Hi all,

I have a 997.1 S Cab.

The car understeers too heavily for my taste in 40-60 mph steady state sweepers. Standard width Ventus EVO V2 19" tires. (235f, 295r), PASM.

Main use of the car is low to medium speed mountain roads, and possibly occasional track.

Note my complaint is understeer in sweepers, such as 270* on-ramps, and not turn in (I do trail brake the car).

If I add the GT3 front LCA's, and go to 18" wheels with 10 mm wider fronts and narrower rears (245f, 285r), will this:

- tune out the understeer on 40-60 mph sweepers
- and make it more throttle steery in said sweepers
- without affecting power-out ability too much
- without causing instability in turn in (this would be bad)
- or instability during high speed hard braking (this would be very bad)

I'm OK with reducing the ability to power-out some but not too much.

No I don't want to go to stiffer springs. The ride quality is perfect and the car doesn't have too much body roll for my taste.

 

Increasing front track and camber will solve that but if you're getting new wheels, stick with wider 19s for same width but less sidewall.

Before doing this have you adjusted the negative front camber and gone to neutral toe on your current setup? That front toe change will seriously help.

 

Not yet.

So dialing out steady state understeer won't make the car evil in other aspects?

TIA

 

Nothing is free. Camber and toe out will create more wear on inside of tire and dartiness in straight line respectively. And you'l have to pay attention to weight transfer on turn in since your front will track-in better to apex. That rear is going to want to come around a bit more. So watch your trail braking and get on power earlier to keep dat *** in check.

 

No it will not. I'm running max neg camber in the front -1.1 I would like -1.5. to -1.8 but oh well. Plus I'm running 0 toe in the front. I also run -1.8 camber in the rear but run some toe in on the rear. As you can see I kill cones on the weekends with the SCCA, but also DD my car and like the setup. I didn't like the Hankook V12's on the car.

 

Plus I run a GT3 front sway bar on the middle setting with a stock rear sway bar.

 

A stock 997, with proper tires and correct alignment (stock alignment with minimal rear toe-in), should not understeer on a 40MPH sweeper. Unless you call a sweeper a far tighter curve than I do... And in that case it means you are overdriving your 911. A classic 911 corner is taken slow-in, fast out. And the 'slow-in' means progressive braking in (not a slam) and 'fast out' means progressive, smooth, throttle not a slam either.

 

^ No I'm not overdriving the car on on-ramps. I bring the car to a bit of tire squeal and it's definitely more understeery than my previous RWD cars.

A 270* on-ramp is a long steady state sweeper after turn in.

 

Doesn't a bigger front sway add understeer?


^ But not any worse than other RWD cars, with 50/50 weight?

 

I would like to try your alignment setup, can you translate "some toe in" on the rear into numbers ? Thanks

 

Are you getting push while on the throttle, brake or neither?

How's your tire pressure? To a certain degree... less air = more grip.

Factory settings are designed to understeer to keep people from swinging the rear end around and ending in a ditch.

 

Yes much worse since our cars are ~35/65 F/R.

 

^ So if a 911 is tuned to be as neutral as say a Cayman in sweepers, it will be more prone to throttle lift oversteer and won't be able to put the power down as well on exits?

 

Push during neutral throttle.
Tire pressure 33f/39r cold. 19" wheels.

Yes but I do autox and track driving so I dare say I can catch the rear better than the average driver, and I think I'll keep the PSM on (but in sport mode) on the track.

 

What does 'neutral' mean? You will be more prone to throttle lift oversteer (relatively) with the same alignment setting on a 911 as a Cayman. Power down on 911s is almost always earlier on 911 with RWD rear engine weight bias. All that weight over the rear helps you get grip on rear wheels and rotate the car. So you can do that earlier in a turn than an MR or FR setup.