Quarter Jr deal

[Tony Curcio]

I downloaded the programs last night. I have 32 single-page calculators and two full blown programs, Quarter Jr and Engine Jr.

Quarter Jr predicts ET, while Engine Jr predicts horsepower & torque. They usually cost $95 each, got all 32 files for $99.00. When/if 250 or more people buy the package on sale, we can all download additional programs.

I had both Engine Jr and Quarter Jr in old DOS format, and wanted to upgrade anyway. The new versions work with torque converter stall speed instead of a factor they used to use, called something like "converter pressure".

It's sorta kinda accurate for getting a ballpark indication of what a change in gearing or added horsepower might do. In my case, the 60 foot times are much slower than in real life. The old program had a way to fudge the result to get it in line with reality. I haven't had time to figure this one out. Also, the best virtual shiftpoints never matched real world on the two race cars I have owned.

Engine Jr. has a parameter for intake duration, but nothing for exhaust duration and nothing for lift for either side, and nothing for center lines. My old program had this stuff. The new one has a parameter for flow in cfm at 28 inches, which I suppose compensates for these things.

The other files have a lot of handy formulae for things like max carb size, header tube lengths & diameters, calculating the volume of an intake port, estimating the cfm for a port once you calculate the volume, estimating the effect additional valve lift will have on flow (not as much as I thought), estimating a combustion chamber cc; compression ratio, cubic inches, port velocity, best fuel injector size, and more.

This stuff is great for looking at cars you'd like to build some day, and might be useful for getting a starting point for a new combination. I feel I got my money's worth, but obviously, there is no substitute for real world testing.

I do intend to upgrade to Engine Pro if it will let me plug in different header sizes and full cam timing. I think this could be a way to find out what direction certain changes take the engine before spending a lot of time and money on parts and testing.