Interesting facts about Tanabe suspension...

[SiRCivic03]

So I was purchasing different spring for my Tanabe coilovers today and I called Tanabe USA's headquarters phone number. I Asked him the specs on my springs height, diameter, etc stuff i couldnt find on any web site and then I got to talking to the guy about rebuilding their coilovers. He said every piece of the Pro SS type II coilover I have is able to be purchased piece by piece, so that if something ever breaks I can call Tanabe USA and they can ship it out. Also the most interesting thing the Tanabe rep said was when I asked him about shocks. I asked if they were rebuilable, and he said that they aren't rebuildable, but that KYB JAPAN makes all the shocks that go into tanabe coilovers. I had no idea about that. They sell the shocks i guess like a cartridge that can be replaced into the original coilover. He even told me that KYB can set you up different valving as well. I had no idea about any of this? I thought my coilovers were just another set of "street" coilovers that were kind of crappy? I'm pretty happy with them now that i know they are a pretty versitile piece on my car. Anyway, just thought i'd share for anybody else that is looking in to Tanabe or has their products already.

[weltall]

interesting


what was the sizes of the springs i have just the basic SOC2 ones

and the weight transfer is horrible cause these springs are really soft

[SiRCivic03]

yea thats what i was having a problem with during autocross too. The springs that Tanabe uses in the rear are the Pro210 65mm diameter by 170mm length and they are 8kg/mm or 447lbs/in. I kept the front springs because they are like 75 lbs/in higher then stock. Tanabe USA recomended getting the pro 210 spring in 12kg/mm but I could not find a set anywhere. I eneded up going with 7 inch by 2.5 diameter 650lbs/inch eibach springs to create some oversteer.

[weltall]

my problem stems from weight transfer to the rear wheels

my front comes up to easily and i spin very very bad

my 8th mile times are nearly triple my second half going down the 1/4 mile

im running almost 9 sec 8th and 12.0 quarter


any thought on how to correct this?

[v1c10us]

^ since the springs are trying to push the car up, and will never try to pull the car down, I would assume that putting very soft springs in the front would mean there are less forces at work trying to lift up the nose..
Raking it might help as well. keeping the front very low and raising the rear with very stiff springs that wont allow the back end to be pushed down would in theory aid in preventing your issues.


To sircivic03, the 447 rear is very soft.. I cant believe they would put those kind of rates into coilovers..
My progress lowering springs are 500, and s-techs are 510, and coilovers are usually much stiffer than lowering springs. =\

[powdbyrice]

my problem stems from weight transfer to the rear wheels

my front comes up to easily and i spin very very bad

my 8th mile times are nearly triple my second half going down the 1/4 mile

im running almost 9 sec 8th and 12.0 quarter


any thought on how to correct this?

hit up mustclime, he might be able to help.

[mustclime]

interesting


what was the sizes of the springs i have just the basic SOC2 ones

and the weight transfer is horrible cause these springs are really soft

Just order some hgher rate springs, you will need the dia, the length and the rate.....hypercoil and groundcontrole are good choices.

[weltall]

yeah yeah ive been meaning to give you a call but ive had alot of other pressing issues pop up

[SiRCivic03]

Yea Tanabe coilovers are very soft front and rear, they are hardley stiffer then stock in both the front and rear. only 6k/mm front and 8k/mm rear. The Tanabe rep I spoke with said that anything +/- 250-300lbs/inch increase will not compromise the KYB strut in the coilover. Go over those specs and you will run into trouble with the strut. I stayed within those specs so i will post up when the springs are installed and provide feed back.

Weltall- just call tanabe USA and ask them to give you the specs for the front and just go to ground control's store website and order the right size springs. That is the cheapest way i have found to improve these coilovers.

[Zzyzx]

my problem stems from weight transfer to the rear wheels

my front comes up to easily and i spin very very bad

my 8th mile times are nearly triple my second half going down the 1/4 mile

im running almost 9 sec 8th and 12.0 quarter


any thought on how to correct this?

I think you are coming to the wrong conclusion regarding your problem... Weight transfer happens, regardless of spring rates, as the only sure fire ways of reducing weight transfer is to 1. Physically remove weight from the car 2. Increase the wheel base/Track of the car and 3. Lower the cars center of gravity & roll center.

So whether you have 4k or 16k Springs on the rear, assuming you keep the same ride height, the same amount of weight is going to be transfered off the drive wheels. The only thing you are going to be changing by stiffing up the rear and thus reducing squat is how much camber change the front end sees at launch.


What you really should be looking at is dampers, given that they govern how quickly weight gets transfered around the car.
For tuning with dampers, think Stiffer = Faster weight transfer. So, if you want to slow the rate in which the weight is transfered off of your drive wheels you'd want to have soft rebound valving on the nose and Soft Bump valving on the rear.

[v1c10us]

I think you are coming to the wrong conclusion regarding your problem... Weight transfer happens, regardless of spring rates, as the only sure fire ways of reducing weight transfer is to 1. Physically remove weight from the car 2. Increase the wheel base/Track of the car and 3. Lower the cars center of gravity & roll center.

So whether you have 4k or 16k Springs on the rear, assuming you keep the same ride height, the same amount of weight is going to be transfered off the drive wheels. The only thing you are going to be changing by stiffing up the rear and thus reducing squat is how much camber change the front end sees at launch.


What you really should be looking at is dampers, given that they govern how quickly weight gets transfered around the car.
For tuning with dampers, think Stiffer = Faster weight transfer. So, if you want to slow the rate in which the weight is transfered off of your drive wheels you'd want to have soft rebound valving on the nose and Soft Bump valving on the rear.

but if you had 1000lb/in springs on the rear and 100 lb/in springs on the front would you not say that the front is not going to come up nearly as easy as if there was a stiffer spring in the front, and the rear will also not go down nearly as much if there is a stiffer spring in the rear?
I understand that technically the force or weight transfer is still occuring, but the actual change would be much less, you might not even notice it because the engine wouldn't be producing enough force to compress the rear springs and there wouldn't be a very strong spring in the front that is pushing against the weight of the car. ?

[Zzyzx]

Your missing the point, how much or little the suspension compresses or extends will only influence how much camber change the drive wheels experance, not how much weight the front tires lose when the car launches. And weight is the important part here, given that to a tire, Weight = Traction.

So reducing camber change by going to stiff springs... basically means nothing to the tire given that its still having the same reduction in traction regardless. Because the same amount of weight is being removed from it.

[Zzyzx]

From reading your previous post, it appears you are misunderstanding the roll of springs & how they work.

Springs dont push against the weight of the car, they compress due to the weight of the car.

Example, if you had two springs one rated at 500 LB/inch and one rated at 100 LB/Inch and you applied 500 LBS to both. the 500 LB/inch spring will have compressed 1 inch & the 100 LB/inch spring will have compressed 5 inches... but 500 LBS will still be reaching the ground for both of them. The spring is reacting to the amount of weight applied rather then activly countering that weight.

[v1c10us]

From reading your previous post, it appears you are misunderstanding the roll of springs & how they work.

Springs dont push against the weight of the car, they compress due to the weight of the car.

Example, if you had two springs one rated at 500 LB/inch and one rated at 100 LB/Inch and you applied 500 LBS to both. the 500 LB/inch spring will have compressed 1 inch & the 100 LB/inch spring will have compressed 5 inches... but 500 LBS will still be reaching the ground for both of them. The spring is reacting to the amount of weight applied rather then activly countering that weight.

you're joking right? thats the same thing.
there are 2 types of springs, i cant remember the fancy names, but one kind is designed to resist expansion, one kind is designed to resist compression.
They have the kind that do both but im not concerned about that at the moment.
a spring that is made fully compressed will not compress, but will resist expansion. meaning that you could pull it with a fishscale and it will read weight, because it is pulling against the scale..
a spring that is made uncompressed will compress under pressure, if it did not push back against the car then it would be fully compressed.
Of course a spring doesnt actively counter weight but for a spring to not push against the car as i said would be foolish.
Its one of newtons laws.. as you stand on the floor it is pushing an equal amount force back at you, otherwise you would fall through it.
for a spring to compress a given amount more weight must be applied to the spring than it is capable of pushing back.
Progressive springs for instance push harder back the harder you push them =\

But I do secede to what you're saying about the weight transfer, indeed the same amount of weight is applied regardless of the springs.

[Zzyzx]

Sorry, bad way of trying to convey that the Force pushing up against the car isnt the spring, but rather the ground. The spring is just the conduit for that force and due to its design compresses Due to thoes forces.

[mustclime]

Time for some wheely bars.........:mangel:

[v1c10us]

Sorry, bad way of trying to convey that the Force pushing up against the car isnt the spring, but rather the ground. The spring is just the conduit for that force and due to its design compresses Due to thoes forces.

My bad haha.