Alignment settings - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Finnegan · 05-02-2016, 09:34 AM

I'm going to be getting a set of summer tires soon, and then an alignment. The tires will be 205-50-17, 255-40-17s. The suspension is stock, 2004 base.

Without going too crazy and wearing these out too fast, can anyone offer some advice about the settings to ask for? I'd like to have a little less oversteer dialed in.

Finnegan · 05-02-2016, 10:58 AM

Correction: I found 225 45 17s for the front.

thstone · 05-02-2016, 02:52 PM

The 225's up front will help to reduce understeer quite a bit. Good choice.

With a stock suspension, you can ask the shop to dial in a little more front negative camber to improve cornering which will also help reduce understeer by keeping more of the tire on the road for improved front end grip. However, be aware that this will also increase the wear on the inside 1/3 of the tire so like most things in life, its a tradeoff. The more front camber, the more inner tire wear. Sorry, there's no free lunch.

Last, try evening out the front and rear tire air pressures from the 29F/36R that the factory recommends to something like 32F/34R. This will also tend to reduce understeer.

JayG · 05-02-2016, 03:13 PM

Yea, what Tom said!

On a stock suspension, you max out around .8 in the front and 1.8 in the rear
I would go for no toe in the front and a smidge in the back

Finnegan · 05-03-2016, 08:38 AM

Thanks for the replies! Now the tire shop has called back and said that they can't get the 225s for the front after all.

JayG · 05-03-2016, 10:02 AM

What tires are you looking for?
If it is Re-71's, you are probably SOL until June

Finnegan · 05-03-2016, 12:52 PM

RE 11s, or, RE 11As.

LAP1DOUG · 05-04-2016, 05:55 PM

Quote:

Originally Posted by Finnegan

I'm going to be getting a set of summer tires soon, and then an alignment. The tires will be 205-50-17, 255-40-17s. The suspension is stock, 2004 base.

Without going too crazy and wearing these out too fast, can anyone offer some advice about the settings to ask for? I'd like to have a little less oversteer dialed in.

If you really want less oversteer, you may have an alignment problem, like not enough toe-in at the rear, or goofy camber front to rear. If your alignment is within spec, and you still want less oversteer (hard to believe), then stay with something like that 40 - 50 mm stagger in front to rear tire width (255 - 205 = 50 mm).

If you really want less understeer, without changing anything else, decrease your front to rear tire stagger to 20 mm or less. Looking back at my records, before I modified my suspension, I ran 255 fronts / 265 rears, and that took out a good bit of the understeer.

Oh, you may need some new wheel with that. I see now, you are probably using those narrow 17" OEM wheels. You really need wheels to match the tire that you want to run (not the other way around)

Finnegan · 05-06-2016, 02:39 PM

Quote:

Originally Posted by LAP1DOUG

If you really want less understeer, without changing anything else, decrease your front to rear tire stagger to 20 mm or less. Looking back at my records, before I modified my suspension, I ran 255 fronts / 265 rears, and that took out a good bit of the understeer.

Oh, you may need some new wheel with that. I see now, you are probably using those narrow 17" OEM wheels. You really need wheels to match the tire that you want to run (not the other way around)

Ha. Yes, I meant I'm looking to decrease understeer.. Thanks for the input.