Let's talk about spring rates for street driving. Eibachs are going!

[PhoenixGTS]

Let\'s talk about spring rates for street driving. Eibachs are going!

I do not think my car is optimized with its Eibach lowering springs. It is just a little too low for real street driving and too boingy for a racey set-up. I want to go with the Aldan adjustable coilovers (so I can raise the height a little and esternally adjust damping) sold by Roe and get to pick spring rates. They say their standard recommendation for an aggressive street set-up is 400 lbs fronts and 600 lbs rears which they think are a little bit stiffer than stock. Anyone know the stock rates and the rates of the Eibachs? Have suggestions which way to go?


And a related question. Why unlike most cars does the Viper use heavier springs in the rear? Especially given the ability to oversteer.

 

[ROCKET62]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Did you adjust your Koni's when you changed out the springs?

 

[Tom F&L GoR]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Here's a list of example spring rates I've kept.

250/450 stock
325/500 Roe (325/550)
400/750 ACR v1
450/650 Woodhouse + my Gen 1 (1rst time)
500/1100 OEM ACR v2
500/800 what ACR owners liked better
550/800 my Gen 1 now
600/800 Verges
700/900 NDW on Archer revalve
500/700

You can draw a little graph of front and rear rates and see the relationship. I think these are good until you go racing at high speeds and use wings, then the car will compress more and you'll need more spring.

The reason the rear springs are stiffer is because the shock (and spring) mount on the lower control arm further inboard (closer to the pivot) than the front shock. Therefore the rear springs have less leverage and need to be stiffer to have the same wheel rate.

As for shocks, mine are full stiff in front, about 1/3 stiff in rear. I think this becomes much more driver preference, though.

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Did you adjust your Koni's when you changed out the springs?

The springs were on the car when I got it. I am SURE they would benefit from increased rebound damping to reduce the bounce, but It is such a PITA to adjust the stock shocks with having to remove them etc, and I really want a little more height (including raising a slightly lower driver's rear which seems to be a chronic Gen II issue) that $1,100 for external rebound adjustable/height adjustable units where I can pick lower spring rates seems like a good deal.

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Here's a list of example spring rates I've kept.

Tom that is a very helpful list - thank you - but does anyone know the rates for the standard Eibach lowering springs to complete it?

Explanation about the higher rate in back totally makes sense.

 

[Tom F&L GoR]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Anthony GTS in 2/06/02 post said:

Eibach spring rates:
Front: 343 lbs. (linear)

Rear: (progressive)
Starting: 457 lbs.
Ending: 800 lbs.

I'm not sure I'd like rears that got stiffer and stiffer...

 

[ROCKET62]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Please do post if you get the Aldans as there seems to be some fans and some that are not too fond of them. It's funny after reading your post about not liking the Eibachs as I have been searching for a set for my Gen 1 for about 8 months now as would love to get rid of the wheel gap.

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Tom thank you so much for making me look bad by using search to find what I am looking for!! I think a lower/non-progressive rate in the rear might really help acceleration traction.

P.S. I was at work when I posted so I could not search

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Tom thank you so much for making me look bad by using search to find what I am looking for!! I think a lower/non-progressive rate in the rear might really help acceleration traction. All I have to say is with the Eibachs being toward the lower end of the scale you listed, some of those 800 pounders must be insane.

P.S. I was at work when I posted so I could not search

 

[Jerry Colpitts]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Check these out. kwsuspension.com I really enjoy my set.

 

[TOOOFST]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

I cut my stock springs and have a stock ride, lowered.
I sold my Eibachs too friggin stiff.

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

I cut my stock springs and have a stock ride, lowered.
I sold my Eibachs too friggin stiff.

Scotty do you have any problems with bottoming out due to not enough spring rate at the lower height?

BTW, I'm still waiting for my complimentary "test" fountain to arrive!

 

[DrDJ]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

I accidently added this to another thread, but here it is in the correct place...

I thought that I was one of only a handfull of people that thought the Eibachs were too stiff. I use NWE spring caps and stock springs. Here are the Intrax spring rates to add to Tom's list:

This a copy of an email that I got from INTRAX on the difference between Eibach and Intrax springs:

"Quality wise we are the same, Chrome Silicon, Cold Wound, etc.. our warranty is technically longer (ltd Lifetime) however the main difference is the lowering height and ride. Are designs are generally more progressive in nature and we lowering the vehicle further. In this application we lower the vehicle about 1.0” front and rear. I have no idea what their spring rates are but ours are,
Front 325lbs/in
Rear 407 ~ 758lbs/in

Hope this answers your question,

Best Regards,

Technical"

DrDJ

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

I ordered the Aldans with 300 front and 500 rear springs shooting for basically a stock rate. Roe called to verify that is what I wanted since the rates were so light. Now I am freaked out I went too soft!

 

[MADDMAXS57]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

PhoenixGTS,

Have you considered the Archer Racing Valved Shock upgrade?

I have them with my Eibachs and they are set to an aggressive street configuration and it is a really great setup IMHO. Not too stiff, not too soft, gets rid of the wheel gap, and really settles down nicely at well above normal street driving rates for cornering.

Just a suggestion. The cost is similar to the Aldens.

 

[Tom F&L GoR]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

If you've never played with them, you may be happy to find shocks will change the ride characteristics much more than you think. The harsh jolt over a bump or pothole is high speed wheel movement that the shock manages. The spring(besides changing ride height) stiffness is how level the car is in mid-turn. Your butt is more sensitive to transients than steady state (i.e. kicking vs. sitting.)

 

[PhoenixGTS]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

If you've never played with them, you may be happy to find shocks will change the ride characteristics much more than you think. The harsh jolt over a bump or pothole is high speed wheel movement that the shock manages. The spring(besides changing ride height) stiffness is how level the car is in mid-turn. Your butt is more sensitive to transients than steady state (i.e. kicking vs. sitting.)

I have had a car with easily accessible rebound adjustments so I have had the opportunity to see how fun and effective it is to be able to quickly make adjustments. The biggest objection currently if a boing in the rear that I assume comes from insufficient rebound damping. With lighter springs I should be able to have a great ride most of the time, but fool the car into thinking it has a higher spring rate via increasing the damping (at least in direction changes if not during continuous turns) when I want to be more aggressive.

 

[GTS Bruce]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Eibach's for 2 years.Never scraped.The stock shock setting is full soft.Not stiff enough with the eibachs.I went 1 and 1/2 turns front and 1 and 1/4 turns rear and is seems good.Possibly could have gone a little stiffer front. GTS Bruce

 

[dun4791]

Re: Let\'s talk about spring rates for street driving. Eibachs are going!

Eibach's for 2 years.Never scraped.The stock shock setting is full soft.Not stiff enough with the eibachs.I went 1 and 1/2 turns front and 1 and 1/4 turns rear and is seems good.Possibly could have gone a little stiffer front. GTS Bruce

Still have this setting after 2 years? Happy with it, or did you go stiffer in the front?

Ive been doing alot of searching on all the sites on this lately because Im doing Eibachs this weekend and am trying to figure out the best setting.

Im going to try 2 turns front, and 1 turn rear, from gathered data. street car with 1/4 mi runs occasionally. No autocrossing...