FrontEngineDragsters.Org Forum

Technical => Roo Man's Room => Topic started by: L79_Acadian on October 05, 2013, 01:54:47 PM

Title: looking for a "once over" on the chassis
Post by: L79_Acadian on October 05, 2013, 01:54:47 PM
Hi Roo,
 OK, I added the diagonal like you recommended. I also made a chute mount and changed the steering box mount also. Any criticism would be greatly appreciated.
I'm also going to go with a smaller tire.
  Thanks,
               Roger
Title: Re: looking for a "once over" on the chassis
Post by: GlennLever on October 05, 2013, 02:24:57 PM
Cable and wiring chases through the uprights of the tubes?
Title: Re: looking for a "once over" on the chassis
Post by: 225digger on October 05, 2013, 03:55:00 PM
shouldnt there be another bar under the front cage hoop  ?  that looks like a pretty big gap
Title: Re: looking for a "once over" on the chassis
Post by: rooman on October 06, 2013, 05:47:17 AM
shouldnt there be another bar under the front cage hoop  ?  that looks like a pretty big gap

Yep, there should be an upright placed 1" minimum to 6" max from the front cage hoop.

Roo
Title: Re: looking for a "once over" on the chassis
Post by: George on October 06, 2013, 07:12:25 AM
The last SFI spec book I bought was only $ 35. The best money I have spent on the car. I will never buy or build/rebuild without a current one in my hand.
Title: Re: looking for a "once over" on the chassis
Post by: wideopen231 on October 07, 2013, 07:22:26 AM
Agree with George. 35 bucks is cheap if it keeps you from having to have car certified second time because of something you didn't know about.  I bought mine 2 years ago and it is best 35 bucks I spent on chassis. Hopefully I have all things covered sfi wise.
Title: Re: looking for a "once over" on the chassis
Post by: L79_Acadian on October 08, 2013, 05:10:10 PM
Glen,thats a good idea,thw cable/wire chases. I think I will put a few in the upright. As far as the bar below the forward cage loop,is that bar required for a 7.50 and slower car?
  Thanks guys,
                   Roger
Title: Re: looking for a "once over" on the chassis
Post by: GlennLever on October 08, 2013, 05:35:00 PM
Glen,thats a good idea,thw cable/wire chases. I think I will put a few in the upright. As far as the bar below the forward cage loop,is that bar required for a 7.50 and slower car?
  Thanks guys,
                   Roger

Roo Man's design
Title: Re: looking for a "once over" on the chassis
Post by: slingshot383 on October 12, 2013, 07:12:07 AM
Frank Parks has been doing that for years, I don't know who did it first........
Title: Re: looking for a "once over" on the chassis
Post by: GlennLever on October 12, 2013, 12:18:35 PM
(http://www.leverfamilysite.com/images/2010_Dragster/Progress_2011_01_11/P1030004.JPG)

(http://www.leverfamilysite.com/images/2010_Dragster/Progress_2010_12_28/PC280004.JPG)

(http://www.leverfamilysite.com/images/2010_Dragster/Progress_2010_12_27/PC260003.JPG)
Title: Re: looking for a "once over" on the chassis
Post by: janjon on October 15, 2013, 08:36:35 PM
Yep, there should be an upright placed 1" minimum to 6" max from the front cage hoop.

Why the 1" minimum away? Why not directly underneath where the front cage hoop attaches to the shoulder hoop? Is this to create some ability of the structure to deflect a bit under impact loads?
Title: Re: looking for a "once over" on the chassis
Post by: rooman on October 21, 2013, 09:51:34 PM
Yep, there should be an upright placed 1" minimum to 6" max from the front cage hoop.

Why the 1" minimum away? Why not directly underneath where the front cage hoop attaches to the shoulder hoop? Is this to create some ability of the structure to deflect a bit under impact loads?

In a word Yes.

Roo
Title: Re: looking for a "once over" on the chassis
Post by: janjon on October 24, 2013, 06:12:49 PM
I notice that L79's placement of the joints of diagonals to uprights is somewhat above and below the intersection of the uprights' joints with the longitudinal tubes, rather than forming the apexes of two triangles between two uprights. I could see how this placement could make the joints more easily weldable to the novice welder, which I am certainly one, without the difficulties of getting into "tight crotches", so to speak. With respect to my question and your reply above, could this placement afford deflection/distortion potential in the event of an impact that would be possibly beneficial to whatever soft tissue might be onboard, and would this represent best practice, or acceptable practice?
Title: Re: looking for a "once over" on the chassis
Post by: slingshot383 on October 26, 2013, 05:45:18 AM
Putting that upright between 1" - 6"  away instead of straight under the the intersection of the bars is to absorb some of the energy in case of an accident instead of transfering all that energy to the driver. There is such a thing as making something too strong as it relates to the transference of energy. 
Title: Re: looking for a "once over" on the chassis
Post by: wideopen231 on October 26, 2013, 12:38:27 PM
Glen,thats a good idea,thw cable/wire chases. I think I will put a few in the upright. As far as the bar below the forward cage loop,is that bar required for a 7.50 and slower car?
  Thanks guys,
                   Roger

Roo Man's design

Not sure Roo Man takes the credit for the creation, I'm just crediting the person that introduced me to the idea.


 I think it goes back a long ways and not sure who did it first.Now if Rooman wants credit for something that old who am I to argue. :)

Our first funnycar built in early 80's had them and Im pretty sure Winston Cherry was not first either.
Title: Re: looking for a "once over" on the chassis
Post by: GlennLever on October 26, 2013, 02:24:51 PM
Glen,thats a good idea,thw cable/wire chases. I think I will put a few in the upright. As far as the bar below the forward cage loop,is that bar required for a 7.50 and slower car?
  Thanks guys,
                   Roger

Roo Man's design

Not sure Roo Man takes the credit for the creation, I'm just crediting the person that introduced me to the idea.

 I think it goes back a long ways and not sure who did it first.Now if Rooman wants credit for something that old who am I to argue. :)

Our first funnycar built in early 80's had them and Im pretty sure Winston Cherry was not first either.
Title: Re: looking for a "once over" on the chassis
Post by: GlennLever on October 26, 2013, 02:26:24 PM
Glen,thats a good idea,thw cable/wire chases. I think I will put a few in the upright. As far as the bar below the forward cage loop,is that bar required for a 7.50 and slower car?
  Thanks guys,
                   Roger

Roo Man's design


 I think it goes back a long ways and not sure who did it first.Now if Rooman wants credit for something that old who am I to argue. :)

Our first funnycar built in early 80's had them and Im pretty sure Winston Cherry was not first either.

Not sure Roo Man takes the credit for the creation, I'm just crediting the person that introduced me to the idea.
Title: Re: looking for a "once over" on the chassis
Post by: rooman on October 26, 2013, 09:10:45 PM
Definitely not my idea but it is the best way to route cables, lines etc and I put them in all of my cars. Frank Parks has the motor uprights in stock for less than it takes to make them yourself if you value your time at more than $10 hour.

Roo
Title: Re: looking for a "once over" on the chassis
Post by: dreracecar on November 27, 2013, 09:34:55 AM
My two areas of concern is the bend in the upper frame rail at the motor plate being to far back and making that section too flexable in an area that should be ridged and the rear end mounting plates are "HUGE"  and will allow the rear end to walk and shake at the hit. The rear end mounting shoud be as close to the round tube uprite as possible and the mounting plates as small accordingly and the framerail bend shoud be up at the rear motor plate.