135i understeer--

[lastMleft]

Originally Posted by The HACK

Noise != Understeer. Heck noise != slip. Unless you're on slicks or r-comps, some noise (as in squeal) is common even when tires are at full static grip levels.

Pay attention to the pitch of the tire noise and the sudden change from squeheyal to "groan".

Hey that's looks like fun even with the noise

[The HACK]

Originally Posted by Rukuss

Hey that's looks like fun even with the noise

That probably looks MORE fun because of the noise.

[z3papa]

Originally Posted by fcman

I use my DD PSSs for AutoX and they work well enough for 4 runs, in terms of heat. Wouldn't want to take them on a track day though

PSS's at autocross and Kmart have at least one thing in common -- they suck.

[lastMleft]

Originally Posted by The HACK

That probably looks MORE fun because of the noise.

I just enjoy tracking.

[3002 tii]

Originally Posted by Ganicki

Whats the best solution to keep the 135i from understeering--H&R Springs and strut brace are the only suspension mods at this point -- thanks G

Strut bar won't do much for understeer

Originally Posted by Ganicki

Am putting on 12 mm spacers also. That should help a little. What about a larger sway bar?

Assuming you mean spacers on rear that'll only make the understeer worse.

Originally Posted by DietTab

fat sticky tires and big negative camber is the biggest change you can make. everything else helps, but the swaybar taxes your tires even more heavily.

+1

wide square tires + camber + stiffer rear springs

[fcman]

Originally Posted by z3papa

PSS's at autocross and Kmart have at least one thing in common -- they suck.

They get the job done if you're just out there to have fun. I outpace the rest in my class by about 6+ seconds per run so I'm not concerned about it.

[z3papa]

I bought them 2 years ago as street and my wet autocross tires b/c they were rated the best in the wet. Within two events, I figured out they would neither be fast in the dry, and marginally fast in the wet. As street tires, they were pretty good but overpriced in my opinion. Sold them off dirt cheap.

[07chupacabra]

Originally Posted by z3papa

PSS's at autocross and Kmart have at least one thing in common -- they suck.

Why's that ? I'm going for a square 255/35/18 PSS setup on my car but I keep hearing people tell me it's a bad idea and will make handling worse. But this is mostly from dealer type mechanics and road warriors.

[katsooba]

1. the 10 minute front camber mod
2. e93 M3 front antiroll
3. m3 rear subframe bushings
4. m3 front control arms

have fun!

1,2 and 4 is a nice home project diy
the #3 is a bit hard for the average diy'er, but doable!

[Cpt_Rum-bo]

I guess I will have a good comparison of track times, since I like making changes then taking it to the track to see the results.

- First 3 outings on the track (Homestead Road-course), car had stock runflats.

- 3rd outing, I added 595 Federals RS-R Racing (245-35-18) to the rears only and picked up 5 secs per lap.

- Now I've done the square setup conversion by purchasing the stock rear rims (261M). Front (245-35-18) will still have Run-flats, while the rears will have the Federals (245-35-18). So will be interesting to see the difference when I go to the track later this month.

- After the run-flats finish, I will have Federals all-around as another comparison.

[dcaron9999]

Originally Posted by Cpt_Rum-bo

I guess I will have a good comparison of track times, since I like making changes then taking it to the track to see the results.

- First 3 outings on the track (Homestead Road-course), car had stock runflats.

- 3rd outing, I added 595 Federals RS-R Racing (245-35-18) to the rears only and picked up 5 secs per lap.

- Now I've done the square setup conversion by purchasing the stock rear rims (261M). Front (245-35-18) will still have Run-flats, while the rears will have the Federals (245-35-18). So will be interesting to see the difference when I go to the track later this month.

- After the run-flats finish, I will have Federals all-around as another comparison.

That is the best way to go with modifications. Do them gradually, assess them, and make adjustments when/if necessary.

You are somewhat upsetting the balance with the different adhesion level of fronts versus rears, as your Federals are in the "Extreme Perfomance" category, and your RE-050 RF are in the lower "Maximum Performance" category.

You must have noticed some sliding and plowing in the front, especially if you have not exploited trail-braking yet.

I went with style 261 and 255/35R18 Dunlop Direzza ZII, but not without trying mismatched and worn out mismatched tires first, similar to your situation. I needed to size the 255/35R18 out for fitment/rubbing, and feal on the track before shelling out the money for a fresh set of square ZII 255/35R18's.

I have to look into the Taiwan made Federal 595RSR EP tires as my next set, and see how much they cost up here in Canada. The ZII's hardly last me a year, and cost a bunch of money. Nasioc members seem to like the Federal's on 3300lbs+ street cars. The 595RSR's seem to have a good dry weather tread pattern and stiff sidewall. Surely sticky too with : 140AAA UTQG rating ...

Edit: Dayuumm ... The Fed 595RSR are %33 less expensive than other command brand name Extreme Performance tires here in Canada!

[Cpt_Rum-bo]

Originally Posted by dcaron9999

That is the best way to go with modifications. Do them gradually, assess them, and make adjustments when/if necessary.

You are somewhat upsetting the balance with the different adhesion level of fronts versus rears, as your Federals are in the "Extreme Perfomance" category, and your RE-050 RF are in the lower "Maximum Performance" category.

You must have noticed some sliding and plowing in the front, especially if you have not exploited trail-braking yet.

I went with style 261 and 255/35R18 Dunlop Direzza ZII, but not without trying mismatched and worn out mismatched tires first, similar to your situation. I needed to size the 255/35R18 out for fitment/rubbing, and feal on the track before shelling out the money for a fressh set of square ZII 255/35R18's.

I have to look into the Taiwan made Federal 595RSR EP tires as my next set, and see how much they cost up here in Canada. The ZII's hardly last me a year, and cost a bunch of money. Nasioc meber seem to like the Federal's on 3300lbs+ street cars. The 595RSR's seem to have a good dry weather tread pattern and stiff sidewall. Surely sticky too with : 140AAA UTQG rating ...

Edit: Dayuumm ... The Fed 595RSR are %33 less expensive than other command brand name Extreme Performance tires here in Canada!

I agree, the change did induce more understeer, but the extra grip in the rears were mind-boggling. The only reason I'm not changing the fronts yet is because I want to see the comparison between the 215's and 245's.

Also, my friend has the ZII's and they have excellent grip but don't last long as expected from Extreme Performance Tires. Figured, it won't hurt much trying the Federals since they're so much cheaper.

Vid with Federals:

[dcaron9999]

What is your current camber setting in the front? Are you planning on installing camber plates or M3 control arms? Without a good amount of negative camber, you may have an issue with fitment. I suppose you already confirmed that the front fender, and strut clearance is fine with your rear style 261 wheel and tire?

In your video, your fronts are complaining a little, but it looks like you havent reached speeds yet to fully experience understeering on stock 215/40R18 Max Performance Bridgestone RE-050 RunFlats. My Extreme Performance Bridgestone RE-11 225/40R18 front tires were begging for mercy at the track, but I was starting out, and had little experience, and no camber at that time. The outside edge of the tires got chewed up really quickly.

As you gain confidence and experience, you will love the fat 245/35R18 square setup, but you will still need serious camber in the front to make them fit ...

[Cpt_Rum-bo]

Originally Posted by dcaron9999

What is your current camber setting in the front? Are you planning on installing camber plates or M3 control arms? Without a good amount of negative camber, you may have an issue with fitment. I suppose you already confirmed that the front fender, and strut clearance is fine with your rear style 261 wheel and tire?

In your video, your fronts are complaining a little, but it looks like you havent reached speeds yet to fully experience understeering on stock 215/40R18 Max Performance Bridgestone RE-050 RunFlats. My Extreme Performance Bridgestone RE-11 225/40R18 tires were begging for mercy at the track, but I was starting out, and had little experience, and no camber at that time.

As you gain confidence and experience, you will love the fat 245/35R18 square setup, but you will still need serious camber in the front ...

Running stock front camber which is essentially nothing. Overtime, car will get coilovers and other supportive hardware. Wheels will fit without touching the fender easily and I have spacers so that it can clear the strut.

The sound you hear from the front is change in concrete, not necessarily me over driving.