Suspension Setup Choice
01-23-2019, 07:29 PM
#106
Rennlist Member
A few comments on suspension setup:
1. All setup begins with the diff. Do you have an LSD? Type? Lockup ratios? If OEM has it ever been rebuilt?
2. Overly stiff sway bars, in the words of Carroll Smith, turn really expensive multi-link suspensions into solid axles. Some cars need big-*** sway bars (for example E46 front, or in the rear of almost any FWD race car), but the 993 does not. You need some warp. Manage roll rate and coupling with spring choice and then refine mid-corner balance with RS bars and transition balance with low speed shock compression settings. Did I mention RS sways? Yes, yes I did. Don't waste your money on anything else.
3. There is no perfect holy grail alignment but there are principles. Align the car to the skill and preference of the driver. If you need the rear end to be locked down and predictable then run higher KT (or T per Bill) and more rear toe. If you want to the car to be free (fast) then you have to be willing to work and drive 'ahead' of the car - and use lower KT and less rear toe. Every other parameter follows this example.
4. Scrub radius, bump, KT, rake... are all underappreciated by the average shop. It's easy to set camber and toe and do an initial cross-weight. It's hard to do the other stuff and match it to the needs of the driver.
5. For shock settings you need to test at the track. Do sweeps and understand how the car behaves at extreme settings. Then refine to taste re. transition balance, quickness, suppleness.
6. We haven't even talked about tires which are arguably the single most important suspension component.
Nice car BTW
1. All setup begins with the diff. Do you have an LSD? Type? Lockup ratios? If OEM has it ever been rebuilt?
2. Overly stiff sway bars, in the words of Carroll Smith, turn really expensive multi-link suspensions into solid axles. Some cars need big-*** sway bars (for example E46 front, or in the rear of almost any FWD race car), but the 993 does not. You need some warp. Manage roll rate and coupling with spring choice and then refine mid-corner balance with RS bars and transition balance with low speed shock compression settings. Did I mention RS sways? Yes, yes I did. Don't waste your money on anything else.
3. There is no perfect holy grail alignment but there are principles. Align the car to the skill and preference of the driver. If you need the rear end to be locked down and predictable then run higher KT (or T per Bill) and more rear toe. If you want to the car to be free (fast) then you have to be willing to work and drive 'ahead' of the car - and use lower KT and less rear toe. Every other parameter follows this example.
4. Scrub radius, bump, KT, rake... are all underappreciated by the average shop. It's easy to set camber and toe and do an initial cross-weight. It's hard to do the other stuff and match it to the needs of the driver.
5. For shock settings you need to test at the track. Do sweeps and understand how the car behaves at extreme settings. Then refine to taste re. transition balance, quickness, suppleness.
6. We haven't even talked about tires which are arguably the single most important suspension component.
Nice car BTW
01-23-2019, 08:39 PM
#109
There are no M13 bolts under the car, most are M12 and a few M14, measure the shank diameter, shank length(below the head), overall length(end to end) and thread pitch. Thread pitch is probably 1.5
Where did they fall from, where is the noise?
Where did they fall from, where is the noise?
01-23-2019, 08:42 PM
#110
front sway mount is M8x25 rear is M8x20, both slide in from the top, the nut can fall off the bolt not so much
01-23-2019, 10:04 PM
#112
Racer
Thread Starter
01-28-2019, 11:15 PM
#115
Racer
Thread Starter
01-29-2019, 12:12 AM
#118
Rennlist Member
Looks to be a M8 x 35? Aren't too many places those are used. They hold the transmission carriers in Tiptronic cars, and they hold the wheel bearing cover plate (but I don't think those could escape). And two are near the bottom of the oil tank, not sure exactly why.
01-29-2019, 12:28 AM
#119
Racer
Thread Starter
Looks to be a M8 x 35? Aren't too many places those are used. They hold the transmission carriers in Tiptronic cars, and they hold the wheel bearing cover plate (but I don't think those could escape). And two are near the bottom of the oil tank, not sure exactly why.
Is there suppose to be that much gap in it?
its also making a slight grinding noise when i turn it
01-29-2019, 12:41 AM
#120
Rennlist Member
Ha ha you're welcome. Now pay me back by selling me your ratty old wheel centers dammit. 
p.s. I found it by searching the parts Katalog PDF for "M 8 x 30". It's really a great resource.
p.s. I found it by searching the parts Katalog PDF for "M 8 x 30". It's really a great resource.