Suspension, Brakes, Drivetrain discuss the wondrous effects of boost and your miata...
Sponsored by:
Sponsored by:

Supermiata Forged Front End Components

 
Old 06-24-2019, 06:28 PM
  #21  
Junior Member
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 138
Total Cats: 15
Default

Originally Posted by emilio700 View Post
Matter of personal taste but I also like to add a 1/4" spacer under the steering rack in addition to the roughly 1/4" correction of our OTR's.
Is that with both the NA and NB front ends?
Tran is offline  
Old 06-24-2019, 07:26 PM
  #22  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 6,132
Total Cats: 1,513
Default

Originally Posted by Tran View Post
Is that with both the NA and NB front ends?
Either. You need to able to recognize what bump steer feels like and how it manifests on track. Make an adjustment, drive it, see how it feels. Know that there is no "perfect" rack height as the curves crossover each other. On a street car, you want it the steering to be neutral on gentle bumps, well above the bump stops. On a track car, I focus more on how it feels further into the travel, closer to the bump stops.

Most NA/NB drivers with really low track cars just don't notice or even realize that wheel tugging back and forth in fast sweepers is bump steer, probably assuming its just stiff springs or bad shocks. Drive a properly set up car (any brand/model) though, and the steering is "calm" through those same fast lumpy sweepers.

That's the long answer. Short answer is..experiment. If I had to recommend a starting point, any car below 5.5" pinch weld heights should use the R pkg OTR geometry at minimum. Below that height, we also space the rack up 1/4". Actually have a product planned for that, on the list for like 6 years. Prototypes in the shop, never finished and put into production. But you can make your own. NA particularly easy.
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.27 SNR

Last edited by emilio700; 06-26-2019 at 08:59 PM.
emilio700 is offline  
Old 06-25-2019, 07:47 PM
  #23  
Junior Member
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 138
Total Cats: 15
Default

Originally Posted by emilio700 View Post
Either. You need to able to recognize what bump steer feels like and how it manifests on track. Make an adjustment, drive it, see how it feels. Know that there is no "perfect" rack height as the curves crossover each other. On a street car, you want it the steering to be neutral on gentle bumps, well above the bump stops. On a track car, I focus more on how it feels further into the travel, closer to the bump stops.

Most NA/NB drivers with really low track cars just don't notice or even realize that wheel tugging back and forth in fast sweepers is bump steer, probably assuming its just stiff springs or back shocks. Drive a properly set up car (any brand/model) though, and the steering is "calm" through those same fast lumpy sweepers.

That's the long answer. Short answer is..experiment. If I had to recommend a starting point, any car below 5.5" pinch weld heights should use the R pkg OTR geometry at minimum. Below that height, we also pace the rack up 1/4". Actually have a product planned for that, on the list for like 6 years. Prototypes in the shop, never finished and put into production. But you can make your own. NA particularly easy.
Thank you for the info. I hadn't fully considered how big of an issue bumpsteer could be on these cars until I saw a photo of me at my local track (Brands Hatch). Paddock Hill bend has a huge compression (Xida race 700/400 4.5" pinch weld + 9J 6UL will have tyre to arch contact here) and it appears that I'm steering right, but the wheel is not! (NA OTR, 1/4" rack spacer)

Tran is offline  
Old 06-25-2019, 08:09 PM
  #24  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,392
Total Cats: 266
Default

If you get R-Package tie rods from Mazda I bet you dont get any bump steer
matrussell122 is online now  
Reply
Leave a poscat -1 Leave a negcat
Old 06-26-2019, 06:18 PM
  #25  
Junior Member
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 138
Total Cats: 15
Default

Originally Posted by matrussell122 View Post
If you get R-Package tie rods from Mazda I bet you dont get any bump steer
Not quite sure how to read this... I know NB front suspension with R-package ball joints is the best, but are you saying NA with rack spacer and ball joints is still bad?
Tran is offline  
Old 06-26-2019, 07:25 PM
  #26  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,392
Total Cats: 266
Default

Originally Posted by Tran View Post
Not quite sure how to read this... I know NB front suspension with R-package ball joints is the best, but are you saying NA with rack spacer and ball joints is still bad?
I'm saying if you and E both got legit r package toe rods the rack spacer is pointless.
matrussell122 is online now  
Old 06-26-2019, 08:25 PM
  #27  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 6,132
Total Cats: 1,513
Default

Originally Posted by matrussell122 View Post
I'm saying if you and E both got legit r package toe rods the rack spacer is pointless.
You measured bump steer on Trans car and know what usage he's tuning it for?
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.27 SNR
emilio700 is offline  
Old 06-26-2019, 08:37 PM
  #28  
Junior Member
 
Join Date: Sep 2017
Location: SF Bay Area
Posts: 85
Total Cats: 6
Default

Originally Posted by emilio700 View Post

Most NA/NB drivers with really low track cars just don't notice or even realize that wheel tugging back and forth in fast sweepers is bump steer, probably assuming its just stiff springs or back shocks. Drive a properly set up car (any brand/model) though, and the steering is "calm" through those same fast lumpy sweepers.
Finally installed my tie rod ends from Supermiata, and all that bump steer is gone. Very underrated upgrade for depowered steering racks. *EDIT* Checked my notes, and I sourced them from somewhere else. They were OEM R-package.
Any suggestion on when to re-grease uppers? I take it that grease zerk isn't for show.

Last edited by moocow; 06-28-2019 at 06:11 PM. Reason: Fix source!
moocow is offline  
Old 06-26-2019, 08:50 PM
  #29  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,392
Total Cats: 266
Default

Originally Posted by moocow View Post
Finally installed my tie rod ends from Supermiata, and all that bump steer is gone. Very underrated upgrade for depowered steering racks.
Any suggestion on when to re-grease uppers? I take it that grease zerk isn't for show.
Bruh it's a placebo. They are pro forged tie rods that do not have R Package geometry.
matrussell122 is online now  
Reply
Leave a poscat -1 Leave a negcat
Old 06-26-2019, 08:57 PM
  #30  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 6,132
Total Cats: 1,513
Default

Originally Posted by matrussell122 View Post
Bruh it's a placebo. They are pro forged tie rods that do not have R Package geometry.
And you have personally measured examples of both, ball pivot location to knuckle seat?
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.27 SNR
emilio700 is offline  
Old 06-26-2019, 09:06 PM
  #31  
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 6,132
Total Cats: 1,513
Default

We have a simple Longacre Bump Steer gauge that's been used to measure many cars over the years, both front and rear. It's useful for us to learn how to correlate how the suspension feels to what the actual bump steer curve looks like. Many light bulb moments when looking at the resultant spreadsheet plotted curve after driving the car. Also interesting to see various OEM tuning philosophies. The AP1 S2000 vs and NA vs and ND1 for example. Wildly different curves that each impart specific handling characteristics. The rear of the ND1 for example, is wonky curve that explains why the car gets so squirrelly in lumpy turns when you add stickier tires to the stock suspension. Stay with slippery OEM tires that don't generate much roll moment and it's a much better balanced and predictable car. AP1's curve clearly explains why it is trying to kill you most of the time. NA's explains why it is so sweet and predictable. Factor in bushing deflection which also affects toe angle and you have a complex mix of factors to deal with when trying to sort out the best handling with high grip tires.
__________________


www.facebook.com/SuperMiata

949RACING.COM Home of the 6UL wheel

.27 SNR
emilio700 is offline  
Old 06-26-2019, 10:27 PM
  #32  
Junior Member
 
Join Date: Oct 2018
Location: Tampa FL
Posts: 175
Total Cats: 13
Default

Originally Posted by matrussell122 View Post
Bruh it's a placebo. They are pro forged tie rods that do not have R Package geometry.

I don't believe that is accurate, I have a set of tie rod ends I ordered a month ago and haven't installed yet, here they are compared to a photo of Proforged tie rod ends on Rockauto. I have a digital caliper on hand if anyone wants me to measure stuff, they look almost identical in dimension to R Pkg Tie Rod ends from what I can tell, but I don't have any on hand to compare.






Proforged Tie Rod ends


HowPrayGame is offline  
Old 06-28-2019, 09:37 AM
  #33  
Senior Member
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,361
Total Cats: 69
Default

Those definitely look like type R tie rods to me. Clean looking castings on the outer shell. I’ll hit it for sure when my current ones die.
k24madness is offline  
Old 06-28-2019, 10:25 AM
  #34  
Senior Member
 
matrussell122's Avatar
 
Join Date: Sep 2016
Location: Seattle
Posts: 1,392
Total Cats: 266
Default

Originally Posted by k24madness View Post
Those definitely look like type R tie rods to me. Clean looking castings on the outer shell. Iíll hit it for sure when my current ones die.
But they arnt. Otherwise they would market as such.


matrussell122 is online now  
Old 06-28-2019, 10:36 AM
  #35  
Junior Member
 
Join Date: May 2011
Location: Miami
Posts: 231
Total Cats: 19
Default

When I was in the market to buy 93le style tie rods, Supermiata's website seemed a bit ambiguous as to what I would be receiving. I found this website that makes it clear that they offer a 93le style tie rod.
https://cdn11.bigcommerce.com/s-79xy...=2&imbypass=on

It would have helped decision making if Supermiata had a side by side comparison of what they sell versus a non 93le option like what is shown below.

Originally Posted by emilio700 View Post
Can't tell from pics. We have all the relevant OEM Mazda parts and have measured on the bench. Pretty clearly defined and repeatable, no ambiguity.
My question would be, what can I not tell? that these two tie rods are not the same tie rod or that they are 100% identical? Because I can see a difference between the two.












andym is offline  
Old 06-28-2019, 11:03 AM
  #36  
Elite Member
iTrader: (15)
 
Join Date: Jan 2007
Location: Murfreesboro,TN
Posts: 1,633
Total Cats: 108
Default

The angle of the tie rod end doesn't do anything for the bump steer. It only effects the working angle which could reduce binding in some situations. The critical dimension is from the pivot to knuckle.
Midtenn is offline  
Old 06-28-2019, 11:15 AM
  #37  
Junior Member
 
Join Date: May 2011
Location: Miami
Posts: 231
Total Cats: 19
Default

Originally Posted by Midtenn View Post
The angle of the tie rod end doesn't do anything for the bump steer. It only effects the working angle which could reduce binding in some situations. The critical dimension is from the pivot to knuckle.
Are you suggesting that a measurement such as this would be irrelevant then?
andym is offline  
Old 06-28-2019, 11:24 AM
  #38  
Elite Member
iTrader: (15)
 
Join Date: Jan 2007
Location: Murfreesboro,TN
Posts: 1,633
Total Cats: 108
Default

Originally Posted by andym View Post
Are you suggesting that a measurement such as this would be irrelevant then?
Yes. You could make a tie rod a curly Q, but it only acts from the pivot on the ITR (rack end) and the ball joint on the ORT (knuckle). In simplified suspension models, its just seen a straight line. Other features of the tie rod ends are to avoid contact with other items or prevent binding at extreme angles of travel.
Midtenn is offline  
Old 06-28-2019, 02:05 PM
  #39  
Elite Member
iTrader: (1)
 
turbofan's Avatar
 
Join Date: Sep 2010
Location: Laguna Hills, CA
Posts: 7,220
Total Cats: 628
Default

After cutting up and measuring standard, R-package, and our forged tie rods, we have discovered that our offering is not fully R-package geometry as we had believed and have updated our website to reflect that. The geometry falls between R-package and standard geometry. So there is still a mild improvement in bump steer characteristics on lowered cars, combined with the benefit of a stronger part. OE replacement, stronger forged parts. Tough to cut open!

We know adding 1/4" (6.35mm) rack spacers reduces bump steer even with R pkg OTR's so we're now gathering data to see if a new, even more offset OTR will have the same benefit as rack spacers.
That will take a while. We'll publish more data when we have a more complete picture.
turbofan is offline  
Old 06-28-2019, 02:15 PM
  #40  
Junior Member
 
Join Date: Jul 2017
Location: Sussex, England
Posts: 138
Total Cats: 15
Default

Originally Posted by turbofan View Post
After cutting up and measuring standard, R-package, and our forged tie rods, we have discovered that our offering is not fully R-package geometry as we had believed and have updated our website to reflect that. The geometry falls between R-package and standard geometry. So there is still a mild improvement in bump steer characteristics on lowered cars, combined with the benefit of a stronger part. OE replacement, stronger forged parts. Tough to cut open!

We know adding 1/4" (6.35mm) rack spacers reduces bump steer even with R pkg OTR's so we're now gathering data to see if a new, even more offset OTR will have the same benefit as rack spacers.
That will take a while. We'll publish more data when we have a more complete picture.
Great to see you trying other geometries. If you can specify your own geometries, have you considered extended lower ball joints with some roll center correction added too? Ie offset the ball vertically as well as axially.
Tran is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Shibby
Miata parts for sale/trade
5
10-04-2017 08:54 AM
twothirdsCobra
WTB
0
02-21-2013 10:01 PM
na8psi
Engine Performance
47
05-31-2010 10:55 PM
zarish
Miata parts for sale/trade
1
03-30-2009 06:41 PM
Splitime
Miata parts for sale/trade
17
08-18-2008 03:08 PM


Thread Tools
Search this Thread
Quick Reply: Supermiata Forged Front End Components


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.