78 replies to this topic

[Kyle Freiheit]

I heard tension should be released at the nut behind the steering wheel

[davew]

As a wise man once told me, and I am taking this to heart (pun intended)

 

We are a bunch of middle aged guys racing chick cars. It just ain't that important.

 

Dave

[Jim Drago]

[Zauskycop]

Alright, I will give my input for what it is worth.   If you are used to a stiff front bar, and go to a soft front bar, you may start experiencing oversteer under braking.   I bet that once you get INTO the corner, since your bar may not have full range (see spacers) the bar is binding up and throwing your front spring rate to ...basically infinity.   If it hits a theoretical "wall" on spring rate, your car is going to just skitter along until it unloads.   You DO know that we ALL run spacers right??

[Caveman-kwebb99]

[Ron Alan]

ROTFLMAO!!! That Mr Webb is pure genius

The beauty of this thread is there is something for everyone...good info, useless info, dickheadness, sarcasm, and great levity. And all without Andrew...miss you man!

[LarryKing]

ROTFLMAO!!! That Mr Webb is pure genius

 

Good Lord. Don't encourage him.

[Johnny D]

He wants to know what hole to put it in front and back and why.

How much experience with said hole and what luck.

Be descriptive please, picture may help. 

J~

[Caveman-kwebb99]

 

Good Lord. Don't encourage him.

 

 

[LarryKing]

[Caveman-kwebb99]

 

I clearly needed to read the swaybar spreadsheet before trying this stunt! 

[CruzanTom]

Why its Swaybar tension Mate! 

 

I am glad someone picked up on my troll humor.

 

CruzanTroll

[Bench Racer]

He wants to know what hole to put it in front and back and why.

How much experience with said hole and what luck.

Be descriptive please, picture may help. 

J~

Keep in mind that minds to go on tangents. As a site moderator you may not approve of the picture. At the same time one picture may be a perfect visual description of which hole to put it in.

[Tom Sager]

The beauty of this thread is there is something for everyone...good info, useless info, dickheadness, sarcasm, and great levity. 

That's a pretty good list, Ron.  I would add:  Lack of reading comprehension

[Johnny D]

I would add:  Lack of reading comprehension

That's why we post videos and pictures.

J~

[Caveman-kwebb99]

That's why we post videos and pictures.

J~

 

 

i THINK i INVENT THAT pICTURE THING LOLOLOLOL

 

[Fat Cat]

Kyle,

 

Not sure about all of your spreadsheet values. In the lower right quadrant you list Unit Conversions and have 180 F to 82.2 C.  The hottest I ever ran was last summer at Roebling (Savannah) when it was 108 F   , which should be 42.2 C.   I am sure it doesn't get that warm in the NorthWest.   

 

This is a fun thread to read (and post) between races.   

 

I was just about to comment on Rob's sway bar position dilemma when I read this. The math works. Really.

 

212 deg F = 100 deg C (boiling water). Subtract 32 from deg F then divide by 1.8 to get degrees Celcius. Yes, it does get over 40 C during summer throughout the US.

[Fat Cat]

Re: 1.8 vs 1.6 bars. I'm going from memory and notes, don't know exactly what spacers you folks are running (and why you're mandated to run a smaller front bar on a 1.8 car but oh well...). Don't send a rover to Mars with these numbers but play along with me...

 

A 1.8 car with 27 mm front, 15mm rear and 700/325 spring rates has a front roll couple (% of weight transfer across front vs rear axle, an indicator of car's balance) of say 66.9%. That's with a (fixed) arm length of 235mm and rear bar on soft (150mm, outer hole). Depending upon bump stop engagement, shock valving and alignment settings the car's behavior it could vary from pushy to loose but tending more toward push. The other rear bars positions give 65.6% and 63.7%. All pretty neutral tending toward more oversteer.

 

===

NOW swap to a 24mm front bar (229mm arm) on that 1.8 and keeping the same rear bar position the FRC drops to 62.9%, a BIG change in terms of balance (~4%) and more oversteer than you'd see even with the 27mm front bar and 15mm rear on full stiff. Going to anything stiffer on rear bar and you get even more oversteer (61.7% and 59.6% respectively). That last one is good for drifting

 

Keeping rear full soft and moving front bar to inner (stiffer) position you'll raise the FRC to 62.9%. That's still about 4% more oversteer biased than the initial 27mm bar but the 'best case' in terms of not inducing too much oversteer on a 1.8 using 24mm front bar. Plus, with the smaller 24mm bar you also have about 10% less roll stiffness (10% more roll angle) so you'll be engaging the bump stops earlier and more aggressively which will induce more oversteer. This is because the rear motion ratio is ~0.73 and front is ~0.66 so anything going on at the rear shock/spring/bump stop exerts more leverage on the wheel than the front. The adjustments do not directly correlate so you really need a spreadsheet (I know someone who has a free one online ) to keep track of changes.

 

My advice would be some combination of: run the front bar full stiff, rear full soft, don't overly lower the rear end (even raise it some), add a little more rear camber, lower the front end a little more than you had with your 27mm bar setup. The last change would engage the front bump stops more / earlier than the rears which could equalize the faster spring rate increase of the rear bump stops. However since the bump stops do have a nonlinear character you don't want to engage them too much or you will transition from oversteer to understeer mid-corner.

 

Hmmm following this thread is very useful actually to understand optimal setup based on sway size/settings.

[Rob Burgoon]

Re: 1.8 vs 1.6 bars. I'm going from memory and notes, don't know exactly what spacers you folks are running (and why you're mandated to run a smaller front bar on a 1.8 car but oh well...). Don't send a rover to Mars with these numbers but play along with me...

 

A 1.8 car with 27 mm front, 15mm rear and 700/325 spring rates has a front roll couple (% of weight transfer across front vs rear axle, an indicator of car's balance) of say 66.9%. That's with a (fixed) arm length of 235mm and rear bar on soft (150mm, outer hole). Depending upon bump stop engagement, shock valving and alignment settings the car's behavior it could vary from pushy to loose but tending more toward push. The other rear bars positions give 65.6% and 63.7%. All pretty neutral tending toward more oversteer.

 

===

NOW swap to a 24mm front bar (229mm arm) on that 1.8 and keeping the same rear bar position the FRC drops to 62.9%, a BIG change in terms of balance (~4%) and more oversteer than you'd see even with the 27mm front bar and 15mm rear on full stiff. Going to anything stiffer on rear bar and you get even more oversteer (61.7% and 59.6% respectively). That last one is good for drifting

 

Keeping rear full soft and moving front bar to inner (stiffer) position you'll raise the FRC to 62.9%. That's still about 4% more oversteer biased than the initial 27mm bar but the 'best case' in terms of not inducing too much oversteer on a 1.8 using 24mm front bar. Plus, with the smaller 24mm bar you also have about 10% less roll stiffness (10% more roll angle) so you'll be engaging the bump stops earlier and more aggressively which will induce more oversteer. This is because the rear motion ratio is ~0.73 and front is ~0.66 so anything going on at the rear shock/spring/bump stop exerts more leverage on the wheel than the front. The adjustments do not directly correlate so you really need a spreadsheet (I know someone who has a free one online ) to keep track of changes.

 

My advice would be some combination of: run the front bar full stiff, rear full soft, don't overly lower the rear end (even raise it some), add a little more rear camber, lower the front end a little more than you had with your 27mm bar setup. The last change would engage the front bump stops more / earlier than the rears which could equalize the faster spring rate increase of the rear bump stops. However since the bump stops do have a nonlinear character you don't want to engage them too much or you will transition from oversteer to understeer mid-corner.

 

Hmmm following this thread is very useful actually to understand optimal setup based on sway size/settings.

 

Thanks Shaikh!