1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Relocating my lower control arms

Thread Tools
 
Search this Thread
 
Old Jul 4, 2006 | 11:46 AM
  #1  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Relocating my lower control arms

Well I'm too poor for coil-overs and too unsatisfied with the amount of adjustment in my camber plates. Time to change the equation!

Let's move the lower control arm outboard!

If I've figured it right, moving the control arm outboard 3/4 of an inch will result in a gain of -2 deg camber.

My question is this:

Has anyone here done this? Do the tie-rod adjusters and tension rods have enough room for that kind of outboard movement?

Thanks!
Reply
Old Jul 4, 2006 | 01:14 PM
  #2  
rbf41182gt's Avatar
Rotary Enthusiast
Tenured Member: 20 Years
 
Joined: Jun 2004
Posts: 1,081
Likes: 2
From: Richmond, VA
racing beat sells adjustable control arms

$375 for the pair, but up to 4.4 degrees of negative camber
Reply
Old Jul 4, 2006 | 01:17 PM
  #3  
custom13B's Avatar
Senior Member
Tenured Member 05 Years
 
Joined: Oct 2005
Posts: 417
Likes: 0
From: High Point North carolina
I think you have the right idea but moving them that much would create problems with the tie rods for sure. Another option is to cut the end off the stock control arms..weld on a steel plate and then drill and tap it to accept spherical rod ends. But if you do this use heavy duty rod ends and make sure to weld that plate securely. You also loose your rubber bushings entirely so it may ride a bit harsh. But then you have maximum adjustability. Exerything involves comprimise with cars,good luck.
Reply
Old Jul 4, 2006 | 06:18 PM
  #4  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
I know RB sells a set of adjustable arms, but if I'm not willing to shell out for coil overs, what do you think the likelyhood of me plunking $375 on the table for the RB product?

While we're on the subject of the RB adjustable arms, since they can be adjusted more than double the length that I want to move my control arm outboard by, doesn't it stand to reason that there is enough slack in the tie rods/tension rods to compensate?
Reply
Old Jul 4, 2006 | 06:25 PM
  #5  
RXn407's Avatar
Rotary Enthusiast
Tenured Member 15 Years
 
Joined: Sep 2005
Posts: 831
Likes: 2
From: orlando
If not, like the man above stated you could get some from an industrial catalog.the issue is making sure they are strong enough. Also have you thought instead of moving the lower arms out, Since youre inventing have you thought of the possibilities for adjusting the camber from the tower and doing some re working from there? just shooting ideas. good luck!!
Oh yeah, and the lowrider guys w/ hydralics cut and extend control arms all the time so maybe if you have a hydraulic shop in your area they might be able to help.
-erik
Reply
Old Jul 4, 2006 | 07:15 PM
  #6  
NTRX7's Avatar
12a turbo first gen
Tenured Member 05 Years
 
Joined: Oct 2005
Posts: 71
Likes: 0
From: Australia
lower control arms

i have read on the Ausrotary forum of guys moving the lower control arms out by redrilling the the mounting point on the cross member, i also remember them saying there was a limit due to clearance problems. do a search on WWW.Ausrotary.com and see how ya go.

Cheers Paul
Reply
Old Jul 4, 2006 | 08:33 PM
  #7  
31rx7's Avatar
Senior Member
Tenured Member 15 Years
 
Joined: Apr 2002
Posts: 515
Likes: 1
From: Hilliard, OH
Interestingly, I have a set of offset bushings made of poly urethane for the front control arms that I inherited with my race car. I suspect that they move the mounting point out by 3/8" or so.

Unfortunately, I have never installed them to see the impact on camber, and I have no clue as to who manufactured them.
Reply
Old Jul 4, 2006 | 08:40 PM
  #8  
peejay's Avatar
Old [Sch|F]ool
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: May 2001
Posts: 12,862
Likes: 568
From: Cleveland, Ohio, USA
Originally Posted by MosesX605
My question is this:

Has anyone here done this? Do the tie-rod adjusters and tension rods have enough room for that kind of outboard movement?
*BARELY*. Longer adjusters would be recommended.

There's something like an inch of adjuster in each tie rod end with stock geometry. Maybe less, I've forgotten the figures.
Reply
Old Jul 4, 2006 | 09:16 PM
  #9  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Originally Posted by peejay
*BARELY*. Longer adjusters would be recommended.

There's something like an inch of adjuster in each tie rod end with stock geometry. Maybe less, I've forgotten the figures.
Where would one go to find longer adjusters?
Reply
Old Jul 4, 2006 | 11:50 PM
  #10  
peejay's Avatar
Old [Sch|F]ool
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: May 2001
Posts: 12,862
Likes: 568
From: Cleveland, Ohio, USA
That, I dunno.

My guess would be, bite the bullet and get some Coleman (?) studs and convert to rod-ends for the steering. But there goes the cheap factor...
Reply
Old Jul 4, 2006 | 11:53 PM
  #11  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Are the threads reversed on the adjuster, or are they the same on both ends?

If they're the same, I should be able to find myself a long bolt with the right thread pitch somewhere...
Reply
Old Jul 5, 2006 | 09:56 AM
  #12  
Bruceman's Avatar
Rotor Power Rules
iTrader: (5)
 
Joined: Jul 2001
Posts: 525
Likes: 2
From: Rochester Hills, MI
Originally Posted by MosesX605
Let's move the lower control arm outboard!

If I've figured it right, moving the control arm outboard 3/4 of an inch will result in a gain of -2 deg camber.

My question is this:

Has anyone here done this? Do the tie-rod adjusters and tension rods have enough room for that kind of outboard movement?

Thanks!
I have done this. It is very difficult to do it acurately/equal side to side. It is possible and the tie rods and tension rods have plenty of adjustment. It is not legal for SCCA CSP autocross.
I have reverted back to the standard holes after changing to good camber tops.
You will get less than 2 degrees more like 1 degree extra. But how much do you need? Depending on your ride height a good camber top will get 2.5 degrees negative.
Reply
Old Jul 5, 2006 | 12:07 PM
  #13  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Originally Posted by Bruceman
I have done this. It is very difficult to do it acurately/equal side to side. It is possible and the tie rods and tension rods have plenty of adjustment. It is not legal for SCCA CSP autocross.
I have reverted back to the standard holes after changing to good camber tops.
You will get less than 2 degrees more like 1 degree extra. But how much do you need? Depending on your ride height a good camber top will get 2.5 degrees negative.
It's legal up here in Kaniukistan for CSP so no worries there. I have camber/caster adjusters installed right now but don't have the coin for coil-overs so my adjustment is limited by the large size of the upper coils. Thanks for the input!
Reply
Old Jul 5, 2006 | 04:33 PM
  #14  
aussiesmg's Avatar
Thunder from downunder
Tenured Member 10 Years
iTrader: (1)
 
Joined: Mar 2001
Posts: 3,843
Likes: 1
From: Convoy, Ohio, USA
My RX3 in Australia had this done, I had just enough tie rod to be safe, JUST. I ran 3 1/2 degrees neg usually and had no issues, I used crash bolts so any difference in the sides can be dialled out in the alignment process.

If price is your biggestissue check these out they are well priced. www.racersareme.com

Oh, and the threads are opposite on the tie rod adjuster this is how they are lengthened or shortened as required

Steve
Reply
Old Jul 5, 2006 | 06:03 PM
  #15  
MosesX605's Avatar
Thread Starter
My wife bought me 2 RX-7s
Tenured Member 20 Years
 
Joined: Aug 2001
Posts: 2,328
Likes: 3
From: Saskatoon, Saskatchewan, Canada
Originally Posted by aussiesmg
My RX3 in Australia had this done, I had just enough tie rod to be safe, JUST. I ran 3 1/2 degrees neg usually and had no issues, I used crash bolts so any difference in the sides can be dialled out in the alignment process.

If price is your biggestissue check these out they are well priced. www.racersareme.com

Oh, and the threads are opposite on the tie rod adjuster this is how they are lengthened or shortened as required

Steve
Thanks!

I'll be sure and report back with pictures.
Reply
Old Jul 9, 2006 | 09:52 AM
  #16  
peejay's Avatar
Old [Sch|F]ool
Tenured Member: 20 Years
Liked
Loved
Community Favorite
 
Joined: May 2001
Posts: 12,862
Likes: 568
From: Cleveland, Ohio, USA
OK.

I recall that the adjusters are 4 1/2" long end to end.

My car as it sits has exactly 3" from tie-rod end to tie-rod end. That makes 3/4" in each end.

You want to have at LEAST the root diameter threaded into something, and root diameter IIRC is 14mm, or 9/16". This means the control arm can be relocated a maximum of 3/8" before things start to get iffy. Hrmm.
Reply
Old Sep 9, 2012 | 09:06 AM
  #17  
wallyrx7's Avatar
Full Member
Tenured Member 15 Years
iTrader: (1)
 
Joined: Jul 2004
Posts: 236
Likes: 2
From: Bucks County PA
I'm bringing this thread back to life!

so I want to move my control arms outward on the cross member. Everyone seems to be talking about this like you can move it 1 1/2 inches but when I took everything apart... the engine mounting brackets are in the way!

So the mounts are just a box so I could go inside but then I would be raising the hole...

Anyone who has done this can you provide some help?

Reply
Old Sep 9, 2012 | 09:21 AM
  #18  
wallyrx7's Avatar
Full Member
Tenured Member 15 Years
iTrader: (1)
 
Joined: Jul 2004
Posts: 236
Likes: 2
From: Bucks County PA
Reply
Old Sep 9, 2012 | 02:40 PM
  #19  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,833
Likes: 3,232
From: https://www2.mazda.com/en/100th/
Originally Posted by wallyrx7
I'm bringing this thread back to life!

so I want to move my control arms outward on the cross member. Everyone seems to be talking about this like you can move it 1 1/2 inches but when I took everything apart... the engine mounting brackets are in the way!

So the mounts are just a box so I could go inside but then I would be raising the hole...

Anyone who has done this can you provide some help?

this is an advanced move, because you're fundamentally changing the geometry of the front suspension, in three directions!

moving the hole UP. this might be good. ideally you want the inner pivot point to be about 5/8" higher than the outer pivot point, this keeps roll center in a good place. so if you move the inner pivot UP, the car can be lower, while still keeping the 5/8" number.

moving the hole OUT. this does two things. it adds negative camber, and increases front track width. negative camber is good, however HOW MUCH really depends on what you're using the car for. a street car is totally fine with -.5 to -1 degree, which you can almost do with just stock parts. race cars need more, but how much more depends on tires. a big fat radial slick might only want -1 to -2, but the 195/60/13 Ra1's they used to run in pro7 want like -6!

the third thing is track width. this matters. especially if you make one end wider than the other. on a car with sticky tires, 10mm of track width can be a big change.

so moving the hole might be good, but you really should know what you're after, and its probably not needed on a street car at all.
Reply
Old Sep 9, 2012 | 06:34 PM
  #20  
84stock's Avatar
Lives on the Forum
Tenured Member: 20 Years
iTrader: (5)
 
Joined: Apr 2003
Posts: 5,547
Likes: 12
From: calgary
Did the negative camber make steering tougher (harder to turn the wheel)?
Reply
Old Sep 10, 2012 | 08:29 AM
  #21  
wallyrx7's Avatar
Full Member
Tenured Member 15 Years
iTrader: (1)
 
Joined: Jul 2004
Posts: 236
Likes: 2
From: Bucks County PA
Originally Posted by j9fd3s
this is an advanced move, because you're fundamentally changing the geometry of the front suspension, in three directions!

moving the hole UP. this might be good. ideally you want the inner pivot point to be about 5/8" higher than the outer pivot point, this keeps roll center in a good place. so if you move the inner pivot UP, the car can be lower, while still keeping the 5/8" number.

moving the hole OUT. this does two things. it adds negative camber, and increases front track width. negative camber is good, however HOW MUCH really depends on what you're using the car for. a street car is totally fine with -.5 to -1 degree, which you can almost do with just stock parts. race cars need more, but how much more depends on tires. a big fat radial slick might only want -1 to -2, but the 195/60/13 Ra1's they used to run in pro7 want like -6!

the third thing is track width. this matters. especially if you make one end wider than the other. on a car with sticky tires, 10mm of track width can be a big change.

so moving the hole might be good, but you really should know what you're after, and its probably not needed on a street car at all.
Great, thanks for the advice. This is a full race car (read as Lemons car) so this is why I am not buying camber plates and doing things correctly

I have a pic of the cross member and hole but am forum illiterate and so can't figure out how to post it.

I will plan on moving the hole upwards then. This makes sense to me because we are at the same time putting springs on the car to lower it, so if we lowered the car by 5/8 inch and raised the mounting point by the same, we would end up even as far as suspension geometry! (please don't call me out on my logic...)
Reply
Old Sep 10, 2012 | 09:51 AM
  #22  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,833
Likes: 3,232
From: https://www2.mazda.com/en/100th/
Originally Posted by wallyrx7
Great, thanks for the advice. This is a full race car (read as Lemons car) so this is why I am not buying camber plates and doing things correctly

I have a pic of the cross member and hole but am forum illiterate and so can't figure out how to post it.

I will plan on moving the hole upwards then. This makes sense to me because we are at the same time putting springs on the car to lower it, so if we lowered the car by 5/8 inch and raised the mounting point by the same, we would end up even as far as suspension geometry! (please don't call me out on my logic...)
yeah seems like that should work
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
fjwheeler
3rd Generation Specific (1993-2002)
22
Jan 9, 2022 01:02 PM
GrossPolluter
Suspension/Wheels/Tires/Brakes
12
Aug 15, 2015 10:32 PM




All times are GMT -5. The time now is 08:28 AM.