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Old 06-27-2007, 06:22 PM   #1
BCT182
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Default Launch Control and flat foot shifting explained

After testing these features I thought I'd share what I have found works for me. It may or may not work for you..... As Cobb states, these features are very abusive on the car. Use at your own risk...

That being said:

The launch control and flat foot shifting maps released by cobb are the same OTS maps with the added feature. To have the featured added to a protuned map, youd have to get a protune. (at least I think)

The maps seem to be okay for daily driving. What I did find that if you are banging through the gears and DO let off the gas between shifts, the rpms CAN fall below the set limiter and when you get back on the gas and let out the clutch it kicks the feature in and causes the car to kinda buck. This can be avoided my setting the limiter for flat foot shifting at redline. Since normally you dont shift at redline, it doesnt stumble durning regular non-flat foot spirited driving.

As for launch control, when set at 4-4500 rmps, it seemed to stumble as if the rpms were not high enough. What I found is if you keep your foot on the accelerator for a couple seconds and watch your boost guage you'll work your way you from 7-8psi.
I attemped to "slip" the clutch and it seems as long as any pressure it on the clutch it seems to re-activate launch control and make the car buck. I found the bumping the tires on the rear up a few pounds (to force wheel spin as opposed to clutch slip) and QUICKLY step up from the clutch you get a premium launch. DONT SIDE STEP THE CLUTCH!

I hope this helps answer some questions, and again, I am a noob and this is just what I understand from the inital testing I've done. I am very happy with the feature and think its well worth the time to do the reflash.

Brett
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Last edited by BCT182; 06-27-2007 at 06:31 PM.
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Old 06-27-2007, 06:27 PM   #2
06BlackSTIwith550WHP
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glad to hear someone has tested it and givin us a review, I would expect what you mentioned at first with the bucking. and glad to hear the launch control makes 7-8 psi at that rpm, but you shouldn't be taking your center diff out of auto when launching it, that is just asking for something to break.
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Old 06-27-2007, 06:31 PM   #3
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Quote:
Originally Posted by 06BlackSTIwith550WHP View Post
glad to hear someone has tested it and givin us a review, I would expect what you mentioned at first with the bucking. and glad to hear the launch control makes 7-8 psi at that rpm, but you shouldn't be taking your center diff out of auto when launching it, that is just asking for something to break.
Good looking out, I edited my post. Dont wanna give anyone any bad ideas.
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Old 06-27-2007, 08:38 PM   #4
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Last edited by Varanont; 09-18-2007 at 12:33 PM.
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Old 06-27-2007, 11:26 PM   #5
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Of course there is a reason. Its safe. The higher they set it, the higher the chance some idiot wrecks their car and attempts to taint the good reputation COBB carries.

It takes seconds to raise the limit, so there is no reason COBB would not keep it low.
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Old 06-28-2007, 08:32 AM   #6
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Quote:
Originally Posted by 06BlackSTIwith550WHP View Post
glad to hear someone has tested it and givin us a review, I would expect what you mentioned at first with the bucking. and glad to hear the launch control makes 7-8 psi at that rpm, but you shouldn't be taking your center diff out of auto when launching it, that is just asking for something to break.

As opposed to setting it on full rear and having the half shafts snap?
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Old 06-28-2007, 02:38 PM   #7
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you don't want to set the FF shift point at redline ideally. you want to set it where your RPMS are going to fall to when you shift, this way when you let out the clutch, the engine speed is right where you need it.
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Old 07-09-2007, 04:47 PM   #8
`04AlpineWhite
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Quote:
Originally Posted by BCT182 View Post
The maps seem to be okay for daily driving. What I did find that if you are banging through the gears and DO let off the gas between shifts, the rpms CAN fall below the set limiter and when you get back on the gas and let out the clutch it kicks the feature in and causes the car to kinda buck. This can be avoided my setting the limiter for flat foot shifting at redline. Since normally you dont shift at redline, it doesnt stumble durning regular non-flat foot spirited driving.



I hope this helps answer some questions, and again, I am a noob and this is just what I understand from the inital testing I've done. I am very happy with the feature and think its well worth the time to do the reflash.

Brett
So, when you do shift at high RPM with the FFS on does the car "bog" for a few seconds (i.e. no boost for about 2 seconds after shifting into the next higher gear)?

I had FFS installed when I did a Pro-Tune recently, and I have been trying to figure out why I get that "bog." I hope it is the FFS, even though I am going to kick myself for being so stupid if it is the FFS.
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Old 07-09-2007, 08:21 PM   #9
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I get ZERO bog.. My boost gauge shows a full 14PSI DURING the shift while the clutch is down, and then 17PSI instantly the moment I release the clutch.
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Old 07-09-2007, 10:20 PM   #10
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Quote:
Originally Posted by powerlabs View Post
I get ZERO bog.. My boost gauge shows a full 14PSI DURING the shift while the clutch is down, and then 17PSI instantly the moment I release the clutch.

Did you keep your foot in the throttle, or were you lifting. I get that problem when I lift off the throttle in between shifts. I haven't had the gonads to keep my foot down, yet.

I think I may have "fixed" my issue by raising the FFS limiter this afternoon, but I haven't had the chance to do a full throttle pull, then shift into the next gear, yet.
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Old 07-09-2007, 10:31 PM   #11
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Quote:
Originally Posted by `04AlpineWhite View Post
Did you keep your foot in the throttle, or were you lifting. I get that problem when I lift off the throttle in between shifts. I haven't had the gonads to keep my foot down, yet.

I think I may have "fixed" my issue by raising the FFS limiter this afternoon, but I haven't had the chance to do a full throttle pull, then shift into the next gear, yet.
I keep it to the floor

But when I don't, it feels normal too...
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Old 07-10-2007, 01:00 AM   #12
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isnt the point of FFS..to keep your foot to the floor on the gas the entire time?
If so, why are you letting up before shifting?
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Old 07-10-2007, 11:28 AM   #13
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Quote:
Originally Posted by devb16a2vtec View Post
isnt the point of FFS..to keep your foot to the floor on the gas the entire time?
If so, why are you letting up before shifting?
Because normal people don't need to drive their daily drivers like they are trying to qualify for a race all the time?

I don't quite feel the need to flat foot shift when I'm driving to school in the morning. Or when I am leaving the grocery store. If you do, good luck having your car last...

Just because the map is there doesn't mean you have to use the feature all the time.

Last edited by powerlabs; 07-10-2007 at 12:50 PM.
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Old 07-10-2007, 11:30 AM   #14
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Originally Posted by devb16a2vtec View Post
isnt the point of FFS..to keep your foot to the floor on the gas the entire time?
If so, why are you letting up before shifting?

Because I drive my STi to work every day. I don't need to be that aggressive on an on-ramp to the highway. I haven't made it to the drag strip to really open it up.

Personally, I don't feel comfortable going full-bore on the street.

^Exactly as powerlabs posted.

Last edited by `04AlpineWhite; 07-10-2007 at 11:41 AM.
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Old 07-10-2007, 12:58 PM   #15
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Quote:
Originally Posted by crazymikie View Post
you don't want to set the FF shift point at redline ideally. you want to set it where your RPMS are going to fall to when you shift, this way when you let out the clutch, the engine speed is right where you need it.
Wouldn't that kill the built-up intertia in the flywheel? If it's spinning at ~7000rpm (or whatever you're shifting at) and you shift and it drops to 5500rpm that 7000rpm spinning flywheel isn't going to want to slow down and that should help accelerate the engine rpm as a whole. Kind of the same principle of using a heavier flywheel if you just drag race for the launch.

I'm mainly interested in just making sure the DBW doesn't close the throttle body.
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Old 07-10-2007, 01:33 PM   #16
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Quote:
Originally Posted by powerlabs View Post
I get ZERO bog.. My boost gauge shows a full 14PSI DURING the shift while the clutch is down, and then 17PSI instantly the moment I release the clutch.
Out of curiosity, where have you set your FFS at?
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Old 07-10-2007, 01:35 PM   #17
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Originally Posted by The Head View Post
Wouldn't that kill the built-up intertia in the flywheel? If it's spinning at ~7000rpm (or whatever you're shifting at) and you shift and it drops to 5500rpm that 7000rpm spinning flywheel isn't going to want to slow down and that should help accelerate the engine rpm as a whole. Kind of the same principle of using a heavier flywheel if you just drag race for the launch.

I'm mainly interested in just making sure the DBW doesn't close the throttle body.

Your question didn't make much sense, but let me try and answer what I *think* you might be trying to ask.

Your engine takes a lot of power to turn over. Even with the throttle body open, you are still compressing a good 150+ PSI of air into 4 cylinders every two revolutions, spinning an oil pump, water pump, power steering pump, alternator, and overcoming friction from over 60lbs of rotating components. When FFS kills the injectors the flywheel will slow down no matter what because of this drag. What is key about FFS is that it keeps the throttle body from closing, so the turbo doesn't slow down very much, and you have full boost available after you release the clutch. Ideally FFS will keep the engine RPMs right where you are going to be when you drop the clutch from your shift. Any less and it will bog, any more and you will cause drivetrain impact.
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Old 07-10-2007, 01:36 PM   #18
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Originally Posted by The Head View Post
Out of curiosity, where have you set your FFS at?
After some experimentation I found 5500RPMs to be ideal on my car. I shift at 6100RPMs or thereabouts.
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Old 07-10-2007, 01:37 PM   #19
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And another question since I'm not seeing the answer in other threads. Is the LC and FFS on the base map only? Reading in between the lines it looks that way. I normally swap to a real-time race gas map at the track and then real-time pump gas everywhere else. Since a post somewhere (here or on the Cobb forums) said this takes up a lot of memory, I'm guessing that it's not something that can be turned off or on via real time maps.
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Old 07-10-2007, 01:40 PM   #20
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Quote:
Originally Posted by The Head View Post
And another question since I'm not seeing the answer in other threads. Is the LC and FFS on the base map only? Reading in between the lines it looks that way. I normally swap to a real-time race gas map at the track and then real-time pump gas everywhere else. Since a post somewhere (here or on the Cobb forums) said this takes up a lot of memory, I'm guessing that it's not something that can be turned off or on via real time maps.
Correct. I tried setting a stock real time map and my car had stock power but LC and FFS
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Old 07-10-2007, 01:43 PM   #21
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Originally Posted by powerlabs View Post
Any less and it will bog, any more and you will cause drivetrain impact.
Seems that our bretheren with throttle cables are doing the drivetrain impact then as I've done in several other drag cars I've owned. That shock (although hard on components) should somewhat help compared to the bog of being too low. Yeah my main issues now are the TB closing when either trying to FFS or simply letting off the gas when shifting and having to wait that split second for it to spool.

Just for reference I'm running a Frank 50 (like a FP green) with supporting bolt ons. My best run to date is a 12.23@116.8mph since that was with the stock 5-spd and I didn't want to blow it up (1.85 60' and granny shifting). I'm now running a PPG gearset with PPG front posi, hence the desire to run the LC and FFS without worrying about the tranny. I'll worry about axles now.

Thanks for the input and comments.
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Old 07-11-2007, 02:17 PM   #22
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Im just so confused....

One question please.. I have my LC and FFS map installed.

if i set my LC to 5500, and want to power shift (WOT Foot to the floor in between clutching 1 to 2 - 2 to 3 - 3 to 4 ... ) And I set my FFS to 5500 ... It bogs stops for a second in between accelerating up the rpm scale (TERRIBLE!)...

However, If i set the FFS to redline or close to it (maybe 6800) and I shift WOT at 6800 I wont notice its there correct?? Please someone no one has a clear for sure answer... thanks!
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Old 07-11-2007, 08:06 PM   #23
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My problems were corrected by raising the limiter beyond a point that I see in normal driving.

I have heard that there is already an updated software pack for the LC/FFS. That should fix some of the problems people have been having.
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Old 07-14-2007, 12:20 PM   #24
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the bog that people are talking about was horrible for me. I went back to stage 2 no lc/ffs map because of it. the car feels so much faster without the new maps when not flat foot shifting. I had ffs set at 5000. we need to get on cobb forums and beg for the new update trey said they might work on. it would turn on ffs only when the clutch is down and throttle is 90% or more. for some reason it felt like I was hitting the limiter when letting the clutch out going into the next gear. if you have to set the limiter at redline for normal driving then you need to change it every time you want to use ffs. if they come out with the 90% throttle update it should eliminate this problem and you can just leave it set at 5000-5500 or whatever. 04 alpinewhite the update they just released solves a problem with the boost staying at the psi you were at when ffs kicked in. without the update if you hit the limiter at 14psi in, say 3rd gear, when you shift to 4th you wont be able to build more than 14psi. it doesn't fix the bucking for normal aggressive driving.
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Old 07-14-2007, 12:53 PM   #25
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Hmm.

I built a flat-shifter for my old turbo Legacy; it was a 555 timer and a few discretes, a pair of transistors, two switches and a relay. The way it worked was that the two switches were closed when the throttle and clutch were to the floor; this activated the 555 which opened the relay for 50-250mS (depending on resistor values). The relay was installed in-line with the ignition, rather than the fuel.

Why? Simple. It allowed the fuel to continue to flow while shifting. Some of this fuel would ignite on either the exhaust valves or the exhaust turbine of the turbocharger. It kept the turbo spun up during shifting.

Obviously this is worse on the exhaust components, but it was dramatic for the following reasons:

(1) Still on-boost after shift;
(2) Tailpipe flames w/awesome "pop" noise.

No, the flames aren't ricey. Why do you think the WRC cars sound like that and **** flames when they shift?

-Matt
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