Pueblo Motorsports Park April 13-14, 2019
So, we made a number of changes over the winter. We rebuilt the engine, just because it was time. The engine had 50K miles on it when I installed it 4 years ago. We raced it for 3 seasons with the stock original short block. It was starting to burn a little oil, so it was time.
During the rebuild, we changed the cam to something a little “bigger”, and added a MSD intake manifold and TB. So now we have a little more power, and the power band has moved up a bit. http://www.racingtheexocet.com/?page_id=40917
Also, we changed tires. I was using a Hoosier R7, 275/50. It’s a great tire, and lasts all season. But, we could never get it hot enough to really work. It’s operating range is 180-200*F. We rarely got it above 140*. I think the car was over-tired.
This year we’re using a smaller tire, 245/40. And we went to a Hoosier A7 compound.
You can see it’s also a much shorter tire, by about 2″. This did a couple of things. The smaller diameter is like going to a shorter gear; like 3.55 to 3.73. It pulls stronger out of the corners, but changes all the shift points and decreases the top end speed. Fortunately, the new engine has a higher RPM limit, so we didn’t lose much top end speed.
It’s a very different car now. Shift points are different, traction is better, engine redline is higher. I have to learn to drive it all over again.
And, the A7 is a much stickier tire at lower temps, so even though the weather was very cold, I did get excellent traction. As cold as it was, I was very close to my best time there.
Well, that experiment didn’t work out very well. The A tires were sticky; but the smaller diameter cost me time. Didn’t see any improvement in lap times. Next year, back to the 275’s.
Well, what do you know? I ended up second in points! not a bad at all. 🙂