M3 Vs MCoupe at the Glen Part II, The Revenge!

Almost exactly a year ago we compared two laps form AC's and Stee's cars at Watkins Glen. Back then the M3 bested the MCoupe by 2/10th of a second with both cars in the 2:16s.
A year later and with different tires, things have changed a bit...





It's amazing to me how evenly matched the E46 M3 and the S54 Z3M Coupe can be. For the past few years AC and I have been having a blast lapping together at local tracks at HPDEs. Now that we have data acquisition (Traqmate) and in car video, we can do a post session analysis, compare our differences and similarities and find areas AC and I to improve. Some of the differences could be chalked up to driving style, others to car capabilities. Sometimes it gets hard to differentiate, but at the end of the day all you can do is give an educated guess based on the data recorded.

First, some info on our cars.

• Both cars have the same stock S54 engine, the M Coupe is limited to 7600 RPM while the M3 revs to 8k. The engines are not chipped.
  
• The M Coupe weighs in at ~3,000 lbs, 400 lbs lighter than the M3's ~3,400 lbs.
• The M3 has SMG, the Coupe has a standard 5 speed but with a 3.46 final drive.
  
• Both cars are on Kuhmo's magical V710 tires, which have enough grip to rip your face off. The MCoupe 245/45/17 and 275/40/17 while the M3 has a square 285/30/18 set.
  
• The M3 benefits from newer suspension technology. Both cars have aftermarket shocks, springs and camber plates. Nicely set up but nothing extravagant or exotic.
  
• The M3 has 4 wheel Brembo set, The MCoupe has stock BMW brakes with Performance Friction rotors in front. Both cars use Performance Friction pads.
  
• Both cars retain full interior, air conditioning, radio etc.
  

Below is a comparison of AC and my fastest laps from our recent visit to the Glen with Group 52. AC in the M Coupe (affectionately known as "The Shoe") was able to cross the line first with a 2:12.3 and I was just behind in the M3 with a 2:12.7. Let's take a closer look:

The main thing to follow here is the graph at the bottom of each picture, the Velocity vs Distance plot. It's important because it shows who was going faster at which parts of the track. On the top right we show which car is leading overall, and by how much. The spreadsheet in the middle shows other interesting stats like time through that segment, min speed, max speed, max g forces and more.

Click on the images to enlarge them. Let's start the lap.



Through Turn 1 we are pretty much identical. Our minimum speeds are within a few tenths, we brake at the same time, and get back on the gas at almost exactly the time. Our net time difference at this point is negligible.






Through turn 2 we lift exactly the same amount, up the Esses we are dead even up to the shift to 5th in the back straight. This is where SMG shows its advantage with a nearly undetectable blip in the graph whereas the M Coupe's standard tranny shift is clearly evident. This extra shift time nets out to a .15 second advantage through that section for the M3.





Segment 3 is interesting. Both cars brake on the back straight at almost exactly the same point, the M3 brakes a little less and carries slightly more speed through the bus stop but the M Coupe carries more speed around turn 5, "the outer loop". The net difference in that segment is a .05 second advantage for the Coupe, which cuts the M3's overall lead down to .1 seconds.




Turn 8, "the Laces", is the first segment where the two cars show an appreciable difference. In the M3 I'm able to brake 1/2 a second later and get back to full throttle slightly sooner than AC in the M Coupe (thank you Brembo and PF-01 :) ), which nets a .6 second gain in that segment. I'm now ahead by .7 seconds overall.





But, AC brings it back in 7, "the toe". He uses a lot of trail braking, and carries 4 mph more minimum speed through the toe.







Then he's able to storm up the hill and pull harder than the M3 in 3rd gear (this probably has something to do with the 400 lbs weight difference). Overall, AC is able to gain back .5 seconds in that segment and cuts my lead to .2 seconds.







Coming up to 8, "the heel", I brake a fraction of a second later, we go through the turn at nearly the same speed, but AC gets on the gas a fraction of a second sooner, and again, the M Coupe out-pulls the M3 in 3rd gear. AC gains another .1 seconds in that segment and cuts my lead down to just .1 seconds.





For the off camber turn 9, I brake slightly less but I only gain .05 seconds. My lead is only .15 seconds.








Through the fast left turn 10, we are both identical with identical segment times.









In turn 11, AC gets on the gas a fraction of a second sooner than I do and again is able to out pull me in 3rd gear. That seemingly tiny difference nets out to a .45 second advantage through that segment and gives AC the faster lap time by .35 seconds.







Here is a side by side video of the above laps. It is a 33 meg download. If you want to hear the individual engines just pan the audio to one side or the other.


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As always, we recommend downloading the higher resolution version above...but if you are in a hurry here is a fuzzier flash version:


M3 vs MCoupe Part II from Axis on Vimeo.

Axis going for a track day world record!

the perfect storm of scheduling has hit the Axis for the next 10 days: 5 cars and an aggregate of 15 track days and at least one autocross.
CG was at Pocono with Adil for a double infield open track day with PDA. Then it's on to Lime Rock on Tuesday with SCDA for a Lotus Clam bake and then straight from there to Watkins Glen for 2 days of open track with Group 52 on Wednesday and Thursday.
Stee will be joining CG for Group 52 then on to Summit Point to instruct at Hyperfest on the 23rd and 24th. badbadM will be doing the spec e30 NASA race there.
I was supposed to instruct at Watkins Glen next Monday and Tuesday but had to cancel because the MCoupe is still at the fabricator getting the roll bar, but I lucked out when HRM Motors' boss Mark Starr had to cancel his spot with Group 52...so I will be at the Glen with CG and Stee next wednesday/thursday then down to Summit to instruct at Hyperfest with Stee...

hopefully our cars will not explode.

Cool thing is that this week saw the debut of Adil's and CG's new toy...the Axis-Gulf S-exige! it is going to be an awesome track car...more on it as the marathon progresses.

Ever wonder how your tire feels?

I was curious so when we were at the last Pocono East track day with PDA, I attached a camera to the bottom of the MCoupe. The camera is pretty cheap but you do get an idea of what your tire goes through on a typical day out.

In this case you can see my Kumho V710's contact patch change as the tire loads and unloads. When it's unloaded only a quarter or less of the tire touches the ground. At the end of the straights you can see the tire compress and flatten under braking.

If you ever wonder why the outside shoulders get worn out so quickly, just have a look at what the tire is put through in the tight right hand hairpin... Consider that my car has negative 3.8 degrees of camber, imagine a car with stock alignment.
Now you know why it's a good idea to put extra air in a street tire on a stock car!

Sound is not so good, you might want to turn the speakers down.



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I used this elCheapo $40 security camera

First round of the American HPDE championship

The usual group of track-tards ran the hotly contested first round of the NA-HPDE Championship at Pocono East on Cinco de Mayo 2007.
An international group was vying for the top prize: India, Venezuela Italy Colombia and the USA all after that most elusive of prizes, a good time....ok and bragging rights.

We'll post Traqmate data files and individual videos later, but suffice it to say that the GT3 Rad eS was unbeatable.
OK, we got to kick Rad's ass when analyzing the data we found he left at least 1 second on the table by being too lazy to downshift, but there was no denying the 3000lbs 400hp car with giant tires. Rad had a 1:11.3, AC a 1:12.0 and CG 1:12.2.
Stee in the Spexster for the first time ever almost got to 1:14 and Adil... he is still in transcendental meditation mode and has not yet shared his data!

The Data analysis is going to be interesting, each one of us was faster in a different section, even Stee with a slower lap time had the fastest apex speed of all in one fast turn showing the handling potential of the Spoxster.













Below is a VERY LARGE Cinerama extravaganza: from left to right, in CG's 997s, from the rear bumper of AC's MCoupe and finally inside with AC, the sound is only from the MCoupe. CG and I had fun for a few laps until I left the braking too late and decided to do the smart thing rather than risk eating hay bales and armco for lunch.

As I said large but I think well worth the wait. On a Mac it will stream, on PC I'm not sure. Click on the window to see it online or the link below to save on you computer.


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First round of the European HPDE championship

Looks like our friends over at Track4fun were contesting the first round of the European HPDE championship* at the glorious Salzburgring in Austria.
Though Zampa, the driver of the GT3 in the video below left, will have to consult JustGoFaster.com's list of tire excuses soon, the sound from his GT3 is just fantastic, I love it.
(photos by Andi111s)


Now speaking of HPDE championships, the Axis will be fighting hard for pointless bragging rights this Saturday at Pocono East, Time trial and lots of cameras, EVO IX vs 997s vs GT3 vs MCoupe vs M3... weeeeeee! Below right is a video of what happened last year around this time.

*"HPDE Championship" also known as the "Track Day Championship" is a self-mocking term among track-a-holics.

Sticky Monsters

I finally got the chance to try the crack that are a new set of Kumho V710 at the track. BadBadM had described the experience in this previous post but I don't think I was fully prepared. Simply put, I could place the car anywhere, I could take any line I could get away with ridiculous slip angles... it was quite a "different" experience. Well maybe more like turning your amp up to 11.
Even with the a full track and no full laps that were 100% traffic free I was able to turn a lap at better than a second and a half faster than I had previously run at Pocono North during a Time Trial. That Pocono North is made up in large part by a superspeedway section only highlights the efficiency of these tires in the turns.


I ran on them for 40 minutes with badbadM in the car with me so with extra weight (albeit extra weight who was spurring me on with glee)

BBM and I were attending an instructor training school so we literally had no time to even turn the cameras on but I did record the session with the Traqmate.
Best I could do is film the Traqview software on the computer screen. It's not much but you can see some of the functions. In this clip I combined my best lap with Stee's best last time he was there. I'm the blue dot in the s54 MCoupe and Stee is red in the e46 m3. You can see how since I've changed the final drive ratio to 3.46 the two cars are very closely matched with any advantage being due to line and tire grip related bravery (stee was on toyo Ra1 at the time).


Download


you can download the Traqmate file HERE
and you can download the free software on the Traqmate site
Photos courtesy of TrackTime Photos

Building an SCCA ITR Z3 Coupe.

We never post enough pictures of our own cars here, buncha lazy bastards we are. Shame too because BadBadM practically built his spec e30car from scratch in his garage after work, ThumperRay changed my whole diff in 15 minutes with one hand tied behind his back and Stee is building a spec Boxster...well, eventually he is.

So when Josh Sirota, an internet friend from GoDogGo Racing sent me some info on his current project, I though it would be cool to share:

JoshS writes:


I'm finally back in a Coupe! I was a very early M Coupe owner. Ordered the car in May of 1998 based on the photos I'd seen in magazines, and picked it up in September. I autocrossed it a few times and found it to be a great car in the wet but a fairly lousy car in the dry. But I didn't buy it to autocross it, it was just supposed to be a fun street car and it was!

That car went all over the country with me and my motorhome in 1999. These photos are from the top of Pikes Peak, the Indianapolis Motor Speedway and somewhere in Minnesota.






Still, in 2000, I found myself at the SCCA Solo Nationals in Topeka, for the 11th consecutive year, driving, you guessed it, a borrowed 2000 M Coupe. It was in Super Stock then and both myself and my co-driver (multi-time national champion) Jeff Reitmeir stunk up the joint. The suspension on that car is not that great on sticky pavement.

I sold my car in 2002 for a new E46 M3. I wanted the latest and greatest stuff with more creature comforts and more horsepower. But what I discovered was that although I enjoyed my gazillion-way power seats, navigation system, 6-speed transmission and all of that good stuff, the M3 just never stirred me the way the Coupe did. I found myself participating more in the online Coupe forums than the M3 forums, even though I didn't have a car. I knew someday I'd be back in a Coupe, but it wouldn't be a street car. I'd been there, done that.

I started Club Racing with the SCCA in 2004. That first season I rented a 4-cylinder Z3 from TC Kline for Showroom Stock B. By 2004 the car was considered well past its prime for the class but I had an absolute blast driving it and did pretty well against the then-dominant '99 Miatas. For reference, I ran in the 1:51 range at Laguna Seca, which is really a great lap time for a car with only 139 horsepower.

I then raced at the National level in Showroom Stock (Mazda3) and Touring (Subaru STi) for the next two years. Had fun but was a little disheartened by how much time and money it really takes to run at the pointy end of the grid at the National level. Here I was, a guy with a car, competing against factory-funded teams with full-time race-prep staff! I did pretty well, especially in the Mazda, but I wanted a fairer fight.

Then, last fall, the SCCA created a new class called ITR (Improved Touring R). IT has been around a long time, it's often considered an entry-level class because many of the cars, especially in the slower IT classes, are very inexpensive to buy. In addition, the cars have to be at least 5 years old, which keeps the manufacturers from being directly interested. But for years the fastest class in IT wasn't all that fast-- the fastest cars were the E36 325i and even they needed a restrictor plate to avoid trouncing the rest of the class.

ITR is just a faster version of ITS. Most of the cars came with somewhere between 180 and 225 horsepower in stock trim. The prep allows for minor engine mods (slight bump in compression, slight overbore, balance/blueprint), but stripped interior, any exhaust system, and bolt-on suspension mods. ITR allows all cars up to 17x8.5 wheels.

One of the cars listed for the class is the Z3 Coupe. This is the Z3 version of the M Coupe I used to have. It came with the 2.8L or the 3.0L engines. But the 2.8L is classed with a minimum weight of 2800 w/driver, and the 3.0L has to weigh 3200 w/driver. Seems like a no-brainer -- 2.8s are easier to find, cheaper, and get to weigh 400 lbs less. There's no way that the additional horsepower in the 3.0 could make up for the 400 lb. penalty, so I went searching for a good 2.8L car.

It took less than a month for me to find my Coupe. It's a '99 Z3 2.8, and it had 99K miles on it. But it was very well maintained by an enthusiast. And to top it off, it was down in Santa Monica, only a 6 hour drive away.

Within a couple of weeks, I found myself disassembling the interior, to prep it for the roll cage. The cage went in with some other related fabrication. While it was at the shop, I acquired a large pile of parts. Once I got it back, I spent a lot of hours in the garage installing parts, and then finally took it to an SCCA pre-season tech day to have the scrutineers look it over and issue a logbook. Although they noted 3 minor issues (the most complex of which is that I still don't have car numbers, class letters, or the other required decals on the car), they issued me a logbook. I'm official!

Speaking of graphics: here's a photoshop of the current graphics plan. If anyone out there is up for it though, feel free to suggest other things. I'd like to do things that aren't too complicated, because I don't have the ability to design really complex patterns. But if you do, I'd appreciate the help!

My intention is to race the car with the original engine, software, andexhaust system, for this season. It won't be competitive, but it's a new class, so the turnout will be light initially. To be competitive, it'll take a freshly built, limit-of-the-rules engine, with a good header, no cats, custom software or replacement ECU, etc. I'll research that and get that done later in the race season.

Without further ado, here are some current photos and a list of the mods
to the car. For many more photos, see my photo gallery.

Interior/exterior mods:

TC Design custom roll cage
TC Design interior panels
Sparco Circuit seat
Evosport seat mount
Momo Mod80 steering wheel
Extreme Performance quick-release
Schroth harnesses
TeamTech window net
Longacre convex interior race mirror
BMW convex left outer mirror
OMP fire system
Kill switch
Deka AGM battery
A/C removed
TC Design towing eyes
TC Design/Jaffster delrin shift knob

Engine mods:

Conforti intake
Zionsville radiator
Dinan cat-back exhaust.

Drivetrain:

Kosei K-1 17x8.5 wheels
Hoosier R6 245/40-17 tires
BMW 3.73 LSD
TCK wheel studs

Suspension:

TC Kline/Koni coilover suspension
H&R front swaybar
Offset control arm bushings
Dinan rear camber/toe adjusters
Korman delrin trailing arm bushings
BMW Motorsports Gruppe N subframe bushings
Strong Strut strut brace

Brakes:

Turner Motorsports brake ducts
TC Design brake duct foglight mounts
Hawk Blue brake pads
Stop-Tech stainless lines