Weight reduction, 4-door car

[gpeluso]

I have a four door.... Can I remove the rear window motors in the doors? How about the evap system ... Charcoal canisters too?

Greg

[Z3_GoCar]

Take this with a grain of salt, because I've not layed eyes on the ITCS, but I think that what ever allowance there is to remove the front door motors, air bags, and electric locking mechanism, should also work on the back door.

What about window glass? are you planning on keeping or removing it? I'd think you could even gut the rear doors, if you put in two mini door bars that extend into the cavity between the main hoop and the down braces. Your best bet is to read the appropriate section of the ITCS FWIW.

[ajmr2]

Club Racing? Solo? Class? Here's a good place to start if it's CR.

http://scca.cdn.racersites.com/prod/assets/2013%20GCR-%20August.pdf

[gpeluso]

Glass is to stay... No true door gutting... Currently running a 2.8 and feel that maybe a 2.5 (m54)might be better in the long run but need to loose 100 lbs.... Looking for every little possibility... Uphill battle with this car.

[gpeluso]

Car is ITR

[RSTPerformance]

Car is ITR

Where are you and what car is it?

Raymond

[gpeluso]

I live in pittsburgh and I ran it last weekend at beaverun and New Jersey the week prior at the pro-it.... Car is off by hp compared to an e36 currently and weights about 125 lbs compared..... If I can lose weight , I feel that the 2.5 (m54 ) will network similar horsepower but just a lighter car.. I currently run a standalone so plugging a different power plant is not hard... I have collected a small pile or used trannies and engines for experiments...2.5 Mtu, 2.8 Mtu , 2.5 m54 and both trannies... Same ratios but different between the 2.5 and 2.8

Greg

[Greg Amy]

We've had this discussion before...I don't recall the "final answer" but there was some disagreement.

The GCR, in the cage regs, states:

"Two side tubes connecting the front and main hoops across both door openings are mandatory."

No mention of "front" versus "rear" doors. Of course, the reason for this is protection of the driver, so the implication is the front doors.

However, the same regs also state:

"Door side tubes may extend into the front door."

...implying they cannot protrude into the rear door?

The regs further continue:

"In Improved Touring, Spec Miata, and Touring the door window glass, window operating mechanism, inner door trim panel, armrest, map pockets, wiring harnesses for door locks, windows, power mirrors, seat wiring, etc., and inside door latch/lock operating mechanism may be removed and the inner door structural panel may be modified, but not removed only if the door bars extend into the door cavity."

Therefore, one can remove/modify all those parts only if the doors bars extend into the door cavity. However, if one is only allowed to extend the tubes into the front door, then it follows you cannot remove those items from the rear door.

Finally, other than the "IIDSYCTYC", the ITCS states the following:

"Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted."

I suggest, based on the GCR cages regs cited above, that you cannot remove those items from the rear doors.

Thoughts? Counterpoints?

- GA

[Andy Bettencourt]

Agreed Greg. And for aero purposes, I would want the rear windows in I think.

[Ron Earp]

Damn I hate to hijack but....

" ITCS states the following:

"Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted."

My new driver cooling system is going to need a place for the radiator to exhaust heat from the car. I'd like to cut a 10" x 3" hole in the passenger side floor pan. I know somewhere in the GCR it states driver cooling systems can be added to race cars, therefore, would this modification fall under the clause above, i.e. legal because the cooling system is a authorized modification?

[Tristan Smith]

Ron,

It says it can be added, but not that the car/chassis can be modified to accommadate it.

I would say no on that one.


Damn I hate to hijack but....

" ITCS states the following:

"Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted."

My new driver cooling system is going to need a place for the radiator to exhaust heat from the car. I'd like to cut a 10" x 3" hole in the passenger side floor pan. I know somewhere in the GCR it states driver cooling systems can be added to race cars, therefore, would this modification fall under the clause above, i.e. legal because the cooling system is a authorized modification?

[gpeluso]

Guess the car must stay porky..... Disappointed but if that is the rules... That's the rules.
Wonder what other 4 door BMW guys have been doing?
Dumb question.... What would it hurt to allow? No cost advantage for rich guys... Plus I bet many who cross between clubs are doing this... Not bitching just real question..
Thanks
Greg

[tom91ita]

.....
I suggest, based on the GCR cages regs cited above, that you cannot remove those items from the rear doors.

Thoughts? Counterpoints?

- GA

Greg,

I agree that it is not real clear and i agree with your reasoning/rationale. i thought windows had to be down to race. like my passenger side window needs to be down, right? is this only for access/escape of the driver?

but I think this should be updated to add something like "window glass in rear doors can be removed if the normal full down position leaves the glass exposed."

in my formative years, the rear doors of my parents luxoboats (1968 pontiac catalina, etc.) had rear doors that had the glass that could be rolled down flush with the door. we could then extend our arms/hands and make airplane noises as we let the air move our hands up and down.

my 97 four door civic lets the glass only go down about 3/4's of the way. IF that car were made into an IT car, the exposed glass should not be allowed.

and if we are allowing the glass out of the rear doors on some cars then i would say do it for all cars.

i suggest the OP submit a change to the rules. I would also like to state that barring someone coming up with an unforeseen issue, the IT board support it.

[cjb25hs]

Rear windows cant be removed but run with them up. Not sure on the removal stuff if you could convert to manual windows which im sure dont exist that may be an option. Im sure there are some other places you can save some weight. Is 100% of all the sound deadening and undercoating from underneath wheel wells etc... All gone? Are you running the absolute lightest wheels you can find?

[Matt93SE]

IMO, if the car can't make weight otherwise, I don't see a reason why an IT car shouldn't be allowed to remove window motors and whatnot. (It falls within class philosophy I would think).
Write your friendly CRB a letter requesting clarification of such, and/or allowance to remove that junk if it is not currently allowed.

But hey, that's just me. These are freakin race cars. I don't need no window motor or washer fluid reservoir in my freakin race car.

... Yeah, I went there. Again.

[pfcs]

when I built my 4dr 142E Volvo, I petitioned the comp board, under errors and omissions, to change the wording about windows. A literal interpretation would have required that the rear windows also needed to be down, but there had been a finding in showroom stock that opened the door for closing them (whoo! near pun intended!)
It was clear to me that the 4 door Volvo would have much better aero with them up.
Also, since the front windows of 144Es were MUCH shorter than 142Es, and the vent windows could tame turbulence to the not so far back door pillar, I would have an advantage over the 2 door cars with their huge front window openings.
Consider this and weigh your choices: aereo or weight?

[JeffYoung]

No on the rear windows. No allowance for it.

No on cutting holes for radiators for driver cooling systems. You can however work out a ducting arrangement from the window.

[Z3_GoCar]

We've had this discussion before...I don't recall the "final answer" but there was some disagreement.

The GCR, in the cage regs, states:

"Two side tubes connecting the front and main hoops across both door openings are mandatory."

No mention of "front" versus "rear" doors. Of course, the reason for this is protection of the driver, so the implication is the front doors.

However, the same regs also state:

"Door side tubes may extend into the front door."

...implying they cannot protrude into the rear door?

The regs further continue:

"In Improved Touring, Spec Miata, and Touring the door window glass, window operating mechanism, inner door trim panel, armrest, map pockets, wiring harnesses for door locks, windows, power mirrors, seat wiring, etc., and inside door latch/lock operating mechanism may be removed and the inner door structural panel may be modified, but not removed only if the door bars extend into the door cavity."

Therefore, one can remove/modify all those parts only if the doors bars extend into the door cavity. However, if one is only allowed to extend the tubes into the front door, then it follows you cannot remove those items from the rear door.

Finally, other than the "IIDSYCTYC", the ITCS states the following:

"Other than to provide for the installation of required safety equipment or other authorized modifications, no other driver/passenger compartment alterations or gutting are permitted."

I suggest, based on the GCR cages regs cited above, that you cannot remove those items from the rear doors.

Thoughts? Counterpoints?

- GA

Ok, so I went and reviewed the new cage section. Something interesting:

9.G.6
Any number of additional tube elements is permitted within the boundaries of the cage structure. Such tube elements may pass through any mandatory or optional bulkhead or panel separating the driver/passenger compartment from the trunk/ cargo area/fuel tank/fuel cell area provided the bulkhead is sealed around such tube elements.

So, you can add an optional rear door bar (becaous it's not a manditory element it could be one tube of 1/2" x 0.080 thin wall) that extends into the door cavity, because it doesn't extend into any of the listed bulkheads, you don't need to add a seal around the optional tubes. Then it also satisfies the door bars (plural, no upper limit on the number of them) requirement for door gutting(not limited to front doors only). Tell my why this doesn't make sense??

[Greg Amy]

Tell my why this doesn't make sense??

I suggest it meets the literal interpretation of the regs (not quite sure how you're going to "seal" the inner door cavity to the tubes and still be able to open the door) and I also suggest it's intorturation and potentially against the spirit of the regs could lead to being deemed non-compliant.

Worth a request for clarification (and/or request for regs change) before spending the money.

- GA

[gpeluso]

How about just letting me remove window motors ..... Keeping glass!.....hahaha
I can not see how this hurts the rules or the class.... How many bmw's are running non-compliant???? Dumb reason to keep away. I will still play, just running out of ideas.

Thanks guys!

Greg

[StephenB]

"additional tube elements is permitted within*the boundaries of the cage structure."

I don't think rear door bars would be compliant unless you are making a case for the passenger area being part of the drivers compartment.



Stephen.

[Ron Earp]

IMO, if the car can't make weight otherwise, I don't see a reason why an IT car shouldn't be allowed to remove window motors and whatnot. (It falls within class philosophy I would think).
Write your friendly CRB a letter requesting clarification of such, and/or allowance to remove that junk if it is not currently allowed.

But hey, that's just me. These are freakin race cars. I don't need no window motor or washer fluid reservoir in my freakin race car.

... Yeah, I went there. Again.

Good luck with that line of thinking. It's been discussed on the forum many times with the conclusion that if it is allowed IT goes to hell, your wife leaves you, and you'll be on your knees in a nasty hotel room working for a place to sleep.

[Matt93SE]

Good luck with that line of thinking. It's been discussed on the forum many times with the conclusion that if it is allowed IT goes to hell, your wife leaves you, and you'll be on your knees in a nasty hotel room working for a place to sleep.

Sounds like a normal race weekend to me anyway! Begging the fast guys for tire takeoffs, sleeping on the trailer floor, and showering in the bathroom sink! (Welcome to the big-budget world of Super Touring! HA!!)

[tsrauto51]

Good timing on this discussion. We are building an E36 M3 sedan to do some endurance races. The rules are more open there. It would be an ITE car anyway. My question is can the rear doors be welded shut?
Brad

[Ron Earp]

Good timing on this discussion. We are building an E36 M3 sedan to do some endurance races. The rules are more open there. It would be an ITE car anyway. My question is can the rear doors be welded shut?
Brad

ITE various from region to region. In NC an ITE car is a race that that meets IT SAFETY specifications, not IT prep levels. So, your ITE M3 can be seam welded, V8 transplanted, with carbon fiber brakes if that flips your lid.

I'm considering an ITE "prep package" for my ITS Mustang to run in an enduro event. We'd have a different engine and brakes, but otherwise it'd be an ITS car.

[tom91ita]

"additional tube elements is permitted within*the boundaries of the cage structure."

I don't think rear door bars would be compliant unless you are making a case for the passenger area being part of the drivers compartment.



Stephen.

Many of us have added a bar between the rear shock tower area. Is this part of the driver compartment? By your reasoning these would not be allowed or did I misunderstand you?

[StephenB]

That would be legal in my opinion because it is within the confines of the required roll cage structure. Well actually as I type this I realize it doesn't even matter if it's required since that word is not within the regs. So I guess now we need classification on what a "cage structure" is to know what is inside of that area.... Ok so now I am wondering what the definition is on inside... inside geographically from all directions or just when viewing from the top or just the side, or does it just need to attach to the cage structure?

So many ways to interpret it... :)

Stephen.

[Z3_GoCar]

I suggest it meets the literal interpretation of the regs (not quite sure how you're going to "seal" the inner door cavity to the tubes and still be able to open the door) and I also suggest it's intorturation and potentially against the spirit of the regs could lead to being deemed non-compliant.

Worth a request for clarification (and/or request for regs change) before spending the money.

- GA

But you only have to seal the tubes if they go through the listed bulkhead between the passenger compartment and the trunk/cargo/fuel tank/fuel cell area; otherwise, you'd also have to seal the front door bars too. As you point out the section on door panel modification doesn't specify front or rear doors. Besides you must admit there's nothing wrong with a literal interpretation. IISYCYC.

[Flyinglizard]

Most 4 dr cars have the seat back into the rear seat area. Do the rules prohibit boring a cage hole through the B pillar? Doing so would allow the rear door to be gutted to meet the NASCAR bar rule.

It also seems as tho you can move the seat back , move the pedals a bit and extend the steering column with a race wheel.


The SMAC simply says, yes gut both doors and carry on.

[JLawton]

In reality I don't think anyone would care, let alone protest if the rear doors were gutted.......... with door bars

Not sure how to interpret the rules in this regard (far smarter people than me are discussing it) but I think it falls within the spirit of the rules.............

[Chip42]

Most 4 dr cars have the seat back into the rear seat area. Do the rules prohibit boring a cage hole through the B pillar? Doing so would allow the rear door to be gutted to meet the NASCAR bar rule.

the rules do not ALLOW cutting the B pillar, only bulkheads and inner door panels with a NASCAR bar. no allowance means not legal to do so.

there have been a lot of cages that are not as good as they could have been because of design compromises to avoid cutting the pillar when forming the NASCAR bars, but thems the rules. I believe it stems from a desire to not see major structural weakening of the stock tub in a situation where the cage has limited allowed attachment points, and I generally support that rationale.

on EDIT:

to even produce a NASCAR rear door bar would effectively be adding "U" shaped "wings" to the required members of the cage in order to have them protrude from the main hoop / rear bracing structure (which must be straight) into the rear door cavity. it could be argued as legal, but why bother? also, in a side-impact, this could increase the forces on the rear bracing structure by passing them directly to the cage rather than the cage reinforcing the area inside of the tub and accepting loads as distributed through same. so the cage would in turn need to have added elements (from base requirements) to help distribute these loads and brace against deformation or collapse from them, again, all within the allowed mounting points.

[quadzjr]

please re-read what Greg already mentioned..

Remember in Improved touring if it does not specifically say you can, then you cannot.

In recap.. It says door bars are mandatory between front and main hoop.. Nothing to do with the rear of the car.

So this is not an allowance for rear bars.

"Door side tubes may extend into the front door."

This specifically allows the bars to extend into the front door. Not the rear.

In Improved Touring, Spec Miata, and Touring the door window glass, window operating mechanism, inner door trim panel, armrest, map pockets, wiring harnesses for door locks, windows, power mirrors, seat wiring, etc., and inside door latch/lock operating mechanism may be removed and the inner door structural panel may be modified, but not removed only if the door bars extend into the door cavity."

Therefore, one can remove/modify all those parts only if the doors bars extend into the door cavity. However, if one is only allowed to extend the tubes into the front door, then it follows you cannot remove those items from the rear door.

To recap per the GCR. Cutting the door structure is allowed provided the cage protrudes into them. It specifically states that the cage is allowed to protrude into the front doors. Nothing allows for cutting the inner door structure of the rear door.