-mail I pointed out to them that it was a Ford part, and that I could not contact TVR as they went out of business 6 years ago. And that my question wasn’t about a a brake proportioning concern but was a specific question about a Ford component that could be answered with a single number, for example 0.4 (fraction of pressure passed through).
When I received another phone call things looked good. The matter had been passed to Ford Technical again, and this time they would be sending some information.
A few days later the information arrived. Sadly it was of no use. I had given them the part number and the information that I needed, and they sent me a page from some Ford manual about how much extra weight should be placed over the rear axle for testing load-sensing proportioning valves.
I don’t understand how anybody could have read my question and sent me this as an answer.
I phoned the number provided on the latter for the Ford Customer Relation Centre and after being transferred twice I spoke to the person who sent me the letter. She suggested I contact the Technical Information Centre directly and gave me a phone number.
Thankfully I checked before calling it, as it is a £1 / minute phone number. She didn’t mention that. I did however find an address to which questions can be sent, so I have sent them a letter which makes the question very clear. We will see what happens.
Gaz shocks were very helpful. In advance of the trip to Center Gravity I wanted to check the spring rates in the kits fitted to TVR. The answer came back within an hour of 400 lb/inch front and 350 lb/inch rear. I asked via e-mail how much new springs were, providing a phone number, and they called me back soon after.
New springs are a very reasonable £25 + VAT / corner (so £30) and delivery is £11.25.
While their standard kit is 400 / 350, some people go up to 450 / 375. Apparently the dampers fitted by TVR to the Tamora / T350 are a bit short relative to the springs used, and this effectively gave the spring some pre-load. This maintained ride height but at the expense of a ‘chattery’ ride.
The Gaz setup does not do this, so should could a more compliant ride in the initial part of the travel. The damping I am running (12/10) at the moment could be turned down a little if stiffer springs were fitted.
Some additional information was provided. Apparently the front springs are mounted very nearly straight, and the rear springs are at a significant angle. This means that the spring rate for the front may go from 400 to 375 effective, but the rear could lose nearly 40% of its spring rate. Therefore some people just put a 400 on the rear to match the front.
This is all useful information to discuss with Chris at Center Gravity.
In addition, Britannia Rescue were very helpful when I had a question about my policy.
If only Ford were helpful as well