STS2 MK1 suspension setup w/host XHead Part:2.0 - Page 4 - MR2 Owners Club Message Board
 
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post #61 of 389 (permalink) Old January 28th, 2009, 13:34
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Quote:
Originally Posted by XHead
Hi Tim, glad you liked the tutorial. I know Lee. Lee knows shocks, not setup.

Skip the other rates and go straight to 600/350 F/R. The yellows will work reasonably well with those rates. It will NOT push. The Toyos will work fine with this setup. The Potenzas that were used by our subject car have less grip. If anything, you may want to go stiffer.

-Steve
Thanks Steve,

I will do that. Maybe Ill just grab some 350, 400 and 600 then. Thats what you meant by little stiffer, right?

Will not push, thats music to my ears.... or eyes... candy... you know, internet and all.

Ill post my experience once its all done and all this snow goes away. I didnt notice an installment on dampeners... Should I use koni's tuning guide as a reference... maybe another installment ? We all want it

Again, thanks for all the help,

Tim
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post #62 of 389 (permalink) Old January 28th, 2009, 13:48
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Quote:
Originally Posted by Nolat
I will do that. Maybe Ill just grab some 350, 400 and 600 then. Thats what you meant by little stiffer, right?
By a little stiffer, I meant you might consider going with 650/400 F/R. Only raising the rear rates will make the car oversteer. That's worse than push.


Quote:
Originally Posted by Nolat
Ill post my experience once its all done and all this snow goes away. I didnt notice an installment on dampeners... Should I use koni's tuning guide as a reference... maybe another installment ? We all want it
Gee, I haven't looked at the Koni tuning guide is years. Like maybe 15 years. I had intended to do an installment on shocks. I will try to get that done soon.

-Steve
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post #63 of 389 (permalink) Old January 30th, 2009, 16:03
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WOW!

I recently saw the "Money as Dept" and understood how todays economy works.
Then I read these threads and understood how suspensions work!
Great info!

I have a question though.
Based on the aforementioned info, the "formula" to find the total roll rate is following:

Total_Roll_Rate = (Car_Weight / 2) * Tire_Factor

The Tire_Factor for the street tire is 0.8

What will be the "Tire_Factor" for a semi slick tire?

I am using the toyo R888 or something similar, and I would like to follow the bar-less setup. So I need to find the spring rates.

Thanks!
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post #64 of 389 (permalink) Old February 1st, 2009, 13:13
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If its not a pure DOT race tire or slick, use the street tire factor.

-Steve
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post #65 of 389 (permalink) Old February 1st, 2009, 16:13
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Quote:
Originally Posted by XHead
If its not a pure DOT race tire or slick, use the street tire factor.

-Steve
It actually is a "street legal semi slick" tire.

I track my MK3 MR2 and will put Ohlins on it. I will start with 400 rear and 650 front and see from there.

Thanks, I am waing the installement for the shocks
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post #66 of 389 (permalink) Old February 11th, 2009, 10:55
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So i've read this like 3 times already.. but have a questions..

Mica: How is the car on the street with 600F and 400R? I plan to go this route, but I also use to car to drive to events.. It's not a daily drive, but I don't trailer it.. How would it be on the street with that setup (sway-bar-less ofcourse..)

My alignment is still "stock", so what can I expect in terms of handeling?

Has anybody used the GC front strut tops? and any review on those?? Last time I checked one of my strut top was not rotating freely so I am expecting some issues with that.. I have to somewhat bring the wheel back to "neutral" after turning, so I am thinking that might be the culprit..

thanks
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post #67 of 389 (permalink) Old February 11th, 2009, 12:07
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Quote:
Originally Posted by Shane Bawa

Has anybody used the GC front strut tops? and any review on those?? Last time I checked one of my strut top was not rotating freely so I am expecting some issues with that.. I have to somewhat bring the wheel back to "neutral" after turning, so I am thinking that might be the culprit..

thanks
GC Camber Plates?
Love 'em. Great quality, and well made:

http://www.pbase.com/mtb_zack/image/97313350

My only 'gripe' is that I wish they had some indexing, but that is minor.
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post #68 of 389 (permalink) Old March 2nd, 2009, 20:54 Thread Starter
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Quote:
Originally Posted by Shane Bawa
So i've read this like 3 times already.. but have a questions..

Mica: How is the car on the street with 600F and 400R? I plan to go this route, but I also use to car to drive to events.. It's not a daily drive, but I don't trailer it.. How would it be on the street with that setup (sway-bar-less ofcourse..)

My alignment is still "stock", so what can I expect in terms of handeling?

Has anybody used the GC front strut tops? and any review on those?? Last time I checked one of my strut top was not rotating freely so I am expecting some issues with that.. I have to somewhat bring the wheel back to "neutral" after turning, so I am thinking that might be the culprit..

thanks
Sorry didn't see any one posting in here.

I will tell you something. I miss the car and drive it to work sometimes. That's 106 miles both ways. 70 of that is one lane backroads and I'm alive Seriously though it's not bad at all. The Koni's do a good job and there is a tiny bounce from the front and that's mostly tires anyway. Remember we race in parking lots not dedicated race tracks.


I will post up my setup for this year in a month or so as I have 4 weeks to get new tires/wheels, all new seals in on the motor, water pump/tb, clutch and rear camber plates in before 28th....and that's after I finish rebuilding my friends MR2 that he bought from me. Wish me luck.

Last edited by MicaCeli; March 2nd, 2009 at 20:56.
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post #69 of 389 (permalink) Old March 7th, 2009, 12:44
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I've just finished putting mine together. I modeled it after some of what you've been saying so far. It still has issues, most likely because I'm only about 1/4 done aligning everything, but I am trying to figure out;

This idea of setting ride height based on the 'virtual control arm' makes sense. Lower the car and you get positive camber, raise it and you get a higher center of gravity. But... is there a way to change that? Roll center adjusters would work, right? The biggest reason I ask is:
1: My car is currently riding almost as high as I can make it go, and it's still sorta too low based on the virtual control arm idea
2: lower CG is theoretically good
3: every car I see XHead driving in is about .1mm off the ground, way past the point I've got

And, the other problem w/ a lower car XHead mentioned was roll center, also suggesting RCA's would help.

Last thought: I am not aligning my car on very flat ground, cause I don't have flat ground handy and I'm only just starting to break in the suspension. I also don't have scales. So, my ride height distribution is probably not ideal- currently, I just tried to match the left and right sides in terms of perch height. differing settings between left and right mostly makes Left Turn vs Right Turn feel different, right? As opposed to drastically mess things up?

Ok, final thought: RE the guy asking about spring rates on the street
It kinda sucks. The streets I usually drive on are really pretty crappy. That said, it's not like hard shocks traveling through the car (which was what I expected), it's more like a roughish boat ride. Lotta bobbing. Interestingly, medium acceleration and/or freeway speeds make it 95% as livable as stock.

Last edited by sliverstorm; March 7th, 2009 at 12:47.
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post #70 of 389 (permalink) Old March 7th, 2009, 13:33
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Quote:
Originally Posted by rocwandrer
to back this statement up:

my car rides better with double the spring rate and appropriate damping in CSP than it did with stock springs and CS race specific damping.

the perception of ride quality created by using damping to stiffen the car is one where driving even on relatively smooth roads seems to feel "rough" but feel relatively cushy over those rare big bumps.

with stiff enough springs to run reasonable damping, the feeling is a almost stock like cushy ride over the small bumps, and a quicker, much harsher impact over bigger bumps.

guess which one makes you remember the ride as "harsh"? The problem for me on the street is that the stiffer the ride rate, the smaller the bump that makes the stiff suspension feel harsh....
the problem with this perception is that of the dampers being used. i dont know what your experiences are based on, so im speculating to some extent. but il hazard that most people with a perception of this type have been running dampers that arrive with whatever valving they arrive with, either "stiff" or "soft" with an adjuster that probably makes broad overall adjustments, and thus you are working around the dampers, not with them to the greater extent. i dont know what dampers you run, but on the most part dampers on MR2's are usually of a budget-dependant nature, and most peoples budgets are fairly small.

as a damper engineer id totally disagree from my experience with damping giving the impression of harshness over stiff springs if utilised correctly. it is dependant on the damping characteristics. if you have the facility to alter damping in every aspect (including changing the valving when your requirements go beyond the scope of the adjuster/s) then you can much better create a balance between ride and performance without the need for significantly stiffer springs. in return the tires are worked less and traction is improved on the driven wheels, and you have much more control across the range compared to stiff linear rate springs. combined with an improvement in cornering performance - most importantly!!

i seem to remember from previous discussion, whilst no details were shared, that Steves approach to damping is from a very different angle to mine. there is more than one way to skin a rabbit, and its hard to argue with multiple championship wins, but i think baseing an opinion on the ride quality of a car through the use of "stiffer" damping with softer springs, when the dampers are not being fully developed around the setup (this is my assumption, that the dampers arent being fully developed. which isnt the case with Steve but his setup philosophy totally defies convention) is not accomodating the full picture. ive personally driven dozens of cars on the road and track that ive developed the damping for with relatively soft springs, along with the many more cars that i havent driven myself but have customer feedback from (from just about every genre of road and racing), which had a better performance/ride relationship than with stiffer sprung setups. there are applications in which this isnt the case, for example high downforce cars, but that isnt the case here.
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post #71 of 389 (permalink) Old March 9th, 2009, 09:02 Thread Starter
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Quote:
Originally Posted by sliverstorm
I've just finished putting mine together. I modeled it after some of what you've been saying so far. It still has issues, most likely because I'm only about 1/4 done aligning everything, but I am trying to figure out;

This idea of setting ride height based on the 'virtual control arm' makes sense. Lower the car and you get positive camber, raise it and you get a higher center of gravity. But... is there a way to change that? Roll center adjusters would work, right? The biggest reason I ask is:
1: My car is currently riding almost as high as I can make it go, and it's still sorta too low based on the virtual control arm idea
2: lower CG is theoretically good
3: every car I see XHead driving in is about .1mm off the ground, way past the point I've got

And, the other problem w/ a lower car XHead mentioned was roll center, also suggesting RCA's would help.

Last thought: I am not aligning my car on very flat ground, cause I don't have flat ground handy and I'm only just starting to break in the suspension. I also don't have scales. So, my ride height distribution is probably not ideal- currently, I just tried to match the left and right sides in terms of perch height. differing settings between left and right mostly makes Left Turn vs Right Turn feel different, right? As opposed to drastically mess things up?

Ok, final thought: RE the guy asking about spring rates on the street
It kinda sucks. The streets I usually drive on are really pretty crappy. That said, it's not like hard shocks traveling through the car (which was what I expected), it's more like a roughish boat ride. Lotta bobbing. Interestingly, medium acceleration and/or freeway speeds make it 95% as livable as stock.

ST classes do not allow for roll center adjusters. I don't understand how you can't get to the ride heights that were recomended. I run 6inch front and 7 inch rear springs and have a ton of adjustment. If you can't get higher (I'm guessing front's) you can go with 7 inch springs.

As for springs I highly recomend HyperCoil springs. I have sets of Eicrack springs that are in 5.5 - 6.5 sizes...they used to be 6 and 7 inches tall, yeah.
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post #72 of 389 (permalink) Old March 9th, 2009, 09:08 Thread Starter
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Quote:
Originally Posted by Jim2109
the problem with this perception is that of the dampers being used. i dont know what your experiences are based on, so im speculating to some extent. but il hazard that most people with a perception of this type have been running dampers that arrive with whatever valving they arrive with, either "stiff" or "soft" with an adjuster that probably makes broad overall adjustments, and thus you are working around the dampers, not with them to the greater extent. i dont know what dampers you run, but on the most part dampers on MR2's are usually of a budget-dependant nature, and most peoples budgets are fairly small.

as a damper engineer id totally disagree from my experience with damping giving the impression of harshness over stiff springs if utilised correctly. it is dependant on the damping characteristics. if you have the facility to alter damping in every aspect (including changing the valving when your requirements go beyond the scope of the adjuster/s) then you can much better create a balance between ride and performance without the need for significantly stiffer springs. in return the tires are worked less and traction is improved on the driven wheels, and you have much more control across the range compared to stiff linear rate springs. combined with an improvement in cornering performance - most importantly!!

i seem to remember from previous discussion, whilst no details were shared, that Steves approach to damping is from a very different angle to mine. there is more than one way to skin a rabbit, and its hard to argue with multiple championship wins, but i think baseing an opinion on the ride quality of a car through the use of "stiffer" damping with softer springs, when the dampers are not being fully developed around the setup (this is my assumption, that the dampers arent being fully developed. which isnt the case with Steve but his setup philosophy totally defies convention) is not accomodating the full picture. ive personally driven dozens of cars on the road and track that ive developed the damping for with relatively soft springs, along with the many more cars that i havent driven myself but have customer feedback from (from just about every genre of road and racing), which had a better performance/ride relationship than with stiffer sprung setups. there are applications in which this isnt the case, for example high downforce cars, but that isnt the case here.
Yes there are many different ways to skin a cat. Send me some dampners with your setup and I will test them out for you

Auto-X and track setups tend to be very different and then setups vary from driver to driver. I would love some better dampners then the off the shelf Koni's but at the moment that is all I have and that is all that is available to us. But then again you cannot argue with results. The car feels fantastic now, it handles like it's on rails. I can toss it into any corner as fast as that gutless little motor will push it and it sticks. Mind you it took me two years of driving to get to this point and without Steve's advice I would still be chasing my tail (literaly since the car would spin almost every run before).
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post #73 of 389 (permalink) Old March 9th, 2009, 11:58
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All you'll ever want to know about roll centers.
http://www.vehicledynamics-expousa.c...5_lukianov.pdf
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post #74 of 389 (permalink) Old March 9th, 2009, 12:19
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Originally Posted by MicaCeli
As for springs I highly recomend HyperCoil springs. I have sets of Eicrack springs that are in 5.5 - 6.5 sizes...they used to be 6 and 7 inches tall, yeah.
ive been working with Eibachs for quite a while now, and they are still the most consistent springs on the market. there are also quite a lot of fakes kicking around, especially in the eastern markets

out of the box they are never more than 1% outside of length or rate spec, if they are as much as 1% then its a bad one. a typical 500lb spring would be +/- 2lbs. and lengths are within mm of what they are supposed to be, and stay that way. there is also the matter of consistency in rate throughout the travel. they really are excellent. Hypercoils arent bad, but their rates out of the box arent as well controlled, 2-3% isnt uncommon in my experience. they are about as durable as an Eibach over time though. both are high quality, another couple of manufacturers that are of similar standard are Lesjofors and King Springs, from Sweden and Australia respectively.
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post #75 of 389 (permalink) Old March 9th, 2009, 12:46 Thread Starter
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Yeah I will admit that I've only run HyperCoil's for a year now but they seem to do the job well. I wasn't kidding about the Eibach's though. I can send you a set that used to be 7inch springs.
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post #76 of 389 (permalink) Old March 9th, 2009, 15:19
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Originally Posted by MicaCeli
Yeah I will admit that I've only run HyperCoil's for a year now but they seem to do the job well. I wasn't kidding about the Eibach's though. I can send you a set that used to be 7inch springs.
no need to send them, il take your word for it. its not a common occurence though, but i guess all springs are prone to sag eventually. how old are they and what rate?
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post #77 of 389 (permalink) Old March 9th, 2009, 15:32 Thread Starter
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Don't know how old (I have a good amount of springs) I think these are 250lb or 300lb.
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post #78 of 389 (permalink) Old March 11th, 2009, 03:50
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Quote:
Originally Posted by MicaCeli
ST classes do not allow for roll center adjusters. I don't understand how you can't get to the ride heights that were recomended. I run 6inch front and 7 inch rear springs and have a ton of adjustment. If you can't get higher (I'm guessing front's) you can go with 7 inch springs.

As for springs I highly recomend HyperCoil springs. I have sets of Eicrack springs that are in 5.5 - 6.5 sizes...they used to be 6 and 7 inches tall, yeah.
I'm not ST- this car just recently got a gze swap (my original motor died, and I was presented w/ the choice of a 4age for $300 or more, or a 4agze for $500. I'm not hard core enough at autox to turn the gze down just to stay in ST ) Not sure where i fall now, I had heard at one point that the gze was allowed as a backdate in CSP, but I'm not sure anymore.

I'm running the eibachs that I got w/ my gc perches. As for height, I'm probably either looking at things wrong, or it's a result of my setup (as per suggestion of people on this board, I put the front perches 2 inches down from stock, and rears at stock. it *was* a cut+weld, not reusing stock perches. In retrospect, maybe 1inch would have been better on the front, but heck- the rears are at stock position and they are maxed already, while the fronts still have some room!). This 'virtual control arm' starts at the chassis bolt for the control arm, and ends in the middle of the round rubber part of the ball joint right? So the arms will be pointed slightly downward?

oh, and can anyone give me a few keywords to search around on fixing the tie rods? From what I understand, the reasons you don't go REALLY low are:
1: positive camber gain
2: screw up roll center
3: hit things on the ground
4: reduced suspension travel

3 is fixed by keeping high enough to not hit things, 4 is less important cause of how high my rates are (though I should come up with a way to monitor average and peak travel). So, I'm left with 1 and 2, which as I understand can be fixed by the RCA's and some kind of tie rod adapter to keep the tie rods in the same plane as the (virtual?) control arms.
Height isn't important to me in terms of looks or anything- I just figure since I have the ability to lower it just about as far as I want, if I can fix the problems then why not do it and reap the advantages.

last edit for now, I promise: any advice on rudimentary tuning of my struts? I've been toying with them, and roughly 1 full turn seems to work pretty good, but I honestly have no clue how to properly adjust them.

Last edited by sliverstorm; March 11th, 2009 at 04:10.
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post #79 of 389 (permalink) Old March 12th, 2009, 03:43
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Finally found some info about fixing the tie rods!

Mostly just wanted to say though, I got a pair of crash bolts today. (front camber was close to 0) Temporary solution for now- I'll figure out the best way to do it later- esp. since it was only $25. But anyway, put them on and... wow. It feels fantastic. It's going to be everything I've dreamed of, I am sure of it. Still far from perfect too, which makes it all even better.

checklist for myself:
reposition control arms (via RCA's most likely)
reposition tie rods (not quite sure yet, but maybe time to pay Aurora a visit)
ensure my roll centers (fore and aft) are where they should be (i.e. not 6ft under!)
come up with a permanent solution for negative camber on those fronts, if the RCA's done get me enough. Most likely camber plates. Rears seem ok though.

Oh, and thank you XHead. Thank you very much. I have a little piece of heaven now. My '2 was always responsive in the steering dept. but just never stuck to the ground, no matter how I drove it. Loved to push in turns. Imagine how it feels, going from pushing like there's no tomorrow, to sticking like glue!

Last edited by sliverstorm; March 12th, 2009 at 03:45.
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post #80 of 389 (permalink) Old March 12th, 2009, 04:20
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Just received my new suspension.

Techno Pro Spirit Ohlins with 11kg (615lb/in) front and 7kg (391lb/in) rear.
I will also remove both antiroll bars.

It is for my MK3 which is mostly for the track.

I will try the new setup and hope to see a much better car.
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