How does ET affect a car?

[Kit]

I was wondering because i'm told by all the vauxhall/ford boys to stick within the tolerances recommended by the manufacturer, then the vw/bmw nuts that I know say that it doesn't mean much at all?

I've been told everything from my wheels will snap off to it'll make no difference at all since lowering has more of an effect on handling and i'll just need to get the archs rolled and pulled, so i'm asking here because there are far more well informed people to be fair.


So does anyone know exactly what having an ET much lower than recommended does to a car, i'm very reluctant to buy a set of Azev C and a set of adapters until I know since it brings it down to about ET 16 when the recommended is ET49

[MJG]

Not normally a problem unless you go mental, that offset shouldn't be an issue.

[superclarkey]

Yeah they are right, Vauxhall and ford use shit beaings that fall apart under normal loads, giving them cool offset wheels would damage the beaings quicker then normal.

but we all know they run gay offset rims because they are infact gay.

On a Nissan/Toyota they run proper bearings so can run what ever you like within reason

[Kit]

Cheers for the info!

I've got to put a gay ass Vauxhall on the road for a bit so I can finally start saving for drifto but i'll make the best of it, always liked the Calibra anyway.

I don't suppose anyone knows someone who can fab up some suitable adapters?

[Bladerider]

Lower ET means its quicker

J.

[Perriss21]

How does E.T affect a car?


he doesn't really care about car's he has his own spaceship

[Kit]

Originally Posted by Bladerider

Lower ET means its quicker

J.

I hear if I lower my ET by 30 I get about +10 bhp, depending on how much dish my rims have got?

Originally Posted by Perriss21

How does E.T affect a car?


he doesn't really care about car's he has his own spaceship

ha....ha.....ha...

[Bladerider]

Nope,

its subtler than that, lower et by 1 means many more powers than 10

J.

[Daddy_D]

Hey I thought in the technical section we will not joke around I think offset does affect the handling but it depends by a lot of things. How light the wheels you are changing to are, what the camber will be...etc. However you will probably hardly notice it. When I fitted wheels from BMW 5 series the car handled differently, but then again so it does if you put 18" compared to the original 15".

[Captain Muppet]

The MX5OC get all twitchy if anyone goes more than 5mm away from standard. They really hate my 30mm spacers, and fuck knows how they'll cope with the ET-6 action that'll be going on the front of my car soon.

[steve.82]

Lower ET changes the scrub radius, and as most road cars have zero scrub as far as I know, lower offset will make it twitchy and a bit jumpy over imperfect surfaces, but more feedback mid corner.

I think quite a few FWD cars run -ve scrub, but we won't talk about them...

[howler]

I guess it must make a difference to handling as you are altering the overall track of the car?

Although I expect different tyres with more rubber on the road makes more of a noticible difference?

[Vova]

Originally Posted by steve.82

Lower ET changes the scrub radius, and as most road cars have zero scrub as far as I know, lower offset will make it twitchy and a bit jumpy over imperfect surfaces, but more feedback mid corner.

I think quite a few FWD cars run -ve scrub, but we won't talk about them...

Very well said. Get on google and search for "Scrub Radius" to get the info and insight in the matter. SportsCompactCar did a good article about it IIRC

[Vova]

Originally Posted by howler

Although I expect different tyres with more rubber on the road makes more of a noticible difference?

Wider tires does not mean more grip, it only means more cooling (thus more wind resistance) and less pressure per square mm. You just spread the weight over a bigger surface area.

Why not more grip? Because grip, is the result of load pressing on the tire * the compound of the tire. In physical terms Ff = Fv * Cf ... Friction Force = Force vertical times Coëfficient of Friction. Even simpler, Grip = the weight on the tire * the grippyness of the rubber.

[docwra]

One thats also worth considering is that some cars dont like spacers - on my Z33 they made the steering vague and unpredictable. Once I got wheels with better offsets the handling was even better than standard

[Kit]

Originally Posted by steve.82

Lower ET changes the scrub radius, and as most road cars have zero scrub as far as I know, lower offset will make it twitchy and a bit jumpy over imperfect surfaces, but more feedback mid corner.

I think quite a few FWD cars run -ve scrub, but we won't talk about them...

The scrub radius can easily be changed back to standard by adjusting the camber though?

Originally Posted by docwra

One thats also worth considering is that some cars dont like spacers - on my Z33 they made the steering vague and unpredictable. Once I got wheels with better offsets the handling was even better than standard

Is there any particular reason why it effected your Z33 more than normal?

[royal]

Originally Posted by Vova

Wider tires does not mean more grip, it only means more cooling (thus more wind resistance) and less pressure per square mm. You just spread the weight over a bigger surface area.

Why not more grip? Because grip, is the result of load pressing on the tire * the compound of the tire. In physical terms Ff = Fv * Cf ... Friction Force = Force vertical times Coëfficient of Friction. Even simpler, Grip = the weight on the tire * the grippyness of the rubber.

There must be more than that going on mate. Wider tyres in drifting DOES equal more grip! if what you were saying was true then we could all run monster wide tyres and still spin them up. If I run anything over around 245 then my car doesn't have the power to keep them spinning.

[howler]

Vova, surely though more surface area generates more friction as there is more tyre in contact with the road?

I get what you are saying about pressure, but that doesn't explain why if you drift on very skinny tyres you get less grip

I guess there is a width vs weight balance to account for?

[docwra]

Originally Posted by Kit

Is there any particular reason why it effected your Z33 more than normal?

My only thought was the the innate geometry setup on the Z just doesnt lend itself to spacer use - Ive never experienced problems like that on the 200's, for example.

[steve.82]

Originally Posted by Kit

The scrub radius can easily be changed back to standard by adjusting the camber though?

Not really, as with the same upright if you change camber you get a corresponding change in KPI. Plus camber should be decided by other factors (sidewall deformation, tyre temps, grip required, wear etc etc), not trying to alter the scrub radius.