Back-end Wiggle at High Speed: how can I eliminate?
 

I passed another car while traveling 95mph (on a 2-lane highway) earlier today. Right as I steered my car back into my lane the back end of the car wiggled a little--and felt as if it was riding on air. In other words, it felt untight and shakey and unsafe. How can I correct this? I want to be able to change lanes at 95 and the backend to feel SOLID and not like it's gonna slip out from under me. For one, I do not have the 'wing' as it is a RS. Would having the 'wing' resolve this problem, or even make a difference in this situation? OR, is should this be corrected with a suspension modification (e.g., a brace or sway bar?). FYI: I recently had the car aligned to:
Front: -2.0 camber
Rear: -1.0 camber

Would further tweaking my alignment resolve this problem?

Please help!

Thanks

You probably have 0 toe in the back, which will cause a 'wiggle' when you change lanes.

was it a quick or casual lane change?

A little quicker than "casual" but I wouldn't characterize it as "quick".

Toe, huh? That's interesting. I'll have to check into that. What rear toe setting do you recommend, and how much additional tire ware should I expect, if any?

Thanks.

I try to keep mine at .5 toe in on the street, which is almost nothing. I think the Evos stock come with @1in toe in, which is why you feel 'loose' when changing lanes now that you have none.

Pardon my ignorance, but when we're talking about .5 toe. That's POSITIVE .5 (as opposed to negative), right?

As of now, my rear toe is:
0.10: left
0.13: right

So, .5 won't significantly increase tire wear, but will act to eliminate the looseness?

Thanks,
Chris

Get a VORTEX GENERATOR! They help keep the car in the direction your steering. I dont know about the camber and stuff like that.

I'd say invest int the wing from mitsu, I've changed lanes "quickly" in the triple digits and the car is solid. But the reason I say the mitsu one is because my friend has an RS and he bought one that is a replica for stock and his center blade flexes like the sti wing.

Need wing. I have noticed the same thing at around ~100mph.

I would say get a factory wing. It should provide enough downforce for highway driving plus make it more stable while changing lanes.... think of what the feathers do for a dart or arrow......

... and ya like the guy above said ... dont get a knock off fiberglass replica... they are junk . leave those for the guys with ralli-arts :eek: :cool: :eek:
lol j/k about the ralliart comment... all in fun...

Ok, good advice guys. But, since I've grown to prefer my rearend wingless, is there anything else I can do to resolve the problem, or is the wing my only solution? Also, assuming there is no other solution and I decide to get the wing, I'm curious regarding how much of a difference the wing will make? Will it be like night and day? Thanks again...

What about one of those under-the-car plates that prevents airflow from collecting underneath the rear of the car??? Would that provide a similar effect without needing a wing? Thanks.

For sure it makes a difference with a wing. I had to do a emergency avoidance on the freeway at night when I spotted a storage box in the middle of my lane. Did the lane change, quick flick and the car was stable as a rock. Can't say the same for the ones after me. Saw white (headlights), red (taillights, White........ people spinning all over the place. The wing should start working around 60mph and up maybe higher? 80+
I've heard the undertray from Vishnu works too. Check their website.
The other thing you can check might be your camber is too much? 2 degrees. That's what I have on my racecar for the track to turn. So maybe dial it back?

How modded is your car? do you have your suspension in full stiff? there are many factors so......

Good luck!

get a good alignment and slow down...

otherwise I would consider the wing. I have never had that problem, I run 0 toe in the front and rear.

Sometimes this alignment might cause the car to wander or track the grooves in the pavement. Nothing you can do to prevent it, just get used to id.

Yeah, I don't wanna put up that wing. I like the wingless look too. I think that evo 9 bumper might work. and put more weight in the rear. I was thinking about relocating battery to rear and modding the rear bumper so it will let out the air under neath. that USDM bumper is totally not aero dynamic.