I’m having problems about 3-4 times a year where the car shifts via the electric solenoid however it stays engaged until it starts smoking. Each time I have to replace the relay which seems to be sticking in the on position. I’ve tried different solenoids and brands of relays. The ground goes directly to the chassis and it’s clean. What can cause this or what am I missing.

Assuming you're talking about the 30 amp square relay? Make sure you have it wired correctly. The #30 terminal must go to the 12v power supply. The relay will operate if you have #30 and #87 swapped and in most cases you would probably never have a problem with it, but internally that will fry the contacts sooner.

What relay are you using and what amperage is it rated at? I've used Radioshack relays with no problems. Should be 30-40 amp rating.

What +12v output device is activating the shift? Is it activated on RPM or on Time?

Check with the manufacturer. I've used a few different styles/brands and a few of them require different size wire and relays. I just switched to a heavy duty solenoid from shifnoid and it requires a bigger wire and relay.

Reason contacts are failing is they are not rated for the amperage. I used one similar to the one at this URL. https://www.rakuten.com/shop/r...ical/product/67-702/
basically a tin can with two big high current connections and two smaller connections to apply 12 volts to. One grounded and the other to the control. Or flip it and tie one to 12v and switch the other to ground. To activate.

Look at these relays. They are not as small as the little 30amp relays but are still more compact than the one posted above and are rated at 75 amps continuous. We use and sell these at my company but ours are special ordered as a double pole single throw.

https://www.delcity.net/store/...F3GtTuhoCr74QAvD_BwE

MSD has a solid state relay available that has 4 relays built in at 20 amps per. You can wire two of them together for 40 amps. MSD Relay

I've considered ditching all of my mechanical relays.

I’m using the 7al3 ras to activate the relay/shifter. The relay is the one that comes with the solenoid. I think I’ll try the one listed above. Thanks.

Here’s something to investigate. When you are doing your burnout, and “if” you are achieving the same rpm level the ras chip value is set to, you are activating the shift solenoid in the burnout also.

If you look at most RPM shifts on a data acquisition display, the shifter output is generally ON for no more the 0.30 seconds. Many as little as 0.15 – 0.20 seconds.

If it were me, I’d chose the relay Curtis listed.

Is it fused? Until you get it figured out it would be cheaper to replace the fuse rather than the relay and/or Shift Solenoid...just a thought.