Koni Yellows and Max Spring Weight

My Konis are supposedly rated at 600 lbs. max rate. Does anyone have experience with running Yellows near the max? I'm looking at 575 to 616# springs (currently at 515). If they can operate efficiently at any of these weights I would prefer the 616s as that weight is much the preferred hz. and they are Swifts, my favorite. I'll check with Koni but wanted to hear from guys that have hands on experience. Thanks.

I run 400-550 pound springs in my Neon and had the Konis revalved. It was an improvement. The most noticeable (and shocking) improvement for me was going from stock alloy wheels and R888s to Slipstreams and Goodyears- took about 10 pounds of unsprung weight off each corner, and suddenly my shocks worked WAAAYYY better.

I think it would make for an interesting GRM article- find a track with lots of rough spots and some curb hopping, then do a comparison based on unsprung weight.

The issue that I seem to recall hearing is that the adjustment in the Konis is really only rebound adjustment (IIRC). As you go to a stiffer spring, you would want to adjust the damping to match the spring rate, but since you can only adjust rebound, the bump damping becomes very poor.

I've never run Koni Sports with spring rates that high, so I can't give any anecdotal evidence, but I can say that I've run them with much lower rates, 200-400 lb/in and they performed well there, so I imagine as you go to higher rates, it would become difficult to maintain proper damping.

JohnyHachi6 wrote: The issue that I seem to recall hearing is that the adjustment in the Konis is really only rebound adjustment (IIRC). As you go to a stiffer spring, you would want to adjust the damping to match the spring rate, but since you can only adjust rebound, the bump damping becomes very poor. I've never run Koni Sports with spring rates that high, so I can't give any anecdotal evidence, but I can say that I've run them with much lower rates, 200-400 lb/in and they performed well there, so I imagine as you go to higher rates, it would become difficult to maintain proper damping.

Yellows are single-adjustable for rebound, so I would expect that to be accurate. Everybody I know running Konis for very high spring rates has them revalved. Out of the box, they're good for street springs.

650 is the top end for a re-valved Koni SA.

Great topic as I'm getting ready to think about ordering a Ground Control/Koni Yellow setup for my GTI.

What would be the highest spring rate you would run for an off the shelf Koni Yellow and still expect some decent performance and longevity for the strut?

I'm thinking about running 300 F / 450 R OR 350 F/ 450 R with Ground Control springs on my car.

How much does revalving cost and is there any warranty if I tracked down a used set of SAs and then sent them in for revalving?

Koni has a lifetime limited warranty only for the original purchaser. That's what I was told when I bought what might be the very last new set of Alfa 164 front inserts anywhere.

Here's some revalving services, including how to get Koni to rebuild your struts. A quick Googling shows rebuild prices are at about $150-200/damper. You'd have to ask the rebuilder if they have any warranties.

http://performanceshock.com/index.php?main_page=product_info&cPath=1&products_id=677

http://www.propartsusa.com/shockdept.html

http://www.eshocks.com/Kon_Serv.asp

http://www.truechoicekoniracingservices.com/products/services.htm

Also, the Koni Race 8611 universal strut inserts are double-adjustable. However, they are not cheap (~$430/insert).

http://performanceshock.com/KONI_86_series_race.pdf

You can also rebuild the Yellows into dbl. adjustables but for about $200.00 more, iirc, there are the Race dbl. adj. For now I just want to max the Yellows. Maybe I should do the 575# spring.

I wouldn't run that high unless the Koni's were specifically valved for it.

I ran a Ground Control setup on my E30 with 550/750 rates, but the Koni's were custom valved to that rate........handling and ride were quite awesome.

z31maniac wrote: I wouldn't run that high unless the Koni's were specifically valved for it. I ran a Ground Control setup on my E30 with 550/750 rates, but the Koni's were custom valved to that rate........handling and ride were quite awesome.

They are supposedly rated up to 600.

Where did you find this info? I bought a set of Koni Yellows for my old car and I didn't get that. It's better than finding out later by putting Konis with 1000 lb front springs on my car.

I suspect they are all valved differently depending on the application.

Spring rate only tells a small part of the story. 500lb springs on a double a-arm setup is a whole nuther game than 500lb on a mac strut. I'm sure they're valved by application, not just by xx lb spring rate.

Also, shocks will be valved per application, so it wil vary from car to car.

I have 550lb-in on the front of my miata and it is pushing it, feels less tidy over bumps than the 375 springs did. I dont know what the Koni rated max is for my application, but it might give you a bit of a place to start.

I've been running 600 lb/in springs on a set of 5 year old OTS yellows for about a year now (they supported 600lb/in for a year, sat for 2, one year on stock springs, now 600 again). They still work great and dont leak.

RexSeven wrote: Koni has a lifetime limited warranty only for the original purchaser. That's what I was told when I bought what might be the very last new set of Alfa 164 front inserts anywhere. Here's some revalving services, including how to get Koni to rebuild your struts. A quick Googling shows rebuild prices are at about $150-200/damper. You'd have to ask the rebuilder if they have any warranties. http://performanceshock.com/index.php?main_page=product_info&cPath=1&products_id=677 http://www.propartsusa.com/shockdept.html http://www.eshocks.com/Kon_Serv.asp http://www.truechoicekoniracingservices.com/products/services.htm Also, the Koni Race 8611 universal strut inserts are double-adjustable. However, they are not cheap (~$430/insert). http://performanceshock.com/KONI_86_series_race.pdf

Thanks for the info! I've thought about the 8611 too I just have to decide if I want to swallow that kind of cost up front. Maybe if I can find the proper GC setup used I can make paying that out less painful.

I was looking at the 8611s too for my Alfa's front set, until I found that one NOS set, and discovered none of the 8611s would fit quite right.

Bilstein also makes universal 2-way adjustable strut inserts, but those are even more expensive at $500-550 a pop!

http://thmotorsports.com/bilstein/bilstein_motorsports_universal_series/35212799/i-1737609.aspx

http://www.bilsteinus.com/uploads/tx_templavoila/Bil_46mm_UniMtrsprtsStruts_flyer.pdf

(Warning: PDF)

Update; I spoke with Bill? at True Choice today. He suggested going as high as 700 but that was pushing it and 600 would be better. This is for the 1080-1050 for a DC5/RSX rear, which have been adjusted to fit my EP3 Civic. The fronts, 8610-1415, are good to 600. So, 450/600 it is until I can afford better dampers. In consideration are Race Konis, Bilstein B-16s, but hopefully the Fortune Auto 510 will work out. The 510s are being tested by an aquaintance and could be a really nice damper.

I will call Koni tomorrow just to double check the max spring weight.

Thanks for everyone's input.

Update; after speaking with Koni it seems 600 will be the choice. The tech wouldn't commit to a number but he spoke more about personal preferences and control, etc. 700 or more is evidently doable but control reduces as the spring increases, etc.

A year or two and then on to better dampers and heavier springs. But upping the spring rate a little at a time has been fun. Started with oem 250/440, next about 280/440, now at 336/515, next will be 450/600, and final will be around 700/1100.

In my EP3 I'm on RSX revalved Koni Yellows for 550# front and 1200# rear 6" eibach ERS springs. I used to run 300# front and 750# rear on a set of factory valved RSX yellows and they were fine, I still have them as back-ups, the seals aren't leaky, they still adjust and that was after 1.5 years 15,000miles of street and autox use. I remember talking to some of the Koni guys and they said because of the rear suspension geometry of the EP3/DC5 platform that they could handle some heavy spring rates and still be ok and not risk destroying the shocks. I changed to the heavier weights when I converted the EP3 to full slicks and knew the race weight.

*I am assuming you are talking about a EP3, if you aren't please ignore all this useless information.

Hey, that's great to hear. Yes, this is for an EP and I'd read about the rear geometry allowing a higher rate but couldn't find anyone who had done it. Maybe I'll go with 700 after all. Cool beans!

I'll wait also till the final weight and balance is known to figure spring weight but it should be 2,250 at the heaviest, probably 2,200. That will be -575lbs.. Current weight is around 2,350, - 425 lbs.. Getting there.

Hasbro wrote: Update; after speaking with Koni it seems 600 will be the choice. The tech wouldn't commit to a number but he spoke more about personal preferences and control, etc. 700 or more is evidently doable but control reduces as the spring increases, etc. A year or two and then on to better dampers and heavier springs. But upping the spring rate a little at a time has been fun. Started with oem 250/440, next about 280/440, now at 336/515, next will be 450/600, and final will be around 700/1100.

Very helpful to me to hear this too. I'm glad I can probably push 450 - 500 without being too terribly afraid then.