Plz help me choose tyre sizes for GA65

[o_man_ra23]

OSIC... well theres a bummer. You seem to be in a dilly of a pickle then, as the offset will kill your width choices.

[Negative Boost]

I dont see how offset could affect tyre widths on the front. The tyre is already 5-7mm away from the strut and looks very close to the gaurd too. You may be able to squeeze 215's under there when you get the gaurds rolled Stefan but keep an eye on the clearance to the strut.
On the rears, chuck some baggy 245's on there

[CrUZida]

Don't forget RA65 struts have more -ve camber on the spindle, so that inturn puts the rim closer to the strut tower again.

But just to explain a bit more, the stock spring seat does not interfere with tyre/rim width. However, this seat is only about 70mm from the top of the strut. A typical coilover threaded tube is probably closer to 120mm long, and its the extra length that interferes with a tyre.

When I do my coilovers I'm going to shorten the threaded tube so that it doesn't interfere with the rim or tyre (my rim is currently 2mm from the strut).


Back on topic, Stefan you are going to have to fork out for some expensive tyres to keep your car on the road in a straight line.
A very decent set of 225's on the rear will be able to keep the rear in tow without too much issue (JCMO with his 225 Potenza G3's doesn't have any dry issues), however being limited to 205's on the front will make things interesting around bends.
Although, with a nice amount of -ve camber you should get oodles of grip, just not a lot of life out of the tyres.

Inshort, decent tyre (minimum Potenza G3), 225 rear, 205 front with -ve camber.

[Stefan]

Thanks for all the replys. Don't worry, I plan on decent tyres, and running some -ve like I am currently anyway.

It's not so much the sleeve that is in the way - these coilovers have shorter threads than the 120mm kit I was originally going to use - but the position of the spring seat. (PS - you can get shorter sleeves crUZida, so no need to buy long ones then shorten). Unfortunately, if I went to shorter springs, I might run out of adjustment at the same ride height. Will have to do some calculations. Not sure that having the seats at the very top of the thread would quite clear the tyres anyway. The fact that these struts have been shortened (~60mm) only compounds the problem.

These seats are wider than most, too - wider than they have to be. I could have the OD lathed down a little...

I was going to take a photo from underneath when the car was jacked right up, but the battery was flat. To give you an idea though:

[Negative Boost]

Piccies no workies

[CrUZida]

All work fine for me

EDIT: Wait, I lie, cache cleared, pics no worky

[o_man_ra23]

Pics worky for me... some MA61 struts converted to coilover (sucks to have to do it to a second set of struts, but could be the only decent option??) and longer control arms might work well?? Give you clearance from the struts, then lipping/pumping the guards may be needed, but shouldnt be much of a hassle. Food for thought??

[Stefan]

Ok guys, I take back what I said about the collars not being the issue. Even if I had shorter springs, and the seats were above the tyres (i don't think there is enough room on collars to do this anyway), I still don't have much room.

I think my only alternative is to run the +12s on the front, with the -8 brake upgrade... and find another pair of rims for the rear. This means yahoo japan and waiting months, or having mismatched rims.

[Stefan]

Here:



Not taken quite straight on but u get the idea.

[MOOKIE]

I had 205s on mine all round i think and they werent too bad.
but.....
When my mate bought it, it had 245s on the back but they were on 14s.

a few questions;
How far are you willing to work your guards ?
Have to spoken to ben purtell about pumping your guards out a bit ?

whats your camber setup like ?
Have you thought about falken azenis tyres ?

mookie

[Stefan]

Like I said, guard clearance the other way isn't an issue, it's only clearance from the strut that is causing me grief, and they're going to be rolled properly yes More neg will only make things worse.

I just need to find another pair of 16x7.5 P1s in +12 and I'm sorted.

[CrUZida]

Are you worried about being outside the legal 25mm increase in track ?

[Stefan]

I wasn't sure what the track legalities were. NCOP thread doesn't seem to detail track.

Is it 25mm per axle or per side?

If 25mm per axle, I'm already screwed:
+27 vs + 14 = 26 axle increase
+27 vs +4 =46 axle increase

[CrUZida]

Whoops, missed that in NCOP thread

Just added this

[Stefan]

I'm going to talk to my engineer when they open again and sort out what my track limitations are, then base tyre size on that.