Z4MC: KW V3s Track Review

[pal]

After the long winter, finally had a chance to try out the Z4MC at the NJMP Lightning course this past Saturday. Having never been on this track before and this being the first time out with the KW V3s, the first session was an easy one trying to get the line and also a feel for the new suspension and alignment settings.

By the third session I was pushing the car at least as much as I used to with the stock suspension and I came away happy and impressed with the improvements. Below are the highlights of what stood out -

- Much better turn in response
- Almost no understeer at all anymore and the car is neutral through most turns
- A couple of times that I went in hot into the turns, it did not show any propensity to oversteer or turn around. Basic corrections helped line it back up.
- Immense amount of grip on turns; this may be partly due to my alignment settings, but I am sure a lot has to do with the KWs.
- Roll is reduced, but not eliminated. I actually like some roll as it gives a good feel. Plus I have the rear shocks at a low compression settings so will play a little to stiffen up the back a bit.
- Car seems to be a lot more stable under heavy braking/ABS. Earlier it tended to squirm a lot. Dive seems to be reduced as well. This is interesting as I was using more agressive track pads (XP10s) compared to last year (Ferodo DS2500s).
- Corner banking does not seem to "throw" the car off like it did before. It seem more planted now and wheels are better controlled. More on this later as some tracks have more banking than NJMP.

Overall, I am satisfied with the suspension upgrade and glad that I finally decided to install it after about a year of it sitting in my basement. Its not a hardcore setup, but its definitely an excellent step up for track events on a car that is daily driven often as well. :thumbup:

tnsbruce was at the track day with his Z4MC and some new modifications. I will let him chime in with his feedback as well.

A mandatory shot of our crew on Saturday outside Moe's where we had some good dinner and catch up for the day.

http://images44.fotki.com/v1449/photos/1/1128101/7359724/IMG_3535-vi.jpg

And one of the 2 Z4Ms

http://images47.fotki.com/v1473/photos/1/1128101/7359724/IMG_3536-vi.jpg

[tnsbruce]

Great day at NJMP - good to meet up with gang for a little track fun.

New mods and impressions since last track day:

CSL wheels - the real ones from Germany - I had these powder coated black by Extreme Powder Coating in Springfield/Lorton, VA. They look cool and Gary did a great job with the powder.

New Tires - Nitto NT05 - this is supposed to be Nitto's answer to the PS2. I struggled with these a bit trying to find the correct tire pessure. It was a cold day at the track and I never felt like I got them up to temperature. Dropping the cold PSI down to 30 seemed to help, but I never felt like I was getting the true potential out of them given their traction rating and company claims. They look cool though....

Strong Strut strut tower brace and firewall braces - this thing is a work of art. Turn in and turn stability seems improved (of course I am changing more than one variable at a time). The one note I would make is that on my car the strut tower brace contacts the elbow on top of the motor that connects to the fuel rail assembly. After the track event I pulled the brace to see how much wear was on the tube caused by the engine moving during use. The brace was definitely wearing away the tube (Thanks Pal!) I used a dremel tool to grind away a portion of the brace so there was no more contact. The brace does have a cut away for clearance for this elbow, but was not quite enough for my motor.

BMS Stage 2 Exhaust - HA HA HA its LOUD - sound is awesome - only loud because we are more uptight over here on the east coast than the rest of you. Sounds great though. I ended up painting the Magnaflow mufflers a matte black to match the general theme of my car and to cover up the welds on the exhaust. Installation was straight forward and everything lined up well. The left muffler sticks out a little farther than the right; I will need to play with it more.

ESS Software - this is another great mod - engine has more grunt at low rpm and feels like it pulls harder up on top of the rev range.

Sunoco GT 260 Race Fuel - with such a small tank on the M Coupe who would of ever thought you would need $80 to fill the tank when pump gas is $2 a gallon??? 100 Octane goes well with the ESS software as it is supposed to adapt to higher octanes. The performance with the race fuel, the ESS software, and exhaust was superb. The car felt to have an extra 20HP or so. I will need to get some dyno time to get some real numbers.

Another observation is that of my driving - this being the first event of the year and only my 10th track event ever - I felt very rusty out on the circuit - this may have led somewhat to my impressions of the tires. I could not keep up with Pal once the turns started, although it was fun chasing him.

Another mod I made was to paint the door handles black as well as the intrument cluster - I will need to post a pic of this. I have always found the silver surrounds of the instrument cluster very distracting. I think your eyes are drawn to lighter brighter things - so when you glance down at your guages you get distracted by the silver of the cluster. With the surrounds now matte black the interior of the car looks much more cohesive and the guages really stand out. I was also able to give the plastic covers of the guages a good cleaning - I was surprised at how dirty these were.

Suspension and more track time are next....

Nice event on the 16th and 17th of May at Summit Point for those that are interested.

[headparrot]

Pal --are those Falkens you are running? Size?

What tires did you run last season?

[pal]

Pal --are those Falkens you are running? Size?

What tires did you run last season?

Yes, those are the Falken Azenis RT-615s in stock size: 225/45/18 front and 255/40/18 rear.

Last season I ran the stock Contis until the fronts started to wear off on the outer edge.

[Dark Schnitzer]

Nice detailed write-ups Pal and Bruce. I wish everyone could be so concise.:thumbup:

I'm wondering if either of you have driven (hard/pushed)...the lighter 3.0 SI coupe with the magnesium block ?? (sport suspension)
I just wanted your impressions of its handling compared to your now modded suspension M's.

The only reason I ask is due to an M coupe chasing me in highway traffic one late evening on a multi-lane hwy at speed. He seemed abit wobbly and even though the M rivaled my lowly Si....he was never able to out maneuver me .

Granted...it could have been his comfort level etc.....but I thought I'd ask in your thoughts at where the Si coupe sits comparatively ??:dunno:

[Palantirion]

Nice detailed write-ups Pal and Bruce. I wish everyone could be so concise.:thumbup:

I'm wondering if either of you have driven (hard/pushed)...the lighter 3.0 SI coupe with the magnesium block ?? (sport suspension)
I just wanted your impressions of its handling compared to your now modded suspension M's.

The only reason I ask is due to an M coupe chasing me in highway traffic one late evening on a multi-lane hwy at speed. He seemed abit wobbly and even though the M rivaled my lowly Si....he was never able to out maneuver me .

Granted...it could have been his comfort level etc.....but I thought I'd ask in your thoughts at where the Si coupe sits comparatively ??:dunno:
There are pics of IMZ4N's 3.0 Sport roadster and CalRick's 3.0 Coupe (SI?) at Willow in this thread: http://www.bimmerfest.com/forums/showthread.php?t=346124

From what I've gathered it seems that the Sport suspension non-Ms may indeed have a handling advantage over stock-suspension Z4 Ms.