Suberman's guide on how to make the car fix his inability to drive correctly.

[ftc~brz]

Originally Posted by Khorne

Yes, this needs to happen. Hey @Ubersuber and @Rocket.BRZ please discuss things for us to watch.

In for the "Battle of the Mom Pics"

[JasperNoone]

Originally Posted by husker741

What a fun thread. Suberman never disappoints. Just upset I missed the initial fun.

[CSG Mike]

Originally Posted by wparsons

@Ubersuber , this is all you need to "fix" the handling of the car:

Skip to about 16 minutes to see the part on handling balance. No change needed to the car, just driver improvement.

That's one of the best videos I've seen explaining under and oversteer...

[jebuwh]

Originally Posted by wparsons

@Ubersuber , this is all you need to "fix" the handling of the car:

Skip to about 16 minutes to see the part on handling balance. No change needed to the car, just driver improvement.

That was excellent. Thanks for posting. I actually learned quite a bit of useful info!

[Ubersuber]

Once more into the breach:

http://www.motortrend.com/roadtests/...?__federated=1

I don't expect anyone to quibble with this driver's expertise.

The BRZ is quicker, same day same driver same track.

The ONLY difference is the BRZ has softer rear springs. The suggestion that the dampers are different has been disproved by others posted to this BB I believe.

The driver's comments as to how the two cars feel and why the BRZ is likely faster are interesting.

Even more interesting would be testing the BRZ against itself with just a stiffer front bar. Should be even quicker because it will get its meagre power down a split second earlier.

Note the lap time margin is around 0.8 seconds, twice the margin achieved by fitting a clutch type lsd.

Tire pressures can be used to tweak handling, and the F1 boys do this also. In this case likely increasing the rear tire pressures is the way to go as tire pressure increases grip and does not affect roll stiffness.

Ditto lowering which changes the load transfer effects and in theory at least keeps the inside tire working harder for longer. Ironically, lowering reduces the load transfer which some here seem to think would be bad for handling.

Indeed, although I don't know the camber rise rates on these cars it seems very likely that front camber rise is at a lower rate than rear camber rise. If so then a quick and easy way to get better handling is to lower the car, assuming rear camber rise is at a higher rate but does not pass over the critical point. This would increase rear grip relative to the front and as long as you don't go crazy with spring rates you will improve front to rear balance in favour of understeer and go faster.

Us old guys already have trouble getting up to street level from the driver's seat so lowering the cars is not going to work well for us.

[gramicci101]

Originally Posted by Ubersuber

Once more into the breach:

This thread is no longer about your wildly inaccurate suppositions; it's about actual suspension advice from knowledgeable people with documented backgrounds in the fields of suspension tuning and driving fast. And correcting @7thgear's grammar. Kindly shove off.

[Ubersuber]

Originally Posted by boredom.is.me

The first thing you said that actually makes sense.

Um, the first thing I said that you realized made sense. I try to keep it simple.

[7thgear]

Originally Posted by gramicci101

This thread is no longer about your wildly inaccurate suppositions; it's about actual suspension advice from knowledgeable people with documented backgrounds in the fields of suspension tuning and driving fast. And correcting @7thgear's grammar. Kindly shove off.

my grammar may be off at times but you bitches can't touch my flair

[Ubersuber]

Originally Posted by Calum

Calum's guide on how to make the car fix Suberman's inability to drive correctly.

Attend a few HPDE classes.

The only time I've had the back end step out on me is when I get REALLY ham fisted with it. My last project car needed that to get it to rotate, so I was pretty surprised the first time it happened in the FRS. But after I learned to drive it more smoothly I found that oversteer and understeer are available upon request, as long as I choose my corner line and braking point ahead of time.

That's not to say I haven't found ways of improving my ability to drive this car quicker by modifying the suspension. But the mods I've made haven't been for improved grip, but improved driver confidence.

It is child's play to get the back end of these cars to step out, the FRS more so than the BRZ. That is actually a problem. You were pretty surprised the first time...but you did learn to drive later.

[Ubersuber]

Originally Posted by Dave-ROR

CSG and I have both moved ours backwards.. but whatevs....

Yes, but what did you try first?...whatever.

If you lower these cars without doing anything else you move grip to the rear so you can then tolerate more rear roll stiffness. Add camber plates up front and you're back where you started.

It is complicated if you are trying to change too much.

I just cut half an inch out of the rear bump stops, nice and simple, really safe and it works.

Cheap too, especially if you do it while changing the rear shocks. The bump stops are only CDN$15 each if you want to keep your old ones intact.

[Ubersuber]

Originally Posted by Dave-ROR

Shifts the load? It artificially increases spring rate at the expense of suspension independence.. so yeah it'll be slighter looser but not changing any weight transfer which is how I read shifts the load.


Just saying

If you make the roll bar stiffer it just changes the rate the load transfer occurs. Load transfer is a function of CG over roll axis x lateral g.

Changing roll bars can't change weight transfer quantum.

[Ubersuber]

Originally Posted by CSG Mike

You can, but you're subtracting grip from the axle with higher pressure. Rather, try a slightly stiffer rear sway bar. This shifts the load slightly more rearward.

Are you sure? By shifting roll stiffness to the rear you aren't adding any grip to the rear tires. If you want to increase rear traction you should increase front roll stiffness.

Weight transfer results from the CG height over the roll axis height (the lever arm) x lateral g. Roll bars have no effect on this number. Neither do springs. Only tire grip can increase lateral g, assuming you can get the power down.

[wparsons]

Originally Posted by Ubersuber

Once more into the breach:

http://www.motortrend.com/roadtests/...?__federated=1

I don't expect anyone to quibble with this driver's expertise.

They also claim the damping was stiffer on the FRS, which it isn't, but they theorized that stiffer damping made the car more tail happy.

Funny, you claimed stiffer damping made it less tail happy (which is false).

Just give up already.

[Ubersuber]

Originally Posted by gramicci101

This thread is no longer about your wildly inaccurate suppositions; it's about actual suspension advice from knowledgeable people with documented backgrounds in the fields of suspension tuning and driving fast. And correcting @7thgear's grammar. Kindly shove off.

Hey, it's my thread even though someone changed the title...