Ground Control coilover owners: What are your spring specs? - Honda Prelude Forum

nighttime · 02-06-2003, 07:00 PM

Im about to get a used set of Ground Control coilovers, but the springs that come with them have *way* too high of a spring rates for my Koni's. (I wont be able to get them revalved for quite some time) The springs that are coming with the coilovers are 600 lb/in and 800 lb/in, so its pretty safe to say that unmodified Koni's wont be happy with that in the long run. So, I want to get either 450 lb/in all around, or maybe 450 lb/in up front and 375 or 400 lb/in in the rear. But I dont know what would be the ideal length to keep them from unseating (esp in the rear) when the suspension is extended, and from binding under compression. So, Id just like to hear what rates you guys are running, and how long the springs are, hopefully that will keep me from constantly exchanging springs. Thanks in advance!

P.S If you are curious, the Prelude this coilover kit is on now doesnt ride that bad considering the spring rates its running. I just dont think its a good idea on Koni's that arent valved for them. Also, I talked to Koni today, they said that the highest I should run is 400 lb/in, and that 450 lb/in is possible, but its probably a bit close to the edge of what you want to do without revalving.

71dsp · 02-06-2003, 07:22 PM

I wouldn't go above 450. That's really pushing it. DR ran 450s all the way around with really good results.

I ran 450 front and 400 rear with good results as well.

What kind of shocks was this guy using? I was running 650 front and 550 rear on my modified Konis that I sold to DR. The ride wasn't bad at all, and the handling was great!

nighttime · 02-06-2003, 07:33 PM

Quote:

Originally posted by 71dsp
I wouldn't go above 450. That's really pushing it. DR ran 450s all the way around with really good results.

I ran 450 front and 400 rear with good results as well.

What kind of shocks was this guy using? I was running 650 front and 550 rear on my modified Konis that I sold to DR. The ride wasn't bad at all, and the handling was great!

Yeah, Im thinking the 450's will work pretty good. Do you happen to remember how long they were?

He has Koni Yellows, unmodified.

71dsp · 02-06-2003, 08:00 PM

That's silly to run spring rates that high if the shocks can't handle it. Good thing you're smarter than that.

Free length on all the ERS springs I used with my GCs was 8".

Jacques · 02-06-2003, 08:08 PM

450lbs F/380lbs R for me.

DR · 02-06-2003, 08:39 PM

I am currently using 650 front, 750 rear. Like Billy said, I had 450 front and rear on my SH which worked great with off-the-shelf konis. They were 8" long.
I have a pair of 340 pound Ground Control springs if anyone wants to buy or trade for them. I would be interested in anything above 800 pounds.

nighttime · 02-07-2003, 12:36 AM

Thanks for all the info, now I feel comfortable with how long these springs need to be. Hopefully I can find some before I get too far into the season, I like to make any changes early, then learn the setup throughout the year. DR, was running 450 all around a pretty neutral setup? (I know its hard to compare cars, as we likely have different alignments, tires, swaybars, etc.) Im thinking that if it does cause more oversteer than Id like (where it is right now is perfect, very easy to mare corrections with the throttle), I can just soften the rear swaybar up a bit. Thanks again guys for all your help on this.

ludikris · 02-07-2003, 06:13 AM

I'm running 450/380. ST bars F/R. Spoon STBs F/R. Tires are Falken Azenis in 15x6.5" steelies with 42/35 F/R. The car is very balanced and controllable. I can get it to oversteer on command, and then hook right back up if need be.

Alignment is -1Â° camber all around with stock (or within stock specs) for everything else.

Probe 2C · 02-07-2003, 07:05 AM

What do your cars weigh and what's the weight bias?

Given that the standard length they give you is 8" (as I read above) you can figure out how much the spring will deflect under normal conditions, and what the optimal spring rate would be.

When I got GC's on my car I customized the length and the rates. You have to take into account the fact it isn't hard to spec them out and screw up. Too low of a rate and you'll have coilbind, too high and you'll have a horrible ride.

fwiw I have 350 6" front and 325 7" rear on my Probe. Looking back I think optimum on my car would have been 400 6" front and 300 7" rear. I drive much more aggressive and have tokico struts which (when adjusted correctly) can handle the spring rate.

In the end though, high spring rates are just a crutch. For a really quality tuned street/track suspension you would want medium spring rates (in the high 200's low 300's) with long lengths and struts with independantly adjustable rebound and compression. This lets you keep the good weight transfer and suspension travel, but you have to control roll and yaw with other things.

For race only applications I would just get extremely stiff springs available and then get struts re-valved to work with them.

In the real world though high rates are good for reducing bodyroll, and trying to get that sport feel. It's just hard to have a quality balanced suspension with high rates.

aklucsarits · 02-07-2003, 08:12 AM

I'm in the same boat, Nighttime. I need to decide on spring rates and order them soon. I have the Koni Sports (Off the shelf valving) as well. I am leaning towards 425F and 400R.

Incidently, what are the best prices you guys are seeing for GCs with custom spring rates and the Koni mounts? Best I have seen is about $360 - ~$255 for GCs, ~$40 for custom spring rates, ~$50 for Koni mounts, $15 shipping.

Andrew

Jacques · 02-07-2003, 09:33 AM

Probe2C, since the questions above pertain to the 5th gen, it ranges from 2954lbs to 3042lbs, depending on trim level.

Probe 2C · 02-07-2003, 10:50 AM

Gotta front/rear weight distribution percent? 60/40?

red92si · 02-07-2003, 11:06 AM

I am also using 450/380... I don't autocross though, only canyon driving

Mugenlude · 02-07-2003, 11:06 AM

Quote:

Originally posted by aklucsarits
I'm in the same boat, Nighttime. I need to decide on spring rates and order them soon. I have the Koni Sports (Off the shelf valving) as well. I am leaning towards 425F and 400R.

Incidently, what are the best prices you guys are seeing for GCs with custom spring rates and the Koni mounts? Best I have seen is about $360 - ~$255 for GCs, ~$40 for custom spring rates, ~$50 for Koni mounts, $15 shipping.

Andrew

Where is this from? I was under the impression that if you order them direct from GC you can specify any rate you want, however, now that I look at the pricing they advertise for $339 plus $40 for the Koni adaptors... I have heard that they will price match whatever you find them for though, so you can try that...

ludikris · 02-07-2003, 11:40 AM

My wife bought me mine for ~$330 shipped direct for GC and spec'd the springs rates.

aklucsarits · 02-07-2003, 12:12 PM

Quote:

Originally posted by ludikris
My wife bought me mine for ~$330 shipped direct for GC and spec'd the springs rates.

Did that include the special koni perches?

Andrew

Jacques · 02-07-2003, 12:17 PM

Quote:

Originally posted by aklucsarits

Did that include the special koni perches?

Andrew

Special Koni perches? My Konis had the GC perches, if that's what you mean. You can order "stock" Konis, or order Konis that have perches for a particular brand spring/coilover, in this case, Ground Control.

71dsp · 02-07-2003, 12:37 PM

Huh? The Ground Controls I had used a machined collar that captures the C-clip on the Koni shocks. The threaded bodies from the GC kit then slides over this adapter. There was nothing extra needed from the Konis. The only thing you did was NOT install the spring perch that came with the Konis. Just use the C-clip.

ludikris · 02-07-2003, 02:12 PM

Quote:

Originally posted by aklucsarits

Did that include the special koni perches?

Andrew

To my knowledge there are no "special Koni perches". You simply order your GCs for stock shocks or for Konis. You don't install the spring cup that is included with the Konis, you use the C clip that is already on the Koni Body (mine is set in the middle of the 5 slots, btw).

Mugenlude · 02-07-2003, 04:01 PM

On the Ground Control site they list the following after the application guide:

Quote:

* $10 per corner additional for billet aluminum Koni or Bilstein adapters. No extra charge for any other shock. Please don't try to make another kit fit on Koni or Bilstein. It doesn't work for GC or any other coilover kit.

Example: 1999 Civic, $299+$40=$339 Total