NJ-GT

Mostly. It is the entire engine/tranny moving. I have the same problems with the Cayman.

So, a stiffer tranny mount + stiffer engine mounts + Cup Shifter Cables: problem gone. Just avoid the Cup tranny mount, the interior sound (grinding) is extremely loud. I think the PDEM are a gizmo and they are not as stiff as a proper stiff static engine mount. Chat with Eddie, Wevo and TS have some nice stuff for trakcar 1.1.

Just adding a stiffer transmission mount doesn't fix the problem.

Mvez

Yep. Had the same shifting problem with my M3, and urethane engine mounts are what fixed the problem. Stop the bigger mass from moving first (engine), then worry about the tranny. Tranny mounts just compliment the engine mounts with a more direct feel, and help transmit all the power more efficiently.

WEVO's seem to work great, I prefer a static stiffness...for the same reasons I prefer linear springs.

Urethane is great, but once you start putting in solid (metal) subframe, engine, and tranny mounts, go ahead and kiss all streetability goodbye. The M3 never sees the street...

CRex

+1 LOL, tried exactly that (cup tranny mount) and the vibrations were INCREDIBLE. Pretty graphical (and conclusive) proof that PDEM doesn't hold the engine in place that rigidly.

BTW a while ago there's talk that PDEM is prone to failing on 997.2 cars. Is there any objective way of testing their functionality?

Veloce Raptor

IMO, sways are the last things to fiddle with when setting up a suspension. They affect the transition of load from weighted to unweighted wheel, and vice versa. If you just want a flatter car on turn in & in corners, consider upping spring rates, presuming the dampers are appropriately valved.

CRex

Here. Tried the cup transmission mount for one week and promptly had it removed. NVH so bad that I practically feared that the vibrations may tear the car apart. It was a fun exercise...

Mvez this mount gets stressed than you think. Urethane is tough but has lower stress/fatigue tolerance than metal. U sure u want the whole tranny+engine mass to be attached by a piece of plastic? When I had the solid mount I was told the cup cars replaced the part with every transmission rebuild...

Cool idea! Video coming your way soon...

CRex

Point taken... car is on OEM springs and shocks. Too chicken to dive headfirst into the waters of spring and shocks mod. Not enough racing expertise in this part of the world and too many snake oil salesmen. Plenty of folks who can install the latest and greatest but when you ask them about the proper spring rates and rebound settings for a particular track everybody goes quiet.

FWIW, the Carrera Cup Asia Series which runs all the relevant tracks here (Zhuhai, Ordos, Sepang) disallows spring changes. Which takes away the teams' incentives to experiment and build that requisite knowledge base...

So in short, springs and shocks have to stay stock out of practical consideration.

Larry Cable

I'm prodding Alex @ SW to figure out an RS 4.0 "upgrade" pack for those of us not wealthy enough to buy anything other than the dive planes!

senna

Do you think the dive planes made any difference?

CRex

Only on the highway. We get stretches of real good, autobahn-like multi-lanes around here and can take occasionally take our cars above 300khm (190 old school). Above 220-240 the car used to exhibit a bit of lightness with its nose. With the dive planes it's planted all the way.

On track? Not feeling any difference to be honest. I think it'll take Walter Rohrl or somebody his league to articulate the improvement if any...

Larry Cable

I neither have the innate skill nor the telemetry to detect a difference!

mdrums

Crap...I had Orbit make up some adjustable sways for the "lowly wanna be" aero beetle GTS. I have the so called crappy Sport PASM stock shocks/springs and couldn't afford $4-5k in new coil overs and I wanted to tame some of the body lean and have adjustable sways. I guess I'm just wasting money....

NJ-GT

Adjustable ARB are never a waste of money, the allow you to balance the car for different tire sizes, older vs newer tires on a given axle, tight tracks, open tracks.

Not having adjustable ARB in my Fiat has been the biggest downside of sharing the car for autoX and track.

NJ-GT

At 125 mph, per independent wind tunnel test (Sport Auto in Germany), the dive planes add 6.6 lbs of front downforce, and the 4.0 end plates and new wing angle add 20 lbs.

IMHO, the gains are insignificant. There are more gains from a gurney lip and reducing ride height.

85Gold

Mike,

What Rad said.

Peter

drl

Sure do look cool though. But for me, not $500 cool.