Well I finally got to try the FCR carbs on track yesterday. The car now hits 7500 in 3rd a solid 100 meters before it did previously and I was stoked thinking I'd finally break the 100 mph mark BUT just as the got near 5800 it seemed to slow down and at about 6000-6100 RPM's nothing happened...................so 96.8 - 97 MPH seems to be where it's stuck on my local track. Coming off turn 2 at around 6K in 3rd (70 mph) it's roughly 1/4 mile up hill run to turn 4 ( 3 is a 150 MPH corner) before braking down to 2nd gear.............if this were a longer run the car would likely pick up a few mph more. For a comparison I drove a friend's 99 Miata and was that just shy of a 100 as well. I would have done some tuning but I was instructing as well as driving, so only had about 20 minutes of down time between sessions.

Now the one oddball thing is there is this peculiar whistling noise at 1/8th steady throttle. (sounds like turbo car) My first thought is I have a vacuum leak but other than the odd sound there seems to be non of the typical vacuum leak symptoms. I do still have a very very minor glich at around 4k if you try to feed in the last bit of throttle to early...........only happens on warm up lap or cool down laps as the I'm keeping the motor over 5K otherwise.

Now the fun part: throttle response is better than the SU's, the motor has a really nice snarl. (The snarl doesn't make it faster but it's still sounds cool) I nearly ran out of gas on track..............the car used to do three sessions on 4.5 gallons.............now in the middle of session three I nearly ran out and was able to use the alternate pit and work my way back (downhill) via the service road...........oops.

next event is late October so I will have to go back to the dyno and sort the last bit of jetting, after making sure I do not have a leaking manifold gasket. Who knows we might put on one of those funky Aero nose pieces and a splitter.............OR I'll just go ride my dirt bike instead.

Finally a note to any GoPro users I mounted the camera on the roll bar, the interior of the car is crystal clear but the glare from the front means no footage of the actual track............I found out I need to mount the camera up by the windshield as the little GoPro doesn't deal with the contrasting light well..................current footage is truly "in car"

Tom

The Go pro has a setting to spot meter, not overall metering.

It makes a massive difference, inside the car is a little dark but outside is perfect.
Thats on the High def model...

I can look up in my instructions on the code it uses if you cant find it.

So would a shorter rear gear help you get to top speed more quickly? Wouldn't change the top speed, but might get there a bit faster.

Dave............absolutely a shorter rear gear would be a improve the lap times. Because I'm no where near the redline in 4th it might even help the top speed slightly. An example would be my old Showroom Stock Miata, in 5th you'd see 108 but 4th it would pull 110 mph. So it may be time to go to a 4.37 rear gear from the 4:11 (just need to find one in a H145). I can remember one of the 80's GTP drivers saying every time they got more horsepower in a car they'd end up adding more downforce, so the speed of the car stayed the same but lap times went down by 3-4 seconds...................if this where one of my motorcycles I'd have swapped out for a one tooth smaller countershaft sprocket...................even if I left the set up as is, I'm now keeping up with the Spec Miatas.

The other thing I forgot to mention is a guy with a 2010 Camaro decked out with all the goodies stopped and told me how much he loved 1200's .................used to have one back in the day.

Tom