This is what I would ask the track day organisers:

1. Is Tiger a homologated road car?

This is what I would ask myself:

2. If it is, is their roll bar any good?

I had a similar question regarding the helmet required in my area for track days/autocrossing/ice racing/snowcrossing. I am still not sure, but I have learnt the paint jobs are better on the bike helmets.

[Edited on 12/2/10 by RK - the expert in uselessness and pointlessness]

[Edited on 12/2/10 by RK]

quote:

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Originally posted by General Bilko
I'd call it "sharing what you know" rather than "brain-dump". And when someone else points out that "what you know" isn't correct, well then you've learnt something new, which is probably what this forum is all about....

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TimC,

I understand your position is you accept the principle of caveat emptor, so if you foolishly believe my assertion that the best brake pads to fit are Tesco Yellow Stuff (from the deli counter) then that's your hard luck. But you assert that I'm selfish to advise you to fit Tesco Yellow Stuff if I don't know much about brake systems.

If you had said that it's wrong for people to wilfully and mischievously advise people to use Tesco Yellow Stuff in the full knowledge it's a very poor choice for brake pads then I would agree with you. But I don't think there are many like that on this forum, and I don't believe that is your point. You suggest it's selfish to post on a subject where you have little knowledge. But this surely is an "unknown unknown" or "I don't know I don't know". And how much do I need to know, and how will you measure that, before I can post on the subject of brakes?

Going back to one of the posts above where someone suggested using T45 for home built roll cages and this was quickly rebuffed, how would that person know their understanding of roll cage metallurgy was below some, unstated and unquantified, level of competence? They may have made one in that material themselves, completely unaware of the need to heat treat. Surely they deserve, as much as the OP, to be made aware of that fact?

The other reason I believe your position is incorrect is the assumption that issues such as "best colour" or "nice wheels" are subjective and there is no one right answer, whereas a technical, regulatory or engineering issue does have a single unambiguous answer and isn't subject to opinion. Clearly that's not the case, and I'm sure you can think of many examples where engineers and scientists haven't agreed on a topic.

So I fear your plea will go unheeded, not only because it's impossible to separate an opinion from a fact in most cases, but also, and probably most pertinently, I suspect no-one will pay a blind bit of attention to what you've asked them to not do....

GB

My suggestion, note "suggestion", to use T45 was not based on some random or arbitrary notion but after discussion with a specialist tube manufacturer of long standing and great experience.
This company supplies tubing and associated pipe products for aerospace at one end of the scale and roll-cages at the other. Their take on heat treatment is that it isn't required for the thin wall tubing being used for motorsport applications.

Whilst not personally qualified to verify that assertion, based on their experience I'm willing to accept it for my purposes - the rest can make their own decisions.

Cheers, Pewe

To comment on both conversations,

If i'm posting something i'm not qualified / expert / experienced in i hope i tend to put a "i think" or a "i believe" or a "I've read on here" so people know how much weight to put on my comment. I like that approach as it means people know i'm not an expert & if i post on something i'm wrong i get to see pretty quickly without hopefully causing or taking offence.

As for the t45 - is the roll cage stuff really thin wall? Was the bloke referring to the chassis? I would have thought (not qualified, random guess) the roll bar would still be far thicker than 1.0 to 1.5mm (what i think is thin wall) and rather scared having something that thin protecting my head.

edit - small typo

[Edited on 15/2/10 by MikeR]

Hi

Well that tube supplier should take a closer look at FIA/MSA regulations for a start. And then perhaps take a look at the ACTUAL real world evidence. I seem to recall certain so called dogs nutsack company making chassis from T45 material without heat treatment and what was the result The customer where left having to weld the chassis after virtually every event from where they had cracked around the welds.

But Hey every one can make there own decisions. Just be nice if they actualy followed the regulations that they where supposed to be following !!.

Cheers Matt

Just about giving up on a forum full of BS.

Matt's right about the T45 tube being cantankerous stuff to use. Dangerous in the wrong hands.

T45 is a dumbed down/poor mans 4130, and needs to be treated as such.

There are a few different specs floating around regarding T45. The essence is that it is reduced carbon/chrome version of 4130, but has added manganese. The problem is that the carbon and chrome don't like to be heated and quick cooled, but need heat treatment after welding.

The material work hardens, which is why it WILL crack with time, if not properly post treated, and even then it will only have an increased life, but not by a lot.

The interesting thing is that T45 appears to now be outlawed in racecars in the USA along with difficulties in using 4130. This has come about because of people using these materials without the proper knowledge as how they must be treated.

There is some DOM tubes about that are very good(and even specced in CAMS rules!!), but are not legal for roll cages here. These don't have chrome or molybdenum, but utilise manganese for toughness.

The only real alternative to cds, is cds! If you read the Blue Book, then no advantage is to be had by using expensive high spec metals, except by having smaller sections, which need (expensive) individual approvals when used in cages designed as such.

Cheers,
Nev.