MR2 SpyderChat banner

1 - 20 of 358 Posts

·
Registered
Joined
·
1,580 Posts
Discussion Starter #1 (Edited)
Current setup as of 6/18/14:

Suspension
OTS Koni sport struts all around. Modified to accept coilover sleeves/perches. Rebound to 1/2 turn below full stiff all around.
no front sway bar, no rear sway bar
600 lb/in front springs, 8" tall, 400 lb/in rear springs, 8" tall.
ebay universal camber plates
TRD front strut bar

Tires
225/45R15 RS3 V2 all the way around. I run 30 psi hot, but I think the V2 RS3s prefer a different psi. at 30 PSI the old RS3 didn't mind a little slip angle and when it got too high (34 psi) it started feeling very peaky and edgey without holding slip angle. My V2s feel like this at 30 psi so I will experiment with lower.

Alignment
Camber -3.4 degrees front, -2.2 rear
Toe 0 in front, 0
Caster oem, roughly 3 degrees

Ride Height
Front 33mm lower than stock accounting for tire diameter
Rear 28mm lower than stock accounting for tire diameter

Other stuff
Corbeau FX Pro drivers seat with Bride type FG side mount. MR2 cloth seat in passenger from a 2001.
Deka ETX18L (DD battery, tired of killing a etx9 every year)
PPE 4-1 header with o2 bung welded in primaries 3 & 4.
PPE high flow cat midpipe
Borla pro XS 2.25" muffler
stock intake for now, have a modified oem maf tube with cone filter on end to go behind the battery.
Camcon Ti set to default settings
NGK iridiums
Quaife LSD


In this thread I'll document my STR build and progress which I hope will help other people in prepping a spyder for STR. This is the first car I have prepped for a specific autox class, before this I ran a V6 mr2 in SSM on street tires which I built before I got into autocrossing.

The base car:
2003 MR2 Spyder with 71k on it. Bone stock except with some 16x7 Enkeis with 205/45/16 Falken Ziex ZE912 all around. Here it is at its first event. I had to remove the foglights to pass MD state inspection since one was cracked.



I am doing my mods in order of which ones will drop the most time, so first up was wheels and tires. I chose to go with the 15x9 +36 949 racing 6ULs all around with 225/45/15 Hankook RS3s. I heard you needed a 5mm spacer in the rear but I decided to test fit anyways. The wheel was hitting a tiny lip on the strut mounting flange by about 1mm so out came the dremel. I did this while the strut was on the car but I had the struts off today so decided to take pics:







And that created about 2mm clearance which I am perfectly fine with.



The wheels fit upfront but were very close to the spring perch so for peace of mind I used the dremel to trim 4mm down the side nearest the wheel turning the circle into a straight line, here the wheel clearance upfront now.



This modification is STR legal, on Pg. 87 14.8 states:
"On strut-equipped cars, the strut’s lower integral mounting bracket,
for attachment to the upright or spindle, is unrestricted provided it
attaches to the stock location. Any resulting change to the position
of the strut centerline is allowed."

Car is 100% ok with these wheel clearances, tires don't rub or touch the spring perch. I plan to start off running 28-30 psi hot since thats what the miatas run.

Note: I would not get the rear wheels balanced because the wheel weights they put on the wheels would probably cause them to hit the strut bracket.

I also installed a 22m front swaybar, front strut tower bar and removed my spare tire, these mods weren't particularly photo worthy though.

Next up is coilovers. I'll be using Koni Sports and will make a ground control style kit with custom camber plates. I will post all the details when I'm finished and I'm sure everything works. Not sure if I will get it done by next weekend, if not I will run stock suspension. I have 2 events planned for next weekend as well.

Finally, I will post any important measurements I take so here is stock ride height with these wheels:
6.25" front (from the ground to the bottom of the pinch weld at the jacking point)
6.125" rear
 

·
Registered
Joined
·
509 Posts
Very interesting post! I want to follow your build.

Btw, what spring rate did you choose for the coilovers?
 

·
Registered
Joined
·
1,580 Posts
Discussion Starter #4 (Edited)
Installing Konis and DIY coilovers

Parts used:
A1 Racing 2.038" Sleeve (use smaller for front 1.92" = OD, rear = 2.00"), I just used the 2.038" sleeves that are 5" tall because I had them from my mk2. Don't go taller than 5" or it won't fit under the Konis.
http://shop.a1racing.com/coiloverkits.aspx?page=2

A1 Racing 2.5" spring perch
http://shop.a1racing.com/cok12460.aspx

You could also use a ebay coilover kit and save alot of money. I liked knowing the exact measurements of the stuff I was buying and didn't mind spending more.

Eibach coilover springs
I went with 2.5", 8" tall 500 lb/in front and rear with the 22mm front swaybar and no rear sway bar. I will run these for a while then test 700 lb/in upfront and remove the front swaybar, the rear will stay the same. Ideally I would want 450 lb/in rear but I had the 500s from my mk2.
http://www.ground-control-store.com/products/description.php/II=443/CA=213

Koni Sports 8641-1420 and 8641-1422
http://www.twosrus.com/catalog/index.php?cPath=23_57

Steps to install:

First, a good write up for a sentra that is literally the exact same thing for the spyder (except the measurements).
http://www.b15sentra.net/forums/showthread.php?t=63477

1420 = Front, 1422 = Rear, do not mix these up, they are different ODs and height!

-take strut housing off car, only tip is to break loose the 19mm nut on the top in the center of the strut top with the car on the ground

-you don't need a spring compressor to take off the stock springs but it is ALOT safer to use one. If not using one, aim the spring top away from you with a large area infront. Stand behind it and use a long socket wrench to remove the 19mm. Becareful because it pops off with strong force.

-drill small hole in the bottom (3mm)

-pump out fluid by pumping the shaft into a container

-measure how much to cut off the top (65mm front, 30mm rear per Koni) then cut it

-drill out bigger hole in bottom (1/2" works, 9/16 is what instructions say)

-if doing the DIY coilover, grind the welds off the spring perch and hammer it off, then slide the coilover sleeve and perch over the strut housing. Don't be dumb and put the insert in because the coilover sleeve doesn't fit over the insert locker.

-Put black rubber sleeve on the koni strut at the top.

-Insert the strut inside as far as you can, put bolt in the bottom with washer/locker, torque to 55 ft/lbs

-I had to dremel off 2-3mm of the outside lip on the rear strut tops for it to fit 2.5" springs, the front strut top fits 2.5" springs but doesn't really secure them. I don't think this is an issue but I will be using camber plates anyways for additional caster.

I would recommend adding additional support for the rear by welding on a dowel rod or anything to hold up the perch besides the sway bar tab. I haven't done this yet.

Bare fronts finished (minus painting)


Front mockup


Bare rears:


Rear mockup


Next up, front custom camber plate and spring tops.
 

·
Registered
Joined
·
1,580 Posts
Discussion Starter #8
Congratulations Levi for joining the growing crowd of STR Pioneers, keep posting your valuable information, I'm practically done, not too much left to do.

Thanks

Andres
There is always more to do! Piggybacks are coming next season, along with a new header (no precats), tire testing (225 R1R vs Kooks), 245/35/17s in the rear, and shocks that cost more than the car, then a ST legal engine rebuild for that extra 5 horsepower. Oh yea and then there is that pesky driver mod :lol:

Anyways, progress so far:

My coilover setup is:
Koni Sports
500 lb/in springs front and rear
22mm front swaybar, no rear swaybar
I am using the stock spring perches both front and rear at the moment.

I was in a hurry to finish up for the two events this weekend so I just put the coilovers together. I wasn't able to weld a perch on the rear for the sleeve to sit on so its just sitting on the swaybar tab. I think this will be ok for now.

For the rear I found the stock 19mm nuts for the shock work the best, the 22mm Koni nuts are too big and you can't get a socket on it effectively.

Here is the rear before I dremeled the stock strut top more (so the spring isn't stuck to it)



Here is the front installed:


I was disappointed with my two 2 dot crash bolts installed upfront. I feel this gave me half a degree of camber at most. I'll measure it tomorrow but I doubt I'm over -1 degrees with both bolts maxed out. I might need to just use a generic thinner bolt to get the -3 degrees I'm aiming for upfront initially.

I maxed out the rear and got a little more camber, again I'll have to measure.

Here it is all finished and after a successful test drive.



Still gotta set ride height but I ran outta time. Also, I got my spring tops and camber plates and it looks like they will fit. Just gotta drill the holes for the studs in the plate, probably will do this next weekend.
 

·
Administrator
Joined
·
4,482 Posts
The front gains a lot of negative camber initially from ride height and then gains less and less. Set the ride height before you go spending time on fancy solutions beyond 2 of the 2 dot crash bolts, IMO.

Have you checked for coil bind? I'm not saying for sure that the swaybar tab will hold, but it for sure won't hold if you get coil bind.

Without coil bind, the max stress in that tab is approximately the spring travel (inches) times the spring rate (lb/in) divided by the weld area (inches). Easy to guestimate, and worth doing before you trust your life to it. I'd say it WILL fail quickly at 20,000lb/in^2 (.577*36ksi) and be beyond my comfort level for myself at more than about 10,000lb/in^2. I'd also guess it will hold, but deform the coilover tube over time, but as I say, I wouldn't just run it without running the numbers.
 

·
Registered
Joined
·
1,580 Posts
Discussion Starter #13
BTW, Levi don't count on the catless headers to be allowed for a long while.

Andres
It's in the fast track though! I will have to get all my friends to send in letters then and I'll post mine here as a draft for other people to use.

The front gains a lot of negative camber initially from ride height and then gains less and less. Set the ride height before you go spending time on fancy solutions beyond 2 of the 2 dot crash bolts, IMO.

Have you checked for coil bind? I'm not saying for sure that the swaybar tab will hold, but it for sure won't hold if you get coil bind.

Without coil bind, the max stress in that tab is approximately the spring travel (inches) times the spring rate (lb/in) divided by the weld area (inches). Easy to guestimate, and worth doing before you trust your life to it. I'd say it WILL fail quickly at 20,000lb/in^2 (.577*36ksi) and be beyond my comfort level for myself at more than about 10,000lb/in^2. I'd also guess it will hold, but deform the coilover tube over time, but as I say, I wouldn't just run it without running the numbers.
I ran it without running the numbers :lol: The tab isn't a single tab it has about 2" of surface area so that made me feel ok about it. I will get the rear welded as soon as I can, hopefully next weekend. It lasted the two events this weekend fine though.

Regarding coil bind, here is the data I have from my mk2 thread:

Eibach 6.00" tall 450lb spring has 3.51" of spring travel from free to coil bind, and takes a 1579lb load to compress to coil bind.
450 lb/in = 1579 lbs of load before bind
550 lb/in = 1918 lbs of load before bind
650 lb/in = 2226 lbs of load before bind

These are for 6"tall springs, I have 8". I don't think I need to worry about coil bind.
 

·
Administrator
Joined
·
4,482 Posts
It's in the fast track though! I will have to get all my friends to send in letters then and I'll post mine here as a draft for other people to use.



I ran it without running the numbers :lol: The tab isn't a single tab it has about 2" of surface area so that made me feel ok about it. I will get the rear welded as soon as I can, hopefully next weekend. It lasted the two events this weekend fine though.

Regarding coil bind, here is the data I have from my mk2 thread:

Eibach 6.00" tall 450lb spring has 3.51" of spring travel from free to coil bind, and takes a 1579lb load to compress to coil bind.
450 lb/in = 1579 lbs of load before bind
550 lb/in = 1918 lbs of load before bind
650 lb/in = 2226 lbs of load before bind

These are for 6"tall springs, I have 8". I don't think I need to worry about coil bind.
Do you run this on the street? Coil bind should be checked based on travel, so the seat on a 6" spring with 3.51" of travel needs to be at least 2.5" below the top of the strut body (simplified view to explain) to avoid coil bind. If you are implying that because it takes 2000lb or so to reach coil bind and the corner weights are ~1/4 of that, you don't need to worry about it, well I guess we will just disagree.

edit: also, that tab has NO WHERE NEAR 2 square inches of weld. Seriously, look/measure again.
 

·
Registered
Joined
·
1,580 Posts
Discussion Starter #15 (Edited)
Setting ride height:

Stock = 6.25" Front / 6.125" Rear

The way I set ride height on strut cars is I get the rear as low as I can until the control arm goes parallel to the ground. The rear control arm was parallel at 5.5" rear, from ground to pinch weld jacking point. I determined parallel two ways, I would measure the inside height of the control arm compared to the outside and using a leveler. Next, I planned to set the front higher than the rear with the same amount of rake as stock, so .125" higher. Unfortunately, I slightly messed this up and ended up with 6" front ride height for this weekend. I also double checked my work today and the rear control arm and here is the shot of how parallel it is with the ground:



Pretty good

Here are my videos from this past Sunday's autox, I'll link you to my fourth run and final run. I didn't edit the video because I thought it was cool to see the before and after running parts. The sound from GoPro sucks so with my stock exhaust its hard to hear when I'm on the gas or off it.

Run 4, starts at 1:30 if you want to skip the grid part.
http://www.youtube.com/watch?v=4GtqbOqor4A

Do you run this on the street? Coil bind should be checked based on travel, so the seat on a 6" spring with 3.51" of travel needs to be at least 2.5" below the top of the strut body (simplified view to explain) to avoid coil bind. If you are implying that because it takes 2000lb or so to reach coil bind and the corner weights are ~1/4 of that, you don't need to worry about it, well I guess we will just disagree.

edit: also, that tab has NO WHERE NEAR 2 square inches of weld. Seriously, look/measure again.
Sorry didn't mean square inches, wrong choice of words. I meant it isn't just one little tiny tab, it creates a mini perch about 2" long. I have run this on street for a few hundred miles and the two events this weekend. I plan to get a perch welded this week.

I think I understand how your explaining coil bind, its where the top of the strut body contacts the spring top? I always thought coil bind was when the spring compress so much that one spring coil is sitting/contacting the lower spring coil and thus cannot compress any further. I think we are talking about two separate things but calling them both "coil bind". What your referring to I would call the shock travel or the shock bottoming out. Correct me if I'm not understanding this.

I had zip ties on all 4 corners to check shock travel. This is after 200 miles of street driving, and two auto-x events.
Front right:


Front left:


Rear left: (If you zoom you can see the black zip tie right above the coil with the white lettering on it.


Rear right: (just below my only bump stop)


All corners had over 1" of travel left until it reached the strut top.

I was only running cut kyb bump stops on the rear right. I didn't run any bump stops on my mk2 and had no problems. I made sure I have enough shock travel to pretty much never bottom out given normal street conditions. This week I plan to add bump stops to the other 3 corners, similar to the one I have now.
 

·
Registered
Joined
·
1,580 Posts
Discussion Starter #17 (Edited)
we mean the same thing, i was trying to say you want strut bottoming before coil bind.
Oh I see what you mean now. Well you shoulda said that in the first place :lol: I agree completely, I was saying that I think achieving coil bind isn't really possible given my spring rates/weight of the car. Maybe I shoulda just said that too!

why so concerned about the control arms being horizontal?
Short answer: Because roll centers go below ground beyond that point and camber curves get really bad as well. (on a mk2, I assume for a mk3 as well). Its a starting point really rather than, as low you can go without rubbing anything.

Long answer: I'm a follower of Xhead and a somewhat blind follower. The more I learn about suspension geometry the more I realize how little I know. However, I have had nothing but success following Xhead's advice. I guess the problem comes with how much changes when running a spyder. The mr2 mk1 and mk2 suspensions are almost identical, the spyder's suspension is somewhat different, especially in the rear.

If you have suggestions for ride height I am all ears. Right now I'm planning on 5.4" rear and 5.6" front.

This week:
-get rear spring perch welded
-install bump stops on other 3 corners
-fix ride height
-if needed, get some more camber using some home depot camber bolts. I'd guess I'm at -1 front, -1.5 rear. Hopefully I can borrow my friends camber gauge
-drill spring tops for 20mm and drill studs into camber plate and install . I will use this to gain caster, however I probably won't have time this week to do this.
 

·
Registered
Joined
·
960 Posts
Oh I see what you mean now. Well you shoulda said that in the first place :lol: I agree completely, I was saying that I think achieving coil bind isn't really possible given my spring rates/weight of the car. Maybe I shoulda just said that too!



Short answer: Because roll centers go below ground beyond that point and camber curves get really bad as well. (on a mk2, I assume for a mk3 as well). Its a starting point really rather than, as low you can go without rubbing anything.

Long answer: I'm a follower of Xhead and a somewhat blind follower. The more I learn about suspension geometry the more I realize how little I know. However, I have had nothing but success following Xhead's advice. I guess the problem comes with how much changes when running a spyder. The mr2 mk1 and mk2 suspensions are almost identical, the spyder's suspension is somewhat different, especially in the rear.

If you have suggestions for ride height I am all ears. Right now I'm planning on 5.4" rear and 5.6" front.

This week:
-get rear spring perch welded
-install bump stops on other 3 corners
-fix ride height
-if needed, get some more camber using some home depot camber bolts. I'd guess I'm at -1 front, -1.5 rear. Hopefully I can borrow my friends camber gauge
-drill spring tops for 20mm and drill studs into camber plate and install . I will use this to gain caster, however I probably won't have time this week to do this.

Levi, that's just a general rule about RC's. You should look at the charts I posted to see where the RC's fall at different ride heights.
 

·
Administrator
Joined
·
4,482 Posts
Levi, that's just a general rule about RC's. You should look at the charts I posted to see where the RC's fall at different ride heights.
Also, the virtual control arm from xheads stuff doesn't neatly coincide with an actual control arm like on the mk1...

Based on experience and without good theory to back it up, I've found the rear should be a good bit lower than the front for the car to really work well. Enough so the car just starts to look funny if you look carefully :)

I'd say go lower until something stops you, like bump travel, then compensate for the roll center locations/fine tune from there. If you are going to stick closer to xheads stuff, you need to ditch the front bar (which my experience also supports strongly.)
 
1 - 20 of 358 Posts
Top