Hey,
I've got a '99 Z28 M6, what can I do to make it feel more solid while turning? The car feels like it has a lot of body roll and is really boyant. I'm looking to spend about $3k or so, where should I spend it to make improvements that I will feel?

 

The best susp. parts I did were:

DMS Springs
BMR Sub Frame Connt.
BMR Panhard Bar
BMR Lower Control Arms
BMR Strut Tower Brace

Big difference over stock!

 

Do sway bars make a big difference or do you feel them at all?

 

Shocks are the FIRST thing that needs done to a 4th gen. The stockers are seriously weak, and are the cause of the all the bobbing and floating around. Most think the springs are at fault, and heavier ones help some, but not like the shocks. What you feel is not the springs being too soft (or the car would bottom out), but the fact the shocks can't control the energy stored in the spring. When the spring extends the shock (which is really a spring damper) can't stop the oscillation and you get that bobbing. Ala Cadillac. For the record, BMW's for instance are sprung much softer than you'd think, they have really good damping. That's why they ride well, but also feel very locked down.

Ask anyone who's changed the stock shocks. That change alone, without any others transforms the car. If I had to choose a car with only really good shocks, like a Koni or Bilstein or a car with all kinds of mods, but stock shocks....... I'd DEFINITELY take the car with good shocks and nothing else.

Can you feel sway bars? Yup. Biggest thing that effects the roll stiffness is bars. Shocks are more critical, but bars are IMHO a much bigger gain, if properly sized than lowering springs or things like STB's and different PHB's. Not that they don't help, they do, but you have to reign in the 3000 pounds of car moving on the suspension first before worrying about some slight deflection in the Panhard bar.

 

Shocks and swaybars are the best bang for the buck. I'm sure Sam can set you up with some good, affordable parts.

 

Yes sway bars make a difference, I only have poly on the stock bars and that was noticeable.

 

My favorite suspension mods to date that improved my car (in order):

1) Front sway bar (I have a 32mm solid Adco)
2) Bilstein shocks (rear only until my front ones come in)
3) Non-factory alignment: camber=-0.5 (maxed); caster=3.7 (maxed); toe=1/32 (in)
4) Strut Tower Brace

The others helped, but were more suttle. The car is now more neutral handling and no longer plows through turns. My next steps need to be to increase rear traction coming out of turns

Sam's advice has been great and really made me believe suspension mods are more fun than HP mods.

-Rob

 

Rob, toe in sounds interesting, I've never heard of running toe in except on the rear of cars, never in front.

 

Dr Mudge,

The alignment specs were per Sam's suggestion based upon my input of what I wanted to do with the car (street, autox, rr, drag--in this order of preference, some description of handling characteristics I like / don't tolerate, & current tire wear pattern)

Hey Sam,

Where are my front shocks?

-Rob

 

I haven't forgotten. Just haven't had a minute to breathe today, let alone get a check-up for ya! Only took me 2 hrs. to eat a Quarter Pounder while on the phone.

Sam

 

Subframe connectors help alot and should probably be the first thing done after good shocks. That way everything else will be able to do it's job fully. You'll notice the difference alot. Car feels much better in turns just from those.

 

I just got my front sway bar (35 mm solid) and bilstien shocks, valved to Sams recommondations, installed.

First impressions...
Driving around normally in traffic, not much difference.. maybe some bumps are felt a little more.. maybe not.... roads aren't really bad here.


Some spirited driving.. That front sway bar really helps in flatting out the front..inspiring some more confidence going into faster sweeping turns.. The weight of the car now seems to smoothly flow, rather than seasaw.. These shocks really do button this car up.. Slow down, a nice crisp turn in, and then roll back on the throttle and zing straight out. - I can't wait till goto the next local autox event.

fooling arond int he backroads, i entered a 90 deg turn a little too fast and started to understeer.. I was amazed how easy it was correct and get back on the gas. It was like I was "easing" the weight of the car to get me back where I wanted to go.

Oh, and it seems I have alot less wheelhop accelerating from a stop. Maybe the rear shocks are keeping it more in control.

I really now enjoy playing around with this car agian.

Thanks Sam!