Tubing size for a 2650 pound IT car

[Ron]

Is it ok to use 1.5 inch .120 wall DOM tubing for the rollcage in a 2650 pound car?

[racer_tim]

Ron, that is the smallest diameter tubing:

IT Cars 2,201 - 3,000 lbs:

1.5" x 1.20 DOM/Seamless/Alloy
1.625" x 1.20 DOM/Seamless/Alloy
1.75" x .095 DOM/Seamless/Alloy


This is from the 203 GCR, section 18.1.3.6.C


------------------
Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html

[This message has been edited by racer_tim (edited January 12, 2004).]

[Greg Amy]

1.75x.095 is lighter and stronger
than 1.50x.120...

[itbgti]

I am now a little confused by this...if someone can please post this entire section from the GCR, that would be great.

Here is my confusion...just talked with a fellow racer on the phone who has a GCR handy, it seems there is some rule that says cars "registered" after 1994 must go by the rules which Tim posted....what does "registered" mean, original log book issue date? or model year of car?

Also, the weights posted, I believe that is WITHOUT driver in the car, correct?

Any input would be greatly appreciated.

[Speed Raycer]

When the logbook was issued, but I believe that if you change the cage out, it doesn't matter anyway as a new cage has to meet the current rules.

IIRC, (no gcr in front of me) tubing size is determined by the spec line weight minus 180 lbs

[moto62]

Originally posted by itbgti:
Also, the weights posted, I believe that is WITHOUT driver in the car, correct?

Not correct. The weight in the itcs is the minimum allowable weight with driver,GCR 17.9,......at the conclusion of a race or qualifying session.
Ray

[Geo]

Originally posted by moto62:
Not correct. The weight in the itcs is the minimum allowable weight with driver,GCR 17.9,......at the conclusion of a race or qualifying session.
Ray

Dude, you got this one so wrong.

The GCR rule you mention is strictly for determining weight and has nothing to do with the rollcage.

GCR 18.1.6.B clearly states "Vehicle Weight Without Driver."

In addition GCR 18.1.6.D also clearly states "For the purposes of determining tubing sizes, the vehicle weight is as raced without fuel and driver."

Furthermore, 18.1.6.D also says "Improved Touring roll cage tubing sizes are to be calculated based on the published vehicle weight minus 180 lbs."


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[Knestis]

Yeah - I looked too but don't remember seeing the "180 pound rule" before. That seems like it snuck in there when I wasn't looking...

K

Edit - and interestingly, I went with 1.75x.095 tubing when I could have gotten by with 1.50, based on this new-to-me information.

[This message has been edited by Knestis (edited January 13, 2004).]

[itbgti]

Thanks for the posts!

Kirk, your post is exactly why I asked...my cage is 1.5x.095 DOM and it has passed three annual techs. I was confused with the first couple of posts, and not having a GCR at the office, I wanted to know about the 180 lb difference...keeps me legal

Thanks again.

Alan

[moto62]

Originally posted by Geo:
Dude, you got this one so wrong.

Duhhhh! Yeah. This is a roll cage thread isn't it.
Ray