[hyperion]

All,

This is a question that we won't be able to answer for a few weeks or months, but I am already wondering what the differences between the US, UK, and JDM suspensions on the STi are. What baffles me is that early reviews of the JDM STi claimed that, for once, Subaru had dialed out the understeer from the car. I remember the drivers gushing about how great the turn-in was, even with the DCCD in the auto position. The car was easy to modulate from understeer to oversteer with the throttle. Yes! It was music to my ears.

Now, I've seen two articles by major magazines (one US, one UK) both noting that the car understeers, especially in slow corners. This is distressing to me to say the least. This will make the (stock) car less competitive at the autocross and frustrating at the track. Plowing is for tractors. Don't tell me I have to buy a Mitsubishi to get a well balanced car! Horrors.

Ah, but I don't want to get into a debate about what is/isn't acceptable understeer. I'd just like to know the exact differences between the US and JDM STi suspensions. Springs? Dampers? Roll bars? Geometry/alignment? Ride height? I'd love to hear that the US only has a front roll bar that's 1mm bigger--an easy fix. But if it's spring rate or something else....it's going to a harder (and less warranty-friendly) to set things straight.

And just to go down on the record, I don't think there will be weight distribution differences between the two models. The 2.5 block isn't much heavier, and if there is more crash reinforcement, then it has to be in the back as well. I bet the weight distribution is nearly identical.

If anyone has some concrete info on this front, I would be grateful to know.

-ch

 

[hatchy]

Don't know the difference, but in the US, many manufactures dial in understeer because it is "safer".

 

[amdmaxx]

.93 g tells me that it doesnt understeer a lot.. lol.. They did it for safety, US drivers are BAD..

 

[darwood]

.93 g tells me that it doesnt understeer a lot.. lol.. They did it for safety, US drivers are BAD..

I'm not sure it's so much the drivers being worse in the US as it is the lawyers are worse. I had two German roommates who were really bad drivers. I mean who shifts at 2k rpms? The other one was so busy talking while driving he constantly had to slam on the brakes to avoid the car in front of him.

 

[Guest]

Re: STI possibly being bought by dealers salesman!!

I agree, this needs to be researched, or someone in the know should set the record straight. This is really important!

 

[hyperion]

I agree. I guess what I am saying is that as soon as I get my car, I'll be measuring the roll bar diameters and getting a read on the alignment. Hopefully the spring rates and damper models will be available from Subaru. Then we just need someone in Japan to do the same so we can get a good comparison.

When I go to get my car dynoed, I will attempt to get its corner weights with 1/2 a tank of gas. This should also give us a data point with which to compare.

The JDM STi has been out for a while, and the Japanese press love technical details like this stuff. Does anyone have pointers to info on that car?

-ch

 

[hyperion]

There were some people claiming that the US STi was coming with the Spec C suspension components. Does anyone know the source of this information? And if true, what exactly does that mean?

-ch

 

[hyperion]

Here's a start:

http://www.subaru.co.jp/impreza/sedan/09/09_02.html

Weight: 3174 (about 90lbs lighter than US)

I think this was posted before, but I thought it would be worth it to repeat.

-ch

 

[darwood]

If you read over on http://www.i-club.com some of the Hawaii guys have posted their impressions of the STi. It's a good read. Pretty much one guy states that it has understeer on throttle and oversteer off throttle.

 

[dcgray2]

Todays lesson:

Don't take your foot off that throttle!

 

[Agent Chobos]

There were some people claiming that the US STi was coming with the Spec C suspension components. Does anyone know the source of this information? And if true, what exactly does that mean?

-ch

That claim comes from the fact that our wheelbase is 100 inches, supposedly 15 mm longer than the "normal" STi. I think the claim was something to the effect that we'll be getting the Spec C geometry, but the components themselves -- i.e. the exact same spring & strut specs -- I highly doubt.

 

[hyperion]

That claim comes from the fact that our wheelbase is 100 inches, supposedly 15 mm longer than the "normal" STi. I think the claim was something to the effect that we'll be getting the Spec C geometry , but the components themselves -- i.e. the exact same spring & strut specs -- I highly doubt.

Damn. Well, let's try to track down some part numbers between the two cars and compare. It would be a shame to have to replace the whole suspension...

(maybe some of the dealers on the list who are taking orders can also get us at-cost parts from Japan. Anyone? Murley?)

Heh.

-ch

 

[Rufus3383]

I was cruising the 350Z board and found the following. As you may or may not know, the 350z has a problem with understeer. Which for those who want to track it is a problem. Well, it turns out that there is now a NISMO suspension kit which "taa!daa!" cures that problem and with it installed the car handles like a Porsche, only better.

There was some speculation on why Nissan would know all along how to cure the problem, yet send over a "sports" car with pronounced "push".
The one word answer would be "Lawyers".

I don't know the mechanical reason why the STI reviewers indicated that the car understeers significantly, but it may well be for the same reason as the 350z was sent over in that condition. So, perhaps, (we can hope) there will be a straightforward solution to the problem as some type of handling kit.

 

[JJ]

I don't think a full suspension change in the STi is nessecary. Maybe just change bushings, and the anti-roll bars, and most importantly get a decent performance alignment.

They may be Spec-C struts and springs with the bushings and the anti-roll bars just being toned down a notch.

 

[amdmaxx]

99.5 percent of my driving gonna be on the streets, non-racing type..
I want a compliant suspension.. I'll the stock one please..

 

[Rufus3383]

How do I post these great 1500KB pictures?

99.5 percent of my driving gonna be on the streets, non-racing type..
I want a compliant suspension.. I'll the stock one please..

The funny thing about the 350Z suspension mods are that they don't make the car significantly less comfortable to ride in. The guy who installed the "Nismo S suspension kit" was a driving instructor who said it felt like the car "lost 500 lbs" once he had it installed, yet he claims his wife can't tell the difference in ride.

He wrote a letter to Nissan telling them off. That after you pay a premium to by the "track" model you shouldn't have to get another mod to get the performance you were lead to believe you were getting.