Gimp
Gimp Dork
9/22/09 6:59 p.m.

The 318ti (E30 trailing arm rear suspension) is getting a limited slip this weekend. Currently, I'm running the stock bar and 560lb rear springs in the back, and I'm happy with the balance of the car.

What changes in handling should I expect (autocross wise) with the addition of the LSD. If there is a change, what direction in springs rates should I go in the back to try to maximize grip/maintain balance?

As a note - I had a set of 6" 650lb springs in the back with no bar, but the car was too loose in the back, mostly related to ride height.

mad_machine
mad_machine SuperDork
9/22/09 7:09 p.m.

My Ti has the "cold weather package" which includes both the heated seats and LSD (early 96.. later cars got traction control) and while I have never driven mine without the LSD.. I find that it digs in pretty well with it. When it does get loose, it is VERY progressive and easy to catch.

Not sure on my spring rates.. but I am running the bilstien pss9 coilover suspension with poly bushes

Strizzo
Strizzo SuperDork
9/22/09 7:18 p.m.

you'll find that it'll tend more to "squat and go" rather than spin the inside rear coming out of a corner(if this was a problem before). this might mean you can get away with a little more rear bar, or you might be better off not fiddling with something not yet broken.

Gimp
Gimp Dork
9/22/09 7:21 p.m.

Not planning on changing anything after it goes in, at first. I need to do some testing first, but I'm trying to get an idea of what to expect.

Other information of interest - my rear Konis are at 50%, and my fronts are suck on full soft. I run the Eibach front bar on full stiff, attached to the control arms.

Jensenman
Jensenman SuperDork
9/22/09 8:24 p.m.

If you weren't having inside tire spin problems with the open diff, chances are the LSD won't seem like much of a change. If it was spinning the inside rear, It's probably now going to want to push more under power. Thus be prepared to do what you need to get a bit more grip up front. The really aggressive limited slips will act like a spool under power, it will push like crazy.

griffin729
griffin729 Reader
9/22/09 8:40 p.m.

Jensenman beat me to it and did it better.

Apexcarver
Apexcarver SuperDork
9/22/09 8:46 p.m.
Gimp wrote: Other information of interest - my rear Konis are at 50%, and my fronts are suck on full soft.

Do you have any crappy stockers sitting around? Over the winter I would be taking advantage of Koni's lifetime warranty if I were you.

friedgreencorrado
friedgreencorrado Dork
9/22/09 9:04 p.m.
griffin729 wrote: Jensenman beat me to it and did it better.

Yup. More thrust at the back, more slip angle in the front. Hook that puppy up. Or rev it up enough to break the rear loose Donohue style..

Apexcarver
Apexcarver SuperDork
9/22/09 9:32 p.m.

actually here are the results of adding lsd

wikipedia said: Physical reactions to LSD are highly variable and nonspecific. The following symptoms have been reported: uterine contractions, hypothermia, fever, elevated levels of blood sugar, goose bumps, increase in heart rate, jaw clenching, perspiration, pupil-dilation, saliva production, mucus production, sleeplessness, hyperreflexia, and tremors. Some users report a strong metallic taste for the duration of the effects. LSD users have reported numbness, weakness and nausea.[23] LSD is not considered addictive, in that its users do not exhibit the medical community's commonly accepted definitions of addiction and physical dependence.[24] Rapid tolerance build-up prevents regular use, and there is cross-tolerance shown between LSD, mescaline[25] and psilocybin.[26] This tolerance diminishes after a few days without use and is probably caused by downregulation of 5-HT2A receptors in Some psychological effects may include an experience of radiant colors, objects and surfaces appearing to ripple or "breathe," colored patterns behind the eyes, a sense of time distorting (time seems to be stretching, repeating itself, changing speed or stopping), crawling geometric patterns overlaying walls and other objects, morphing objects, a sense that one's thoughts are spiraling into themselves, loss of a sense of identity or the ego (known as "ego death"), and other powerful psycho-physical reactions.[27] Many users experience a dissolution between themselves and the "outside world".[28] This unitive quality may play a role in the spiritual and religious aspects of LSD. The drug sometimes leads to disintegration or restructuring of the user's historical personality and creates a mental state that some users report allows them to have more choice regarding the nature of their own personality.
friedgreencorrado
friedgreencorrado Dork
9/22/09 10:13 p.m.

In reply to Apexcarver:

I saw that in Consumer Reports. If I were in the mood to buy, I think I'd choose the cannabis instead.

Or maybe I'll just have another beer.

Gimp
Gimp Dork
9/22/09 10:20 p.m.
Jensenman wrote: If you weren't having inside tire spin problems with the open diff, chances are the LSD won't seem like much of a change. If it was spinning the inside rear, It's probably now going to want to push more under power. Thus be prepared to do what you need to get a bit more grip up front. The really aggressive limited slips will act like a spool under power, it will push like crazy.

I've been having HUGE inside rear wheel spin problems, and I'm seeing trails.

Jensenman
Jensenman SuperDork
9/23/09 7:57 a.m.

Then the limited slip should fix that. The flip side: when a limited slip locks up, it keeps the rear wheels from turning independently which makes it act sort of like a spool. Most street type limited slips aren't that aggressive, meaning 1) you will still probably have some spin, just not as pronounced as before and 2) the car will want to go somewhat straighter on acceleration if the inside rear tire isn't spinning. Anything you do to add weight to the outside front tire will help put more load on the inside rear.

Off the top of my head, I'd consider going stiffer with the front shocks and softer with the rears (helps control transition maneuver weight transfer in the front and allows the inside rear tire to droop more quickly). I'm not overly familiar with the specifics of the E30 setup, so hopefully someone with more hands on experience will pipe up and give you some guidance.

bludroptop
bludroptop Dork
9/23/09 8:21 a.m.

Jensenman
Jensenman SuperDork
9/23/09 8:27 a.m.

Oooh, the colors.....

dj06482
dj06482 Reader
9/23/09 8:58 a.m.
mad_machine wrote: Not sure on my spring rates.. but I am running the bilstien pss9 coilover suspension with poly bushes

Sort of OT, but how do you like the PSS9 setup? That's one option I'm considering for my E36 ('97 328is w/Sport Pkg.), so I'm eager to hear from someone with real-world feedback.

mad_machine
mad_machine SuperDork
9/23/09 11:01 a.m.

it's stiff and VERY adjustable both in the Dampners and the height. I love it.

As for stiffness. I have the fronts set to 7 and the rears on 5 on my ti. Keeps the rear more planted and keeps the car from pushing too bad.

My antiroll bars are funky though. Due to rust and lack of maintance. Soon after i got the car, one of the front bar mounts ripped out of the body. Been running one mount ever since. I managed to cut a good mount off of the parts car I had.. so I will be fixing that this winter and replacing the bars with something stiffer.

Grassroots Motorsports Magazine

Subscribe Today

Also get your instant access to the digital edition of Grassroots Motorsports Magazine!

Learn More
IMrrxju9CTcskHbcevU8rcD9118a5jsx