Need ?? Chassis inspector for NHRA certification

Coleydog · 08-23-2017, 12:46 PM

I need some input on the cage I'm doing, just cross bracing tube size (side impact), would like to discuss this. I don't know if these inspectors can be contacted or will answer my questions, but willing to try. Yes, I have a rule book.
Mike

Hacksaw · 08-23-2017, 01:28 PM

Any Divisional Tech guy will gladly help answer your chassis questions. Better yet, call someone that does chassis certs. Tell us your concerns and myself or someone else should be able to answer. ( lower kidney bar? )

Coleydog · 08-23-2017, 02:31 PM

Main hoop, vertical corner to corner diagonal, an X. If a side hit, nothing to keep the hoop from moving over with the impact, Imo. Cross seat bar is 1-1/4 ,065 4130, can it be the same size or ?? It's all 4130 now.

Hacksaw · 08-23-2017, 08:29 PM

The lower diags that fit under your main hoop cross bar and travel towards the tunnel will be your answer. 1-1/4 x .058" is the min. use .065" if that's what you have.

Coleydog · 08-24-2017, 05:24 PM

That's what I was thinking too, like the lower diagonals. But I want to go to the top corners somehow tying into cross bar. Maybe not needed but sure looks weak in that direction, how strong is 4130? How hard a hit can hoop at the roof take? Could be I'm over thinking this, car maybe will go 10.90 at best. I also want to build this once and be done with it, taking to long now.
Thanks for your input
Mike

Hacksaw · 08-24-2017, 08:38 PM

Mike: IMO There is no need for a cross x or diags into the upper corners of the main hoop. (not considering the halo). You could add a x rearward to compliment the two back bars, if it makes you feel better. Moly is a very strong material. Check it yourself, compare bending to mild steel, smash it with a hammer, put a file to it.

08-23-2017, 12:46 PM	#1
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Need ?? Chassis inspector for NHRA certification I need some input on the cage I'm doing, just cross bracing tube size (side impact), would like to discuss this. I don't know if these inspectors can be contacted or will answer my questions, but willing to try. Yes, I have a rule book. Mike

08-23-2017, 01:28 PM	#2
Hacksaw Senior Member Join Date: Sep 2016 Posts: 880 Likes: 201 Liked 306 Times in 172 Posts	Re: Need ?? Chassis inspector for NHRA certification Any Divisional Tech guy will gladly help answer your chassis questions. Better yet, call someone that does chassis certs. Tell us your concerns and myself or someone else should be able to answer. ( lower kidney bar? )

08-23-2017, 02:31 PM	#3
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Re: Need ?? Chassis inspector for NHRA certification Main hoop, vertical corner to corner diagonal, an X. If a side hit, nothing to keep the hoop from moving over with the impact, Imo. Cross seat bar is 1-1/4 ,065 4130, can it be the same size or ?? It's all 4130 now.

08-23-2017, 08:29 PM	#4
Hacksaw Senior Member Join Date: Sep 2016 Posts: 880 Likes: 201 Liked 306 Times in 172 Posts	Re: Need ?? Chassis inspector for NHRA certification The lower diags that fit under your main hoop cross bar and travel towards the tunnel will be your answer. 1-1/4 x .058" is the min. use .065" if that's what you have.

08-24-2017, 05:24 PM	#5
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Re: Need ?? Chassis inspector for NHRA certification That's what I was thinking too, like the lower diagonals. But I want to go to the top corners somehow tying into cross bar. Maybe not needed but sure looks weak in that direction, how strong is 4130? How hard a hit can hoop at the roof take? Could be I'm over thinking this, car maybe will go 10.90 at best. I also want to build this once and be done with it, taking to long now. Thanks for your input Mike

08-24-2017, 08:38 PM	#6
Hacksaw Senior Member Join Date: Sep 2016 Posts: 880 Likes: 201 Liked 306 Times in 172 Posts	Re: Need ?? Chassis inspector for NHRA certification Mike: IMO There is no need for a cross x or diags into the upper corners of the main hoop. (not considering the halo). You could add a x rearward to compliment the two back bars, if it makes you feel better. Moly is a very strong material. Check it yourself, compare bending to mild steel, smash it with a hammer, put a file to it.