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Jason_323i wrote:Trackday Z3M coupe and race e21 ideal combo

Yep. The MZ3 is in the shop and getting stripped to be a full blow race car too. I see you have a Compact with an S50, we have one of those too. It's a time trail/track day car. It's not my personal car, but belongs to one of the guys at my shop. He and I are headed to the track this weekend to do some development with the E21 and the Compact. It should be fun!

-bj

You heading to the Texas Motor Speedway, my sister lived in Keller for a few years so I made it the track a couple of times.

Jason_323i wrote:You heading to the Texas Motor Speedway

Nope, but I've driven that track many times, though. I had a pretty spectacular race in an E30 there.

I'm headed to MSR Houston. It's not a track I'm particularly fond of, but I'm instructing with the organization that is putting on the track day which means free track time for me!

-bj

you said you have a 4.10 LSD, any details on that?

Testing went well at the track. The E21 race car is really coming along. She about 90% of the way there. The car currently weighs 2250 lbs with a full tank of gas (7 Gal) and me in the car. The cross weights are a 50.5/49.5 split. The front/rear balance is 54/46.

New for this weekend:

• Wilwood 4 Pot front calipers
• New cooling fan
• All new gauges
• Ride height lowered
• Fresh Alignment
• Corner balanced
• Poly trailing arm bushings installed
• Revised fuel tank (only using the right side of the OEM tank)

Things still needing work:

• Body work
• Aero changes
• ECU tuning, especially part throttle
• New wheel and tire package
• Further weight reduction/redistribution

I finally have some video of the car getting around the track. This is at MSR Houston in Houston, TX.



Enjoy,
-bj

Nice! Not a real 'technical' track but pretty fast. Car behaved like it should? Any engine or brake overheating issues?

Jeroen wrote:Nice! Not a real 'technical' track but pretty fast. Car behaved like it should? Any engine or brake overheating issues?

Not very technical at all. It is one of my least favorite tracks here in Texas. It has almost no elevation changes, which is what I find the most disappointing. Yet, being at a ho-hum track is better than not being at the track!

Brakes were amazing. Especially compared to the stock calipers. The last test day I had, I was running The stock brakes front and rear with an E30 master cylinder and bias valve. The brakes were horrible and rear biased even with a split friction pad setup: Hawk DTC-70 Front / Hawk HT-10 Rear. I also had brake cooling ducts at the previous test day.

This time I left the rears alone, but remove the brake cooling ducts, and installed Wilwood 4 pot calipers and stock rotors. I used Wilwood Matrix A compound pads. The braking was consistent with no fade even over a 30 minute session. (I think part of the problem with the old setup was that I wasn't getting the DTC-70s up to operating temps.) Pedal feel was exactly what I expect of a modern race car.

The aftermarket radiator/oil cooler setup is amazing. With 95 degree air temps, I could never break 190 degrees on water temps and 205 on oil temps. Oil pressure was rock solid as well. She is almost running too cold.

She's becoming a really good race car!

-bj

Good to hear! Must say that I sometimes find the pedal feel slightly soft, think the stock E21 brake booster in an unknown condition is to blame. Anyway, great ur having fun and the next track you're trying will only be more fun and with more 2nd/3rd gear turns oil and coolant temp will probably be slightly better too.

The car is really coming a long, now. Here's some video from Gateway Motorsports Park in St. Louis, Missouri.

This was a cold morning session on Nitto NT-01 tires and a 210 lbs passenger.



Enjoy.
-bj

Don't you have decent tracks around there? nice sound and powerful enough, looks good!

Jeroen wrote:Don't you have decent tracks around there?

I'm not sure how you meant that, but Gateway in not a very good road course. There are some great tracks in Texas, but Gateway in St. Louis is where I did my first track day years ago. I made the 10 hour tow to St. Louis to see old friends--not for the track. Gateway is only 1.67 miles long, most of which is a NASCAR banked turn and a straightaway.

-bj

No offense, what I see is that most tracks in the US are so different to the ones we have here in Europe. Less technical, less demanding, very wide and more high speed. Guess it's just what you're used to, or perhaps this is done to accommodate the roadholding of the average US built car oops gotta watch out for Camaro man now

Jeroen wrote:No offense, what I see is that most tracks in the US are so different to the ones we have here in Europe. Less technical, less demanding, very wide and more high speed.

It varies greatly from track to track. The track in the video, Gateway, is a very non-technical high speed track. At track like Hallett in Oklahoma my average speed would be 20 mph less. Hallett is tight and very technical. But, in general US road course are indeed higher speed and larger. I don't know if less technical or demanding is fair, though. They certainly are less busy, though.

I think a lot of it has to do with the difference of US roads and the venues for early US tracks. US roads have always been wider and straighter than European roads. A lot of that had to do with population density, terrain, and the fact many US roads were developed much later than roads in Europe. The early US road course tracks, were mainly airports where there were many long run ways with sharp turns at either end. Later US road courses were built in a similar fashion, but instead of runways, the straightaways were drag strips.

Oh, I took no offense by the way. Gateway in particular is a boring track.

Yeah I guess the difference between the normal roads has its influence as well, and just what you're used to. Here we are used to tracks that are more technical where you need to develop a strategy to connect series of demanding turns which can be a challenge to start with, redefine that strategy as soon as weather conditions change (rain or something lol) or when you make one mistake in braking, potentially messing up a whole series of turns. I remember F1 drivers telling me about the local track here that if they messed up three turns before the straight, that would still influence their top speed on the straight. But that also has to do with the fact that this is a short and narrow track btw.

Keeping all these challenges in mind you still need to find a spot to overtake and include that in your strategy otherwise you'll loose your position again in the next turn. Oh well, with higher average speeds you have other challenges haha. Apologise for the OT, I love the video, keep 'em coming

Here's another one. This is a 3.1 mile track just outside of Dallas, TX.






-bj