GrimmSpeed Strut Tower Brace - Review

[Gopherboy6956]

Originally Posted by fatoni

since you have no doubt, i would love to hear why. i have no idea how a strut tower bar would add understeer

Sure - stiffening up the front or rear will cause that end to become more prone to sliding - If you stiffen up the rear, it will cause more oversteer. Stiffen up the front (with springs, strut bars, sway bars) will cause more understeer (pushing).

Now, this bar caused understeer may only be noticeable to those with the car set pretty neutral in the first place. I would imagine on a 100% stock vehicle, the bar would only lessen some of the natural oversteer.

Originally Posted by BRZTimeTrials

Is everything else about your car's suspension stock?

Now - I have Tarmac 0 coilovers, whiteline rear camber bushings, and of course wheels and tires - which should be relevant in the conversation sitting at 17x8 with Dunlop ZII's 245/40.

I also have my alignment set at -1.5 Front, -2.5 rear. I am going to flip that around for next season and see how it goes. Should help balance everything out just changing that.

[Frost]

Originally Posted by Gopherboy6956

Well, in the course of my research, I read an article in Car and Driver on a guy who runs a K&C Machine for lots of motorsports teams, and he was quoted as saying something along the lines of "...he has never seen an aftermarket strut bar provide a measurable handling difference."

Nice write up - is this C&D article online? I've used rear strut bars on a MR2 and to me it made a very noticeable difference (I wanted more oversteer for AutoX - exactly like what you needed) compared to without PROVIDED it was installed properly.

[Gopherboy6956]

Originally Posted by Frost

Nice write up - is this C&D article online? I've used rear strut bars on a MR2 and to me it made a very noticeable difference (I wanted more oversteer for AutoX - exactly like what you needed) compared to without PROVIDED it was installed properly.

Sure is - right here:
http://www.caranddriver.com/features...g-it-tech-dept

[fatoni]

Originally Posted by Gopherboy6956

Sure - stiffening up the front or rear will cause that end to become more prone to sliding - If you stiffen up the rear, it will cause more oversteer. Stiffen up the front (with springs, strut bars, sway bars) will cause more understeer (pushing).

Now, this bar caused understeer may only be noticeable to those with the car set pretty neutral in the first place. I would imagine on a 100% stock vehicle, the bar would only lessen some of the natural oversteer.



No - I have Tarmac 0 coilovers, whiteline rear camber bushings, and of course wheels and tires - which should be relevant in the conversation sitting at 17x8 with Dunlop ZII's 245/40.

I also have my alignment set at -1.5 Front, -2.5 rear. I am going to flip that around for next season and see how it goes. Should help balance everything out just changing that.

i dont know if thats how it works. or at least its not a very inclusive description of grip. if that were the case, why would manufacturers spend millions trying to improve chassis rigidity when all it does is reduce grip? i get that messing with the front roll couple will change the nature of the car but a strut bar isnt going to change that. the bar was measured to reduce deflection by up to a couple hair thicknesses. i could see it maybe sharpening response but i still havent really heard an explanation as to how it effects understeer.

[Gopherboy6956]

Originally Posted by fatoni

i dont know if thats how it works. or at least its not a very inclusive description of grip. if that were the case, why would manufacturers spend millions trying to improve chassis rigidity when all it does is reduce grip? i get that messing with the front roll couple will change the nature of the car but a strut bar isnt going to change that. the bar was measured to reduce deflection by up to a couple hair thicknesses. i could see it maybe sharpening response but i still havent really heard an explanation as to how it effects understeer.

Well - i'm not going to lay out the physics on understeer and oversteer - that's what wikipedia is for. [ame="http://en.wikipedia.org/wiki/Understeer_and_oversteer"]Understeer and oversteer - Wikipedia, the free encyclopedia[/ame]

And Here's your explanation on how strut bars affect understeer, keeping in mind understeer is a direct effect of a stiff front end of the chassis:
http://lmgtfy.com/?q=How+does+a+stru...ect+understeer

With my current setup, which is VERY close to neutral or even a little biased to understeer as is(because I'd rather keep it safe on the road course), this bar increases the tendency to of my vehicle to understeer.

If you add this bar ONLY to any car, it will either increase the amount of understeer or decrease the amount of oversteer to that vehicle. The vehicle's current setup will dictate the outcome - so like I said, on the stock BRZ which is biased towards oversteer, there will likely not be any major change - because the car will just end up being more neutral.

But, if you already have stiffer suspension components, a camber adjustment, or larger sway bars - the outcome could be noticeable - which it is for me.

[fatoni]

Originally Posted by Gopherboy6956

Well - i'm not going to lay out the physics on understeer and oversteer - that's what wikipedia is for. Understeer and oversteer - Wikipedia, the free encyclopedia

And Here's your explanation on how strut bars affect understeer, keeping in mind understeer is a direct effect of a stiff front end of the chassis:
http://lmgtfy.com/?q=How+does+a+stru...ect+understeer

With my current setup, which is VERY close to neutral or even a little biased to understeer as is(because I'd rather keep it safe on the road course), this bar increases the tendency to of my vehicle to understeer.

If you add this bar ONLY to any car, it will either increase the amount of understeer or decrease the amount of oversteer to that vehicle. The vehicle's current setup will dictate the outcome - so like I said, on the stock BRZ which is biased towards oversteer, there will likely not be any major change - because the car will just end up being more neutral.

But, if you already have stiffer suspension components, a camber adjustment, or larger sway bars - the outcome could be noticeable - which it is for me.

here are my suggestion: before you try to get all cute with that google search, you look at the results. in the first two link, it says a strut bar eliminates weight transfer which shows they dont know what they are talking about. in the second link they imply that flex reduces grip so a strut bar would increase front end grip. its not hard to come to the conclusion that that means less understeer. they later go on to say a rear strut bar reduces understeer so i think that kinda shows they dont know what they are talking about. the rest of the links are just a bunch of forums that are typically having the same conversation we are having and coming to all sorts of random conclusion.

you are trying to convince me that somehow a strut tower bar generates understeer. i have a suspicion that you have been avoiding giving me an explanation because you dont understand the topic at hand. if im wrong im sorry but i would love to hear your reasioning.

[Gopherboy6956]

Originally Posted by fatoni

here are my suggestion: before you try to get all cute with that google search, you look at the results. in the first two link, it says a strut bar eliminates weight transfer which shows they dont know what they are talking about. in the second link they imply that flex reduces grip so a strut bar would increase front end grip. its not hard to come to the conclusion that that means less understeer. they later go on to say a rear strut bar reduces understeer so i think that kinda shows they dont know what they are talking about. the rest of the links are just a bunch of forums that are typically having the same conversation we are having and coming to all sorts of random conclusion.

you are trying to convince me that somehow a strut tower bar generates understeer. i have a suspicion that you have been avoiding giving me an explanation because you dont understand the topic at hand. if im wrong im sorry but i would love to hear your reasioning.

Try it and let me know.

[fatoni]

Originally Posted by Gopherboy6956

Try it and let me know.

im not doubting your experiences. what im questioning is the way you state your opinion as fact when its based on zero quantitative data and half opinions you tried to spoon feed me was the opposite of what you were trying to prove. suggesting things like offsetting a strut bar with a sway bar is probably not an appropriate solution. and i imagine that with all your mods, its just the nature of the car youve built. cars that are stable at a road course typically deal with significant understeer in an auto x setting strut bar or not.

[Gopherboy6956]

Originally Posted by fatoni

im not doubting your experiences. what im questioning is the way you state your opinion as fact when its based on zero quantitative data and half opinions you tried to spoon feed me was the opposite of what you were trying to prove. suggesting things like offsetting a strut bar with a sway bar is probably not an appropriate solution. and i imagine that with all your mods, its just the nature of the car youve built. cars that are stable at a road course typically deal with significant understeer in an auto x setting strut bar or not.

Well - I don't care anymore - I don't want to spend time trying to explain it.
However, what I know for fact is - Tower bar went on, car as currently setup understeers.

To fix, i'm going to re-align and if that doesn't work, i'll get a thicker rear sway.

[finch1750]

Originally Posted by Gopherboy6956

Well - I don't care anymore - I don't want to spend time trying to explain it.
However, what I know for fact is - Tower bar went on, car as currently setup understeers.

To fix, i'm going to re-align and if that doesn't work, i'll get a thicker rear sway.

Fwiw all his complaints in his last post you had included in your posts from the beggining (set up may vary, can be changed multiple ways, neutral track setup understeers in autox)

[Grip Ronin]

i learned the value of a solid front bar when i put a non-adjustable 3 point on my other car. huge difference. i believe a strut bar only induces initial understeer because your driving style maybe be use to feeling the front flex at the beginning of the turn. throughout the turn you should notice increased grip and response because both tires are being planted much firmer and equally then before the rigidity upgrade. my 2c

[Willis85]

Installed mine last weekend and took it for a spirited drive througha little local Canyon network and it was a big change but enough to know that when I was pusing it the front was a lot more locked in.

Really like the product, wish I could get more grimmspeed products for my 86.

[brillo]

for those with stock suspension on the FR-S, did the bar make the car feel more neutral?

[BlackyRose]

^^^^

In for this also. I am staying all stock and dont track or autox my car. Thoughts??