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      09-25-2014, 02:20 AM   #1
peter_s
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First trackday in the M4 today!

This afternoon I'm going to my first trackday with the M4! Can't wait.

Did a 55,1 sec lap with my 370Z bone stock. Lets see what the M4 can do if it's dry tonight!

Here are some laps in my old Mini a couple of years ago. Ran R-compounds on that one.
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      09-25-2014, 04:17 PM   #2
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Just got back from the track.

The car performed like a dream. It handled really well and even the brakes held up. They got a little mushy after a couple of laps but it didn't get any worse than that.

The engine pulls really well. It kept up with the best of them even with the Michelin Super sports. The MPSS held up great for 4-5 laps then I ran a second slower because of the lack of grip, not bad for a street tire.

Car was very predictable and I really like how the diff works. This track is quite fast with poor run offs so I kept the traction control in the M mode, I can probably squeeze a couple of tenths out with the DCS off. I can tell you that the M mode doesn't protect you fully from stupidity, still have to respect the car! I almost had a nasty spin going 90mph in a fast turn.

Best logged time I saw on the display was 52,4 sec. My best time in my Nissan 370Z has been 55,1 on street tires I think. Quite a difference I must say! I'll double check the logs tomorrow and I'll post a comparison. between the two cars.
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      09-25-2014, 06:29 PM   #3
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I had the same issue with the tires... got pretty greasy 10 minutes into a session. I'm going to swap them out for next season.
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      09-25-2014, 09:26 PM   #4
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Nice review. Reading all of these is making me jealous, I want to drive one of these beasts on the track!
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      09-25-2014, 09:45 PM   #5
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Nice review. Please post finding from your logger, I am sure there will be some interesting bits
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      09-26-2014, 02:39 AM   #6
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Will do mate!

I check the logs from last time out with the 370. It wasn't 55,1... best I've done was 56,1! So 3,3 sec faster, incredible.

I'll post the graphs a little later.
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      09-26-2014, 04:19 AM   #7
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Here are the logs with some conclusions. I log with a Racelogic Performance box. I really recommend it, it's much less of a hassle than Harrys for instance. OK, you don't get video, but for logging purposes it's really good. Best $400 you can spend on a performance mod, you can learn how to drive better!

Red graph and numbers are M4, bone stock, MPSS
Blue is Nissan 370Z with 275 tires in the front and 305s in the rear Dunlop sport max race SP tires. Street tire similar to the MPS+. Better pads otherwise stock.

So here is the logged track so you get an idea about the track:

GPS coordinates are not 100%, but all the logged timing, VMAX and VMIX are spot on.


Here is the graph comparing the best laps. Or rather the 2nd best lap from the 370 (4/1000 off), because the VMIN were closer compared to the M4. Gives a better comparison:



As you can see the biggest difference is top speed and the high speed corner on the backside of the track (middle of the graph). The dampers in the 370 didn't give me the confidence to push even though the grip is quite similar. I didn't think the difference would be that big. VMIN was 131 kph in the M4 and 122,5 kph in the 370Z.

I have always liked the balance in the 370 very much, but this is a testament to the chassis in the M4. That part of the track looking at the logs impressed me the most. Top speed is just top speed, this is handling and what kind of confidence the car gives you.




Looking at absolute VMIN and VMAX we get the following numbers:


Not much to say, but one interesting thing is the G forces. The M4 generates a little more which is surprising considering the tire widths on the 370. I think the narrower tires gets better grip because the construction flexes a little bit more. And of course the compound is a little better on the MPSS.






Lap data from the 370Z:



Lap data from the M4:



If you look at the ideal laptime at the bottom you'll see that I'm much closer in the M4. I contribute that to that it's easier to drive. The 370Z is much more on or off with the grip. Snappier when it oversteers, you have to man handle it a little more with the shorter wheelbase.

Both cars are great fun to drive, and I still maintain that the 370Z would be a better track car if you go all out on mods. The double wishbone suspension in that car is fantastic, it also feels more like a mid engined car to drive. It will never be as fast, but I think it's potential is great. I'm going to miss that car very much, it's soon on it's way out
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      09-26-2014, 05:14 AM   #8
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Thanks,

Really good info there.

M4 has significantly better braking deceleration on the plots.

A couple of questions, what tyre pressures did you run? do you have adaptive suspension and if so what settings?
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      09-26-2014, 05:37 AM   #9
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The 370Z is a great track car; I used to track my G35 (same platform and engine and suspension as the 350Z, just about 200-300 more lbs for luxury equipment inside) extensively and it was a great track car. But yeah, the M4 beats it, from all reports. I look forward to getting home and getting my M4 and tacking to the track.
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      09-26-2014, 05:53 AM   #10
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Quote:
Originally Posted by robbo mcs View Post
Thanks,

Really good info there.

M4 has significantly better braking deceleration on the plots.

A couple of questions, what tyre pressures did you run? do you have adaptive suspension and if so what settings?
Sorry, forgot to mention that. I have the M-adaptive chassis, and I ran it in sport plus all the time. I even found it a little soft, but that was also because of the tires. The side walls are a little soft. Great tire the MPSS, but it's not a track tire.

I started with 2,1 bar, what's that 32? Most tires were up to 2,5 after the session, with the left front up to 3,0 as the most after I pushed too hard.

It's interesting with the brake distance, It's basically the same yet the speeds were quite higher with the M4. A set of track pads and you would really dare to push it further. Brakes were OK yesterday but didn't give me the confidence needed to be able to push.

Quote:
Originally Posted by Dave 90TT View Post
The 370Z is a great track car; I used to track my G35 (same platform and engine and suspension as the 350Z, just about 200-300 more lbs for luxury equipment inside) extensively and it was a great track car. But yeah, the M4 beats it, from all reports. I look forward to getting home and getting my M4 and tacking to the track.
Yeah, it's a fun car that doesn't get enough credit IMHO. For the money it's absolutely fantastic. I wouldn't mind stripping one and build a proper track car out of it.
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      09-26-2014, 09:19 AM   #11
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Quote:
Originally Posted by peter_s View Post
I started with 2,1 bar, what's that 32? Most tires were up to 2,5 after the session, with the left front up to 3,0 as the most after I pushed too hard.
With hindsight, do you think those were the right pressures? Heading to the track in a couple of weeks on the stock tires and wondering what would be the best starting point (without having to waste the whole day figuring it out!).
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      09-26-2014, 09:31 AM   #12
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I would probably start with 1.8 in the front and 2.0 in the rears. Alt 1.8 all around, something like that. It's great to have the ability to see the pressures in the display, but there wasn't a chance to take a look while driving

I rode the side wall some actually so the MPSS aren't as stiff as I was led to believe.
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      09-26-2014, 09:41 AM   #13
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Sorry, forgot to add that I think 2,2-4 warm would be good.
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      09-26-2014, 09:51 AM   #14
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The Performancebox is a great tool. It was the best purchase I could have made to improve lap times. If you use the Driftbox Tools software you can create a virtual race between previously recorded laps at the same track. Here is a video of race I did with some friends. We each took the Pbox out for a session and then bench raced our laps. http://userpages.xfoneusa.net/~brian...rick-elise.avi.
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      09-26-2014, 10:19 AM   #15
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Quote:
Originally Posted by peter_s View Post
I would probably start with 1.8 in the front and 2.0 in the rears. Alt 1.8 all around, something like that. It's great to have the ability to see the pressures in the display, but there wasn't a chance to take a look while driving

I rode the side wall some actually so the MPSS aren't as stiff as I was led to believe.
Very helpful. Thanks for the advice.
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      09-26-2014, 11:12 AM   #16
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It appears to me that you had more confidence in high-speed corners with the M4. Looking at the speed data, on higher-speed corners, even though you were approaching from a significantly higher speed, you braked less and maintained higher speeds through the corners, and of course accelerated faster shown with the slope of the curves.

Also, on the last hairpin (guessing here), you decelerated into it at nearly the same rate, but was able to get on the throttle earlier as well.

Not knowing the track or how a 370 drives, my educated guess would be that you felt more comfortable with the M4 at higher speeds. If true, it speaks well for the car, considering this is your first time out on track with it
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