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

[stugray]

Originally Posted by wparsons

The bump stops don't limit suspension travel though, they're very soft and just progressively raise spring rate before bottoming out. You can squish them pretty far into their range of squishing with just one hand.

DO you mean "squish them like a spring" or "squish them like an earplug"?

The only "bump stops" I am familiar with are firm and definitely "stop" travel when they are reached (like a turnip :-)
So these are more like "bump squish(es)"?

[stugray]

Originally Posted by BRGT86

i find that taking a huge shit is the best mod if you're broke. it's free and helps increase power to weight ratio, and most importantly you feel better too.

I have suggested in the past (for those thatwant lightened pulleys to help with overall vehicle weight) that you could just shed your wheel weights too.
That is unsprung weight so you get a double benefit.

I crack up at the track when I see someone who spends thousands shedding a couple of pounds from their car, but can barely squeeze into an X-Large racing suit....

[wparsons]

Originally Posted by stugray

So these are more like "bump squish(es)"?

Correct.

[Captain Snooze]

Originally Posted by BRGT86

i find that taking a huge shit is the best mod if you're broke. it's free and helps increase power to weight ratio, and most importantly you feel better too.

Well, depending on one's economic view it is not free. There was the initial outlay of buying the raw materials. I also think it's a pretty (not literally) good mod even if you aren't broke.

[Ubersuber]

Originally Posted by stugray

DO you mean "squish them like a spring" or "squish them like an earplug"?

The only "bump stops" I am familiar with are firm and definitely "stop" travel when they are reached (like a turnip :-)
So these are more like "bump squish(es)"?

The BRZ bump stops are very firm. Once the waisted sections are compressed against each other it takes considerable force to actually compress the, presumably, urethane foam. They cannot perform their primary function if they are not highly resistant to compression when actually operating as bump stops.

Just put one in an ordinary wood vice and you will find that the bump stop becomes functionally incompressible once the waisted segments are in full contact with the bulged sections, as you would expect. They most definitely limit suspension travel and it would be pointless to include them if they did not, their primary function is to protect the shock absorber from bottoming out, secondarily they prevent the spring or suspension members from internal contact with themselves or the car body. In the distant past this was their only function.

If you have the physique of a gorilla, and possibly a matching intellect, you may find it easier than I did to gauge the compressibility of these bump stops. I am sceptical that a normal person can significantly compress these bump stops by hand.

The internally contradictory posts suggesting both that these bump stops are easily compressed and that cutting a segment out might adversely affect handling are illustrative of the inaccuracy of many of the posts in this thread.

To make a chassis easier to drift without substantially increasing torque at the rear tires one would increase roll stiffness at the rear of the car. To initiate a drift more easily one might also include additional rear suspension jacking (the infamous early 911 tendency as well as the Corvair and pre mark IV Triumph Spitfires).

Fitting harder bump stops or longer bump stops, or both, would also make the chassis easier to provoke into a drift. The best way is still to add power.

Reversing these changes and going the other direction would make the chassis more stable and return the bias towards understeer.

[Ubersuber]

Originally Posted by Captain Snooze

Well, depending on one's economic view it is not free. There was the initial outlay of buying the raw materials. I also think it's a pretty (not literally) good mod even if you aren't broke.

You should ensure you do so outside the vehicle also or the sprung weight of the entire package remains the same, even if your dump bounces.

[Ubersuber]

Originally Posted by boredom.is.me

Skinnier tires.

Eat my complete sentence with punctuation and capitalization!

Not likely to have much effect since you are changing both ends of the car in the same way. Suspension camber changes might result in skinnier tires changing front to rear balance but since narrower tires respond better to camber changes and you get more camber change at the rear of these cars, you would likely gain more driftability with wider tires than going skinnier as long as your wider tires weren't also grippier.

Try a set of these:

http://www.thewheeldeal.com.au/produ...&reviews_id=16

[stugray]

Originally Posted by Ubersuber

Fitting harder bump stops or longer bump stops, or both, would also make the chassis easier to provoke into a drift. The best way is still to add power.

Reversing these changes and going the other direction would make the chassis more stable and return the bias towards understeer.

I was actually being on your side (would that be playing the Devil's advocate?) by suggesting this exactly.

I figured IF the engineers were tasked with "making the car easier to drift" that they might have done it by controlling the roll abruptly using overly tall bump stops.

IF that were true, then your suggestion of cutting them down would make sense to make the car less likely to drift (be stickier)

[boredom.is.me]

Originally Posted by Ubersuber

You should ensure you do so outside the vehicle also or the sprung weight of the entire package remains the same, even if your dump bounces.

The first thing you said that actually makes sense.

[Dave-ROR]

Originally Posted by stugray

I was actually being on your side (would that be playing the Devil's advocate?) by suggesting this exactly.

I figured IF the engineers were tasked with "making the car easier to drift" that they might have done it by controlling the roll abruptly using overly tall bump stops.

IF that were true, then your suggestion of cutting them down would make sense to make the car less likely to drift (be stickier)

I've love to see Suberman drive my FWD track car.. if he thinks these cars are prone to bad oversteer behavior...

[Ubersuber]

Originally Posted by stugray

I was actually being on your side (would that be playing the Devil's advocate?) by suggesting this exactly.

I figured IF the engineers were tasked with "making the car easier to drift" that they might have done it by controlling the roll abruptly using overly tall bump stops.

IF that were true, then your suggestion of cutting them down would make sense to make the car less likely to drift (be stickier)

Yes, I realize that and yes that would be playing devil's advocate.

It is painfully obvious (if only because they said so) that Subaru/Toyota spec'd this car to be able to drift, albeit modestly and with the electronics deactivated, at least only as far as the car lets you. In fact if you really try or one is really incompetent, the electronic nannies will step back in even if you switch them off, hence all the talk about the "pedal dance". Not only that but if this emergency reactivation of the electronics is activated the car will not let you switch off the assists until you park, shut off the car and restart.

To make a modern car driftable with even half assed modern tires (which the Michelin Primacy's are) and only 151 lb ft of torque is quite an achievement.

I found the ride unacceptably hard from the rear axle. I found the tendency to drift without sufficient provocation tiresome. I prefer a car that goes where it is pointed. I was very surprised that merely cutting the rear bump stops could affect the rear spring rates as much as it obviously has. Adding the Bilsteins was just a better idea yet, but I've found in the past Bilstein does a very good job of designing an upgraded shock which works well with stock spring rates, in cases where the OEM went a bit too cheap on this very important suspension component as Subaru/Toyota did on the launch version of this car. Bilstein are a well known OEM supplier, a cut above the run of the mill Sachs, though Sachs is perfectly capable of producing very good spec shocks and I understand Subaru/Toyota have gone to Sachs in an effort to improve the handling of these cars. I think either Sachs or more likely Bilstein has been called in to fix another Toyota product line: the latest Lexus IS 350 (the GS series is the same) and both the F Sport and the IS F benefitted from improved shocks. These are branded Toyota but I'm pretty sure they are built for Toyota by Bilstein.

The irony associated with all the puerile attacks on my posts in this section arises from the fact that everyone who modifies these cars to make them more effective for the track moves the roll stiffness bias towards the front axle. The more power you add the more you must move the roll stiffness forwards. Everybody knows this, well at least everybody that understands how suspension works. I just achieved the same effect without increasing the already quite stiff front axle spring rates.

[Dave-ROR]

Originally Posted by Ubersuber

The irony associated with all the puerile attacks on my posts in this section arises from the fact that everyone who modifies these cars to make them more effective for the track moves the roll stiffness bias towards the front axle. The more power you add the more you must move the roll stiffness forwards. Everybody knows this, well at least everybody that understands how suspension works. I just achieved the same effect without increasing the already quite stiff front axle spring rates.

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

[Ubersuber]

Originally Posted by Dave-ROR

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

Well, that may be why you are fitting clutch type LSD...

If you aren't adding any power you might not notice that you could be quicker if you did the opposite.

You will note that Subaru/Toyota are moving the roll stiffness bias of the FRS towards the front axle for 2015. It has been suggested that they employ talented engineers. I'm pretty sure the TRD spring and roll bar kits will both move the roll stiffness bias forwards also.

[Dave-ROR]

Originally Posted by Ubersuber

Well, that may be why you are fitting clutch type LSD...

If you aren't adding any power you might not notice that you could be quicker if you did the opposite.

I am? I haven't even driven the BRZ more than 50 feet in the last 2 or 3 months but I am putting a clutch type LSD in it?


Setup depends greatly on driver style and preferences. The car you like (based on this thread) is a car I'd HATE to drive. You'd hate any of my cars on the track too.


On the street, it's whatever. I drive like a responsible person on the street normally so oversteer has never been a concern of mine. Your threads remind me of all the S2K idiots who spun cars in intersections because they can't control the throttle. That's another car I made more loose on purpose. :shrug: