06+ Civic Si 2/4dr Spring Rates and Drop Guide

[FA5SI]

Here are some springs I did research on and also contacted several companies to get information on the drop and spring ratings... Please add any other lowering springs spec/information thats not listed, and I will add it on the list



Company //// Ride Height F/R //// Spring Rate F/R :: (L) Linear (P) Progressive

• Stock '06 Si Coupe //// 0" / 0" //// (L) 200 lbs. / 230 lbs.
  
  
• Eibach ProKit//// 1.0" / 1.2” //// Coupe (P) 137-222 in. lbs / 143-262 in. lbs
• Eibach ProKit//// 1.2" / 1.0” //// Sedan (P) 137-222 in. lbs / 142-262 in. lbs

• Eibach Sportlines //// 1.4" / 1.4” //// (P) 125-222 in. lbs / 131-262 in. lbs

• Skunk 2 //// 1.5” / 1.4” //// (P) 135-184 in. lbs / 125-273 in. lbs

• Tein H-Tech //// 0.79” / 0.67” //// (P) 220 in. lbs / 250 in. lbs

• Tein S-Tech //// 1.54” / 1.42” //// (P) 230 in. lbs / 270 in. lbs

• Tanabe Sustec GF210 //// 1.0” / 0.75” //// (L) 187 in. lbs / 225 in. lbs ; +20-30% est.

• Progress Group //// 1.3” / 1.2” //// (L) 240 in. lbs / 330 in. lbs

• Neuspeed Sport //// 1.6” / 1.6” //// (P)+-218 in. lbs / +-448 in. lbs

• Neuspeed Race//// 2.0” / 2.0” //// (P)+-303in. lbs / +-460 in. lbs

• H&R Sport //// 1.5” / 1.3” //// (P) N/A in. lbs / N/A in. lbs

• Comptech Sport //// 1.0” / 1.2” //// (P) N/A in. lbs / N/A in. lbs
  
  

• HFP Springs //// 1.0” / 1.0” //// (P) N/A in. lbs / N/A in. lbs

• B+G Sport //// 1.6” / 1.6” //// (P) 25%+ in. lbs / 25%+ in. lbs

[SiRyan]

Nice, you forgot comptech....

[Zeuceone]

no he didnt. third one from the bottom.

[SiRyan]

sticky this thread....

[Ruthless909]

Originally Posted by SiRyan

sticky this thread....

x2......

[samx109]

sticky RIGHT NOW :) repped +1

[06NaviEX]

Nice work! +rep

[skandal57]

does anyone know any numbers on the HFP kit? i havent beem able to find out anything

[02SilverSiHB]

nice work. Not surprised about eibach's numbers....they very rarely will tell you due to competition.

[juji88]

sticky this

[Hondacivicsi23]

I thought skunk 2 was a 2 or 2.25 in. drop .......

[FA5SI]

Originally Posted by Hondacivicsi23

I thought skunk 2 was a 2 or 2.25 in. drop .......

I reconfirmed with them they said it was 1.5/1.4... hmmm can anybody else clarify this?

[brthorner]

Here is some more info for the file:

Tanabe makes two versions of the GF210...one for the LX/EX and one for the Si. I have the details on the Si model:

They are also Linear.
Front drop = 0.6"
Rear drop = 0.5"

Front rate = 3.4kg/mm
Rear rate = 4.1kg/mm

They also make their DF210 springs for the Si. The GF210 series is described as being 20% to 30% stiffer than stock, whereas the DF210 series is described as being 15% stiffer than stock, yet these two sets of springs have the same spring rates! The only difference is the drop. However, the GF210 lowers the car 0.1" more in the front, whereas the DF210 lowers the car 0.1" more in the rear. But obviously Tanabe feels really strongly about these particular spring rates, for some reason. Anyways, here are the specs on the DF210 springs as well:

These are also linear.
Front drop = 0.9"
Rear drop = 1.0"

Front rate = 3.4kg/mm
Rear rate = 4.1kg/mm

I almost bought the GF210 springs, but then I found out that Swift is going to be releasing their Sport Mach lowering springs for the Si in the next couple of months, so I'm waiting to see the details on those before making my final purchase...but the Swift's basically already have my vote.

Although, based on the specs above (and thanks FA5SI!!), the Progress springs kinda intrigue me now, particularly since they sell for like $150 or something. Does anyone have them installed, and if so, how do you like them??

Brian

[irichard]

remember to say which fits on what (2dr or 4dr)

[Zeuceone]

theres also the vaoghtlan or something like that. mfinlay04 has them.

[Yodums]

This thread has been stuck.

[brthorner]

In order to convert lbs/in to kg/mm, multiply the lbs x 0.0178579673.

So the Progress springs for example are 4.3kg/mm in front, and 5.9kg/mm in the rear.

[Highrev1]

FG Civic Si FG Civic LX
Front spring rate 200 170
Rear spring rate 230 200

Wheel Rate Estimates
Front wheel rate 190 161.5
Rear wheel rate 138 120

Wheel F/R bias 1.38 1.35

[Firestrife]

nice thread definitely sticky.
How bout some numbers on the Mugen suspension?

[Quickkidd]

i remembered that tai from corsport said that the skunk 2 springs will lower it around 2.25"