Cost of Installing a Weld in Cage (FD)

[stacy]

Shaun,

More thoughts..

I kept the original dash, just had it flocked with carbon sheets for switching where the centre console used to be. Looks pretty good I think.

A tricky roll cage will be limited if you are performing no shell prep. Path of least resistence and all that, so do seam weld if you go to a full multipoint otherwise you will suffer from a degree of shell flex hampering performance. You want all the movement directed into the controllable components as a guide.


Just think it through holistically if that makes sense - shell/cage/bushing/suspension/tyres. Make everything fit the bill.

As an example I once watched a Jag racer (bit of a Herbert) go and spend over a grand a corner on wonderful tricky dampers. I wanted him corner in the car and could see the shell flexing. Afterwards I talked to him in the paddock and he was complaining that he could make them full soft or full hard and not tell the difference. No sh*t sherlock..

For cage development I would look at Custom Cages, and if you want a work of art from previous World Champions talk to Gartrac in Chiddingfold. Their labour rates are less than you\'d think too (less indeed than many \'specialists\').

Depends on location of course.

Looms are the devils work as far as I\'m concerned, it\'s the one thing we don\'t touch (unless it failed as we\'ve had). IMO too high a risk of introducing unreliability unless you\'re paying a shed load (and even then if it\'s not done properly), so stick to the original and rip out what you don\'t need?

Must go.

S.

[stacy]

Shaun,

T45 cages are perfectly legal for both MSA and FIA use, and the cages have been homologated properly by the suppliers before sale to you.. You can buy Custom Cages cages in kit form and have them installed by a preparer, it\'s very common. Alternatively they will install themselves in either CDS or T45.

It\'s not a fad, it\'s been in serious motorsport for years. They save significant weight and weight which of course is high up and thus increases the lever arm. Other alloys are now also around I believe, again perfectly legal if you\'re having a pro install.

Talk to a pro cage manufacturer.

There are arguments against T45, but being inherently illegal isn\'t one of them.

S.

[AtomicRex]

Tony runs a standard dash, and we run a carbon replica.  It is a fraction of the weight and looks identical in shape.  It is a personal opinion and depends on how far you want to take your weight saving exploits!
 
All of our shells are seem welded, as Stacey rightly says, suspension needs to work against a solid platform.  There is no point in having flex within the chassis, as this wont allow you to set up the suspension and obtain reliable feedback.  Likewise we are developing a new ARB, this will be using different mounts as the mounts on the standard car are chocolate...and will introduce flex thus not allowing the ARB to do its job correctly.
 
I disagree with you Stacey about needing to go to Custom Cages.  Our cage is a hybrid and works very well...come and see it if you are in any doubt.  Bill at Gartrac is fantastic, although if you think their rates are cheap.....:0....Id hate to see what you think is acceptable!  Bill fitted a bespoke cage to my Atom, and the quality of the work was amazing!  We have had a good number of happy cage customers now...so come and see it
 
I also disagree with you about the loom too.  It isn\'t the devils work, they are very easy.  I have fitted a complete new loom to all my cars, and they have worked first time, and apart from an indicator bulb that had blown, without fault.  If you were running the Apexi ECU then keeping the existing engine loom and ripping out the unnecessary stuff would be fine....then building a chassis loom.
 
My looms come with markers at both ends and in the middle to identify the wire in a hurry.  They are correctly matched to the current draw on the item....fuel pumps for instance.  They use motorsport fuses, that can be instantly reset if they blow (spikes can cause a blade fuse to blow, but the item will be fine to continue)
 
I have never had a custom loom fail, and it gives you piece of mind that you know it will work as it is meant to.

[AtomicRex]

Shaun,
 
T45 cages are perfectly legal for both MSA and FIA use, and the cages have been homologated properly by the suppliers before sale to you.. You can buy Custom Cages cages in kit form and have them installed by a preparer, it\'s very common. Alternatively they will install themselves in either CDS or T45.
 
It\'s not a fad, it\'s been in serious motorsport for years. They save significant weight and weight which of course is high up and thus increases the lever arm. Other alloys are now also around I believe, again perfectly legal if you\'re having a pro install.
 
Talk to a pro cage manufacturer.
 
There are arguments against T45, but being inherently illegal isn\'t one of them.
 
S.

I never said that the cage was illegal.
 
Unless the design has been specifically designed for the particular car...then it will need to follow the exact design laid out within the Blue book. No one has designed a cage for the Rx7 that has been to MIRA and subsequently tested for homologation. To fit a cage made from T45 would therefore be a waste of money...as it is basically the same in everyway apart from material of the CDS cage. there is no weight saving benefit...the only thing you gain is added strength as the extra thick tube made from T45 will be stronger than its CDS counterpart. However being the CDS cage is already strong enough...what is point???
 
By the way...this comes direct from Custom Cages...If you had seen some of the parts we have developed....you would know I don\'t skimp on spending the cash unless unnecessary. I spent ages with Custom Cages talking about this, and considered having my own cage made.....but stuck with the standard one.

[shaunwil]

Cheers guys ! Some wonderful information.

The idea at the minute is to get most of summer over, save up some cash and get it done over the colder months.

Looking at jons rates he would be the guy fitting the cage into the car

I\'m probably going to go back to tweeks and sit in all their display seats again before making the seat decision.

I suppose another question would be can I run a digital dash with the Apexi PFC ?? Although if I kept the standard dash then I would keep the FD Dash bits too

On the dash front, how much can I take out under there ? I still have the aircon system under there !

Maybe the cage isn\'t the first step. I might start removing interior weight first and take it from there ! I\'ll have to get it weighed at every step

I\'m happy enough to do any wiring myself. Doesn\'t really worry me too much. Probably if it was a complete lighting loom would be controlling the up and down of the headlights !

Cheers

Shaun

[AtomicRex]

Depends on what you want to get from the digital dash??
 
The system we are putting together at the moment for our own cars runs on CAN.  It allows the ECU, the dash and even the wiring loom all to talk to each other, and react to known scenarios.
 
I have my old digital dash here for sale at the moment...I used this in conjunction with an Apexi PFC with good success
 
Your best bet is to strip the car and all of its sound deadening....and then get the seam welding and cage in place.  That way you can start building around it.
 
If you are planning to rewire the car then strip everything from under the dash...nothing under there is needed...then get Sophie (ChrisRx7 better half) to flock your dash for you.
 
The screen is bonded into place....best you do that last, as less chance of it getting broken!

[stacy]

Hi,

Gartrac charged me £35-£40 an hour for work they\'ve undertaken, which seemed to me to be a lot less than many others I have experience of.  It was a work of art too, as well as being very open about why they do things.

I hadn\'t realised you were flogging your own cage design, apologies, doing you out of business wasn\'t my intent. I would say though that while you haven\'t homologated your design with T45 that doesn\'t mean others haven\'t done so, so a comparison across multiple providers would do no harm. Custom Cages have increased in cost recently, but they will sell the kit direct, and I have had zero bad feedback from the dozen or so active (& winning) racers I know who run them. Worth investigation.

If your loom is a proper design (eg; doesn\'t stop the ECU when an indicator fuses), properly rated (no nuclear fuses/wires to burn your hand even when it doesn\'t blow..), properly labelled (priceless when dealing with problems in the field..) and properly installed (and it sounds like it is) then you have my respect. I still maintain though that automotive electrics is not a subject which comes naturally to humans, so would contend you are still "one of the few".. ;-)

S.

[stacy]

Hi,

As there seemed to be a danger that I was living in some parallel world, had completely the wrong end of the stick, and was vigorously waving it around (it does happen), I have just called Custom Cages.

They advised me that their FD RX7 cage comes with the same certification in either CDS or T45 for MSA approval, and the T45 cage is c10kg lighter.

Cheers

S.

[AtomicRex]

If the cage is only to MSA approval then it will be a lot lighter since the cage wont be as complex.  I dont personally see a point in limiting yourself to MSA only, as they are a law to themselves and could suggest that FIA is the way forward!  Plus the resale value of the car decreases as you are limiting the series that these cars can run in.
 
The cage in my Orange car was installed by Custom Cages, and the cages we have installed in our customer cars have been from Custom Cages too!  They are a very good cage, we have made a few changes however...using another company more local called Caged. They do the cages for the cars such as the Lotus two-eleven, and build the chassis for caterham.

[stacy]

Blimey, this could run and run..

The cage they offer is the same - CDS or T45. I refer to their diagram.

The vast majority of cages used in the UK today meet MSA criteria. You are not restricting your use unless you intent to run in FIA only events which require FIA paperwork - perhaps Historic Appendix K (but the FD is not eligible anyway).

Events abroad are usually run to MSA standards, and I have in fact run my RX7 (with an MSA cage) in FIA events, to FIA regulations, and fully complied.. I also have an Appendix K Lotus Cortina with papers eligible for a European series.

Again, unless you are fully (for example) Appendix K compliant and competing in historic events I am not aware of any increase in resale value in this context. Indeed a well known brand might be argued to be a safer bet than a bespoke cage from a less well known provider - regardless of how good the work is.

Look, I have no axe to grind here and didn\'t wish to antagonise you - I am just trying to point out some things which to the uninitiated might prove to be misunderstood.

S.

[AtomicRex]

Hey Stacy,
 
I wasn\'t spoiling for a fight in anyway...just enjoying the discussion

[shaunwil]

Wow I\'m away for the afternoon and a mad conversation ensues :Giggle

I\'m off this week so with my head in the air about it I\'ve just got back from tweeks and I\'ve ordered a Sparco Sprint 5 http://www.sparcousa.com/pseats_comp.asp?id=622 Its a side or base mount so I\'ll laser some adapters out of 3mm mild steel and get it fit.

It was the only one that felt really nice and wasn\'t huge. Looked very small compared to all the other seats on display. Plus it was the cheapest They didn\'t have the colour I wanted instock so they chucked in free postage so worked out good value

Going to get it fit and then work out harness positions for it

Shaun

[BlitzBoy]

Well lucky Shaun you dont want to enter a Drag Series because neither cages being talked about in your thread are legal for a Drag racing series lol

Be great if you do enter the Nippon, that would make 3 Rx7s in the series.

[Archbish]

surely it\'s easier to install an inflatable cage???  Just velcro it to the carpet and zip tie to sunvisors, and you\'re there already.  In the event of an accident, there is even a nice soft bit to hit your head on!!

[shaunwil]

lol, very much demolition man then !

The nippon would be some serious time off. would be the slowest of the 3 FD\'s :Giggle

Shaun