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-   -   ELBJ + Tire Longevity questions (https://www.miataturbo.net/suspension-brakes-drivetrain-49/elbj-tire-longevity-questions-99389/)

NASSEX 02-20-2019 06:31 PM

ELBJ + Tire Longevity questions
 
Car: 1995 NA8 Turbocharged >200whp 340ish treadwear tires

What's the least amount of negative camber possible when you install Extended lower ball joints.. I'm contemplating and researching on weather I'll be better off just replacing my LBJ's with oem replacements (Less expensive) to save some money (about $100 in savings).

I'm getting an alignment in about 3 weeks and looking towards going with these specs: www.supermiata.com/miata-race-alignment-info.aspx - SuperMiata Race Alignment Specs

Ideally I'd like to go with the Street alignment specs. However with addition to it, I want to use a mix up of somewhere between the duel duty/race alignment ride height specs. The reason why I am leaning towards the street alignment is because I'm wanting to run the current tires (around 340 treadwear + 1 year old) all this season and hope to maybe get a 1000 mile road trip to Tail of the Dragon and back this August, out of them.
And before that road trip, I'm hoping to attend about 3 to 4 monthly autocross events (I'm a newb first timer).
Plus if I can afford to, would be nice to fit one potential track day at Summit Point Motorsports Park.
So as you can see, I have a lot of hopes planned for this season. Last summer was all spent on rebuilding the engine and restoring the car while getting bit up by mosquitoes basically.

My concern is if I aim the ride height towards 4.25" to 4.75" (pinch welds) will I still be able to get away with regular front cam bolt adjustability to achieve -1.4° front camber on both sides?
If so then I can save the money from getting the ELBJ's.

My second question is, say I do get the ELBJ's, and I go with the Duel Duty Alignment specs, do you think the tire wear from it would be too aggressive for my hopes and dreams this summer? :)

Street Alignment:
5.00 ~ 5.5" front pinch weld height
.06 ~ .18" rake, rear higher
Front camber: -1.4°
Caster: >4.5°
Front total toe: +1/16" .03"
Rear camber : -1°
Rear total toe: +1/8" .06"

Duel Duty Alignment:
4.5 ~ 5.25" front pinch weld height
.06 ~ .18" rake, rear higher
Front camber: -2.5°
Caster: +3.5 ~ 4.0°
Front total toe: 0
Rear camber : -2.0°
Rear total toe: + 1/8", .06"

Race Alignment:
4.25"~ 4.75" front pinch weld height.
Zero rake with driver and fuel
Front camber: -3.2° ~ 4.2° depending on pyrometer readings
Caster: ~ 4.0° or max available once you reach camber targets
Front total toe: 0
Rear camber : -2.8°
Rear total toe: +1/16 for <200whp. ~1/8" for greater than 200whp

Thanks everyone! Sorry I had carried on a bit long on the details in explanation!

concealer404 02-20-2019 06:41 PM

Camber doesn't really affect tire wear much, and if you can't hit 1.4* of camber without ELBJs, your car is trashed.

Scaxx 02-20-2019 06:54 PM

Agreed to all points.

cpierr03 02-20-2019 07:14 PM

You're overthinking it IMHO, I'm able to hit slightly better than target camber at dual-duty specs with OEM ball-joints.

ELBJ are for those that want more camber without going too low, or for dedicated track cars that run very aggressive camber.

doward 02-20-2019 07:48 PM

Set your ride height.
Get an alignment.
???
Done.

NASSEX 02-20-2019 10:15 PM

Oh wow yea I must be some kind of a overthinking skitsophonic person truly bcuz I definitely thought way too much into it the past few days, along with everything I read yesterday lead to believe lowering the FRONT creates more positive camber while the rear was still negative (camber gain). I was trying to understand why so I kept doing a bit more research (yesterday previously) to gather a understanding, and the funny thing is after reading your guys' posts, i said ok.. checked back at the sources I glanced through previously (while in a deep overthought process) and suuurree enough, I somehow hallucinated it backwards. Out of 4 different websites/resources separately. All lead me to believe that lowering the front increases positive camber instead of how the rear reacts. So strange. I have no clue how that happens.. maybe stress?? :| IDK I do overwork myself at work. But yea, thanks for the help. Lol Better stay off the track when I'm there. Just kidding that's not a healthy joke. I do appreciate yaws help!

sixshooter 02-20-2019 10:36 PM

With high treadwear tires like those you will want to stick to the street alignment and standard ball joints. You won't see enough lateral grip to require the camber.

NASSEX 02-21-2019 09:16 AM


Originally Posted by sixshooter (Post 1523933)
With high treadwear tires like those you will want to stick to the street alignment and standard ball joints. You won't see enough lateral grip to require the camber.

Thanks that was my other concern. I am also running crappy Tein advance z dampers (tbh they aren't so bad now that i modified the top hat&bumpstop arrangement) with the 7k/6k spring rates they come in. Which probably isn't too bad cuz my tires aren't ultra sticky. I'm most likely going to add either a NB FlyinMiata 1" solid front sway bar or the RB tubular one. And seeing how that rides to determine if i should get rid of the stock rear sway bar.

I'm low on money and would rather get some drive time this season with the most i can get out of my setup.
I'd rather not go up or down in spring rates for the tein advance z coilovers since theyre only supposedly good for a +1/-1kg difference, according to their website. That way i could potentially put that money towards better dampers and tires next year. Adding and removing sway bars seems like the best option for me. Thanks for your advice on the alignment spec suggestion. I'm going to be getting the alignment done in about 2 1/2 weeks from now. Cuz all the ball joints and tie rod components are being replaced by me soon.

sixshooter 02-21-2019 10:08 AM

7k/6k are too close together to be balanced, even with a tubular front bar and no rear.

concealer404 02-21-2019 10:18 AM

Confirmed for garbage. I would suggest not spending money on further suspension parts (including the too-big FM bar you're looking at) until you get coilovers that don't perform sexual favors for food stamps.

Schroedinger 02-21-2019 11:15 AM

I agree that you should just get an alignment and drive the thing. No suspension parts until you're ready to do it right. Work on fixing problems you're actually having instead of imagining.

However- if your ball joints are shot and need replaced anyway, I would go with the extended. My reasoning is as follows:

- if you're really planning weekly autocross with 200hp, you're going to kill those tires quickly and probably be on stickier tires sooner than you think.
- you are more likely to kill the outside edges of the tire at autocross with too little camber than kill them from too much camber while driving around.
- swapping the ball joints is a bit of a PITA, and you don't want to it twice.
- you can easily get up to 2.5 degrees front camber on stock ball joints, but it comes at the expense of caster, which fucks with your steering.
- do ELBJ's, get 2.5 degrees of camber, which is really not much, and all the caster you want.
- if you're lowered, do the R package tie rod ends while you're at it and get rid of the bump steer.

NASSEX 02-22-2019 04:27 PM


Originally Posted by Schroedinger (Post 1523989)
- if you're lowered, do the R package tie rod ends while you're at it and get rid of the bump steer.

I'm going to follow everything you said. But in terms of trying to save money (Those R package tie rod ends are another $140 for a pair!!). I am looking at them, and they seem to only be 3mm taller or shorter than the regular tie rod ends. Please please plz correct me if I'm wrong there.

https://revlimiter.net/blog/2011/03/tie-rod-end-swap/

Would it be JUST-AS effective while being much more affordable to perhaps raise the steering rack up ~3mm or so, using shims, and take a close level surface'd look at the geometry to check if it will solve the bump steer problem? Something is telling me the problem and solution lies somewhere larger than a 3mm difference. I think I'm missing something about the difference in the R package ends vs normal.

I'm just doing the math and 140$ is 14++ hours at work for me, where as making some shims and raising the steering rack is about 3 to 4 hours tops. But I just want to ask you ahead of time if it is a okay solution to do so. I'm sure others have tried it in the past?

I like everyone's suggestions, and I am going to follow through with the advice given down. I just need to try and do my best with the budget I work with. What do you think, are the steering rack lifting shims a good idea (as long as I make sure the geometry is level to avoid bump steer) that way I can save the 100$ over the cost of normal tie rod ends. If it's known to be either not possible to correct the issue or it's unlikely to help, then I will try to go along with the R package ones.

Today was payday so today is the day I make the decisions!

Schroedinger 02-22-2019 04:57 PM

I did the tie rod ends as a "while you're in there" when I swapped my ball joints. If you don't want to spend the money, I would say just do the ball joints and see if the bump steer bothers you. I don't have any experience with shimming the rack, can't help you there. Bear in mind that you'll need an alignment after you do the ball joints, and you'll need another one if you go back and do the steering.

NASSEX 02-22-2019 05:38 PM


Originally Posted by NASSEX (Post 1524150)
https://revlimiter.net/blog/2011/03/tie-rod-end-swap/
Would it be JUST-AS effective while being much more affordable to perhaps raise the steering rack up ~3mm or so, using shims, and take a close level surface'd look at the geometry to check if it will solve the bump steer problem? Something is telling me the problem and solution lies somewhere larger than a 3mm difference. I think I'm missing something about the difference in the R package ends vs normal.

I don't know why but I had a feeling whether it's 3mm or more, the difference is going to depend on the application. What package your car is, and how low you are. I'm pretty sure based on the estimated height that these appear to be, that if I went with spacers it should help save a little bit of money as well as allow me to dial in the exact height difference a little closer to my setup specifically. Because those spacers look way thicker than 3mm!
https://cimg8.ibsrv.net/gimg/www.mia...c9e47526e8.jpg
Garage Star Steering Rack spacers

What I'm ganna do is go with the regular tie rod ends to save 100$ and then after I install all of the new ball joints, I will decide on a final ride height, sit the car onto the ground. Then give it a very close examination on the off-centered tie rod -to- steering rack height. If it's pretty far off, then I will add in the custom shims since I have a fair amount of left over scrap metal. This seems like the best choice for me with all of your guys' thoughts combined. - Update
PS Didn't mean to turn this into a poor man's anti bump steer thread. :Þ

cabowabo 02-23-2019 11:32 AM

I've been running -3.2f/-2.8 on 225 RS4's since Sept 2017 (mostly street, some track sessions) and they're still going strong. Camber doesn't shred tires that much, but for pure street car you'd never need that much. Quit worrying about bump steer, it's a non-issue in your street car, but fwiw I noticed no real difference on track with/without those steering rack shims.

NASSEX 02-24-2019 10:35 AM


Originally Posted by cabowabo (Post 1524214)
I've been running -3.2f/-2.8 on 225 RS4's since Sept 2017 (mostly street, some track sessions) and they're still going strong. Camber doesn't shred tires that much, but for pure street car you'd never need that much. Quit worrying about bump steer, it's a non-issue in your street car, but fwiw I noticed no real difference on track with/without those steering rack shims.

1) What's your ride height at the pinch welds?
2) are you running extended lower ball joints?
3) 90-98 NA?

wondering

cabowabo 02-25-2019 11:16 AM

~4.5, yes, 97.


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