I assume you are talking in True Wind. 18 True would look something like 22 Apparent going upwind. The Capri 22 is a fractional rig - meaning that the jib doesn't go all the way up to the masthead when it's raised. Fractional rigs tend to use smaller headsails. So on a masthead boat the "Working jib" would often be the 135% while on a fractional boat it would be around a 110%. Depowering a fractional rig would normally be done by reefing the main before changing down the jib. To power up you could use a larger jib. But a larger jib will not be necessarily faster. If it causes excess heel or cannot be trimmed in properly it may be slower or not point as high. If you have rail meat you may be able to carry it.
The carts on the cabin top are for a jib in the 100% J size. The sail couldn't be trimmed to its best shape if the sheet had to go around the shrouds. On the inside carts it could be trimmed in properly for upwind sailing. But the jib is limited in length by the spreaders.
On Sailboatdata.com there's a picture of a Capri 22 showing a jib that looks like a 110%. It is sheeting on the tracks near the rail. The picture doesn't show cabin top carts as far as I can tell. Those may be a PO addition.
The blown out 112 with the high clew won't perform for racing. The J for the boat is 8.12. So your sail with the 13' foot looks more like a 160 with almost 5' more foot than the J (No wonder it is cut high!). Your sailmaker, who if local, can make the best recommendation. The Capri 22 was marketed as a racing boat and its designers Gary Mull and Frank Butler know a thing or two about how to make a boat go. Outfit the sails as designed making adjustment for local conditions. It is also a very good looking boat.
I thank you for a very detailed answer. Racing this year was an eye opener for my wife & I. We just downsized from a Cal-33 which we use for cruising and racing, but the lady is only racing. Moving to a Capri 22 from a Cal 33 was an eye-opener for sure! We had to learn how to sail all over again and with your help, we’re still learning.
one more question, what about downwind? Oil change or use the 110? I’m not sailing Spinnaker yet until I learn how to sail it properly & comfortably..
Thank you for your answers and looking forward to hearing from you again.
Wayne Morris Delta Flyer.