Increasing Rear Offset (numerically +38 To +45)

[SLAPS]

Hi All,

I have a set of jap rims which are:

F: 17x8" +38

R: 17x9" +38

The rims are surprisingly light; the fronts are slightly lighter than the std gtst rims where as the rears feel about the same.

The fronts sit nice with a 235 no scrubbing. The rears however with a 255 are an issue.

I've spoken to wheelworks who said a manufacturer 'typically' makes a larger cast and then machines down the hub slightly to achieve a given offset.

So.. heaps of meat on mine (looks like a built in spacer) I am looking at machining down the hubs slightly to say a +45 on the rear so I can run a wider rear tyre without scrub and excessive camber.

With the 17x9" +38 there's 14-15mm clearance between the wheel and the hicas tie rod end so plenty of room for a +45.

With a +45 on the rear the front and rear outer edge of the wheel will closer to being equal.

Compared to stock wheels.

17x8 +38 sit out +21mm

17x9 +38 sit out +34mm

Where as 17x9 +45 sit out +27mm.

Should I go more than +45 given there's still another few mm available?

As I am moving the rear wheels in closer to each other will it be less likely to under steer but possibly be a little more over steery?

Edited March 16, 2009 by TheRogue

[toddlls]

I have 38 offsets on back with a 17x9 rim and 255 tyres were too wide even with flaring rear guards a little. Ended up going back to a 235 stetched to fit on rear which no tyre scrub now felt, arse-end little more slippery but meh-got it set up for skids anyhow.

Will be watching to see how you go here mate

[SLAPS]

I'm hoping a 255, as much + offset I can squeeze, a rolled guard and a little little camber it will just fit. :S

In comparison to the std wheels the nuts screw on to the threads bugger all so fingers crossed there's plenty of meat.

Edited March 16, 2009 by TheRogue

[nisskid]

there are much more effective ways to balance ur cars over/understeer than track changes.

[Mr. Oizo]

just get better tyres.

[joeyjoejoejuniorshabadoo]

yeah... ummm... i wouldn't

[SLAPS]

there are much more effective ways to balance ur cars over/understeer than track changes.

The issue is I am trying to get as much semi-slick tyre under the rear as I can.

I doubt I'll be able to pull safely off any more than 2-3mm.

Either way these rims will do for now; I just don't like the idea of spending 1.5-2k on a set of rims when the car is only used for a little fun at the track and not driven on the street.

just get better tyres.

Not when your already at semi-slick level.

Edited March 16, 2009 by TheRogue

[nisskid]

The issue is I am trying to get as much semi-slick tyre under the rear as I can.

I doubt I'll be able to pull safely off any more than 2-3mm.

Either way these rims will do for now; I just don't like the idea of spending 1.5-2k on a set of rims when the car is only used for a little fun at the track and not driven on the street.

Not when your already at semi-slick level.

ok, then id be thinking less about track change, and more about clearance, what clearance issues are there on the inside?

also what gaurd modifications have u done if any?

[SLAPS]

I was simply curious how changing the rear track to improve clearance would neg affect handling if any. i.e rear track being less or more than front track etc..

Either way I spoke to the Troymeister; I will be fine with a 245 semi slick on the rear and rolled guards.

Semi's are apparently wider that the same sized road tyre so I shouldn't fit a 255 on the 9" rim as it will bulge a little too much.

Troy runs a 9.5" rear with rolled guards and no issues due to ride height.

I'm running 350mm with plenty of clearance so dare so I will be fine also.

Edited March 17, 2009 by TheRogue

[nisskid]

let me put it this way, the added tyre width will more than cancel out any tiny amount of oversteer bias u might have got from the track change. saying that, personally i would have just pulled ur guards out more.

[SLAPS]

Yeah but I hate molesting my car.

Its black, stock looking and I really want to keep it looking that way but that may change

Edited March 17, 2009 by TheRogue

[Roy]

Check your PM re my spare set of TE37s, before i flog them off you should trial fit them to your car...

[SLAPS]

Thanks. PM Sent.