Aftermarket suspension making handling worse?

[7thgear]

Originally Posted by ultra

I should add - my preferred method is to look at what other folks are doing who are successful in AutoX or Time attack and go from there, doing my own testing.

I'm a copycat and proud of it. The trick is knowing who to take setups from and who to ignore.

Having said that, I'm planning on running my 86GT stock for awhile until I feel that I've fully mastered it before I go around messing with it.

Suspension setup fetishism can be a heck of a money pit.

the thing to worry about are the people who know jack about tuning but happen to be good drivers

i know a couple of people that have dumped big money into their car and have perfromed very well at events, but when i start talking to them about their setup they just blink. They bought off the shelf parts and had a mechanic put them on, end of story.

it's quite bizzare, but such is life.

[touge-n00b]

Originally Posted by 7thgear

the thing to worry about are the people who know jack about tuning but happen to be good drivers

i know a couple of people that have dumped big money into their car and have perfromed very well at events, but when i start talking to them about their setup they just blink. They bought off the shelf parts and had a mechanic put them on, end of story.

it's quite bizzare, but such is life.

Sounds like a lot of pro race drivers actually. I've heard many an interview with F1 drivers and while they can tell you what a car feels like and what it needs to do versus what it does, they honestly don't have a clue as to how to achieve those desired results. "The guys in the pits will work their magic", a line a lot of pros seem to say.

Some people would rather concentrate on driving, not so much engineering. So I'd much rather have someone set my car up for me, or at least tell me what I can do to get the car to behave the way I want it to. So feel free to flame away, but I know from experience that that is how many people who love driving/racing feel.

Which is probably the reason I personally will leave the car stock save for wheels and tires, at least for one season.

[blu_]

Originally Posted by #87

Encourage those people to buy aftermarket parts, giving the companies revenue for more development is what we need. If someone buys a part with the wrong idea behind it, it's up to them to do the research and know what they are getting into.

While that might be true for some of the companies many vendors are definitely just out to middle man you a bunch of crap they make high margins on.

For what its worth I usually mod my car very slowly after identifying things that really bug me. I would say 90% of the time I am happy with my mod in the long term.

Over the course of 2.5 years of owning my STI I changed out the swaybars, kicked the front camber out a bit, did a lot of bushings, and put a tune on it. Besides that I had a few appearance mods and that was it.

[ultra]

Originally Posted by 7thgear

the thing to worry about are the people who know jack about tuning but happen to be good drivers

it's quite bizzare, but such is life.

Well spotted, sir! How could I forget the biggest variable of them all - the driver?

Even though I've competed and practiced a lot and have spent buckets on tuning cars in the past, I've still been utterly destroyed by better drivers in much more basic cars on more than one occasion!

Humble pie is good though - nothing like a reality check to make one try harder

Dunno if you guys can see this but here's a vid of me in an Evo getting pwned by a guy in another Evo. The other guy's car (Hossam - bottom car) was nearly stock and he'd only picked it up a week earlier!

He went on to take down some of the most insanely modded trailer queen race cars in that same DD Evo of his once he got *really* used to his car.

http://www.facebook.com/photo.php?v=...type=3&theater

[Ubersuber]

The stock spring rates are very good.

More expensive struts and rear dampers would be a good idea and, interestingly, Toyota/Subaru are upgrading the dampers for 2015.

Unless you want to lower the car (which isn't really necessary given the very low center of gravity from stock) then a set of good coilovers makes sense but be aware that 90% of the value of those coilovers will be better damping.

Fit stickier tires to this car, stock, and you will be hard pressed to improve the handling by adding anything else.

[cdrazic93]

I see it like this;

subaru has to make the best suspension possible without raising the price of the car to ridiculous heights. Yes, they could have added Bilstein super high dampers and some nice springs matched to it or some really customizable penskes or Ohlins TTX's from the factory, but then youd be paying through the tooth for that.

For the components inside of the nonadjustable suspension that they cost to produce, Id say its very very well designed.

But, when you have the ability to adjust things, the parts become exponentially more expensive because of the durability while still being adjustable, thats where the cash comes in.

for @7thgear's comment about those drivers who are exceptionally good but braindead about cars, I think of myself as a Niki Lauda around them ;D

[Ubersuber]

For a given tire grip and suspension character, lowering the car may not increase cornering speeds.

Shorter springs are necessarily stiffer. These work the tires harder by transferring forces more rapidly. This does not necessarily increase maximum grip. This is why "wet" settings are softer than "dry" settings.

Additional roll stiffness requires more attentive driving because everything happens more quickly. If you are slow on stock suspension you will be even slower on stiffer suspension. Learn to drive first, then spend the money making the car better. These cars are already much more competent right out of the box than we are as competition drivers. One reason they put a smile on your face every time you drive is they will save your a$$ when you first try to find the limits, giving you just a friendly nip if you get really over ambitious before they bite you hard if you ignore the happy little tail wag.

[DarkSunrise]

While I agree the stock suspension is very good at the track, you can definitely improve on it with quality aftermarket coilovers. Here is some third-party data on stock vs. KWV3's on an FR-S. This is with stock Primacys.

Laptime:
Stock - 1:26.875
KWV3 - 1:25.377

Avg MPH:
Stock - 58.9 mph
KWV3 - 59.8 mph

Peak MPH:
Stock - 95.8 mph
KWV3 - 94.1 mph

Lateral grip:
Stock - 1.12 g
KWV3 - 1.15 g

Braking grip:
Stock - 0.85 g
KWV3 - 0.84 g

http://www.modified.com/tech/modp-13...t-results.html

[dradernh]

Originally Posted by DarkSunrise

Laptime:
Stock - 1:26.875
KWV3 - 1:25.377

http://www.modified.com/tech/modp-13...t-results.html

Good comparison piece.

Wonder how much of the improvement (or lack of) was due to each of:

1) Improved Damping
2) Drop
3) Improved Camber
4) Change in Track Conditions after the Shock Swap & Alignment Check, if Any.

[blackhawkdown]

This is why my wrx is stock. This is why my future brz will be stock, except getting rid of them nasty altezza lights.

[DarkSunrise]

Originally Posted by dradernh

Wonder how much of the improvement (or lack of) was due to the:

1) Improved Damping
2) Drop
3) Improved Camber
4) Change in Track Conditions after the Shock Swap & Alignment Check, if Any.

Yeah I was thinking the alignment could have accounted for some part of the improvement, but since they didn't measure alignment before the swap, it's hard to say. They do mention they didn't make any changes to camber or toe after the suspension swap, so it was effectively an alignment check.

I think the benefits of good aftermarket coilovers won't be fully realized without stickier tires. When they added RS3's, that dropped another ~3 seconds off their times.

[wparsons]

The gap in performance between stock and good coilovers gets bigger with stickier tires. As you add grip from tires, you need more spring rate (and dampening) to control body motion.

[Takumi788]

Anyone that has been to a HPDE event has heard the speech saying to avoid spending money on parts for your car. NASA was very thorough with this and followed it up with "The best part of your car to work on is the nut between the seat and the steering wheel."

There was an instructor with a BRZ with nothing done but slicks and a muffler delete running incredible laps.

[Ubersuber]

The point about the manufacturer's cost increasing the base price is a valid one.

However, decent struts and shocks might have added say $500 to the base price? And that's being generous since the labour cost would be the same regardless of shock type and even at retail with no credit for the replaced shocks and struts the price for four Bilsteins is maybe $500.00.

I think Subaru knows this and, after two successful model years, can now justify adding proper gas pressure shocks. I hope they fit inverted struts as these improve steering feel noticably. Front suspension also feels quite a bit more solid with the inverted struts.

Spring rate and tire grip are not related in the simplistic manner suggested, as many who have overspent on suspension have discovered. Spring rate affects the speed with which tire grip is developed, not the absolute grip. Tire grip for a given suspension is related to the load deforming the contact patch which is very tire dependent. The load/grip curve is just that, a curve rising to a point and then suddenly dropping away. Changing the roll rate (which is what spring rates do) may not place your car on a more beneficial spot on this curve as you enter a corner and, in some cases, may actually push the car beyond the limits of the tires more quickly. The maximum grip may or may not be developed with higher roll rates. This problem certainly occurs in the cold or the wet and on snow a stiff suspension is truly incompetent.

Unless you change the suspension arcs as well, stiffer shorter springs don't affect the contact patch grip, merely change the rate at which it transfers from inside tire to outside tire. I recognize that's a big "merely" but I'd be most interested to see objective lap times on the same track with the only difference being spring and roll bar rates. No toe links or lower rear suspension arms or roll centre adjustments etc, just spring rates. By far the trickiest aspect of modifying street suspension is getting the camber change curve right, the object being to keep the tire upright and the contact patch developing more or less even temperature across the tire. Very, very few compliant suspensions can control camber over an ideal range which is one really important reason for ultra low stroke racing suspensions which in turn depend on smooth tracks to perform (anyone see Kimi's recent imitation of an Alitalia jet at Silverstone as he hit the dirt he thought was the direct way back to the tarmac?)

What would really interest me is stock springs and bars, with Bilstein B6 and the shorter bump stops from the TRD lowering kit, as compared to say the full TRD install of their lowering springs, dampers and bars but on the same tires. The BRZ has a stiffer roll rate at the front compared to the rear than the FRS or the GT86 and is generally easier to drive quickly, and therefore usually will be quicker around a track. Begs the question as to what the quickest front and rear roll rates should be whether spring rate or roll bar rate plus of course those pesky rising rate bump stops that kick in partway through compression but otherwise have no spring effect in droop. Be careful what you think you want especially if you intend to drive quickly on regular roads.