Ms3x flat shift

[swifty35]

Question with the ms3x flat shift feature the flat shift hard limit rpm is the rpm it would drop to as the clutch is depressed and flat shift is activated? E.g engine hard limiter is 8200rpm and flat shift hard limiter is set to 6000 rpm as the clutch is depressed the rpm would quickly drop to 6000rpm or it slowly drops rpm until it reaches 6000rpm?

[jsmcortina]

It depends on the size of your flywheel.

James

[swifty35]

The heavier the flywheel the slower the rpm would drop your implying? Also what's the best way to set the flat shift hard limit do a log and see how low the rpm goes in between shifts to get your flat shift hard limit value?

[acedeuce802]

If you assume that your car doesn't coast down during the short duration of a shift, you will be going the same speed throughout the shift. Therefore you need to figure out, based on your gear ratios, what rpm your engine will be at when you shift. This is the rpm you want to target. If you shift faster than the target rpm is met, then you'll just let the clutch out and that will bring the engine rpm down to the proper rpm. Really the target rpm is preventing the rpm from dropping lower than the ideal shift rpm if your engine speed drops faster than you can shift.

[TheSilverBuick]

I've been testing out the flat shift feature with a Buick 455 that has a steel flywheel. For testing I set the cut values down to like 3,000rpm so I can test shifting at around 4,500rpm in case it didn't work or the pedal sensor needed adjustment (it does) I wouldn't wing the engine into dangerous rpm territory.

What I found is it is hard to break the habit of lifting, lol. I swear in my mind I'm not lifting at all but the datalog doesn't lie. At these lower throttle levels, I'm getting around a 200-300 rpm flair when depressing the clutch, so it needs some adjustment. I have noticed it doesn't grind 4th gear like it liked doing when I previously tried "no-lift" shifting before turning on the flat shift.

As mentioned, shift time is relevant to approximate where the rpm will be to cut to, so I tallied it up as well. I shift like a long haul trucker, lol. Anyways, just some data to look at.