good review, can't wait to see the vid.

 

Het guys, sorry I was on a business trip yesterday traveling to Ohio so I couldnt chime in.

Guys I was shocked! And a little upset! I too love my evo and would never own a Suby but its very impressive. I ran a 1:41.9 with the spare tire and jack in trunk and with my friend riding shotgun. AND my brakes really need some help. So dont fret, IMHO, the EVO is still faster but the Suby had a much better mid corner grip.

The evo upon entry would be rock solid, turn in, and the rear would rotate and point toward the apex. This is the time to get on the gas. But this is where the problems start. This is where the EVO really starts to roll and a lot of force gets transfered to the rear outside tire. I believe this is where the problem lies. The rear of the evo actually toes in upon compression causing a push. Thats why the rear bump steer kit is so important. That alone I think will transform the evo. Martin and I would like to test that.

So when the evo perfectly starts to rotate and points to the apex and you get on the gas, it starts to 4 wheel slide and push where the Suby gets a movin.

Both cars were very impressive! Martin and I were passing Porsche Turbos and a Lotus Exige S while we were dukein it out. Both cars had Bridgestones, mine had new reo1r's and the Sti had the previous version (reo7o's?) So pretty even there.

But above all, that was one of the most fun track days Ive had and Martin is no slouch!!!

I think a diff or diff controller could help, but not address the real problem with the rear geometry. Not to mention the cost difference. But we hope to test all of it, step by step and give you guys the real info. The goal is to develop a bolt on kit that will give big results. Expect quality as you do with anything from AMS.

 

Yes, when still on stock suspension last year, this was always my biggest problem. I'd enter well and mid-corner well, but when I felt it was time to get back on the gas, I'd push wide with a 4-wheel slide. That doesn't happen anymore with my Gerrard Ohlins, but it was definitely a problem on the stock stuff with tons of body roll.

 

Some months back I watched a small video made by Whiteline where they test a IX and a MY06 STi, both cars instrumented and the test results showed exactly the same behavior you guys are talking about. The STi showed more grip, and like Warr and Martin said, when it was time to get back on the gas at mid corner the EVO would push and slide more than the STi, still the EVO lapped slightly faster than the STi.
When I get home I'll try to upload the video or post a link to it, so you guys can compare Whiteline's findings to what you guys have experienced.

 

Interesting review. Might not be very relevant but my old WRX on coilovers, corner weighted, rear sway bar, azenis tires, FR strut bars, steering rack bushings, etc... under steered in mid-corner quite a bit. Nothing that could not be solved by pumping the throttle to shift the car but certainly not like my Evo. The Evo is so much sharper at the turns with just Tanabe Springs as a modification. I do have to admit that my old WRX was faster at the turns than my Evo right now, mainly due to the crappy tires the previous owner put on the Evo. Must...find...tires...

 

I have an '03 -> 50%/50% distribution with a limited slip rear and open diff in front. I LOVE this setup, and is the reason why I don't want to get a new evo. I get fantastic rotation in the corners. When I get on the gas mid-corner, it feels like it just grabs the road more. This setup has worked well for very stable and predictable throttle steering. In my opinion, +1 for viscous coupled centers and open front diffs!

Great review! But it kinda makes me mad.

 

Well, I think there are many band aid fixes available. Anything increasing overall stiffness will make it better but not solve the real issue. IMHO, its a geometry issue in the rear causing a mid corner push. Remember, when you get on the gas, even a little bit, you transfer weight to the rear. The more you compress the rear tire, the more it toes in, the more it understeers.

There are many negatives to just making the car stiffer. But the fastest car will be a soft one with proper geometry through its suspension travel. You dont want to be so stiff that when you hit a rumble strip it throughs the car off line.

We're going to try to prove that stiff isnt the only way to go fast. Step by step we'll keep you guys updated.

 

Having the open front diff certainly does not contribute to your rotation. The later Evos with FLSD and ACD will perform far better coming out of turns than with the open front diff. That's one of the best upgrades you can do on an 03/04 for racing purpose - FLSD.

 

Seeing that none of the Evos that have come to the US have had AYC (Active Yaw Control), and also seeing that STis come with an manually adjustable torque transfer capability, could this be why the EVO seems to push more that the STI.

I have a feeling that a JDM Evo vs STI would yield slightly different driver opinions.

Just my noobie 2cents.

T.

 

Sigh ... just one more confirmation of what I really already know, but my wallet refuses to admit, time to upgrade the suspension on my little beastie.

Thanks for the info Martin and Lawrence.

l8r)

 

The yaw control is not relevant to torque split. The ACD handles the locking of the center diff, but it's still always a 50/50 torque split. We don't have a way to change that without changing the center diff (or maybe an ACD controller? not sure).

 

We're going to do some rear bump steer measurements and see what it is on a stock car. Whiteline has bump steer correction kit that we carry, we'll see what that does upon installation. We should have some real world track results with some basic suspension modifications thanks to Lawrence!

 

I'm still learning so excuse my ignorance. I was under the impression that AYC controlled the transfer of torque on the rear from side to side.
And this would improve handling through a corner by shifting power to the rear outer wheel and therefore improving turn-in at the front.

Thanks.

 

yes, but you mentioned this in reference to the STI ability to control torque front-to-rear, not side-to-side. AYC does attempt to split torque between the rear axles, but it can't change that only 50% gets sent to the rear (and front). Here's a blurb I found when searching:

"Competition oriented models of the Lancer Evolution do not include the AYC/S-AYC system, as it is less durable and heavier than a standard mechanical limited slip differential. Also, in the hands of a professional race driver, the benefits of SAYC are negligible."

 

HAHA got you. All the fancy acronyms are just basically saying...."here you go you crappy driver". hehe

Thanks for the info.