# AFCO rear springs



## Audiguy84 (Nov 14, 2006)

does anyone know where I can get the rear springs, how strong the springs shouldbe, and what am I looking at to pay?


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## Audiguy84 (Nov 14, 2006)

okay I did some searching as no one posted yet it looks like 4"tall with 2 5/8 inside diameter should work, where would be a good place to get the spring? 

Edit: what kind of spring rate should I be looking at?


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## Neb (Jan 25, 2005)

Google is your friend on this one: 

http://www.afcoracing.com/springs_2_58id.html 

They're cheap though, $100-150 for the pair IIRC 

I just don't know the best spring rate offhand though, maybe someone can chime in.


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## Audiguy84 (Nov 14, 2006)

Thinking a 600 lbs rate will be good?


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## DaCabrioGuy (Sep 12, 2011)

Sorry to threadjack, but I am also looking at getting afco rear springs. I was wondering how much lower the afco spring would be compared to my perchless st coil setup. Thanks in advance.


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## Neb (Jan 25, 2005)

I got about 3/8-1/2" compared to my H&R's


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## PLAYED TT (Oct 17, 2010)

600 is bouncy as fuk. I need to stiffen the rear shocks but other then that your on point op


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## Audiguy84 (Nov 14, 2006)

if 600 is to bouncy what should I go with? Maybe 500?


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## Audiguy84 (Nov 14, 2006)

Bump for some info??


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## Marcus_Aurelius (Mar 1, 2012)

Audiguy84 said:


> Bump for some info??


I normally pass on most "going low" threads, but since you're the one asking... Bounciness isn't a factor of spring rate, but rather the ability of the force/shock absorbers (AKA shocks) to control the spring movements. The spring movements or oscillations are natural and suppose to happen at a rate dictated by the chosen natural frequency for the car.

What doe this mean to you? A shock that can't control 600 lbs in the rear of 2500+ car with a .7 motion ratio is questionable and seriously weak in its valving. :screwy: 

To put it in perspective:
- 500 lbs in the rear of a Quattro TT is 500 X 0.7 = 350 lbs effective rate at the wheel (pathetic)
- 600 lbs in the rear of a Quattro TT is 600 X 0.7 = 420 lbs effective rate at the wheel (weak sauce)
- I run 1300 lbs (910 effective rate) with zero bouncing, and that's because the valving is not crap and can control the spring motion for the choosen rate. 

IMO, you can't run cheap coilovers without paying a big price. Going low and using hardware/spring combination that makes practical sense is mutually exclusive. Unfortunately, you can only pick one and the decision is yours. :beer:


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> - 500 lbs in the rear of a Quattro TT is 500 X 0.7 = 420 lbs effective rate at the wheel (pathetic)
> - 600 lbs in the rear of a Quattro TT is 600 X 0.7 = 350 lbs effective rate at the wheel (weak sauce)


Check that math again, Max.


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## Neb (Jan 25, 2005)

Marcus_Aurelius said:


> I normally pass on most "going low" threads, but since you're the one asking... Bounciness isn't a factor of spring rate, but rather the ability of the force/shock absorbers (AKA shocks) to control the spring movements. The spring movements or oscillations are natural and suppose to happen at a rate dictated by the chosen natural frequency for the car.
> 
> What doe this mean to you? A shock that can't control 600 lbs in the rear of 2500+ car with a .7 motion ratio is questionable and seriously weak in its valving. :screwy:
> 
> ...


Well I don't think it has to do with running cheap coilovers. (although define 'cheap') My H&R's (not cheap but not top either) are super bouncy with these springs. Unless you get the shocks revalved I doubt you can find a set that wont' be bouncy.

That's why I'm saving for a revalved set of proper 'get-low' H&R's soon enough. The bounciness of AFCO with regular H&R struts drives me mental.


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## 20v master (May 7, 2009)

Neb said:


> Well I don't think it has to do with running cheap coilovers. (although define 'cheap') My H&R's (not cheap but not top either) are super bouncy with these springs. Unless you get the shocks revalved I doubt you can find a set that wont' be bouncy.
> 
> That's why I'm saving for a revalved set of proper 'get-low' H&R's soon enough. The bounciness of AFCO with regular H&R struts drives me mental.


It has everything to do with running cheap coilovers. You changed the spring rate without changing the shock to match. Of course it's going to be bouncy. Getting them revalved is what you need to do to cure the bounciness that you hate. Where do you send your ST's or FK's or VMaxx or KSport or any of the other less expensive brands to get the shocks revalved? Will that shock even be able to be revalved to the spring rate you've chosen? How long will it last, assuming it can be valved to what you want? Getting these answers regarding H&R products would be much more likely/easier than with some of the other brands. Same with Koni or Bilstein.


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## Neb (Jan 25, 2005)

I have H&R's, not the super cheap brand so I have no idea if you can revalve those ones. I was looking at buying a new set of coils that are revalved all around (front/rear) to handle going super low


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## 20v master (May 7, 2009)

Neb said:


> I have H&R's, not the super cheap brand so I have no idea if you can revalve those ones. I was looking at buying a new set of coils that are revalved all around (front/rear) to handle going super low


So you're going to buy new and revalve them, or buy a new set that is setup out of the box for what you want? Either way, it seems like you should skip both of those options and revalve what you have and buy the springs to match, you don't need "new." H&R's are the same inverted monotube shock design as Bilstein, so I'd assume it would be easy to find places to revalve them. We need Max to confirm all this though. :thumbup:


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## Neb (Jan 25, 2005)

Well the place gets a new set then revalves them and matches them up with springs.

If I could find a place to do the same I'd probably go that route (depending on cost). I have no idea what it costs to revalve H&R's, nor do I know if there's certain specs that you revalve too?


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## Marcus_Aurelius (Mar 1, 2012)

20v master said:


> Check that math again, Max.


I think you mean check that dyslexia, results swapped for you! :laugh:


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## Audiguy84 (Nov 14, 2006)

HEY MAX WHAT DO YOU THINK OF THIS WEBSITE?

http://www.hypercoils.com/spring-rate-calculator/


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## 20v master (May 7, 2009)

Audiguy84 said:


> HEY MAX WHAT DO YOU THINK OF THIS WEBSITE?
> 
> http://www.hypercoils.com/spring-rate-calculator/


Why are you yelling? You'll need to weight the spindle, control arm, ball joint, brake disc, caliper, and strut/spring, wheel and tire, and lug bolts/nuts/any other hardware attached to those parts, as well as corner weight obviously, to be able to plug in the measurements.


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## Neb (Jan 25, 2005)

20v master said:


> So you're going to buy new and revalve them, or buy a new set that is setup out of the box for what you want? Either way, it seems like you should skip both of those options and revalve what you have and buy the springs to match, you don't need "new." H&R's are the same inverted monotube shock design as Bilstein, so I'd assume it would be easy to find places to revalve them. We need Max to confirm all this though. :thumbup:


After a bit more reading, it looks like they also shorten the struts as well. So I think it's a bit more complicated of a process.


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## 20v master (May 7, 2009)

Neb said:


> After a bit more reading, it looks like they also shorten the struts as well. So I think it's a bit more complicated of a process.


Who is "they" and why are you being so secretive?  Why don't you post up where you're getting this info so others can look into it and provide some contacts for people looking to do this? :thumbup:


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## Marcus_Aurelius (Mar 1, 2012)

Neb said:


> Well I don't think it has to do with running cheap coilovers. (although define 'cheap') My H&R's (not cheap but not top either) are super bouncy with these springs. Unless you get the shocks revalved I doubt you can find a set that wont' be bouncy.
> 
> That's why I'm saving for a revalved set of proper 'get-low' H&R's soon enough. The bounciness of AFCO with regular H&R struts drives me mental.


Ben, it has everything to do with "cheap coilovers" (vmaxx, FK, ST, etc.). Before even getting into revalving. If you look at the default valving in a set Bilstein PSS or H&R RSS clubsports, you'll see that the spec valving curves are very wide from the factory (meaning that they'll accept a substantial spring rate change +/- and still fall within what the curves will control effectively in both compression and rebound phases).

Now, if you do the same with the cheap lineup in the market, the default valving curves are so narrow that any slight change in rate is way outside of what they can and will control appropriately (even if those could be revalved, they could only work for one specific spring rate because of the shock's internal makeup). :thumbdown:


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## Audiguy84 (Nov 14, 2006)

caps lock was on b/c I'm at work and we use Renolds ERAcess and it only works with caps lock on.


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## Neb (Jan 25, 2005)

20v master said:


> Who is "they" and why are you being so secretive?  Why don't you post up where you're getting this info so others can look into it and provide some contacts for people looking to do this? :thumbup:


Because as soon as I post up a good idea people like to take it haha. This was from their site.



> Combined with our partners at AH Exclusive, we supply H&R kits which will drop much lower than any other kit available on the market, without sacrificing comfort.
> 
> These kits are ultra low monotube derived coilovers, using bilstein damping technology. These have been specially shortened by H&R special suspension and combined with custom springs for comfort. We can also supply low race kits with or without adjustable damping settings. Since January 2013 most special Ah Exclusive Coilovers can be supplied in a special black plated finish. This coating has the same resistance properties to road dirt and salt corrosion as the normal ultra low coilovers but give the enthusiast a cleaner looking and more unique coilover.
> 
> ...


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## Neb (Jan 25, 2005)

Marcus_Aurelius said:


> Ben, it has everything to do with "cheap coilovers" (vmaxx, FK, ST, etc.). Before even getting into revalving. If you look at the default valving in a set Bilstein PSS or H&R RSS clubsports, you'll see that the spec valving curves are very wide from the factory (meaning that they'll accept a substantial spring rate change +/- and still fall within what the curves will control effectively in both compression and rebound phases).


I was more referencing how bouncy the afco were across the entire board of coilovers, 'cheap' and not. Mind you, when I ordered my AFCO's I didn't really have options for spring rates (IIRC) as it was a few years back. But even with my H&R's the ride is still super bouncy. I just figured it was due to the springs, not the coilovers.


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## 20v master (May 7, 2009)

Neb said:


> Because as soon as I post up a good idea people like to take it haha. This was from their site.


L33T! www.still-static.com?


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## Audiguy84 (Nov 14, 2006)

I'm running hpa shs series coils (kw v1) and never really experienced bouncy coils but my coils are for an r32 so i don't know if that matters much


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## Marcus_Aurelius (Mar 1, 2012)

Audiguy84 said:


> HEY MAX WHAT DO YOU THINK OF THIS WEBSITE?
> 
> http://www.hypercoils.com/spring-rate-calculator/


Useless!!! It's not that simple, not even close! If it was that easy, all the "cheap" entry level coilovers would have usable products for the platforms that they are selling to. Or better yet, they are so crappy because they're probably using something similar to select springs for a platform. 



20v master said:


> You'll need to weight the spindle, control arm, ball joint, brake disc, caliper, and strut/spring, wheel and tire, and lug bolts/nuts/any other hardware attached to those parts, as well as corner weight obviously, to be able to plug in the measurements.


But even if you have the unsprung weights calculated and everything, how do you possibly get proper spring rates without the main piece of information missing? As you know, it's impossible to do without a target Natural Frequency and then some testing to finalize feel and balance to work around that chosen target NF. It took me hours of plugging numbers, doing calculations with a real suspension spreadsheet, manual camber curving, measuring suspension stroke front and back, choosing a Natural Frequency that would work for all the data collected and my specific use, and then finally get optimal springs rates and balance after trying 3 different combos. Lots of work to really do it properly!


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## Neb (Jan 25, 2005)

Audiguy84 said:


> I'm running hpa shs series coils (kw v1) and never really experienced bouncy coils but my coils are for an r32 so i don't know if that matters much


They get bouncy when you add the AFCO spring. the springs that come with the coils are usually fine.


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## Raek (Aug 1, 2003)

All of this math makes bags look more appealing.


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## warranty225cpe (Dec 3, 2008)

Raek said:


> All of this math makes bags look more appealing.



Haha, and it begins..

opcorn:


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## Marcus_Aurelius (Mar 1, 2012)

Raek said:


> All of this math makes bags look more appealing.


Are you being sarcastic??? Maybe more appealing at going low and sucking even more at life? 

The only way to go low and retaining some kind of handling characteristic (which makes owning an AWD sporty car what it is) is to do the math and the hardware changes to make it happen. Bags IMO are better suited for show cars with limited street use ... but what do I know :wave:


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## 20v master (May 7, 2009)

Marcus_Aurelius said:


> Bags IMO are better suited for show cars with limited street use ... but what do I know :wave:


:laugh: But Max, that's what everyone here drives, right?


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## Raek (Aug 1, 2003)

[pretentious comment]When I want to drive a real car, I drive my BMW. The TT was bought strictly for replacing my aging "limited street use" MKIV.[/pretentious comment]

"Sucking more at life" is subjective...it really depends on opinion. :wave:

Editing cause that comment, albeit pre disclosed, really makes me seem like a douche. However, to clear things up, I really didn't get the TT to make it into a driver's car. IMO it's still a [mostly] FWD 4 1.8T. 

The BMW is, from an enthusiast's view, mostly purist. The only thing I modded was suspension, and it was just in handling's name.

I was merely stating, that if you're not interested in the performance of the vehicle and just want to go low, air suspension is a viable choice when compared to revalving shocks/etc. If you're getting AFCO springs, you're more likely to not care about the performance of the vehicle's suspension.


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## Audiguy84 (Nov 14, 2006)

I care about handling a lot more then I care about being low, So as it sits I think I'm going to pass on the AFCO springs unless they come out with at minimum a 800lbs spring. While I was searching I found that H & R makes a spring that is supposed to sit lower anyone know anything about it?


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## Raek (Aug 1, 2003)

Audiguy84 said:


> I care about handling a lot more then I care about being low, So as it sits I think I'm going to pass on the AFCO springs unless they come out with at minimum a 800lbs spring. While I was searching I found that H & R makes a spring that is supposed to sit lower anyone know anything about it?



I actually bought AFCO springs thinking I would swap them in right away when I redid my suspension. Upon better judgement, I tried with the stock ST Coil springs and removed perches. It's low enough for me, and also bouncy enough as it is 

Not too sure if I'll be throwing the AFCOs on or not...if you're having any doubts, it's probably smarter that you pass.


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## 20v master (May 7, 2009)

Audiguy84 said:


> I care about handling a lot more then I care about being low, So as it sits I think I'm going to pass on the AFCO springs unless they come out with at minimum a 800lbs spring. While I was searching I found that H & R makes a spring that is supposed to sit lower anyone know anything about it?


AFCO is a custom spring, meaning you can get them in whatever spring rate you want. As we've said over and over, the motion ratio of the rear suspension dictates a much higher spring rate than the front, and as long as your shock is matched to the spring rate, it won't be bouncy and can still handle well. There are several companies that make springs like this, AFCO is just one of them.


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## Audiguy84 (Nov 14, 2006)

Well from their website they only list from 300 to 600lbs rates. I understand that the rate of the spring is determined by the valving of the shock along with the specs of the vehicle but as max said earlier the higher quality of suspension that you have the wider the range of spring rate (to a degree) that you have. I went on hpa's website to see if they had any specs listed but they didn't


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## 20v master (May 7, 2009)

Audiguy84 said:


> Well from their website they only list from 300 to 600lbs rates. I understand that the rate of the spring is determined by the valving of the shock along with the specs of the vehicle but as max said earlier the higher quality of suspension that you have the wider the range of spring rate (to a degree) that you have. I went on hpa's website to see if they had any specs listed but they didn't


Yeah, but I'm sure they or anyone else that makes the springs can make what you want. You don't have to use AFCO. Your HPA coilovers are KW's, with probably some changing of the valving, which I'm sure they won't release to you. My KW's are really old (in my GTI, purchased from Germany in 2003) and they were just Koni's, but I think they started making their own shocks at some point. You could contact KW NA and see if they could point you in the direction of upgrading, as well as possibly supply the spring rate you are looking for.


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## Neb (Jan 25, 2005)

I would just call and ask. When I needed spring rate info on my H&R's they were more than willing to give me the info I was looking for.


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## Marcus_Aurelius (Mar 1, 2012)

Audiguy84 said:


> Well from their website they only list from 300 to 600lbs rates. I understand that the rate of the spring is determined by the valving of the shock along with the specs of the vehicle but as max said earlier the higher quality of suspension that you have the wider the range of spring rate (to a degree) that you have. I went on hpa's website to see if they had any specs listed but they didn't


It doesn't have to be Afco, somehow the Afco brand became synonym to aftermarket replacement springs. There are other names like the Eibach ERS line, or H&R in the proper length and ID, that are much more popular and used than Afco for that kind of things. A 4" spring with X rate is going to be the same from whatever manufacturer, but Afco does have higher spring rates available in the size that will work for our platform.


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## Audiguy84 (Nov 14, 2006)

Ohh ?? Where did you find the 800 lbs springs at?


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## Marcus_Aurelius (Mar 1, 2012)

Audiguy84 said:


> Ohh ?? Where did you find the 800 lbs springs at?


Speedway or anywhere that's a distributor for Afco. :beer:


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## Chickenman35 (Jul 28, 2006)

Marcus_Aurelius said:


> Speedway or anywhere that's a distributor for Afco. :beer:


www.pitstopusa.com is a good site for coil over springs etc ( Afco, Eibach, Hypercoils, Integra, Suspension Springs Specialists, QA1 ). They carry a ton of high quality racing parts and safety equipment :thumbup:

http://pitstopusa.com/c-131948-springs-coil-over-springs.html

My buddies and myself used them all the time for parts on our Autocross/Hillclimb pony cars. Mainly for Circle Track cars but lots of stuff that can cross over to Import use. :beer:


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