Or sanctioned drag racing/autocross/etc...

 

I believe it would be possible to solve a launch control, but not as it works now with the AP. Right now its tuning for perfection, launch control is a totally different mode that works a different way (keeping the revs at 4200 even if the tires start slipping or the load increasing)

The reason I say it can be done is because the AP can reprogram the ECU and therefore a new piece of code could be introduced.

The current rev-limiter change is 9000 changed to 10000, always. It is changed by reflashing the ECU, and I don't think you want to reflash in mid-launch. So my educated guess is: No it cannot be done as everything works now.

 

Couldn't you just hold the RPM's at 4200 yourself and dump the clutch? No need for a launch control.

 

The trick is that when you hold 4200 rpm and dump the clutch you will increase the load on the engine. That will make the RPM drop. Here you have to press more gas to maintain 4200. The problem is that if you press too little the engine bogs, if you press too much the rear wheels spin.

And that's the reason a launch control program always beats a human off the line. It can maintain proper power level with the perfect amount of slip (i think its around 10%) until the car is up to speed and then go full force.

That's how Nissan GTR can put down such incredible 0-60 times. I think the M3 E46 CSL with DSG gearbox also has this ability.

 

(BTW, these posts should probably be moved to the general accessport discussion thread)

As PerSmitt mentioned, the point of LC is to modulate throttle based on a few important variables: engine load, RPM, wheel slip, and instantaneous acceleration. This is what a human does during a drag launch, it's just that a computer can do it much faster and more accurately, and can have a programmed "map" of those variables for the entire sequence from initial clutch engagement through completion of engagement. As far as the AP goes, we know the ECU receives or calculates those necessary data, so in theory it should be possible, although the data rate must be fast enough.

However, don't forget that the ECU would have to perform a feedback function in which these data are used to modulate throttle application. This does NOT occur in normal driving. In normal driving you supply the throttle and the computer reacts accordingly, there is no feedback back to throttle.

So- what is the only case when the ECU does do this??? CRUISE CONTROL.

In short, I think it would be theoretically possible to hijack/duplicate/modify the cruise control code to turn it into a launch control function, which could be accessed and turned on/off with the AccessPort. The driver would have to manually release the clutch in a particular fashion, but the computer could modulate throttle perfectly based on RPM, wheelspin, speed, etc. I'm sure this would be very difficult to set up and perfect, but if anyone can do it, Jeff and/or Cobb can. I'd be interested to see what MM thinks of all this.


I am not sure, but I think this would not be a problem- suppose the cruise control code was modified and used for this. As soon as someone reached Wide Open Throttle and full clutch engagement in 1st gear, the LC system could turn off just as cleanly as the cruise control system turns off when you tap on the brake, you instantly revert back to normal driving input/output. The accessport re-flashes the entire ECU code; as long as this duplicate function code was included, it could be run simultaneously and the LC operations could simply disappear by the end of 1st gear.

 

You are quite right about that. If the code is modified then there is no problem. It was just someone who suggested using the current rev-limiter, but setting it to 4200. I just wanted to point out why that was impossible as things look right now.

I'm going to be silent on this subject now and not spam this thread further.

 

Question:

I bought my Cobb AP from Jeff when they 1st came out. I need a new tune so do I get his tuning services for free or do I need to pay?

 

I would contact him and ask.

 

Lol, I was actually joking about setting the rpm to 4200.

 

Hah.....well, joking around has resulted in plenty of good ideas.......just runnin with it for now. If you've ever experienced any of those top-notch launch control systems, you'd agree it's worth looking into....

 

In the GTR's case the launch control also has the nice side effect of turning your gearbox into a box of scrapmetal :P

 

I would love to do that but the last 3 emails I sent him never got a reply.

That's why I am thinking I need to pay for support so that I get a reply.

 

MAke sure you send it to jeff at mazdamaniac.com. If you are sending it to his AP email account it is probably getting auto deleted.

 

You can send emails to ap at mazdamaniac.com as Hund is helping to provide responses to various requests.

I'm not sure of the exact language but my understanding is once you're past the 6 month tuning service period any additional tuning would require a fee.

There is a link to pay that feee via http://www.mazdamaniac.com/cobb/accessport.htm

In preparation for getting any new tunes, make sure you're accessport is using the most up to date firmware as well.

 

People, people... type emails like ap [at] mazdamaniac [dot] com

Otherwise spambots will pick them up and give Hund an even more severe workload. The Hund will probably have enough with us spamming it

 

thanks, edited.

 

The Manaic is currently sitting at his computer as I type doing logs.
Should make some people happy.

 

Customers purchasing their AccessPORT directly from MazdaManiac will receive this Custom Calibration Service® at no additional charge!

 

New calibration in my inbox! Too bad I am in Iraq until next week

Thanks Jeff and hahaha to everyone who didn't get one. j/k, don't hurt me

 

New calibration as well!! ^

Jeff, I sent you a brief question to jeff@ about mine.

 

Right, but the part you're mising is that the service only lasts for 6 months after you purchase the accessport. If you're one of the first people to have bought the accessport that puts you close to a year if not longer since your purchase.

You didn't specifiy how long you had the AP. If anything, I'd just email and check to see if you're still within the 6 month window or if you will have to purchase the service.

 

Me too!
This time it was only three weeks for the turn-around.
For all those who are getting impatient, its getting better.
I'm not FI so its not a big deal to me waiting for a few weeks to get my tune back.
Thanks again Jeff.

 

I'm sure that would be handed on a case by case basis with the customer no doubt coming out on top.

The flip side of that are these people who bought the AP and then stored their car for the winter and after 8 months are now demanding tunes or customers who otherwise never sent in logs and then turn up after almost a year demanding calibrations.

I'm more than positve that if the situation is reasonable there will be exceptions granted.

Glad you got your calibration Jon.

Here's a little tip for those of you who are planning on going turbo. Before you install your turbo be sure that you get your AP and download your base calibration. About 1/3 of the time the base calibration is very close to your final tune so the vehicle will still be driveable.

I see cases where people are installing their turbo which renders their vehicle useless until they get their AP. Use your head, think ahead and get all the stuff you need before being impulsive and installing the turbo in a hurry. Nobody is making you bolt that thing on right away.

 

Well, wait a second now. Just a note, I'm one of those "patient" guys - I have no reason not to wait for my tune, haha. No rush here.


However: The 6-month rule would definitely not apply to most situations here, because the 6-month rule is in effect right next to the part that says a 48-hour turn around time. Until that part is true, the 6-month rule cannot be put into effect, as Jeff has stated before.

 

MM has been a busy bee lately. With the exception of 3 or 4 difficult cases, all maps have been sent out.

Enjoy!