Drifting Discuss Drifting and drifting techniques here.

My new knuckle setup on my FD!

Thread Tools
 
Search this Thread
 
Old 01-25-13 | 07:55 PM
  #1  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
My new knuckle setup on my FD!

redesigned some knuckles and i love the out come!!!

Name:  image-4_zps3a732f25.jpg
Views: 457
Size:  93.5 KB
Old 01-25-13 | 08:20 PM
  #2  
joshuaput's Avatar
Electric is the mood.
 
Joined: May 2005
Posts: 468
Likes: 1
From: !
schwooo
fds are awesome with like 48degrees of angle. whats this at? I bet thats going to blow minds.

Also those tires are awesome in the rear.
Old 01-26-13 | 12:21 AM
  #3  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
That's about 75-80 degreas
Old 01-26-13 | 12:35 AM
  #4  
Battle Cat's Avatar
Space cadet

iTrader: (78)
 
Joined: Nov 2007
Posts: 10,308
Likes: 3
From: LOS ANGELES
hows your inner clearance on the LCA?
Old 01-26-13 | 01:28 AM
  #5  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
I fixes the problem where the caliper hits the lca with my knuckles And my wheels hit the frame or they would turn more!!
Old 01-26-13 | 12:50 PM
  #6  
ballinnmiami240sx's Avatar
Senior Member

iTrader: (2)
 
Joined: Mar 2006
Posts: 665
Likes: 0
From: gloucester
your calipers on?
Old 01-26-13 | 01:12 PM
  #7  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
Lol yes they are on! That picture is fully bolted up and only one inch higher than ride height!
Old 01-26-13 | 02:18 PM
  #8  
Battle Cat's Avatar
Space cadet

iTrader: (78)
 
Joined: Nov 2007
Posts: 10,308
Likes: 3
From: LOS ANGELES
im still waiting to see if any one makes a LCA that allows for more angle/clearance
Old 01-26-13 | 10:37 PM
  #9  
driftfcbuckey's Avatar
RX7-Factory
iTrader: (8)
 
Joined: Jan 2008
Posts: 2,674
Likes: 18
From: Vegas
Measure it up! Looks good
Old 01-26-13 | 10:45 PM
  #10  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
Well with my knuckles you don't need aftermarket lcas! And if you want more angle you need to modify the knuckles any how so why even bother with them?
Old 01-27-13 | 09:56 AM
  #11  
ballinnmiami240sx's Avatar
Senior Member

iTrader: (2)
 
Joined: Mar 2006
Posts: 665
Likes: 0
From: gloucester
im planning to make new lca's soon.
Old 01-27-13 | 10:08 AM
  #12  
boogerburns's Avatar
Junior Member
 
Joined: Jan 2013
Posts: 5
Likes: 0
From: Marietta
Thats some mad angle! What did you do to them to clear the lca?
Old 02-05-13 | 09:10 AM
  #13  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
I fixed the roll center by dropping down the lower balljoint on the knuckle by one inch and shortened the tie rod pickup and turned it in!
Old 02-05-13 | 04:33 PM
  #14  
mannykiller's Avatar
Garage Hero
iTrader: (93)
 
Joined: Aug 2009
Posts: 4,205
Likes: 18
From: Quartz Hill
I'd really like to see the actual knuckle if you have a pic of them..
Old 02-11-13 | 12:18 AM
  #15  
SpAm@FC's Avatar
Senior Member
iTrader: (4)
 
Joined: Jun 2003
Posts: 734
Likes: 1
From: Austria
more pics please!
Old 02-11-13 | 06:17 PM
  #16  
MadJap's Avatar
Junior Member
 
Joined: Feb 2013
Posts: 1
Likes: 0
From: Russia/Moscow
It's really very cool!!!!
More pics please!!!)))
Old 03-11-13 | 12:15 PM
  #17  
mannykiller's Avatar
Garage Hero
iTrader: (93)
 
Joined: Aug 2009
Posts: 4,205
Likes: 18
From: Quartz Hill
updates? knuckle pics?
Old 03-14-13 | 10:51 AM
  #18  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
soon guys! i have been overly busy down at Pettit Racing rebuilding the 20b!
Old 03-14-13 | 12:00 PM
  #19  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
Well here is my secret!
Name:  IMG_20130314_101309_zpsc2d75085.jpg
Views: 641
Size:  108.5 KB
Old 03-14-13 | 06:14 PM
  #20  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Originally Posted by campo
Well here is my secret!
How do you think the strength compares to stock? It is hard to see the material thickness in the photo with the paint on. Looks like chopped and turned... Did you V groove and fill with weld?
Old 03-14-13 | 07:48 PM
  #21  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
yes its v-grooved! i have an old buz box welder that will melt 5 inch thick steal so i know they wont break. the steal plate i used for the drop and bracing is quarter inch.
Old 03-15-13 | 08:05 AM
  #22  
mikerbike's Avatar
Dreamin' of Rotary
 
Joined: May 2009
Posts: 145
Likes: 0
From: Utah
Did you get a funky/intense camber curve, since your upper and lower arms are further angled apart than they were before? Or do you not really care about that kind of stuff?
Old 03-15-13 | 11:33 AM
  #23  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
You aren't going to leave that huge spacer/bolt in single shear on the tie rod end... right?

Melt 5 inch thick steel? Not with 220V and house current. And not that you would ever need to. I'll take your word that your welder has enough juice for a multipass on 1" cast steel/iron penetrating .25" at a time though.
Old 03-15-13 | 12:31 PM
  #24  
campo's Avatar
Thread Starter
Full Member

iTrader: (3)
 
Joined: Feb 2011
Posts: 147
Likes: 0
From: GA
Originally Posted by mikerbike
Did you get a funky/intense camber curve, since your upper and lower arms are further angled apart than they were before? Or do you not really care about that kind of stuff?
the straight line driving has intense neg camber but at full lock the tires have full contact leading wheel and trailing wheel like i wanted.

Originally Posted by RogueFab
You aren't going to leave that huge spacer/bolt in single shear on the tie rod end... right?

Melt 5 inch thick steel? Not with 220V and house current. And not that you would ever need to. I'll take your word that your welder has enough juice for a multipass on 1" cast steel/iron penetrating .25" at a time though.
No im not gonna leave them like that, even though they are all grade 10. it was just a mockup i made but im going to drill out the knuckles and put in copper bushings so there is no taper and then i just replace the copper bushing over time when they wear down.

and it wont melt 5" on a quick pass but its a 50+ year old welder and i can melt these knuckles to a pile of scrap if i wanted. its intense. i can take a video of it when i get back from vacation if you'd like
Old 03-16-13 | 11:26 AM
  #25  
RogueFab's Avatar
Full Member
iTrader: (2)
 
Joined: Feb 2013
Posts: 158
Likes: 0
From: Pacific Northwest
Originally Posted by campo
the straight line driving has intense neg camber but at full lock the tires have full contact leading wheel and trailing wheel like i wanted.



No im not gonna leave them like that, even though they are all grade 10. it was just a mockup i made but im going to drill out the knuckles and put in copper bushings so there is no taper and then i just replace the copper bushing over time when they wear down.

and it wont melt 5" on a quick pass but its a 50+ year old welder and i can melt these knuckles to a pile of scrap if i wanted. its intense. i can take a video of it when i get back from vacation if you'd like
My concern isn't the hardware, it is the Z distance from the knuckle casting to the point where the heim is mounted. Your stress in that pin is much more significant from bending load than from shear, and your bending load is proportional to the moment arm length (Z/vertical dist). Furthermore, your linear steering force required is inversely proportional to the Y/forward distance from your knuckle pivot axis to the tie rod hole. Without taking measurements, it looks like you cut about 1/3 of steering moment arm off, and tripled the Z distance. With those numbers, you will have more than 450% of the load in that pin that an OEM setup has. If you want to see a free body diagram or more engineering analysis, let me know.

One other drawback will be deflection in that long bolt (or any other long hardware you use). With the long moment arm and high loading, you will see some serious movement at the heim before the tire moves (which will of course be worse with the engine installed and when the car stopped).

You did an amazing job cranking a ton of steering travel out of that setup, and I am only posting this so that I can alert you of what in my opinion is a safety issue. I am glad you are innovating, and I would love to see this thing drifted at steering lock with this setup! Just don't want to see it break and harm anyone

Thanks for considering this. If you want to take some measurements I can measure my OEM stuff and do a more detailed analysis for you. I'm a mechanical engineer with a background from industry that includes FEA and other structural analysis, and my business is designing metalworking tools with Rogue Fabricaion.



All times are GMT -5. The time now is 08:16 PM.