flatshift

[zukitek]

I recently drove Matts subie at TGPR during the santa run PDX and fell completely in love with his flatshift. Up to that point I saw it mostly as a dragracer feature. I knew my Megasquirt was capable of doing it but really didnt consider it a "musthave" feature. I rigged a stoplamp switch to my clutch pedal and ran the input to the MS and configured my tune for flatshift and man Ive been missing out. Flatshift rocks . If you have a megasquirt and have not tried it ...you are missing out. Its sooo nice.

[nicktcr]

Well that settles it...guess I'll have to give that a go.

[zukitek]

real easy on our cars too. just go to the parts store and buy a stoplamp switch and screw it into the top hole of the clutch pedal bracket , run the wires , and set it up in the tune and viola. The switch that is currently in that hole works backwards so it wont work . You need one that will be closed when the clutch pedal is applied rather than open .

[TouringBubble]

I had this on the Evo until I swapped master cylinders and that caused issues with switch engagement. I also have it set up on the Beetle, but don't really use it much.

You're right, people think it's for drag racing, but it's great to saving time for any shifts. At the drag strip it was good for about 2/10 in the Evo ... that's for three shifts. Imagine gaining 1/10 on every straight away on a road course every lap. It's absolutely worth it!

[jledford]

By going to a twin disc and using the flat shift feature on my AEM EMS in my old Laser I was able to shed almost 0.5 seconds off of my 1/4 mile ET. A lot of that was because of keeping boost between shifts. However even with the flat shift a simple single disc organic clutch would build too much heat on the launch to completely disengage during the pass where the twin would shift all day long at 9k rpms

I would think a twin disc and flat shift on a road race car would make for good times.

[zukitek]

bTW the switch I used was a standard ignition part# SLS115. Its a stop lamp switch for a datsun 510/710. I chose this switch because it has wires coming out of it with simple bullet type teminals on it instead of requiring me to go to the salvage yard and hunt down a connector to plug into the s14 switch. I got it on ebay for 9 bucks shipped . It has 10mm1.25 threads so its a direct screw in gig.

http://www.rockauto.com/catalog/moreinfo.php?pk=44551

[TouringBubble]

Good call. I went with one from a Honda Civic from the 90s. two prong blade type connector. Not as easy as yours, but it works. I think it was also 10mm 1.25.

I had to build a bracket for mine, but it sounds like the 240 has a top clutch switch bracket already?

[zukitek]

yes it was extremely easy on the 240 because it has a hole at the top of the pedal for a cruise control cancel switch which is a normally open switch so that's why I could not use that one. Suffice it to say if you want to do this and retain your cruise control you would need to either put a short pin in the cancel switch connector or use a relay to change the polarity of the switch output going to the cruise module but most guys will just remember not to push in the clutch while the cruise is set . Mine still works fine but since it originally came with an automatic transmission this was not an issue with mine . I have just always remembered to tap the brake pedal to cancel the cruise before applying the clutch....and yes even now the cruise control still is operational along with the AC.....Im just a geek like that LOL

[HPEVOX]

GT-R got flat shift too… lolz. Evo does too but it need mo powah.

[AlanB]

Ricky, Matt, etc- Is the MS flatshift feature set to come into play within a certain RPM range (near redline), or does it revlimit every time the clutch is pressed? Seems like it would pretty much negate rev-matching - heel/toe downshifts if the threshold isn't set high enough.....
Sounds intriguing. I left the 'launch control' wire unhooked but have it zip tied up next to the ECU and can hook it up easily.

[zukitek]

you can set it to work at whatever RPM you like. For instance mine is active above 3000 RPM and above 50% throttle position and the upper rev limiter is set at 4500 RPM and once those conditions are met then its active when ever the clutch is pushed in. It does not affect normal driving around since the TPS condition has to be met before anything happens regardless of the clutch position.

[AlanB]

Ricky, how does this look compared to your tune:

Launch retard above (RPM) = 4100
Retard to (deg) = 10
Enable Launch Control when TPS above = 95%
Launch Launch hard limit = 4000
Limiter Method = Fuel cut
Cut X Sparks (not sure if it changes when you change to fuel cut) no change
From Y events (not sure if it changes when you change to fuel cut)no change
Flat shifting arming RPM : 5000 (this needs to be lower than the value below)
Flat shift mode retard above 5200?
Retard to (degrees) : 0

[zukitek]

I don't think Id go that high on the TPS threshold because the RPM may go higher than you launch limit momentarily depending on how fast the engine wraps up plus . Miata might not get there that fast but my LS1 will if you pussyfoot around getting to 95%. The rest looks good . I have not had a chance to use launch because Im using alpha firmware and the fuel cut version is broken in the code right now and spark cut is just too violent for me on launch control. I wouldn't think changing the x sparks from y setting would affect yours since you are using fuel cut.

[AlanB]

right on. I'll prolly start with something around 85 instead. thx

[Chuck Baader]

Ricky...how does the flat shift work in normal driving...not WFO?