MS6 Suspension Data & DIY Bilstein Coilovers

[KevinK2]

I had always assumed this was a popular Type-2 Torsen, but it appears to be a variation of that theme, with the same parallel axis for both the outer gears and the side gears. The original Type-2 has 3 pair of outer gears (6 total), while this one has 12, shorter outer gears, all meshing with each other (no pairs).

Torsen Type-2:


Like Phate? (animation, just 6 short, outer gears):

https://www.youtube.com/watch?v=W96fOdMZnXE

The animation shows wheels spinning in opposite directions. But outer gears would spin slowly when in a corner, with side gears at different speeds, spinning in same direction.

Just a curiosity. Torsen now has many different versions supplied to the OEM car makers.

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[aviator79]

Are the Suspension Spring Specialists, aka "Blue Coils" basically a drop in spring? I had been planning on buying BC coilover height adjusters and QA1 springs. I am not finding blue coils for sale anywhere. Guess I can call manufacture.

Also saw some post with what looked like other possible options:
MS6 Suspension Data & DIY Bilstein Coilovers

Driving home from FL to CT in the next few weeks and car will be riding on bump stops whole way home which causes ass to pucker every time I go over a big bump, but made it down here fine. Shipping some stuff home but will still be overweight. Would love to get stiffer springs before that but likely not going to happen. Problem is even empty rear is too heavy for OEM springs so need to fix when I get home.

[OverBoosted]

Originally Posted by Tomas Nintendo is on all counts correct. 350 lbs pig tail springs compared to stock. Rear. Best DD set up so far. Much firmer than stock. Minimal squat left. Not bouncy. MS6 rear 250/500 springs. Gets bouncy. Prepare for light neck injuries. MS6 front with FSD and 425 springs (hands down best front DD set up ever for MS6) Filling rattling full homo only set up (for me) with 600 springs, front

I know this is super old post. But what/where did you get the upper mount to turn the bilstein shock into a coilover. I see where to get all the other parts.

[dagrimey1]

My 500lbs aren't bouncy I'm running the QA1s easy to find and fairly cheap on ebay.

Can't believe I using Tapatalk again!

[OverBoosted]

Originally Posted by dagrimey1 My 500lbs aren't bouncy I'm running the QA1s easy to find and fairly cheap on ebay. Can't believe I using Tapatalk again!

Here is the original design i was going to remake, just using the BC upper spring mount

[eroler1]

whats up with this new account spammers? the other one copy pasted something about viagra

[Tomas]

Originally Posted by OverBoosted I know this is super old post. But what/where did you get the upper mount to turn the bilstein shock into a coilover. I see where to get all the other parts.

BC racing

[OverBoosted]

Originally Posted by Tomas BC racing

Thank you! Putting together a set for the rear right now and will be doing the fronts soon.

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[dagrimey1]

Every clowns BC as a cheaper option but I love their CS and parts catalog.

Can't believe I using Tapatalk again!

[phate]

Been a while. Lots of life happening, so not a lot of racing this year. But, we have done 3 events and tweaked the car a bit with the intent of going to nationals the first week of September.

First event out was mostly a shakedown of the rebuilt trans. I took all of the old internals and put them into a good case. I've done a couple very short change intervals to flush out any remnants of the failure. So far, so good.

First event was on asphalt, I threw a string alignment at it and went at it. Local event with 175 drivers, I indexed 3rd, Johanna indexed 10th. Car is respectable and we mostly remember how to drive.

2nd event started with a test and tune on Friday. I had wanted to work with camber this year because I suspected more grip was out there. I started at last years setting of ~-3.0° front, and -3.5° rear and got a couple baseline runs. We added a net of -0.4° camber to the front end after zeroing out toe, and it completely woke the front end up So much added that we needed to hunt for rear grip. Added -0.4° out back and we're back to a balanced setup.

If some is good, more is better, amiright? We added nearly everything the front end has available, around -0.7° more. That much was not better, lol. Braking suffered and it was too easy to lock up a tire. The lateral grip didn't suffer, but turn in was pretty dead. So, no tnt time left, we backed out 0.3°, which should be around -3.7° in the front and -3.9° out back. I'll get it on a rack to verify.

So, we skipped Saturday and ran sunday competition. Concrete site, and the car ran great the first few runs. About 4 runs in we lose rear drive and I have some suspicions of what it is because the car doesn't make ugly sounds like things are broken. Load it up and call it a day. Had I not coned away my fast run, the car was on target to be the fastest car there. Index and raw. The car is working (when it has rear drive).

Suspicions confirmed back home, but i was wrong about which one it was - the drivers front wheel speed sensor had vibrated out of place because the alignment peg has been broken for about 5 years. Easy fix, but we corded the front tires due to wheel spin in fwd mode.

That brings us to this past weekend - Peru Champ Tour. I had intended to run my normal ESP class, but it turned out that we only had 2 cars actually showing up in ESP. That means no possibility of contingency payout, so lots of back and forth with some other folks, and all of ESP decides to roll the dice with Street Mod (a significantly faster class). So, 2 drivers in SM, 2 from ESP, and it turns out that ASP and DSP had the same idea, so we have a 9 driver class in SM, with ESP being the "slowest" of the bunch haha. Johanna is gunning for Ladies index, so she'll run ESPL by her lonesome.

First day, first run, I lay down a FLYER. It was damn fast, but with a cone. I think the competition sees this. No one is close to that time, yet. 2nd run I clean it up but am 0.2s off of my first run, but still damn fast and no one is near it. Lots of cone calls on competitors and I'm in the lead. Third run is slow, but no one goes faster so I'm leading by 0.4s going into the 2nd day.

2nd day, first run feels ok but I'm not pushing the car hard in some key sections. The competition is clearly faster today, but with my lead and yesterday's cone calls, I think I have a shot. 2nd run (video below) feels better and is 0.7s faster, but still slow in 1 section that i shouldn't be. Third run i try to go flat through the slalom end offsets and bail on it after upsetting the car. Competition still had a chance, but no one can close the gap and I take the win in street mod Johanna takes the ladies index win by a pretty solid margin in the last heat of the day. The car rips.

YouTube Short

YouTube Short

Coming up, we have a 3 day local event that we'll use as final Nats prep. Friday the 16th is Test and tune and I want to dial in camber and tire pressures. The high speed rear grip could be better, so I'm going to work on that if the course allows. The 17th and 18th are competition and we'll clean up any remaining issues (car and driver) with those days.

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[KevinK2]

That looked fast & smooth. You were almost on the base of the cones on the tight lefts at the beginning! What type of cars were 2nd & 3rd on that mixed group ? SM would allow power upgrades ..

[phate]

Originally Posted by KevinK2 That looked fast & smooth. You were almost on the base of the cones on the tight lefts at the beginning! What type of cars were 2nd & 3rd on that mixed group ? SM would allow power upgrades ..

I've attached a screenshot of the results. 2nd place was a true SM car, 3rd an ESP car (and Nats winner of last year's ESP class), 4th and 5th ASP, 6th DSP.

Going to SM, I would need to pick up about 2 seconds on a 60s course to have a chance with the most competitive of them. Even if I could build the car that much faster, I'm not sure I want to spend what it would take. I've definitely thought about it, just not sure I could make it competitive.

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[KevinK2]

Originally Posted by phate I've attached a screenshot of the results. 2nd place was a true SM car, 3rd an ESP car (and Nats winner of last year's ESP class), 4th and 5th ASP, 6th DSP. Going to SM, I would need to pick up about 2 seconds on a 60s course to have a chance with the most competitive of them. Even if I could build the car that much faster, I'm not sure I want to spend what it would take. I've definitely thought about it, just not sure I could make it competitive.

SM allows unlimited power on the original block, and the Audi S4 may not have made enough power to deal with the extra weight, and/or you were the better driver. With your busy schedule, I think you should stay in ESP. You are near the limit of the drivetrain as it is .

[Fstrnyou]

That Audi, BMW, and Evo are pulling double duty.
You were 3rd fastest on day two but still manged to bring home the win.

Congrats.

[KevinK2]

Originally Posted by Fstrnyou That Audi, BMW, and Evo are pulling double duty. You were 3rd fastest on day two but still manged to bring home the win. Congrats.

That Evo turned a clean 43.285 on the 2nd run. Very fast !

[phate]

Friday was TNT, and we mostly just worked tire pressures up axle by axle gaining a bit of grip each time. We put about 25 runs on the car, and at the end of the day, the front tires were getting some spin off the line. I swapped out the rear diff coupler that evening with a spare that I brought and Saturday the car was back to normal.


The car is pretty happy running low 40's for pressures. It makes the car a little more sensitive to drive at the limit, but the grip is up and it's still very forgiving. None of the oft spoken of Hoosier instant loss of grip. About 34s into this video you can see me over driving a touch:

YouTube Short

YouTube Short

Saturday I couldn't put a full run together, and ended up 3rd overall on index about 0.5s back from 1st. Sunday (video above) was much better driving and landed 1st on index.

2 weeks until Nats.

[KevinK2]

Originally Posted by phate ... The car is pretty happy running low 40's for pressures. It makes the car a little more sensitive to drive at the limit, but the grip is up and it's still very forgiving. None of the oft spoken of Hoosier instant loss of grip. About 34s into this video you can see me over driving a touch:

That's a tricky right at the 34 sec point ... you have lots of room before and aft to create different lines. I'm sure you figured out the optimal line to be position for the next left.

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[phate]

Originally Posted by KevinK2 That's a tricky right at the 34 sec point ... you have lots of room before and aft to create different lines. I'm sure you figured out the optimal line to be position for the next left. .

That, and the surface crests at that point, too. It's part of a runway, so everything slopes away from center. It makes everything a bit tricky.

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[phate]

GRM's write up

https://grassrootsmotorsports.com/ar...d-mazdaspeed6/

[KevinK2]

Nice work. Both came in 2nd to same car, likely professionally prepared by ProParts USA.

https://www.scca.com/downloads/47295...esult/download

ESP class

[phate]

For me, nationals was a struggle this year. We arrived midday Monday in order to get some test runs in, and that went ok. No setup changes based on TNT.

Johanna was running first heat, I was running 5th heat. Temperatures were good for her in the mid 70's, just like what we've been running in back home. Car seemed to work well enough for her, and she was just barely out of 1st place after day 1 with a 0.042s margin.

5th heat, for me, was HOT. We haven't run the car in hot weather like this all year, and it threw things off unexpectedly. First run out I find that grip just isn't what it should be, and I feel like I'm fighting the car. Make a small pressure change, the balance is better, but the grip still isn't where it should be. I do my best, but it lands me in 4th place, and a full second out of 1st place. Thinking about it that evening, I suspect that we should have gone down in pressures - I just didn't realize it at the time.

Day 2, Johanna clearly has the speed, but gets into the cones on the first run. 2nd run is a safety run to get a clean one in the books, but it's slower. 3rd run the speed is back, but she nudged a cone in a wallom section that was really tough to be fast in. She ended up in 2nd place.

Day 2 for me, I make the call to drop pressures by ~5psi because it's just as hot as day 1. First run out, the car feels WAY better and I'm on pace. I'm tip toeing through several sections because of how the car was yesterday. Run 2 I push harder everywhere and I'm 0.2s behind the leader for the day, and the other fast guys are into the cones so I'm sitting in 2nd place going into my 3rd run. I pull up to the line for my last run, and I hear the announcer say the 2nd place driver has coned away his 3rd run, so I knew I was in the running for 2nd place at that point. I'm in a pretty good place with my 2nd run's time, so I push harder on my 3rd run everywhere, but end up pushing way wide in a sweeper and have to check up the car. That run is just a bit slower than my 2nd run, but I'm sitting in 2nd place. That holds up as all other drivers finish their runs, and I end up in 2nd place overall.

[Db09ms3]

BEEEEEEEEERRRRRR! Congrats to you both.

[KevinK2]

Originally Posted by phate ....Going to SM, I would need to pick up about 2 seconds on a 60s course to have a chance with the most competitive of them. Even if I could build the car that much faster, I'm not sure I want to spend what it would take. I've definitely thought about it, just not sure I could make it competitive....

I agree about SM. One thing that seemed possible was to stay in ESP, and lower the car, especially the rear, to reduce WT. Stiffer springs & shock tune. You made a great adjustable rear bar for tuning the balance. Just a thought on how to beat that Camaro. More power would reduce reliability.

[phate]

I've suspected the rear suspension is losing a bit of camber during cornering because of how the car feels, how the tire angle looks in pictures, and how the wear looks on the rear tires (and how OPR builds up on the insides, even running more negative camber in the rear than the front). I picked up several new offerings from our Russian friends at polyurethan.ru. They offer several versions in the green poly (harder), which I was pretty excited to see.


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I took a few hours this past weekend to measure a handful of rear suspension bushings, and it's pretty enlightening.

I picked up a 20T press a couple months ago, and the wider frame allows me to put 2 corner scales in side by side. I can measure loads up to about 2500lb with this setup. So, I put a steel bar through the bushing, and placed each end in a v-block and spread them across the scales. I measured distance from the scale top surface to either the bushing casing, or the press ram depending on which arm I was measuring. Every bushing got 3 test runs, and I averaged those 3 data sets, then averaged the stiffness across the deflection range to get a single spring rate per bushing. Not perfect, but I think it tells us everything we need to know.


Upper control arm bushings

• SPC Rubber Bushing (current inner pickup bushing)
• Orange Poly - 3-06-694 (current outer pickup bushing)
• Green Poly - 3-06-6941
• Green Poly - 4-06-24751

Load vs Displacement:



Rate vs Displacement:




Average Stiffness
SPC Rubber Bushing - 12,287 lb/in
Orange Poly - 3-06-694 - 24,345 lb/in
Green Poly - 3-06-6941 - 16,782 lb/in
Green Poly - 4-06-24751 - 13,161 lb/in





Lower control arm bushings

• Stock Bushing
• Orange Poly - 4-06-2792 (current inner and outer bushings)
• Green Poly - 4-06-127

Load vs Displacement:



Rate vs Displacement:



Average Stiffness
Stock Bushing - 26,357 lb/in
Orange Poly - 4-06-2792 - 32,269 lb/in
Green Poly - 4-06-127 - 27,449 lb/in


*******The big thing to remember here is that each control arm has 2 of these bushings in series that act exactly like springs in series.


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What does this mean for me...First, I calculated the loads the UCA and LCA see by assuming a 1.7g load and corner weight of 700lb. The LCA sees almost 4,000lb, and the UCA sees about 2,700lb. I more typically see about 1.5g, but we've occasionally seen higher when coming off a banked section or when the car settles after a sharp decline.


That note above about the springs in series...here's where that comes into play. For the UCA, the resultant spring rate is 8,166 lb/in. It sees a 2700 lb force...so that deflects the upper point 0.33"...and a little bit of trig (assuming the LCA pickup point is the point of rotation) says we lose 3.1° of camber just in the upper control arm, alone.

For the LCA, the resultant spring rate is 16,135 lb/in. At 4,000 lb load, the deflection is .24"...resulting in 2.3° camber loss at 1.7g.

Total camber loss at 1.0g - 3.2°
Total camber loss at 1.5g - 4.8°
Total camber loss at 1.7g - 5.5°



More on how we help this later

[phate]

Originally Posted by phate More on how we help this later

Step 1: buy a mill.

j/k, but I've wanted one for a while since I moved and lost access to a machine shop several years ago. This should open up a lot of possibilities, and I'm looking for a lathe to accompany it.

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