I think they did and are specifically looking to avoid lawsuits.

 

^ I've thought about that but I don't believe it. OEM springs are firmer in the rear. Plus, they'll often use the same rates for GD impreza, which has a strut rear.

I really don't know why they choose to do it that way.

- drew

 

I can only assume a large company cant measure every motion ratio for every car, and that often times a spring balance comes out for a car before the car is release in an effort to be ahead of the competition.

Then of course you cant go backwards and change it after the fact cause then you'd be admitting your initial setup was wrong possibly damaging future new car sales.

 

Is it possible that the JDM Evo had lighter rear springs from the factory since those cars had AYC? If so, then the aftermarket based their coilover spring rates on that formula.

 

That's another theory but why wouldn't they change it for USDM? It's not difficult and they sell a good amount over here. And I'd still want firmer rear springs with AYC. I really don't get it.

- Andrew

 

It's simple, a harder front spring will stop the car tripoding. More rubber more grip!

 

While that is kind of true, you're also loading the front outer tire more (increasing weight transfer) causing more understeer mid corner.

The real killer when it comes to rear lift is either too much rear bar or not enough droop.

 

I disagree.

more front spring will reduce roll angle and reduce the positive camber when loaded in a turn, thus increasing grip. The inside rear tire is useless, the more tripoding the better.

 

pretty sure JDM have the same spring rates as USDM.

Front: 280 lbs/inch
Rear: 310 lbs/inch

that's for ADM and presumably JDM also, which both have AYC.

May be a case of laziness and sticking to a template where the front is always stiffer than the back? Seems odd, considering ohlins have videos of them testing R&T on an evo X at the nurburgring. Be interesting to find out. I know some companies have stiffer rears, eg. BC's V1/BR come with 7/8 spring rates (at least down here they do, i assume the same in the US?) but then ER's come with 10/8... :/

 

This is quite interesting, looking at SSE ,Cyber and the HKS T/A cars they all run heavier front springs, can anyone explain this?

 

Do you have a source? If I were any of those I wouldn't tell anyone my real rates.

- andrew

 

Please keep in mind there is quite a bit of difference between suspension needs of a high downforce car at 150mph and an autocross car that needs to rotate easily.

 

Do you think that they are even to the point of actually generating high downforce though? I remember reading from a JTCC aero engineer a basic widebody kit with some canards, splitter, and big wing isn't really getting into the range of large downforce. They were mostly just breaking even on cancelling out lift.

On a production car it took efforts on the levels of touring cars to make significant figures. Though this is only random readings Ive gathered, I don't personally have and experience in it.

 

Would I see any benefit on swapping the rates on my Ohlins r&t with the stock spring rates? Ie changing from 10fr/8rr to 8fr/10rr? Car gets used on the track and autocross.

 

Yes. More grip for the front tires and better rotation.