Spring rates

[autxr]

I've seen the spring rates listed for a variety of springs in the past, does anyone have any of those listings handy?

I'm curious about TRD (and any others) and the "standard" springs in the Ground Control kit.

I suppose if non of you can help I will use the phone (phone? what's that?) and call these places...

Scott

[autxr]

Here is what I have so far:

TEIN HA:
Front: 7.0 kgf/mm = 391 lb/inch
Rear: 9.0 kgf/mm = 503 lb/inch

TEIN SS (the US market ones):
Front: 5.0kgf/mm = 279 lb/inch
Rear: 7.0kgf/mm = 391 lb/inch

TRD Sportivo (Japan)
Front: 3.0 kgf/mm = 168 lb/inch
Rear: 4.4 kgf/mm = 246 lb/inch

So, the TEIN are a bit on the stiff side... Probably about where I'd like to be, Though, those rates are actually pushing it a bit for an autocross site that is bumpy.

Edit:
Ground Control (off the shelf)
Front: 425 lb/inch
Rear: 250 lb/inch

Ouch, can we say understeer city (I asked twice what rates they have, and got the same answer both times, this is almost opposite what you would expect). They claim 0.5 inch lowering with the stock kit at the top of the perches (I'd lower about 1 inch). It's possible I'd buy this kit with opposite rates!

I need to find out how far Koni thinks I can go on their shocks...(I'm not looking to have them re-valved yet).

Kind of tempting to actually get the Teins (either) and just sell my stock Konis...

Scott

[gtsxr]

If you take the later approach, I may be interested in a set of slightly used Koni's.

[scapamouche]

Well, Scott- you've driven on the Tein HA kit before- that's what I Have in my Celica. The dampers were set wrong at the time, though.

[Raymund]

heres some more stuff on the sportivo set.:)

Front Shock Absorber 745/647N(76/66kgf)
Rear Shock Absorber 1656/931N(169/95kgf)
Front Coil Spring K=29.4N/mm(3.0kgf/mm)
Rear Coil Spring K=43.1N/mm(4.4kgf/mm)
Front Stabilizer Bar

[Celica RZ]

Koni recommended a 1.75" max drop for my application. I have 375 lb/ft front and 425 lb/ft rear springs with the coilovers. I had the front's dropped pretty close to that 1.75" and the rear near stock height, maybe .5" off. I had the rear shock set at max hard and the front about halfway, the ride was really stiff! I wish I could tell you how they rode with the Koni's but 10 min after installing the Koni's someone decided to use my car to stop from 45mph instead of their brakes.

from speaking with Koni they said I was pushing the upper spectrum of the shocks with my spring rate. The shocks could handle another 100lb/ft but of course, accelerated wear on the shocks would occur.

[ishido]

Damn, you guys are full of all kinds of useful information :)

Any idea what the stock spring rates are?

[traitor]

I believe the factory rates are 180 front
160 rear

I'm getting a set of Koni's with GC's next week, I had no idea the rates were that messed up. who thought that up, a granny in snow? I really thought I wanted 300 front and rear but, that seems low. any suggestions, I had 450 front and 550 rears on my Civic and don't wanna go thru that again. want something nice and useable, any suggestions on rates?

[autxr]

I actually think that the rates with the TEIN SS kit (listed above) are quite reasonable. I would really consider something close to those for a street setup.

I might go with something close to those.

Scott

[afghan]

I spoke to Jack B on a few occasions, and he said;


(I think this was it) 350 front and 400 rear for a good set up.

He use to have a celica and has helped a few with their setup.

[Raymund]

Originally posted by traitor
I believe the factory rates are 180 front 160 rear

i dont think the fronts are 180. The sportivos are 168lb/in.

[Unity112]

I guess just to add to another option to the list. Hotchkis springs run from 164-242 in front and 350-380 in rear, progressive rate.

The Teins for me run nice and neutral around most of the corners, and give a strong bite of oversteer if you take the corner too hot. (I even have it set at one click stiffer in the rear). They reward smooth drivers though.

For the price custom GC/Koni are a good value, but the Teins will allow you to go more aggressive if needed. Max is 9 or 503.6 in front, and 10 or 559.5 in rear.

[autxr]

Progressive rate springs will NEVER see a day of time on my car.

When I set up for a turn, which handling am I going to get? The soft one, the hard one, or will I get to have the fun of correcting in between? Even better, if the front sets down (under braking) befor ethe rear, I get to correct once in front and a second time in the rear.

Scott

[traitor]

it's not about the money, it's about the time. the reason I'm buying Koni's and GC's is because we're in America. it takes about 2 monthes to get Tein's and then what happens if you blow one, got to wait another 2-3 monthes to have them rebuilt. you have to send them back to Japan, no one in the states can repair them. the same with the Zeal's, I really thought I wanted those. what if I blow one, same boat, send them to Japan. if you blow a Koni you can just send them to TrueChoice and get them custom valved. that can probably be done in about 3-4 days, just not worth the wait for me.

[afghan]

I believe Tein opened a office in California as of last month so it shouldn't be a problem.

[Raymund]

Has anyone ever ponder the actual spring rate of these springs at the wheel (wheel rate). The front mac-pherson dampers/springs are placed much closer to the hub compared to the double-wishbone rear suspension. most of the springs rates mention above shows stiffer rear to front bias. How about actual wheel rate? It would be nice if someone can figure out the wheel rate ratio to evenly increase the springs rates for the front and rear.

[autxr]

For the front it is basically 1:1, Mac. struts make it easy. in the rear it is likely less than 1:1, but I couldn't tell you what. Good thought on doing the math, maybe one of these days I'll go out with a tape measure and figure it out...

Stiffer rear is pretty common in a car with front engine and front drive.

Scott

[Unity112]

Originally posted by autxr
Progressive rate springs will NEVER see a day of time on my car.



:) didn't think it would fly with you but it was worth a shot.

[autxr]

OK, just got off the phone with Koni. For their off the shelf shocks, they really don't suggest going up much in spring rates. They happily told me that accelerated wear would be the result.

Since I would likely be nearly triple the stock spring rates, I can see their concern.

So, since I don't feel like spending money twice, I;m starting to lean towards the Tein or other dedicated setup.

I could also just get the Koni's revalved and call it good, or go with softer springs (yuck).

It would still handle nice with 300 pound springs in back and 200 in front (20% stiffer than the Sportivo kit, 28% softer than the Tein SS kit).

Tough call. I can probably get decent money for my Koni's, springs installed, ready to go. Something to be said for doing it that way (damn it, I was trying to avoid all this spending. Maybe I will stay stock).

Got to think about this a bit (I'm not in a position to just throw out $550 in shocks after 3 months, and I don't have a spare car to send them all out for revalving, nor the desire to do so).

Scott

[GTS LAID]

so its the TEINs then... yay? not yet yay?

[autxr]

right now it's nothing. I have a decently competitive stock car and if I can't afford to keep it that way, I'm not going to do a thing.

If I were to do some shopping, I would likely consider the Teins. The US distribution is set up and they are even starting to offer rebuilding. I've not heard how good the rebuilding service actually is.

The new thread about Truechoice is an interesting one, I might need to give them a call. If a set of custom valved Koni's with GC sleeves and springs are priced right, I would certainly consider that an option.

Scott

[traitor]

see truechoice thread

[autxr]

Yup, posted in that thread. My call was informative though. THey do seem to think that the Koni's will withstand up to 400 lb springs. It's possible in their $1600 price tag you will get custom valved shocks for your application.

I'm starting to think my Koni's can handle things, I might go with GC and keep the rates moderate. That would get me through a season for a reasonable cost, and if I'm still happy after a year I can upgrade and either keep the Koni/GC setup as spares, or sell them.

Scott