gdogg

iTrader: (38)

hack job indeed alan!
i'm very intrigued by this modification... as my 1st goal is to drastically improve my cars handling before any major power mods- i'm on the same train of thought a gpatmac... as i'd be a lil concerned about transferring the "load" to another part of the car-

with front/rear strut tower braces and rear sways- i have been getting more comfy with the handling---- this xbrace i wonder how much i can expect...considering my susp is basically stock......


aloha from the summit of *-^-Mauna Kea-^-*

evwoo

I been driving around with the X-Brace and I can tell you what is good and bad from my personal experiences. I think people should have an open mind. firming up the chassis will affect the handling because the suspension will react a lot faster and harder. My STI is riding very stiff and that part I don't like. I am losing traction cornering when the road is bumpy because all wheels are not contacting the road surface. I guess thats the point of adjusting the spring rates and damping for different conditions like a Coilovers setup.

I think if I just throw in a stiffer adjustable rear bar will not solve the problem, wingless wonder. I will just make the rear stiffer to break the traction hence less understeer and more bounce in the back.

By this weekend, I should have the Cusco front brace on and hopefully it will balance out the stiffness in the back. I wish there is some way adjust the stiffness or the X-Brace, but there is none. If the rear is still too stiff, maybe I need to take all the brace off to get the car not so stiff and start over with coilovers and adjustable rear bars.

I watched a video of a WRC Subaru 04 driving against a stock STI and noticed the WRC turn sharper but not very smoothly. It doesn't have the nice arc that the stock STI makes when turning. I think it is also how the steering input and feedback I feel from the steering wheel before and after the X-Brace.

Is that what I should expect from a stiffer setup regardless it's coilovers , stiffer springs and shocks and sway bars? I have not driven another suspension moded STI to feel how it drives. Can someone give me some feedback?

As for the tire pressure on the car. I went back to the stock numbers 36 fr 30 bk and the car understeer a lot less. I tried 39 fr and 33 back and the car bounced around on the fwy and very stiff in the back. I don't know what should be the obtimun tire press for the stock tires.

Wingless Wonder

iTrader: (7)

Yes, it is, but not all coilovers are created equal. Look at what other STi owners are using because some may be stiffer than stock even at the mildest settings, while others are designed with the everyday driver in mind.
If the road is rough, that will be true. Anti-sway bars limit body roll but at the expense of the independent action of the suspension. Like spring rates, if the anti-sway bar is too stiff for the road conditions you will lose grip as the wheels bounce off of surface irregularities.
A WRC car cannot really be compared with a stock STi. WRC is fully race-prepped with full seam welding and roll cage, race suspension, and quick steering rack similar to the Rev-Lab unit.

You might consider testing your car's suspension at the track (road course). While road courses tend to be smoother than the public roads you are driving on, at least it has greater safety designed into it with runoff areas and one-way traffic. It's fun watching those touge runs on import DVDs but most of those roads are closed to public access while being filmed, or they are not public roads in the first place.

Thanks for posting your impressions of the x-brace.

--
0==WW==0
"…axles of evil…" - george w. bush

BLITZSTI

iTrader: (2)

you cant be serious right? last time i checked under the hood my car didnt look like this. sorry to get on your case but a sti street car compared to a wrc sti is... not realistic

evwoo

Thanks for your feedback Wingless Wonder. I will try the test at the track. I was trying to explained the nice rounded turn as I turn the steering wheel. I guess I am trying to say the slip angle is less so I have to turn hard to get smaller incremental response. Maybe that is understeering or the grip of the rear tires do not release evenly untill they break loose. I do noticed the last 2 days my car feel less bouncy due to lower rear tire press. The hotter the air temp I also notice the softer the suspension feels as well as the tires.


BLITZSTI, I think you miss my point. I did not try to compare under the hood of the WRC car vs stock STI. I am not taking about power, but power do affect how the car turn such as breaking the rear wheels to help create over steer. I am trying to say that the WRC cars jerk around during cornering. That maybe due to all the stuff Wingless wonder discuss like Stiff roll cage, body reinforcements, stiffer suspension, quick steering rack as well as alignment.

I noticed better handling cars don't necessarily requires a stiff setup like a Porsche Boxster as well as a Lotus. So what brand of coilovers do you recommend for mostly street driving and some track? I don't want to use pillowball strut tops. I rode in a STI with Tein Flex and it was loud and hard when it hit rough roads. I also don't want to lower the car very much. Is the STI 05 coilovers a good compromise between the stock STI vs a Cusco Zero 2?

evwoo

I am getting close to more balanced stiffening my STI. After adding tha Cusco chassis brace, the car actually bounced less now Maybe the front is stiffer now so the rear doesn't stand out. Still have understeer but not so much to bother me as much. Don't know if I should add the strut brace in the front cos so many people says It is just for looks and add weight. Or go to an adjustable bar in the rear so I can tune out the remaining understeer for the way I corner on medium speed turn, but not getting the stiffness back again in the rear.

I was driving north on 110 fwy to the end in Pasadena and a Z350 catching up to me. I increased my speed to between 90 to 100 around the turns and he could not or dare not keep up my pace. The traffic was very lite. The car can go more but I feel no need to push harder on the street and don't want a ticket. The car corners very safely at that speed. I remembered with my previous WRX wagon, I had a hard time going at 85 around the same turns. Well, different tires, susepension, and sway bars. Wee! thats the fun of getting your car improving from how it feels when I first bought it 2 1/2 months ago.

dc11r

its quite unrealistic to say that you can feel the front as stiffer, or adding this brace to the rear makes you FEEL that the rear is stiffer.

adding the x-brace, actually increases the rigidity of the CABIN, not the trunk area. when you twist a car, the twist happens at the center of the twisting ends.

evwoo

DC1 1r:

In response to you comment is appreciated. I can only express how my body feel how the brace work in relationship to the road surface.

Why did you say it's not possible? when we add a stiffer RSB, don't we feel that the rear end bounced more and feel the road irregularities? The RSB is not total inert of side effects, which is increased of stiffness due to the tortional rigidity.

As for stiffening the area between the rear strut tower and tying that to the seat support at the bottom is located at the rear section of the chassis section. It is right above the rear suspension where it will have the most direct transmission of forces to the car body.If no additional stiffing happens in the front, then, isn't there an imbalance? The maker supposed that X-Brace is to support the rear section to compensate the insufficient stiffness of the car, but if it is over stiffen, ( STI may be different with WRX due to not only body stiifening but also the design of the rear suspension, spring rates, damping trailing arms, sway bars, tire press. etc..

I am just saying in my example of 05 STI, it appears to be too much of a good thing and when I drive straight down the road with surface bumps, the impact of how I feel the front end bounced up vs the rear will tell me which end is stiffer. Since I cannot adjust the spring and damping rates with the stock suspension easily, I can add bandaid fixes instead of throwing a LOT MORE MONEY TO ADDRESS THE PROBLEMS, unless I go to coilovers and adjustable sway bars.

If the cars, WRX, STI or any others are up to our expectations or our choice how it should perform, then we don't need to add anything. Wingless wonder hit on the point that the stock car is Subaru's idea of compromise may not be you idea is the best compriomise how we like our cars handle and drive. That is the beauty of personal style and needs. Even race car driver setup their cars differently for thair taste and style. I have heard of modified suspensions that perform worst than stock, just like adding a BOV may cause the A/F ratio to be off or lean out and make the timing retard.

This is to say if someone cannot hear or smell as sensitive as other does not mean some people cannot feel the difference. I think that is personal. I don't doubt that someone find no benefit to additiion of a strut bar or brace to their Subaru while other insisted they feel a difference. If MFG makes products that doesn't work, who would buy it and why will they take a chance to make the product? I think MFR in good faith, make products that change the way our cars react. We reserve the choice to buy or not buy the product. If we can try the upgrades beforehand, we won't be buying and selling stuff when they don't fit out expectations and style.

dc11r

dont take this as an insult, but i have NO idea what the hell you just said. i guess the makers of the xbrace must have failed to tell you that they tested all sorts of bars during their design process to see if they worked. they WELDED bars between the front struts (to mimic a FSB), another one to mimic the RSB, and even made a subframe X. none of those things changed a thing! so those things are USELESS. ive been in the game for MANY years now, and to everyone that has always argued that they FELT a difference when adding a FSB/RSB, ive always challenged them that they couldnt feel it. that it was all in their head. if i took out a normal style straight through RSB (not the Xbrace) out of someone's car without telling them, they WILL NOT notice the difference. and the same goes if i reverse the process. I can tell a person i installed the STIFFEST RSB in their trunk, and would like their initial impressions. you know what that person would tell me? they will tell me they feel a LITTLE to a BIG difference. its all a placebo.... placebo for MOST cars. FSB/RSBs actually work in some cars, just not most. for BMW E36 3series, i know they actually work.

I know for a fact the X-Brace DOES work for the impreza body, bc it actually "caps" off the cabin. what do i mean by this capping? this is a VERY ROUGH analogy: take a kleenex box, and open up the ends so the box is completely see through. now, close one end. the box is not stiffer than before, but theres still a lot of play. thats kinda how the car is stock. the firewall actually helps cap the front end. now if you close the other side of the box up, you now have a very solid structure. thats what the X-brace does.

now you ask, how about an RSB? open up one of the sides back up, and put a pen through the box near the end so it acts like an RSB... it does absolutely nothing!

Wingless Wonder

iTrader: (7)

And how do you happen to come by this information? Do you have an x-brace installed in your Impreza? This thread was started by someone asking for unbiased impressions of the x-brace but it turned out that he was a vendor trying to promote sales of his product.

Your member profile show that you just registered as a member on this board on August 8th and your only posts are regarding the x-brace. Do you also work at CarLab? You seem to be steering the direction of the conversation, just as Andrew Quillin did when he posted as Lampost77392. If you would like to present your research as 'fact', then come on board i-Club as a registered vendor. I've previously PM'd the details to Andrew.

Why don't you guys just let members post their own impressions? They may not be chassis experts but their seat of the pants experiences should count for something. Or are their favorable impressions of the x-brace also a placebo?

--
0==WW==0
"…axles of evil…" - george w. bush

dc11r

i dont work for the carlab. but ive worked in the industry for a while, and i know how things work. i mean, it doesnt take a rocket scientist to figure out that RSBs dont work in a chassis like the Impreza's.

evwoo

Well. I guess cusco as well as many venders don't know what they are doing as to sway bars and all the clients who bought them cannot feel or experience any improvement or differences. I highly doubt that. I am with Wingless Wonder, I am new on this board but I have driven many cars and have owned WRX Wagon, Audi S4 Avant, BMW M3(older version) as well 911S, Lotus Europa. I am not a young person at 50 but still feel capable to drive well. I have been on the tracks many of you never been on such as the old Riverside raceways, Sears Point, Lime Rock, Laguna Seca, Macau, and even Nurg in Germany. I was a very active member of BMWCCA and driven Christopher Cross's M1, M6, 2002 Turbo, Steve Macqueen's 930 Turbo, 360 Modena in HK. I have even driven Latest STI spec c in HK.

It's just like in Hi End Audio that people says they cannot hear any difference since all digital as just 0 and 1. I have been thru so many debate on issues in audio and now find the same closed minded people around. That is the same saying all coilovers feels the same even if they have the different spring rates, rebound and compression in shocks. Everything has some effect, just if you can detected it or not. Our body is even more sensitive than test instruments. Just like total harmonic distortion same for 2 picece of amplifier and yet they sound so different. Even double blind test detect changes that I conducted. Sorry to digress, just cannot believe RSB doesn't make changes to Impreza or STI. I did not say the changes are for the better. In fact who is to say what is better? I already said each person has their own preference and as we improve our skills and experience, we become more sensitive to changes quicker. The key is to change one variable at a time and test it over different conditions. Sometimes we need to go backwards to go forward if changes do not meet our expections.

dc11r

i thought you abbreviated RSB as rear STRUT bar. not rear sway bar.

SWAY bars and STRUT bars are 2 COMPLETELY DIFFERENT things accomplishing DIFFERENT goals.

the X-brace is a style of STRUT BAR so-to-speak

a sway bar, you feel the difference night and day, and alters the handling completely.


please get your terminology correct. i too have driven an STi spec C in HK, as well as the 360, as well as a zonda, as well as a GT3 cup, Ferrari F50... blah blah.

Silver Mojo

iTrader: (9)

Evil

evwoo

dc11r:

I practiced as a mechanical engineer prior and consult for Hi-End Mountain Bike companies on suspensions designs as well as suspension bridges . I think I do have a little experience in structural and spring effects. As for driving experience, thats great that you have a lot, but that does not take away my experience.

By the way I picked up RSB from this forum. I did not invent it. You are the one who jump all over my experience and assumed RSB as rear strut bar and not rear sway bar . Here' an exerpt from someone's whose been posting in this forum.



""Yeah, I understand the oversteer and understeer effects of larger and smaller swaybars. I have a Cusco 22mm adjustable RSB. I also understand that you must find a balance in order for your car to handle neutrally. What I don't understand (still... I must be an idiot) very well is why we don't increase the sizes of both front and rear bars once we have found that balance.

BAN SUVS: Okay, unfortunately I have a WRX so your advice wasn't dead on but I still understand what you're saying. You said that a larger (than the stock 22mm on my GGA ) front bar would make my car hang with the big boys. Do you mean that it will increase grip? Or will it just make my car feel more "crisp" (make it respond more quickly to my inputs).

Also, everyone keeps mentioning that as you get bigger SBs, your get closer to having a solid suspension. I think I'm missing something because I believe that a solid suspension would be ideal for cornering on a perfectly smooth surface.

SO. Once again, is the only drawback of having a large diameter SB that hitting a bump in the road while cornering at or near the limit of adhesion will cause a total lack of control?

BTW, thank you all for your responses especially moss and I LOVE SUVS.

EDIT: I don't know why the hell I wrote that the GGA has a 22mm FSB because it has 20mm stock bar. My bad.""