RPM dip doing onto stop, w/ racepak graphs

Charlie Yannetti · 05-01-2024, 10:04 AM

I have the same graphs in my Roadster.. if I raise the cruise RPM, it goes away.. BUT, then I have to run more numbers in the box, and stay on the stop longer.. not a fan of that, and it cuts back a MPH or two at the top end, as you're actually shortening the track so to speak..

Adger Smith hit on an important issue, SHIFT POINT.. my stop comes on at .10, and the shift point is .20.. it makes perfect sense that the shift is causing an additional drop in RPM.. especially while taking power away.. I'm going to move the shift point out at bit to see if that's a fix.. the car I worked on this weekend has the stop come on at .10, but the shift is at .90.. graphs look great..

Having a torsion bar front end, I was assuming that the touch down after the launch may have been disrupting the floats, and causing the dip.. NOW, I'm not believing this to be the case.. raising cruise RPM doesn't change the touch down after launch.. WE'LL SEE!!!

05-01-2024, 10:04 AM	#1
Charlie Yannetti Senior Member Join Date: Jan 2005 Location: Alpine, NJ Posts: 560 Likes: 181 Liked 183 Times in 79 Posts	Re: RPM dip doing onto stop, w/ racepak graphs I have the same graphs in my Roadster.. if I raise the cruise RPM, it goes away.. BUT, then I have to run more numbers in the box, and stay on the stop longer.. not a fan of that, and it cuts back a MPH or two at the top end, as you're actually shortening the track so to speak.. Adger Smith hit on an important issue, SHIFT POINT.. my stop comes on at .10, and the shift point is .20.. it makes perfect sense that the shift is causing an additional drop in RPM.. especially while taking power away.. I'm going to move the shift point out at bit to see if that's a fix.. the car I worked on this weekend has the stop come on at .10, but the shift is at .90.. graphs look great.. Having a torsion bar front end, I was assuming that the touch down after the launch may have been disrupting the floats, and causing the dip.. NOW, I'm not believing this to be the case.. raising cruise RPM doesn't change the touch down after launch.. WE'LL SEE!!! Last edited by Charlie Yannetti; 05-03-2024 at 11:13 AM.