Mastering the art of the S197 3 link suspension (sixty foot)

[lindertw]

update: I went to MIR last night (29AUG14) for their Midnight Madness...

front struts set to full loose
rear shocks set to +3 clicks from full loose
3560 lbs w/driver
DA started near 1100 ft and worked down to 400 ft later in the evening (per drag times DA calculator)

1st pass rear tires set to 14psi, 6k rpm launch
2nd pass rear tires set to 14psi, launched off the limiter @ 6.5k
3rd pass rear tires set to 16.5psi, launched off the limiter @ 6.5k
all remaining passes rear tires set to 15psi, launched off the limiter @ 6.5k

best run of the night was 12.491 with a 1.642 60' (new best 60'). MPH was down all night, possibly because I was running less pressure in the rear tires(?) Mounted my gopro to the panhard bar to watch the tire at launch:



additionally, a friend captured a couple of launch vids - I'll post those as soon as I get copies...

There were 60 or 63 cars in super street, and I think I was the #12 qualifier. I dialed in a 12.49 and gave it a go. I've never really paid attention to trying to cut a light, and as such I managed to red light during the first round of eliminations (-0.011 red). I was exhausted anyways, so it's good I was able to pack up and head home. Once I get everything dialed in and consistent, then I'll worry about cutting a light

Being able to put the pedal to the floor @ launch was lots of fun. I spoke with a couple of guys in the staging lanes and they said both front wheels came up...

 

[BMR Tech]

Congrats. IMO, there is no better feeling than setting new PB sixty foot times, outing after outing. Especially when you have a manual trans.

Keep it up.

 

[Fabman]

update: I went to MIR last night (29AUG14) for their Midnight Madness...

front struts set to full loose
rear shocks set to +3 clicks from full loose
3560 lbs w/driver
DA started near 1100 ft and worked down to 400 ft later in the evening (per drag times DA calculator)

1st pass rear tires set to 14psi, 6k rpm launch
2nd pass rear tires set to 14psi, launched off the limiter @ 6.5k
3rd pass rear tires set to 16.5psi, launched off the limiter @ 6.5k
all remaining passes rear tires set to 15psi, launched off the limiter @ 6.5k

best run of the night was 12.491 with a 1.642 60' (new best 60'). MPH was down all night, possibly because I was running less pressure in the rear tires(?) Mounted my gopro to the panhard bar to watch the tire at launch:



additionally, a friend captured a couple of launch vids - I'll post those as soon as I get copies...

There were 60 or 63 cars in super street, and I think I was the #12 qualifier. I dialed in a 12.49 and gave it a go. I've never really paid attention to trying to cut a light, and as such I managed to red light during the first round of eliminations (-0.011 red). I was exhausted anyways, so it's good I was able to pack up and head home. Once I get everything dialed in and consistent, then I'll worry about cutting a light

Being able to put the pedal to the floor @ launch was lots of fun. I spoke with a couple of guys in the staging lanes and they said both front wheels came up...

Great video, thank you for posting.

 

[lindertw]

Congrats. IMO, there is no better feeling than setting new PB sixty foot times, outing after outing. Especially when you have a manual trans.

Keep it up.

thanks Kelly - and that reminds me, I need to respond to the ARB thread

Great video, thank you for posting.

thanks, I'm really looking forward to the other vids (you can see the guy filming me at the 53 second mark above).

 

[Fabman]

Looks like the car has quite a bit of anti squat.....and you've added more by the look of the holes.
How did you find adding more A/S effect you?

 

[lindertw]

Looks like the car has quite a bit of anti squat.....and you've added more by the look of the holes.
How did you find adding more A/S effect you?

I need to recalculate it... The information I posted in the AS/IC sticky was when I had the UCA in the upper hole and LCA's in the upperhole (and it was like 105%).

With my setup now UCA in upper hole, LCA in middle hole, taller front tire (28") and shorter rear tire (26") it's surely changed. I want to put the car on corner scales so I have good values for front/rear weight bias. I'll venture a guess I'm in the 125-ish % range now.

I feel like this setup will take all I can throw at it.

 

[Fabman]

I need to recalculate it... The information I posted in the AS/IC sticky was when I had the UCA in the upper hole and LCA's in the upperhole (and it was like 105%).

With my setup now UCA in upper hole, LCA in middle hole, taller front tire (28") and shorter rear tire (26") it's surely changed. I want to put the car on corner scales so I have good values for front/rear weight bias. I'll venture a guess I'm in the 125-ish % range now.

I feel like this setup will take all I can throw at it.

That's about exactly where I am (depending on your ride height)
Works really good for me so far. Its a longer moment arm than using the lower hole in the upper mount.
Should be a less violent launch with less likelihood of breaking loose somewhere after launch.
I haven't tried any other combinations though which is why I asked. I just set it up basically the same as I did my oval track cars.
(but with more uphill angle to the lowers since roll steer doesn't matter here) Love to see/hear about other peoples setups.

More tech vids like this, that was super killer!

EDIT: Now that I look closer at the drawing my lowers are way flatter than that.
You must be using different relo brkts. Mine are the classic BMR units, plus I think my car is lower than yours. Hmmmmm.....

 

[lindertw]

...depending on your ride height...

EDIT: Now that I look closer at the drawing my lowers are way flatter than that.
You must be using different relo brkts. Mine are the classic BMR units, plus I think my car is lower than yours. Hmmmmm.....

I have BMR relocation brackets (latest version, with three adjustment holes). My ride height is approx 28.5" from floor to top of the fenderwell arch at all corners. The cobra jet springs I have are the 2008 variants (p/n M-5300-Q) and really only lower the rears to level out the car.

 

[Fabman]

I have BMR relocation brackets (latest version, with three adjustment holes). My ride height is approx 28.5" from floor to top of the fenderwell arch at all corners. The cobra jet springs I have are the 2008 variants (p/n M-5300-Q) and really only lower the rears to level out the car.

What REALLY matters is the delta between the front pivot point and the rear pivot point....

 

[Fabman]

here is what mine look like with the DR's on:

Not the best pic, but you can see the angle is only slightly up.

 

[lindertw]

here is what mine look like with the DR's on:

Not the best pic, but you can see the angle is only slightly up.

such a great looking car...

 

[Fabman]

such a great looking car...

Well, thanks.
I was just trying to point out the control arm angle and this is the best I could come up with.
You can just see it peaking out in front of the tire...

 

[429244]

here is what mine look like with the DR's on:

Not the best pic, but you can see the angle is only slightly up.

What a great looking car. What is the rear rim and tire combination?

 

[Fabman]

Thanks!
15x10 race stars and in that pic I had 325/50/15 Hoosier DRs.
I am running 275/60/15 M/T Pros at the moment.

 

[lindertw]

updated videos from my 29AUG14 outing at MIR. First two vids go along with the undercar vid posted above:

full speed


slow motion


and another pass @ 6.5k launch with 16.5psi in rear tires (spin)

https://www.youtube.com/watch?v=109lSnicrAk

 

[Fabman]

updated videos from my 29AUG14 outing at MIR. First two vids go along with the undercar vid posted above:

full speed


slow motion


and another pass @ 6.5k launch with 16.5psi in rear tires (spin)

Great slow mo! Are you using a Gopro for that or something else?

 

[lindertw]

Great slow mo! Are you using a Gopro for that or something else?

my buddy had something like a sony handycam with a very small tripod (gopro was still on the panhard bar for these runs)

 

[Fabman]

my buddy had something like a sony handycam with a very small tripod (gopro was still on the panhard bar for these runs)

Great footage....

 

[fdjizm]

Nice vids man that bitch is putting in work!!
I need my car to launch like yours so bad! lol

 

[lindertw]

test and tune at MIR tonight (12SEP14), learning occurred - and a new best 60'

run 1
weight 3570 lbs
front strut full loose
rear shock +5 clicks from full soft
15psi cold in rear tire
6500 rpm launch off limiter

run 2
weight 3570 lbs
front strut full loose
rear shock +6 clicks from full soft
15psi cold in rear tire
6500 rpm launch off limiter

run 3
weight 3570 lbs
front strut full loose
rear shock +6 clicks from full soft
16psi cold in rear tire
6500 rpm launch off limiter

run 4
weight 3570 lbs
front strut full loose
rear shock +7 clicks from full soft
15psi cold in rear tire
6500 rpm launch off limiter

new best 60' is 1.638 down from 1.642 from my last visit. Car felt much better in run 4 configuration listed above. I need to have my tuner up the rev limiter to 6800 rpm, I think I need that extra 300 rpm @ launch.

Speaking of launch...

left front wheel is up, and I think the right front wheels is up too (tough to tell with the flash).

Fun fact: I averaged 25.4 mpg on the 80+ mile trip to the track, and 5.6 mpg while making runs