ot

 

I like to measure my ride heights from center of hub to edge of fender.

- Andrew

 

ot

 

ot

 

not properly.

http://www.whitelineautomotive.com/O...erEVO7_8_9.pdf

says the front/rear rake should be about 15mm (guard to centre of wheel).

now IX's apparently where 5mm LOWER on the rear than 8's, so I am not sure if this should be 20mm...

thoughts?

 

In addition to weight transfer, what about suspension travel??? I drove a 'lowered' [with springs] and it just felt awful. Turn in was about the same as stock MR, but any road imperfections (bumps, pot holes, etc.) threw the chasis. On several occasions it felt as if the car bottomed out. I am not a fan of changing the rake of the car for aesthetic purposes and don't believe doing so will improve performance (IMHO).

 

That is where spring rating come in. If too soft thats what you will feel. I never felt the car bottom out on my Sports and definitely not on the Spec Rs. I even have been unsprung on one of my home tracks right into full braking (Grattan hump).

Right in the braking part of that track:
http://i85.photobucket.com/albums/k6...EvoTurn4_5.jpg

Swifts have a 19mm rake. I would like to know what the OE is at.

I am confident that it does make a difference.

 

as I said b4, I think an 8 has 15mm rake, IX has 20mm.

whiteline upgrade kit suggests 15mm is the go.

I still don't really know how we can set rake AND then do a corner balance? obviously the CB will unset the rake, but I guess not by much??

 

Thanks tephra

 

I too am confident that rake is very important, but must be misunderstanding something....

The swifts Spec R drop the front more than the rear (from memory the front drop is ~35mm and the rear drop is only 20mm), which means it is more severe than factory...The rake with the swifts should be (according to my understanding) = 20mm (factory rake) + 15mm (35-20mm drop) due to swifts which is 35mm....35mm rake vs 20mm rake....

So, I am still confused and was hoping that IndyEvo would come back and add some good engineering perspectives....

 

different spring rates??

ie the rears might compress MORE than the fronts thus giving normal rake??

 

A level rake is a level roll axis. Ride height measurements are a good way to guess where the roll centers are and thus the rake of the roll axis, BUT by themselves are not real measurements of rake. It's a good way to compare vs. stock though.

Remember....lowering the car 1 inch does not necessarily mean you are lowering the roll center 1 inch.

- Andrew

 

so your saying the different between front and rear (Hub Centre -> edge of fender) is not rake?

 

Sort of. In practice that's what I look at with cars that I know and measure from stock as a baseline. So yes I would say the Swifts have 15mm more rake than stock for example (from the 35mm front 20mm rear drop).

But really it's the roll axis. That's just a bit tougher to measure.


- Andrew

 

All that's very difficult to measure though. Which is why most people set rake by just playing with it a lot and seeing what works and what doesn't. All the bench racing on the internet doesn't match up to a good test 'n' tune day.

Just remember rake affects things in a big way because it changes suspension geometry. This changes where the tire is on the camber curve at a given weight transfer.

Once I get my coilovers on, my take on the whole thing will be to just ask the fast guys what they're running and set my car that way.