D2 Coilovers?

[91h22cb7lx]

i have d2's but i blew my motor before i could put em on, bought another accord a few weeks ago and they will be going on this summer. my buddy had both d2's and function and forms.. personally i liked the f2's better because they actually click when you change the settings and it felt like it had more adjustability with less settings, but my buddy did pretty good in autox in his eg with d2's.

[azian21485]

I know this isn't technical at all, but I feel a linear rate spring w/ even a very small preload (like 1/4") will make the spring more "charged" because the spring will always want to go back to it's original state. Therefore, having the preload and an additional force, the spring will act like a stiffer spring w/ no preload.

Preloading a spring does in fact "charge" it. If a 1000lb/in spring is preloaded 1 inch, the spring will be exerting 1000lb/in energy outward. Hooke's law states this.

Regarding preloading a 1000lb/in spring 1 inch and then placing a 500lb load on it. Preloading the spring will cause the spring to exert a 1000lb/in force up. Placing a 500lb weight is not enough downward force to overcome the 1000lb/in upward force. Draw a free body diagram =) Once the load exerts 1000lbs, the spring will act just as normally as it would have with no preload.

This comes back to your car. If the load (your car) exerts the spring's preload, the spring will act normal. If the load doesn't exceed spring preload, the spring will not compress. In simple terms, 99% of the time you will not be able to preload the spring enough (i.e. preload greater than corner weight of car) to change its characteristics.

I had a good link in the past when trying to understand this myself. I'll try to dig it up.

[Granite CB7]

The only time preload will effect a vehicle's characteristics is when preload is greater than the load (In this case, your car) that is placed on it. Take a 500lb spring and preload it 1 inch. Place a 400lb load on it and the spring will not compress. Place a 501lb load on it and the spring will compress very slightly. Place a 1000lb load and the spring will compress 1 inch.

So what does this mean? Let's say you have a 1000lb/in spring on each corner of the car. You preload each by 1 inch. Each corner of your car weighs 500lbs. So when the car sits on the springs, the springs will not compress at all since they are exerting a 1000lb/in force upward while the car is only exerting a 500lb/in force downward. In fact, the springs will not move at all until it sees another 501lb/in force (From bumps in the road or load transfer when cornering). This is NOT a good setup because you basically have a car with no compliance until it sees a certain amount of force.

The reason I said you had to preload the rear springs by more than an inch was a very crude guesstimate. Using 500lb rear corner weights and a 500lb rear spring, you'd have to preload the rear springs by more than 1 inch to get "no compliance" characteristics. Other wise, preloading will not change anything (which is a good thing).

Edit: Please realize I am using linear rate springs as an example since I assume they use linear rate springs on d2 coilovers. If they are progressive rates, then yes preload will change your spring rates.

I respect your input alot, and honestly, you seem way more knowlegable on this topic than me, which I'm not striving to be a suspension know-it-all! I'm learning too, so please don't think I am arguing w/ you D2's have linear rates too BTW, which is a good thing for a full coilover

I'm just sort of confused about your #'s, which the preloading by an inch may be throwing me off. A 1000 lb/in spring does require 1000 lbs of force to compress it 1 inch, but any significant weight will compress the spring. It's not like it suddenly compresses 1 inch once 1000 lbs is applied. Even the 1000 lb/in spring w/ 1 inch of preload, w/ a load of 500 lbs, I feel it's still going to compress because it's all progressive up to the spring compressing its full inch.

I know this isn't technical at all, but I feel a linear rate spring w/ even a very small preload (like 1/4") will make the spring more "charged" because the spring will always want to go back to it's original state. Therefore, having the preload and an additional force, the spring will act like a stiffer spring w/ no preload.

[cali-racer]

i have them on my cb7 right now, i love them!

edit: they're cheaper on honda-tech.com! i paid $785 shipped.

http://www.hondamarketplace.com/zerothread/1931708

[azian21485]

Yes, in a sense you are right, I did not install an 8K spring in the rear BUT by increasing the preload you can sort of "imitate" the characteristics of an 8K spring but w/ a 7K spring. Also, I'm sure length of the spring, coil diameter, and other factors would determine how much preload is needed. By saying 1 inch, I feel more factors need to be evaluated before just throwing preload specs out there.

It was my estimation and I'm not saying I'm right but I can tell you this, even 5/16" increased preload made QUITE the difference

The only time preload will effect a vehicle's characteristics is when preload is greater than the load (In this case, your car) that is placed on it. Take a 500lb spring and preload it 1 inch. Place a 400lb load on it and the spring will not compress. Place a 501lb load on it and the spring will compress very slightly. Place a 1000lb load and the spring will compress 1 inch.

So what does this mean? Let's say you have a 1000lb/in spring on each corner of the car. You preload each by 1 inch. Each corner of your car weighs 500lbs. So when the car sits on the springs, the springs will not compress at all since they are exerting a 1000lb/in force upward while the car is only exerting a 500lb/in force downward. In fact, the springs will not move at all until it sees another 501lb/in force (From bumps in the road or load transfer when cornering). This is NOT a good setup because you basically have a car with no compliance until it sees a certain amount of force.

The reason I said you had to preload the rear springs by more than an inch was a very crude guesstimate. Using 500lb rear corner weights and a 500lb rear spring, you'd have to preload the rear springs by more than 1 inch to get "no compliance" characteristics. Other wise, preloading will not change anything (which is a good thing).

Edit: Please realize I am using linear rate springs as an example since I assume they use linear rate springs on d2 coilovers. If they are progressive rates, then yes preload will change your spring rates.

[uslspct]

I've been looking at these as well since I will be doing a full suspension redo. I pretty sure I was set on Skunk2 springs and Nuespeed/Koni yellows but Granite has always raved about his setup, and some others too. For the price it seems like a win. Maybe someone will have the Neuspeed setup at the CT meet and then I can ride in theirs and yours(Granite) if you're going. Both seem to have great reviews. I would think a true matched coilover would be even better than the Neuspeed setup.
And I think I'm gonna seriously consider them for my Fit setup.

[Granite CB7]

Unless you're preloading the spring more than 1 inch it isn't going to change anything from an "unpreloaded" spring. This is a good thing btw.

You can't change spring rates unless you change the spring.

Yes, in a sense you are right, I did not install an 8K spring in the rear BUT by increasing the preload you can sort of "imitate" the characteristics of an 8K spring but w/ a 7K spring. Also, I'm sure length of the spring, coil diameter, and other factors would determine how much preload is needed. By saying 1 inch, I feel more factors need to be evaluated before just throwing preload specs out there.

It was my estimation and I'm not saying I'm right but I can tell you this, even 5/16" increased preload made QUITE the difference

[azian21485]

I absolutely love my D2's, they've been on the car for 2 straight years now, been through over 30K miles and 2 winters. I wouldn't want anything else. Spring rates are 11K F/7K R (w/ increased preload, prob. 8K by now) which translates to 616 lb/in F/496 lb/in R. I don't have any strut bars installed yet, but when the car had just the D2's, it was amazing. I know have Prothane/Hardrace bushings all around. It rides stiff, feels awesome, very controlled. If you want to ride low, get something stiff, I don't care what full coilover you get (maybe not Tein) but make it stiff. I could go on and on but I won't LOL.

D2's are made in Taiwan, wasn't completely happy about that but ARE rebuildable in the USA. I had one shock w/ in the first year that started knocking and it was replaced FOC b/c of the warranty, other than that, no problems.

Be sure for the rears to make your own rubber gasket or plumber's putty for the top hats, you'll get water inside the car if you don't.

Unless you're preloading the spring more than 1 inch it isn't going to change anything from an "unpreloaded" spring. This is a good thing btw.

You can't change spring rates unless you change the spring.

[street_beauty90]

i'm getting some d2's also, as soon as i sell my suspension setup.

[mcdizzle]

I absolutely love my D2's, they've been on the car for 2 straight years now, been through over 30K miles and 2 winters. I wouldn't want anything else. Spring rates are 11K F/7K R (w/ increased preload, prob. 8K by now) which translates to 616 lb/in F/496 lb/in R. I don't have any strut bars installed yet, but when the car had just the D2's, it was amazing. I know have Prothane/Hardrace bushings all around. It rides stiff, feels awesome, very controlled. If you want to ride low, get something stiff, I don't care what full coilover you get (maybe not Tein) but make it stiff. I could go on and on but I won't LOL.

D2's are made in Taiwan, wasn't completely happy about that but ARE rebuildable in the USA. I had one shock w/ in the first year that started knocking and it was replaced FOC b/c of the warranty, other than that, no problems.

Be sure for the rears to make your own rubber gasket or plumber's putty for the top hats, you'll get water inside the car if you don't.

thanks, this is the exact reply i was looking for. reading this makes me definitely want the d2s. my ground controls are only rated at 400lb/f and 300lb/r. i prefer something stiffer and ill be running a progress rear sway bar as well. hopefully the guy pm's me back with a price for when he gets his uninstalled.

[Granite CB7]

I absolutely love my D2's, they've been on the car for 2 straight years now, been through over 30K miles and 2 winters. I wouldn't want anything else. Spring rates are 11K F/7K R (w/ increased preload, prob. 8K by now) which translates to 616 lb/in F/496 lb/in R. I don't have any strut bars installed yet, but when the car had just the D2's, it was amazing. I know have Prothane/Hardrace bushings all around. It rides stiff, feels awesome, very controlled. If you want to ride low, get something stiff, I don't care what full coilover you get (maybe not Tein) but make it stiff. I could go on and on but I won't LOL.

D2's are made in Taiwan, wasn't completely happy about that but ARE rebuildable in the USA. I had one shock w/ in the first year that started knocking and it was replaced FOC b/c of the warranty, other than that, no problems.

Be sure for the rears to make your own rubber gasket or plumber's putty for the top hats, you'll get water inside the car if you don't.

[GHOST 2.2]

thats the kind of response i was looking for. i still havent decided what im doing as of yet. i really liked my konis with ground controls, but ive been wanting to go to a full bodied coilover for a while now. i might even spend a little more and get the form and functions, havent totally decided yet.

if your going to get the F2s wait until the revised type 2 comes out... there seems to be a rise in problem with their product concerning that its missing parts...or studs spinning due to welds between the aluminum top hat and steel studs. supposively the revised type 2s are gonna be all steel.

[mcdizzle]

yea ive been doing some research on d2s.... they are made in taiwan (like most parts) but so far ive seen more goods then bads. a lot of people were satisfied with them, but some werent impressed with the camber plates cause of wishbone suspension. and the fact if the shocks were to go bad, theres not an american based company that can fix it. (probably gotta send it out)

im highly considering D2s over the F2s since theres some issues with the guys breaking their coils or its just not holding their name.

thats the kind of response i was looking for. i still havent decided what im doing as of yet. i really liked my konis with ground controls, but ive been wanting to go to a full bodied coilover for a while now. i might even spend a little more and get the form and functions, havent totally decided yet.

[GHOST 2.2]

yea ive been doing some research on d2s.... they are made in taiwan (like most parts) but so far ive seen more goods then bads. a lot of people were satisfied with them, but some werent impressed with the camber plates cause of wishbone suspension. and the fact if the shocks were to go bad, theres not an american based company that can fix it. (probably gotta send it out)

im highly considering D2s over the F2s since theres some issues with the guys breaking their coils or its just not holding their name.

[mcdizzle]

i love mine!!!! actually my will be for sale once i find stock springs and shocks

pm me with a price and how many miles are on yours and i mite snag them from you before i pay full price for a set.