Testing the HiRev 7500
Wow now you really got me thinking . It always seemed to me that when I ran a duel point Excel with good points and a high performance condenser my top end power was really good (better )you think it could have to do with the timing being pulled from the box on the high RPMs on the rev 7500 box
Very possible. As RRR said above there are times in high gear you want to pull some timing out but you have to test for that.
I can’t say all but most every engine wants less timing at peak torque and more timing at peak power. Which is the opposite of what happens when the box retards and you don’t know it’s doing it.
My mentor told me this story. And it’s true. They learned two important things.
They had one of the very first GM Magna Pulse ignitions. And he and two others were all involved in a Modified Production car.
He was close to running the National record and they all thought the new ignition could put him closer to running on or even setting the record. So they install the ignition, one of the guys grabs his timing light, and they set the timing as it was before with just the points.
They go to the track with the owner and it wouldn’t pull the hat off your head. They couldn’t figure it out.
Back at the shop, a different guy grabs HIS timing light and the timing is off several degrees. Now you have three guys pointing fingers at each other, claiming the other two can’t use a timing light!!
One of them gets the big idea to grab all three timing lights out and hook them up. And all three read differently. By several degrees both advanced and retarded.
That was lesson 1.
Then they got the bright idea to put the distributor and ignition on the test bench just like it runs in the car. And they learned what I’ve been showing in these videos. It had a bunch of retard in it, and the engine didn’t want the timing retarded.
Lesson 1 is all these ignition systems retard with RPM and they are all different even between the same part numbers and date of manufacture.
That’s lesson 2. It’s still true today.
Guys are giving up power by not checking this and accounting for it.
I hate giving up horsepower more than I hate ear aches and watered gin. And I hate both of those.
Everyone should find a guy local to them with a test bench and have them hook the ignition up just like it is in the car and test it.
IMO it’s worth every penny.