This past weekend I went to our SCCA/PCA track day with the coupe. Unlike February the track was dry so I had a chance to evaluate the changes: Mid-Close Ratio 4 speed, 14 lb flywheel, removal of the fan & about 60lbs of weight savings.
(This was at Spring Mountain Motorsports Park there is tons of you-tube video from that track online if you want to see the layout)
The close ratio gearbox transforms the car, no more having to rev the snot out of it in 2nd to cover the 3000 RPM gaps, I can now choose to shift where I couldn't for fear of bogging the motor and NOT shift where I had to because I can pull the next higher gear....not to mention 1st gear is now usable in at least one spot on the track. The flywheel adds a nice little snap to the motor as well.
The best part was heading up the hill to the turn 4/5 complex I glanced at the Tach to see it sweeping past 6000 RPM's, it's pulling 6100 before the brake zone which makes 96 mph. previously I was doing about 92 mph.
Also this weekend was run in conjunction with MFest 3, BMW drivers in 400-600HP many of whom had not a lot of track experiance. I ended up with a M5 owner as a student and he was almost immediately turned into a 1200 convert. He originally rode along just to see the line at speed but had so much fun that he wanted to go again. He kept telling his buddies about having big HP cars go by on the straights and then we'd be back on them in the corners or guys who'd run up on us at the end of a passing zone and then taking half a lap to catch up again. Now the down side of the 2 of us laughing and enjoying the 1200's cornering speed is his extra 210-220 lbs killed the straight line speed and it didn't stick real well in some of the left handers (remember LHD car - passenger on right), not to mention the tires would go off after about 5-6 laps, the tires are pretty old and this was their last event anyway.
So after 15 years of knowing I needed to pry open the wallet, knock the moths back and spend so money on a proper gearbox I was left thinking "why didn't I do this sooner" It is really an absolute ball to drive, even more now than ever.

Tom

Nicely written account.

I think the mid-close ratio gearbox would be good for the street too since the revs drop sooo much during shifts.

Ironic you mention the Mid-close for the street, that is exactly what I was thinking. I try to keep the car near streetable because I have the title and with the way race cars land in my lap I could end up with another single seater, as the wife as forbid the sale of the car a 3rd time, putting it back on the street would ensure it got driven. Plus my son is now 15 and he and his friends think Dad's Datsun is a cool old school car, it might make him a him a car he could drive to Autocross. He has said he couldn't have a 1200 as a daily driver becuase he'd worry about it be stolen.
In the meantime, I'll be installing an O2 sensor to see what the SU's are really doing. The car runs solid but you never know till you check.

Tom