Our KONI managers of R&D and Motorsports just got back from several test sessions for the IRL and were working with several teams running the new 2822 4 way adjustable KONIs that come on the Dallara chassis.

They said the Dallara chassis is delivered from the factory with 75 mm (3 inch) free length springs with a 3,000 lb spring rate. From the data that most of the teams were used to running and from previous testing, most decided they needed to get into the 7,000 lb spring rate range with the standard rocker motion ratios to get the wheel rate they wanted. Problem is there aren't too many 7,000 lb x 3 inch springs around and they aren't really too reliable at that size. So most of the teams have changed the rocker geometry so the ratio is closer to 1:1 and they now working in the more reliable 4,400 lb range.

And you thought putting 600-1,000 lb springs on a Honda product was getting aggressive with it's .7:1 ratio. On the otherhand, our Hondas aren't exactly high aero winged, ground effect cars racing on tracks banked like salad bowls either.

 

Egad, the beating their brains and internal organs must take.

Just curious - what are your plans for the Devin? Vintage racer?

Scott, who is in love with the Lotus Elite....

 

Lee,
Is that you from koni? I'm interested in getting my "street" single adjs revalved/shorten for my spring rates (500/700). Can you tell me what I'm looking at? You can email me privately if you like. richygonzalez@hotmail.com

 

Wow...Considering the cars only weigh like 1500lbs, that's amazing. If somebody were to ask me to guess what spring rates those cars run, i wouldnt even be close to that. I'd prolly guess 1500-2000 or something...

 

Springs rates are huge on those cars because of the downforce they generate. A CART car at 200mph generates something like 7,500 lbs of downforce. I assume an IRL car is close to that.

 

Yeah exactly, it makes sense when you factor in the downforce. I kinda forgot about that. But still.... What happens in those slow, 30-50mph corners? WAAAAAAY too much springs. Ah, I guess that's why those guys get paid the big bucks to figure out the necessary compromises...


Edit: I'm talking more about Indy cars here of course, since IRL never sees speeds so low...


[Modified by jsi, 9:03 AM 2/28/2003]

 

Which is why they need the "high" profile tires to help out with the suspension some...

 

[QUOTE]Just curious - what are your plans for the Devin? Vintage racer?QUOTE]

My Devin is one of last, biggest V8 kit cars they made, somewhat Cobra like but more swept and Italian in shape. It was originally a barely finished, barely used drag race car with a 327 Chevy/3 speed. From my research it is one of the most complete, original kit cars remaining, most got hacked up over the years. It is very complete except the interior but will need a body off, frame up resto. My uncle got it in 1973 from the original owner and it hasn't run since and sat in his Dallas backyard until 1997 when I convinced him that I was the car's best shot to ever be restored.

My plan is to build it as a streetable car that can do the occaisional lapping day. I have no interest in vintage racing it really because I already have a racecar and don't want to spoil it with too much roll cage (just a reinforced bar only). Once the CRX racecar is done, I hope to slowly begin to go through it. Unfortunately the only time my wife has mentioned the word "divorce" was in the same sentence with "Devin" so I'm going to have to convince her of the merits of the project before much family money hgets spent on it.

 

Good luck with that!

Scott, who understands on the too many cars thing...

 

good god those are some massive spring rates!!!

i think i would rupture my kidney with those.