Thanks Matt

That explains enough for me to be satisfied with what BS/BS Mod is.

Whilst I appreciate the advantages to be gained now I also think that I want my car to be "forgiving" until I am a better driver and thus I will leave it on the mod list for a later date.

Nice jibe at SB. Will we ever let him forget about his "fuel surge" moment?

Matt

[Edited by Molds - 12/5/2002 10:08:39 AM]

 

Reading some other posts I have seen mention of a bumpsteer mod and then geometry setup.

What is bumpsteer and what kind of mod is used to correct it?

Ta

M

 

Molds - check out this link to Powerstation as they are the main place offering this mod.

I had it done a month ago and the diffrence to the handling of the car is incredible. It has virtually eliminated understeer, made the car more confident on high speed cornering and generally feels sharper. I thoroughly recommend it!

Paul

 

And could do a search for Bump Steer Mod - loads of hits returned

 

IMO bumpsteer is the phantom mod you'll never really learn much about or understand. I tried to research it and understand it but couldn't get my head round it (i'm a simpleton when it comes to suspension, steering, etc). Its one of these things you just have to do. So, with my £120ish pounds in tow I went to Falkland Performance who did the bumpsteer mod and set up the geometry. Had I been misled.....no

The car really is that different, far more sporty and planted feeling with much better turn in and more predictable all round. I noticed is on the very first corner and just 'd from ear to ear.

 

What is actually altered, adjusted? Springs, struts?

So, understeer - where you turn into a corner but the car doesnt turn in enough?

I know I am being a Muppet but as I have never been on a track, and am a bit of a chicken, I'm just trying to understand these things...

 

Correct, understeer is where you turn in and the car just ploughs on

As I said, you'll be doing well to understand what bumpsteer is all about just trust me and the others that it is worth it. Afterwards you'll be amazed how much nimbler and grippier the car feels.

 

I think in that case I can say I have experienced this once. I have a mate with a CTR. He took me for a blast and then first time he saw my Scoob I of course returned the courtesy.

At then end of his road is a roundabout. I know a circle doesn’t have sides as such but imagine one of the kind of rectangular roundabouts. It goes all the way around but is a bit shorted on two "side".

Not wanting to disappoint we went up to the roundabout and you can see a good mile+ in each direction. No traffic so I tootle back down towards his turning. Then coming back on our selves I take a fast approach to the roundabout. Round we go, round we go, and round we go, oooooh fantastic, then on the last "side" I got the old Capri syndrome. Front wheel pointing around the roundabout but we start drifting out. I let up a bit on the power and it nipped back into order.

I was a bit disappointed because we managed a circuit at about the same speed in the CTR without any complaint. To be fair he is a better driver than me but still...my "invincible" Scoob (tongue in cheek).

So I presume that was understeer?

Thing is, how come I can give someone £120 and they make it like a new car? Surely if it requires minor mods to achieve the "new car" then it would come like that out of the box? Is there as downside to the bumpsteer mod?

Sorry to whiter on. I am just interested. At least SB not posting in General I may not (touch wood) get flamed for going to fast on the roundabout because no one else does eh?!

 

Nah - I agree in that roundabouts are often (relatively) safe to go quickly around although only the flat ones with no objects on them so you can see in all directions and all the exits.

I had my geometry aligned with 4 wheel laser alignment kit and it made the handling a lot better (much less understeer although still a bit when pushing harder). I think it's generally the case that people recommend you getting this done first (it's cheaper!). Get the wheels set to the "Prodrive" settings as per the SIDC FAQ) and then get the bumpsteer mod done if you want almost all the understeer removed. I think they re-align the geometry after doing it as obviously it will have changed.

Also, you can reduce understeer by changing (improving ) your driving technique!

 

Kenny,

Understanding the BSM is not that difficult? (well the simple version anyway). On the old shape cars, when the front suspension is loaded up, the front wheels splay outwards (toe out). If this happens when you are cornering (likely) then this will induce understeer (where the nose runs wide). This is very frustrating as it limits the speed you can carry through the corner and you have to wait longer to get on the power on the exit also. It also ruins the "feel" you get throught the front end if it is not "planted".

The BSM moves the steering rack down which stops the static toe from changing when the front suspension is loaded up (dynamic toe). This gives you more grip and more feel which equals a much more satisfying (and better gripping/faster) car to drive.

It's usually also done with a proper 4 wheel alignment and Geometry setup also, which by itself, can transform a Subaru (or indeed any car) anyway

The "downside" of the mod is it means the car is a bit more "tail happy" and less forgiving (which to me is actually an advantage). The reason they used to come out of the factory like this is because an understeering car is easier to drive and mass market manufacturers don't want a car getting a reputation for being difficult to drive, which can damage sales as the car is marketed as the "average everyday person's sports car". Having said that, from the MY01 WRX, most of the Bump Steer has been elimiated from the car's setup as standard

[muppet mode]Kenny, I'm surprised you like the mod TBH, as it can increase cornering grip which is likely to invoke fuel surge [/muppet mode].

Hope this helps,

Ta,

Matt

 

I actually loved the bumpsteer because it made the car more tail happy and tricky to drive. Its a lot more like the VTS in terms of its balance and poise through the bends and as a result I'm a lot more happy with it. As I said countless times in the 'fuel surge' thread having come from one of the most tail happy hatches on the market I find it very hard to believe I backed off - hence the fuel surge + crap/badly worn tires theory.

The scooby got tail happy in the wet a few days ago and I corrected it without even realising - it was almost second nature. It was only half a mile down the road when I reflected on it that I grinned and realised how much fun it actually was

I think for me to have understood the bumpsteer mod I'd have actually had to get under the car and watch as they did it, which I didn't

Downside: I'm told it can increase tyre wear and dramatically so if you track the car.

 

Molds,

It doesn't turn the car into an unforgiving, knife edge experience or anything, just makes it less unforgiving. It's still one of the most benign fast cars I've driven after the BSM, just more planted and direct.

Kenny,

IIRC, the BSM actually reduces the wear to your tyres as you do a lot less understeering and because of that, less inside tyre scrabble. You may be getting it confused with the Prodrive geometry settings which takle the problem by changing the geometry to try and compensate for the designed in BS, which is a compromise and does increase tyre wear, especially on the inside edges of the front tyres. The BMS doesn't have this problem because the toe is set at the optimium setting all the time.

Matt

 

I can stop worrying about my Toyo's so much now