Hey guys, I have an MS3 cam and a 3600 stall. I just have a few questions about the stall/cam setup because I've never driven anything like this before. When I'm cruising at highway speed, I let off the gas, then the car seems like it's surging, just at the idle speed in overdrive on the highway. As soon as I get on the brakes or the gas, it goes away. Is this just a typical thing with a decent size cam and stall mix?

 

What you are feeling is engine surge due to the high duration cam running at low RPM. You only feel the surge when the converter is locked up. When you hit the brakes, the lockup disengages and you no longer feel the surge.

My cam surges up to about 1800 rpm which, with my 3.42 rear, is about 60 mph. I have tuned my lockup to occur at 55 mph which is much higher than stock but still gives me a bit of surge.

 

Your car shouldn't drop to idle speed on the freeway during coasting, that means the converted is unlocking. You should have a competent tuner look at your tune. The brake pedal switch will initiate an unlock however.

 

Well I don't mean actual idle, just idle when I'm off the gas cruising. That's at like 1900-2000 rpm now. And ok yeah it makes sense it would do that since it happens at lower rpms cuz of the cam. Thanks for the input!

 

The converter can be set to unlock when you lift off the gas without requiring brake input. I prefer mine this way.

 

That would annoy me lol.

 

That is a tune issue..

 

It has it's ups and downs.

Primary down is it reduces MPG slightly in situations where there is highway traffic and people can't ******* stay in the proper damn lane. It also probably increases lock up disc wear.


Primary ups and why mine is set this way is it gives you a little engine braking so the car drops speed quicker if you let off the gas and also makes it easier to drive hard on winding roads because you can lift throttle to unlock the converter then get back on it hard to accelerate unlocked without moving your foot to tap the brakes to unlock (which can also sometimes slightly upset the balance). Also seems to give you a little more control for passing because you can let off to begin the pass in 4th unlocked but if need be still have the option to roll in harder to downshift into 3rd.


I wouldn't say it's a big deal either way and is fairly trivial. My brake switch failed and the car defaulted to how it is now and I kinda liked it so I changed it to be that way.