I see numerous Evo's running wider track, via spacers, low offset wheels, and more.
Specifically front track being wider than normal

Low-wheel offset can be attributed to space-gathering to fit 285's next to the front strut.
But overall trend is widening 10-20mm/per side front track.

I would like to ask those using wider track, why?
How does it affect the steering feel, how does the front behave in bump-compression/rebound-droop?

Does the steering "feel weird" from movie the wheel-center away from steering axis center? Effectively creating a moment-arm which can affect steering feel and behavior as the wheels when turning now scribe an arc rather then turning around an axis?

Wider-track lowers weight transfer side to side.
Is 1"- 1.5" Vs OEM 59.6" front track-width having a significant influence on the handling?

I have some ideas based logical assumptions, but would appreciate users/racers feedback and advice. Of course am always looking for optimization and improvement, but would like to step in informed knowing a bit more what to expect.

Thank you

Am not very concerned with rear track, mainly with front because 65% of the Evo weight is in the front, not to mention under heavy braking and corner entry when maybe 80+% is on the front, I am lead to believe the front characteristics are the "driving force".

 

Evo x stuff fits and is wider I believe. Geoff did this from what I recall. Not sure how that changes sai. Probably doesn't help roll center though. Just wanted to add that method to your background of concepts

 

Yes, a while back I read Geoff's build story,
But I would like to hear directly from users facts, data- experience, etc.

 

not trying to hijack the thread or anything, but those running the EvoX control arms- Does anything need to be done to the axles or is the difference little enough?

Too much Scrub Radius should make steering a bit more heavy, and generally too much of it is no good.

 

Running a +38 offset is the same as running a 20mm spacer an +18 offset. The fact you have a spacer doesn't do anything to the feel when the net offset is the same. The only reason to do it is to be able to have 4 wheels with the same offset so you can rotate the wheels each event.

After rolling/pulling my front fender 3/4", I just leave the 20mm spacer on year round. Without it the car looks goofy with how far the fenders are from the winter 235s.

As far as feel, the lower offset may cause more tramlining with the increased scrub radius but the positives of being able to fit 285s far outweigh any negatives.

 

I know you know this but I just wanted to clear up what was said because I think you said it wrong. A +38 with a 20mm spacer is equivalent to a +18.

As to the main topic at hand I'm curious to hear peoples feedback on the effects of running a wider front track than rear. Its extremely common but solely for the purposes already stated more so for fitment as well as ease of rotating wheels front to back rather than to change the handling characteristics.

 

Oops, a proof read would do wonders for my clarity.

 

I think we established that low-offset wheels and/or spacers, which move the wheel/tire assembly outward ~20mm are common and have some effect on steering. Perhaps given smooth track the effects are moderate, and only a concern if the car is DD going over typical bumpy roads etc.

What would be great is to hear from users of low-offset wheels and spacers what benefits are derived from wider front track, aside from being able to fit wider tires?

In addition it would be great to hear from those who have used Evo X arms, with or without spacers/low offset wheels, how the change/upgrade affected handling and lap times, cornering speed, etc.
Rumor has it that it improves turn in, what about ultimate grip and ultimate corner speed?

 

i'm not sure that anyone DDing an evo with stiff springs, wide tires, and spacers is concerned about comfort over bumps. I mean even stock an evo sucks over bumps.

besides, spacers are cheap. buy them and test them yourself as almost everyone has a different opinion on relative comfort levels.

 

No issue with comfort, nor spacers or not.
Just with performance:
Does widening front track 10-20mm per side improve cornering speed, lateral grip, on same tire same track, same driver, same car.

That is what I am after learning.

 

yes, but more of a theoretical performance improvement than anything else. a couple % change is track width isn't exactly earth shattering.

 

Griceiv

Thanks for that. Logically it seems like a moderate improvement:
Looking from geometrical side, as engineer, estimate front GC height of some 20" above ground, and now position it in the middle of a bar that is 59.6" wide.
The GC of the Mass will cause leverage by the mass: this leverage translates to increase-decrease of weight distribution on each side of the 59.6" wide track-with ball joints at the end.
Spreading this arm of 59.6 to 60.8" is not going to be earth shuttering change, because the CG height is pretty short from lower control arm position up to CG 20" above ground, maybe some 15". So its 15" above and nearly 30" horizontal distance- wether 29.8" or 30.3" the change is moderate and thus relative weight transfer will be affected very moderately.

I guess I'll leave it alone until the bug itches me enough to seek the last bit, and hope I can feel the difference.

 

If you ever drove a gocart, you would not make a stupid claim like this.

 

I own a 125 shifter kart, yet I made the claim anyways...

evo setup != kart setup

 

I own a 125 TAG kart,
And I don't know why would anybody "call somebody stupid" even if the statement was not exactly technically driven or even appropriate.

It says something about you, far more than about the person you directed the comment to.

To do good on my offer to calculate the weight transfer, let me please fill in the audience that is interested in technical discussion at cordial level, rather than insulting somebody, yet not even offering motivation-
What is 2% difference in weight transfer?
If it results in reduced lap times or additional maximum achievable cornering speed (max G and Velocity), please- bring data in.


Now to my calc:

Assuming the evo weight is 3400lbs, and 80% of that weight is on front axle under braking and 65% under steady state cornering

Assuming front CG at 20

Knowing that the front track is 59.6" for stock Evo (and maintained if stock offset wheels are used such as 17x9.5 Et38

And knowing that Evo X arms result in 60.8" front track with same wheels (1.2" increase)


Under most extreme situation, 1.5G cornering load, at steady state cornering with 65% of total weight on the front axle:

Total weight transfer with stock track is 1107lb

Increasing the track to 60.8" decreases weight transfer to 1085lb

Difference is 22lb out of 1100lb, so barely 2%

For those that are anyway running low-offset wheels and/or spacers to accommodate wider tire (285+, I run 275 no problem on 35mm offset with stock fenders), this upgrade makes totally sense.
They anyway will push the wheels out to clear struts, so by adapting Evo X arms they will benefit form restoring proper geometry and minimizing any scrub-radius, therefore restore steering feel and retain the benefit of pushing wheels out to gain enough space to house large tires.

For us who are OK at 275's, which fit nicely on 35mm offset wheels, its up to individual to decide if the additional expense makes sense.

incidentally, I found set of Evo X arms for $265 shipped, and Robi sells the steering-arm extensions for $250 (or you can make your own for $?).
In addition wide-aftermarket fenders are advised, although stock-fenders have successfully been spaced out to clear wide low-offset tires and such.

Hope this helps you in your choice of setup

I will likely someday upgrade because I feel an Evo with spaced out front fenders and tire/wheel package to fill it looks awesome. Vane, I know, but...I love looking at it.