Opinions on Chrome Molly Cages in Excels

[Crazy Dave]

I would like to know what people think of the idea of allowing chrome molly cages into the excels series. There are obvious pros and cons, but does this paint the wrong picture of being too expensive and increase the perception of how much it is going to cost to go in the excel series.

I have heard people claim that you can get a chrome molly cage for under $2000-, which I find very very hard to believe, but if it is true, then don't see any issues. Other issues are that need feedback from peoples experiences

How long they last, I have heard rumours of them cracking and needing inspections after 5 years.

How much weight is actually saved.

Are the safer, or safer in some situations and not as safe in others or about the same all the time.

Are they a performance advantage and if so how much. If they make the car more rigid, lighter than an equivalent steel cage, lower weight distribution etc.

And anything else you can think of.

I have included a poll with only 3 options for a consensus of the entire rallying community here as the excel series is an introductory series plus a series where people can go and play on an equal field without spending truckloads of dollars, so is somewhere that most may end up at at some stage if they have a change in circumstances, plus is a good way to help rallying grow so affects us all.

[Spac]

If you think oyu need a chromoly cage, then you are probably missing the point of the Excel series.

Chromoly is more likely to crack/break than mild steel of similar strength. I haven't heard of one cracking in use, but in medium-big crashes, chromoly ones have been known to crack/break.

Chromoly needs high-level welding skills, mostly due to the thinner walls. Where most competent backyard welders can weld together a safe CDW/CDS cage, most cannot do the same for chromoly.

Last I heard, homologation of any cage not made from CDW/CDS, required engineer certification (this includes chromoly). There are one or two approved engineers in the country. This approval costs ~$2000 alone.

The chromoly tubing is more expensive than CDS/CDW, but not ridiculously so. Cant remember figures, but my brain is telling me that the tubing is about 170~190% of the cost of CDW (very free to be corrected on that one!).

The density of the material is about the same as that of mild-steel. But for a given dimension, chromoly is signifcantly stronger - so you can make the tubing lighter (thinner walls and/or smaller diameter) and still have the same strength.
You could build a chromoly cage that is a similar strength to a CDW cage, but it would weight a fair bit less (sorry, no figures, too lazy to go and figure it out).
Alternatively, you could build a same-weight-as-CDW cage from chromoly and that it would be significantly stronger/stiffer.
In reality, most chromoly cages are built somewhere in the middle of those two extremes - a bit more strength/stiffness, and a bit less weight.


As someone who is unlikely to ever rally an Excel, but thinks the series is a great idea, I reckon that there's no place for chromoly cages in the Excel series.
If you're spending enough money to build an Excel that's good enough to justify a chromoly cage (ie: the best of everything), then you should f$%k off and build something else, and not foul up the series that's specifically designed to cater for entry and low-budget competitors.

[tortfeaser]

Who cares if someone wants to spend up big on a CroMo cage in an Excel? If someone wants to spend that cash to get a safer car for the same weight, go nuts.

Why option B? Its not like vehicle weight is ever measured at an Excel series round so a weight penalty is dumb.

If having a weight penalty is a serious option then having an appropriate minimum weight should be all the all that is needed to ensure that a CroMo cage isn't a significant advantage.

Over regulation for no good reason FTL.

5 yearly inspections not required. They don't crack on their own but in a bingle are more likely to crack than a CDS/CDW steel cage. But they'll take a bigger hit before they do (for the same tube size).

[paulfletcher]

Originally Posted by tortfeaser

Who cares if someone wants to spend up big on a CroMo cage in an Excel? If someone wants to spend that cash to get a safer car for the same weight, go nuts.

Why option B? Its not like vehicle weight is ever measured at an Excel series round so a weight penalty is dumb.

If having a weight penalty is a serious option then having an appropriate minimum weight should be all the all that is needed to ensure that a CroMo cage isn't a significant advantage.

Over regulation for no good reason FTL.

5 yearly inspections not required. They don't crack on their own but in a bingle are more likely to crack than a CDS/CDW steel cage. But they'll take a bigger hit before they do (for the same tube size).

Agree with these comments

Fletch

[Damo]

Originally Posted by tortfeaser

Who cares if someone wants to spend up big on a CroMo cage in an Excel? If someone wants to spend that cash to get a safer car for the same weight, go nuts.

What if someone wants to spend up big so they get a significantly lighter cage? (In a low cost, otherwise restricted class where it is hard to shed weight elsewhere).

In my opinion, it starts turning it into a $$$'s race, and goes against the whole idea of the Excels.

[Ben Wilson]

Mark will probably chime in here, but I seem to recall that the difference in weight was something like 30kg. Hardly nothing, but not enough to really make a major difference to the performance.

There is a lot more variation than that in crew weights.

[tortfeaser]

If there's a class minimum weight it is of miniscule importance how much the cage weighs.

If $ are important bring on claimer rules. And here comes the usual argument. Yes the Excel series could be cheap, and most want to have it that way. But if someone wanted to spend up big there's no way to prevent it.

Restrict cage materials? Then someone will spend squillions on suspension development. Have a single source supplier for suspension? Spend up big on new tyres. Control tyres? Spend up on rebuilding a new motor every event. Engine sealing? Spend up big on testing/practice.

There's no way to reduce spending if someone wants to spend. So stop trying to reduce spending by controls on things that can improve safety.

How about tightening up the existing rules to stop the little anomalies going on - power steering racks in non PS cars with no pumps. Antiroll bars absent/present/connected/disconnected. Various induction schemes. Emissions stuff absent/present. Probably all legal, but it seems outside the spirit of the thing, which I understood was like restricted Group N without the pain of homologation (although I think both the single and twin cams were homologated, although it is soon to expire).

[Ben Wilson]

Originally Posted by tortfeaser

How about tightening up the existing rules to stop the little anomalies going on - power steering racks in non PS cars with no pumps. Antiroll bars absent/present/connected/disconnected. Various induction schemes. Emissions stuff absent/present. Probably all legal, but it seems outside the spirit of the thing, which I understood was like restricted Group N without the pain of homologation (although I think both the single and twin cams were homologated, although it is soon to expire).

You have to leave some room for the owner to tune the car to suit their tastes, except for the emissions stuff, I can't see any of those things making a huge difference to the performance of the car.

[tortfeaser]

Its like saving 30kg, on its own its no big deal, but all those little things add up to a more competitve car in a control series and to a bunch of $ spent on development.

I really like the Excel series, wish it was around before I bought my car. Am jealous of Fro getting into it. But overregulation will kill it. Someone spending a bunch of $ won't kill it, the other competitors will think he's a knob and ignore him. But strangling it is not the way to go.

The PS stuff would make a difference - different ratio racks. Individual tuning is fine but it seems inconsistent to permit this kind of stuff but disallow a mod that could improve safety with no performance benefit (if weight is controlled).

[Damo]

Tort - the problem is controlling the weight. How many club/state events have you been to that have had a set of scales?

There is no use in introducing an arbitrary weight figure if there is no way to test it.

All the little 'anomalies' that you've listed are already covered in the regs (Group N for engine. PRC for everything else unless specifically mentioned), would only make a small improvement, and are relatively cost neutral/cheapish to do. As such, I would see them as being in the spirit of the series.

For a driver like me, the 30/50kg/whatever isnt going to be the difference between my usual placing at the back or me winning the series - but for a newbie considering building an Excel, the perception that they may need to spend $6k on a moly cage may be the difference between them starting rallying, or taking up drifting instead.....

[tortfeaser]

There is no perception you need to spend $6k on a CroMo cage. Just like there's no perception you need to spend $6k on Reiger suspension.

I mention the weight thing 'cos Dave thought a weight penalty for a CroMo cage was a serious option. If you're that serious about penalising those who want to pay more for less weight then isn't it massively inconsistent for the Excel series not to weigh cars?

[Damo]

That would be why that one does not have any votes!

[Spac]

All previous points are valid.

We've established that a decent chromoly cage will cost an extra ~$3500 compared to a similar CDW cage, and will bring some small but tangible performance benefits.

$3500 is a f$%kload of money to spend on one performance* item in a low cost, controlled category. For $3500 you could do any number of legal performance mods / more regular maintence that will be far more beneficial than a chromoly cage.
I'd go so far as to say that if any of the current Excel series car owners were handed $3500 to spend on their car, none of them would be ticking the option box marked "chromoly cage".

So maybe it's a moot point - I can't see too many people seriously taking up the option. What concerns me is that maybe someone is at the point where they're going to build Teh Killar Excel - a supposedly low cost econobox that 'needs' a chromoly cage to complete the puzzle. Remember that the class specifically prohibts things like cannister shocks because it's meant to be a cost limited class. To allow chromoly cages would obviously be a contradiction to the original philosophy.

Yes it's a philosophical argument rather than a technical one.

But to take the other view (and allow chromoly cages) will sell out one of the main reasons for the class' existance - at which point, prohibiting cannister shocks, quad throttle bodies, CR gears sets and all of those other cool things is/would be stupid.
And then you'd have to remind me: What's the point of the Excel series?

Way I see it, if you want to play with the bling, there's a whole world of PRC classes to do it in.

None of this is intended to dump on the person who wants to put a chromoly cage into an Excel-series Excel. Good on them for seeing an avenue to increase performance - but as the question has been asked from a legislator's point of view, it's been answered as such.

*In this context, a chromoly cage IS a performance item. Ask anyone who's got one (or wants one) why they want it, and you'll always get the same answer: weight. They do nothing that a CDW cage doesn't, from a safety point of view.

[smee]

How will allowing cromo cages sell out the series.
If someone is willing to put one in then let them. Does not mean they will be the shiz driver. Within the rules they could put in a cage that runs to a multitude of points and weighs the same as a standard 6 point CDS.
A cage is a cage is a cage at the end of it.
In other classes with regs around what can and cannot be done people are throwing money left right and centre to find that etc .5 second per lap kilometre advantage.
To me, it smells of sour grapes. If I can't afford to do it, then why should anyone be allowed to do it.
Yes, you can get in on the ground floor relatively cheaply, but there are also those who will go the extra yard by plating, welding or doing what ever they can to get an advantage.

[mrbob]

One thing that nobody has mentioned is the possibility of sharing homologation. I could have it wrong, but AFAIK you can homologate a CroMoly cage into a car, then use those papers to build the SAME cage into the SAME model car.

One thing I like about the excel series (which i WILL be in, once time/money/wife allows) is the fact that evryone works together and helps out with advice etc. If everyone (or even a few) chipped in for the homologation - I'm sure a cage builder could standardise a cage for the series and it would actually be reasonably cheap for everyone. I'm not suggesting a "control cage", but just to have it available for people that can justify the cost for safety/performance.

**DISCLAIMER** As I have stated, this is just my understanding, and I could have it massively wrong!!