last season i put a new topend in my 91 indy 500. I put in new wisecos. i put on about 350 miles since the rebuild. This summer i want to make any improvements i can. It always had poor take off power but really good mid to top end. what can i do to improve take off with out doing any mods to the motor? I do however like its mid and topend but dont wanna rob anything from it. Anyone have any ideas or suggestions? thanks in advance!

A progressive helix and matching spring are exactly what you are looking for, what you are talking about is exactly what a progressive helix does. I put an SLP 38/34 with SLP Black secondary spring in my 500 efi and it's night and day difference taking off from a stop and the low speed acceleration. It now absolutely snaps. Top end is no different from before. I would contact the aftermarket manufacturer of your choice about the proper helix for your setup, I've had good luck with startinglineproducts.com but I'm sure there are many good suppliers.

if your running snow, i like to run a straight helix. there are many other ways to get a good holeshot. drop your needles a hole and see if it improves. if not go the other way. check your engagement rpms and hold slightly below that for takeoff.