Suspension Theory/Chat Thread

[Borbor]

Originally Posted by Highrev1

Just an Ass... .97 up front to be exact.

The square of that would be 0.94; which means the wheel rate is 423.

My apologies, I just came to this thread today so I havent' had the time to go through all 20+ pages of posts.

Lemme go do some reading, and then I'll give you my 2 cents :)

edit: Belch, I tried looking for the application of your car (track only, more track than road, more road than track, or street only); but I can't for the life of me find where you posted it on the thread.

You did mention you are getting double adjustable konis (28xx series? )...if so I'm guessing it's going to be more track than road application anyway. Correct me if I'm wrong :)

[Sirbelch]

So, if the front is .97 for a 450 lbs spring rate will be 423. If the rear ratio is 1.1 (these are Gregs numbers, so correct him if im wrong ) for a 525 lbs spring, that puts it a 433.

I'm getting Red Shift Motorsports Double Adjustable Konis. You would have to ask Greg what series they are cause I am getting them from him (someday). I'm going to be a more track than road but still a DD (I can take a beating, but not a full track beating). The tires I have now are Kumho Estca STP 235/40/17 on Motegi Tracklites 17x8 +45.

[Highrev1]

I am getting the 28's Monotubes mmmmm

[Sirbelch]

What am I getting?

[aki]

Me and a friend installed the Mugen Sports suspension on my car over the weekend. I've also had two sets of camber bolts installed to the fronts to give more negative camber. I was going to have it done at a shop that also deals with racing cars (www.rogerkrausracing.com). But I couldn't wait since the car is my DD so I got it done at Big O Tires--egh, regretting it since I had to repeatedly explain to them what I wanted to do. Have a feeling it would've been better had I went with plan A.

I've pushed it a bit, but am really wanting to get my new tires on (dang powder coat shop has had my wheels for over a month! ergh!) since the fronts are so worn out. Hence I can't drive it as hard as I'd want to. But wow, it's totally different now. At the limit it's a lot more neutral, and feels like it can almost get into a throttle-lift oversteer (though still not quite). Definite improvement, as I don't see to be fighting the demons of understeer like I had before. Curious to see what happens when I swap out crappy stock HXM4 all-seasons to RE070s.

Right now have lots of neg camber both front and rear:

FL: -1.8 FR: -1.9
RL: -1.8 RR: -1.7

Gonna drive with this for awhile to see how I like it (wanted neg camber to the rear since I don't want rubbbing with 18x8 et38, esp if I get 235/40/17). Might get a rear camber to reduce it to -1, and if I'm still not happy maybe get the BE-RS 21mm sway.

[LucasBlack]

blast you aki!!!! we were all supposed to stay stock together, and just theorize and dream about what to do suspension-wise! you've ruined us.... :)


but on another note, you know good and well not to refer to your cars handling as being, or approaching, "neutral". you can reduce understeer; yes. but then realizing that with an increased possible limit, the car will still lean to either understeer or oversteer when approaching or passing that limit.
neutral, to me, is still having grip when you haven't reached running at 10/10th's to see what the car does once it breaks that line....

anyway, kudos on the neg. camber, kudos on the gear (how much was that mugen setup for ya?), and have as much as mature fun as possible!

[aki]

Originally Posted by LucasBlack

but on another note, you know good and well not to refer to your cars handling as being, or approaching, "neutral". you can reduce understeer; yes. but then realizing that with an increased possible limit, the car will still lean to either understeer or oversteer when approaching or passing that limit.
neutral, to me, is still having grip when you haven't reached running at 10/10th's to see what the car does once it breaks that line....

anyway, kudos on the neg. camber, kudos on the gear (how much was that mugen setup for ya?), and have as much as mature fun as possible!

Got it used for about $900-ish shipped--worth every penny IMO.

Also, I said it's approaching neutral--doesn't mean it is But a big factor is that my front tires are a lot more worn than the rears, so that impacts the handling dynamics quite a bit. So I can't really so for sure until I get my new wheels/tires on--which is proving to be a royal pain dealing with this powder coater. Until then, can't really give a better review of the suspension since the tires are the greatest limiting factor at this point.

[Sirbelch]

If your fronts are that worn, they should be slickish and have more grip than the still tread having rears. Hows the ride on the streets.

[Highrev1]

Play with your tire pressures, that can influence things greatly..Take some tire temp to ensure full use of the tire

[Highrev1]

Just an FYI don't run high high pressure to get the car to rotate

"If you run really high pressures to get the car to rotate, you will find the car will have more of a tendency to snap oversteer. Running lower pressure as a means of getting rotation will afford less "snappiness" at the limit because the tire is softer. Furthermore, the lower pressures in back allow a slightly higher slip angle at all lateral acceleration levels; so the tire has more lateral movement throughout the entire turning sequence (from low g to high g), and that's usually what you are after. High pressures induce oversteer by actual slip of the tread (oversteer), which is a little harder to control and can catch you off guard, especially on by fast courses."

[aki]

Originally Posted by Sirbelch

If your fronts are that worn, they should be slickish and have more grip than the still tread having rears. Hows the ride on the streets.

The ride is very civil, which is why I chose these over HFP (haven't rode on HFP, but I've heard it's bumpy). Pot holes 'n such don't make a disconcerting crash. Definitely feel more of the road, but it's just a notch above stock in terms of harshness. To put it into perspective, the new Mazda 3 and Miata feel a lot more harsh, as does my co-worker's Scion xB. I'm not like younger people who can stand "track" setups that make your butt sore after a long commute. I'm picky about how harsh the ride is, and I gotta say I'm very pleased with this suspension.

And dunno, the more these tires wear out the more they slip. I'll be glad to get rid of them when my wheels (hopefully) get done tomorrow.

As for tire pressure, they're always on the under-inflated side, mostly because I neglect to check up on em I'll post pics when the new tires come on.

[Sirbelch]

Originally Posted by aki

I'm not like younger people who can stand "track" setups that make your butt sore after a long commute.

Thats me

[eugenekim.net]

ditto ^

[Borbor]

Going back to what highrev said, every tire has an optimal range of temperature and pressures they should operate under. Stick a driver who knows what he's doing in a car with pressure that's on the low side and he's more than likely to rip it right off the rim You won't get tire temps unless the tire deforms. Most of the time, this means putting a lot of load on the tire. With someone that will never put a lot of load on the tire, lower pressures mean the tire will deform adequately with a moderate amount of load. Stick a real race driver on too low of pressures, though, and he'll be liable to destroy the tire by overloading the tires. Tire pressure is a huge factor in how much load a tire can carry.

[aki]

Originally Posted by Borbor

Going back to what highrev said, every tire has an optimal range of temperature and pressures they should operate under. Stick a driver who knows what he's doing in a car with pressure that's on the low side and he's more than likely to rip it right off the rim You won't get tire temps unless the tire deforms. Most of the time, this means putting a lot of load on the tire. With someone that will never put a lot of load on the tire, lower pressures mean the tire will deform adequately with a moderate amount of load. Stick a real race driver on too low of pressures, though, and he'll be liable to destroy the tire by overloading the tires. Tire pressure is a huge factor in how much load a tire can carry.

Hmm, is that why my tire crapped out when taking a turn hard? Inside rear tire blew, and I spun out. Never knew why it happened, but it frazzled my nerves. But like I said, if it was running low PSI that wouldn't be intentional--that'd be neglect

Originally Posted by Sirbelch

Thats me

I meant to offense to ya =P i was sarcastically pointing fun and ppl who set their coilovers on the hardest possible setting thinking stiffer = faster. So painful to ride in those cars, egh. Think I'm gettin old, hahah.

[Highrev1]

I have done that on a spin out, but under AUtox conditions I have run as low as 12psi to help get the rear to rotate more and workt he rear tires better. Never an issue but that was on race rubber with stif sidewalls.

I know about the getting old thing, I am running bone stock right now and gonna swap in and out my knois just to save my back.

[eugenekim.net]

Originally Posted by Highrev1

I have done that on a spin out, but under AUtox conditions I have run as low as 12psi to help get the rear to rotate more and workt he rear tires better. Never an issue but that was on race rubber with stif sidewalls.

I know about the getting old thing, I am running bone stock right now and gonna swap in and out my knois just to save my back.

you're 28 fooooooo...

[Sirbelch]

Originally Posted by aki

I meant to offense to ya =P i was sarcastically pointing fun and ppl who set their coilovers on the hardest possible setting thinking stiffer = faster. So painful to ride in those cars, egh. Think I'm gettin old, hahah.

I have 500 lbs springs, but the dampers are set just a little bit harder than full soft. Its really not too bad on full soft.

[aki]

Originally Posted by Sirbelch

I have 500 lbs springs, but the dampers are set just a little bit harder than full soft. Its really not too bad on full soft.

But compared to the Mugen SS's 173 lbs/162 lbs, so that's like riding on rocks =P Puzzled how the Mugen can get away with springs softer than the stock Si, yet have the stiffer rebound and compression dampening.

Do you know what your shock valving rate will be--or at least, what you plan on setting it at?

[Sirbelch]

Originally Posted by aki

But compared to the Mugen SS's 173 lbs/162 lbs, so that's like riding on rocks =P Puzzled how the Mugen can get away with springs softer than the stock Si, yet have the stiffer rebound and compression dampening.

Do you know what your shock valving rate will be--or at least, what you plan on setting it at?

I have no idea. I'm trusting the boys at Redshift to give me something good. I have been told that the dampers will be stiffer than the flex's I have now.