Hey Lurch-meister, question about ecu launch control

What's it doing?

The primitive versions I've seen simply are a lower rev limit so you can floor it and it holds it at like 4500 or wherever, then after launch, rev limit goes up to wherever. I've always assumed that systems like your Motec do something more.

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Grant Hughes

Not on my car...at least not yet! I have no launch control, no (until this weekend) manual boost control, no clutchless shifting, and no other fancy "driver aids."

It reduces power. Can be done with...hold on a minute...disclaimer time.

Disclaimer: I am not an engine management guru. I am learning tons and consider myself an enthusiastic hobbyist, but I verify what I learn before applying it to my or any car. It is good to have an experienced "collaborator" on these things to discuss individual engine/car requirements. If you other knowitalls see something wrong or misguided in my post, feel free to point it out. Now back to the previously scheduled no-nothing diatribe...

It reduces power. Can be done with revs (as you suggested), or boost (on boosted cars, of course), or ignition/fuel...whatever. In competition cars, not typically done with brakes as in street car applications (ABS crap).

I think most of the simple launch button things are just, as you say, rev limiters.

Traction control is more complex. It reads wheelspeed from driven wheels and compares it to ground speed. A table is constructed that takes the % wheelslip and associates it with a corresponding reduction in (fill in the blank...boost, fuel...etc.) to reduce power.

WRC teams have (to my understanding) experimented with (and maybe are using) ground speed radar, as they have no UNdriven wheels and are often under canopy where GPS is not reliable.

With a Motec, if you can sense it, you can use it and log it. So you can read speed anyway you want (they tried to sell me GPS based logging...I turned em down).

For FWD, I considered using Front to Rear, and we wired in the ABS wheelspeed sensors for the rear, but could not get reliable signals from them. My concern was the intentional and extraneous skidding that occurs in a 2wd overweight (read "modern" rally car. We would get around that by tapping off the brake pressure switch that operates my brake lights (and add another one for the handbrake) to turn off the TC when braking, but this is all at theory stage right now. Besides...I kinda like driving a RACE CAR not a ROBOT that keeps one from having fun, is boring to drive, and could be operated by a trained monkey.

That said, I am working on some speed based boost control. Turning down the boost based on vehicle speed...or perhaps gear based like the Mazdaspeed3 and SRT4 use, but starting with speed cuz it's easy and quick to program. Then my dash switches will be 4 "ranges" of boost determined by speed maps.

The reasoning for this is as such... If you can't use the power, you're just eating up tires, gearbox parts, axle parts, and engine parts for NOTHING.

That said, there ARE places on American rallies where 450hp would be very useful. If you have any tire left to use when you get to said places.

As Derek says, it's all about the tires. Let's say there are 2 places in the first leg of a rally to use the power. They are at mile 7 of SS2 and mile 9 of SS3. If you have uncontrollable wheelspin, you are going slower. You are using up tire. By the time you get to mile 7/SS2 or especially mile 9/SS3, you will be going SOMEWHAT faster thx to the monster engine, but perhaps not fast enough to make up for the time you spent beating up your equipment the rest of the stages.

By controlling the power output, you are faster when a 200hp car is the ticket. And you have tires left to take advantage at the stupid hp parts of the rally.

And the car doesn't get beat to poop as bad.

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Lurch
Eric Burmeister
The west coast...of Michigan



Edited 1 time(s). Last edit at 06/05/2007 07:26AM by Lurch.

Lurch Wrote:

...We would get around that by
> tapping off the brake pressure switch that
> operates my brake lights (and add another one for
> the handbrake) to turn off the TC when braking,
> but this is all at theory stage right now...

Scratch that. Won't work. You'd have TC active coming into the corner, and then full power for LFB. Bad.

Thinking out loud on this stuff

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Lurch
Eric Burmeister
The west coast...of Michigan

WRC uses crazy traction control that I don't even want to think about. Just always wondered if the advertised 'launch control' on some systems was something more than a rev limiter. I had that same thought with boost control. A lower setting with low boost to limit wheel spin, and a high setting for Cog when you hear a L3 to 700 over crest into 450. Oh, and I still dream of a day where this is occuring at a Parc Expose. Though I think it may just be me, probably with a beer in hand, and pissing everyone off. I wonder if that's illegal. I'm sure it will be eventually. Will also be the only time I flip that feature on.

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Grant Hughes

What a bunch of numbnuts (the youtube clip). Way to waste turbo hours...by showing off flames in a parking lot. Of course, those guys are most likely posers who will never use their antilag in a way that makes it beneficial.

Antilag is built into the Motec, too, and tried it at Pikes Peak, but I have it turned off normally. Turbos don't grow on trees.

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Lurch
Eric Burmeister
The west coast...of Michigan

I'll continue my diatribe on goodies that are available electronically with a modern engine management system...not because I want to show off or anything. I just find it super interesting and love to learn and I like to share what I learn with like minded folks.

As I stated above, I don't use a lot of this, because I have this love-hate relationship with technology. You see, my driver side thinks this rally stuff should be hard. That is what rallying is. True grit.

But my geek side loves learning about what the stuff can do to make the machine more competitive where the tires meet the dirt. I am certain I would be a better engineer if I weren't also a driver. And vice versa.

Anyway.

Clutchless shifting: Any sensor can be used to program any engine parameter, right? So an electronic strain gauge mounted on the shifter lets the ECU know when you are pushing on the shifter hard enough that you want to make a shift. At that moment, it cuts ignition (and possibly fuel) for X milliseconds to relieve stress on the dogs and let the box slide right into the next gear.

I use a clutch, but might experiment with this later. Would be simple to set up.

Drive by wire throttle: We used this feature for 2 reasons. First, the stock Mazda3 uses a DBW throttle and Motec already had developed the software to run it for a project car they worked on for Mazda. Second, it allows some neat advantages, like non-linear throttle curves, throttle plate manipulation for things like antilag, etc. The car is funny tho when it's cold, as it tries to keep itself running and sits there cracking the throttle by itself for a while before it warms up and the idle evens out.

Datalogging: Man, this is a motorhead/geek's dream. I actually know what happened during a run! I'll expand on this in a bit...gotta get something done over here.

toodles

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Lurch
Eric Burmeister
The west coast...of Michigan

Lurch Wrote:
-------------------------------------------------------
> Antilag is built into the Motec, too, and tried it
> at Pikes Peak, but I have it turned off normally.
> Turbos don't grow on trees.

We turned it on for about 1/2 of the actual race day run on Pike's Peak. Of course, we were on a brand new turbo that we only cared about working for 12 miles, but EGT's got a bit high so we killed it just past Glen Cove.

I like the shifter idea. The computer response time would have to be quick but it sounds like a valid idea to me.

What model of Motec are you running?

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Grant Hughes

Yes, the shifter is proven. You can buy the strain guage directly from motec if you want. Ed Bergenholtz has it set up on his 1200hp FWD Mazda6 drag car. I spoke with Ed about it and the engineer who helped us at Pikes Peak. It is probably EASIER on the trans parts than just using the clutch, once the timing is dialed in.

Ed mounts a Mazda MZR (Duratec) north-south waaaay out front and puts a Hewland RWD tranaxle behind it running the front wheels. Nutty.

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Lurch
Eric Burmeister
The west coast...of Michigan

So Eric. All of this fancy Motec stuff sounds sweet. I am curious what a Motec system costs for the average consumer. Not a fully system with all of the bells and whistles but maybe a basic system that someone would start with?

Someone just sold this M4 for 2800 WITH a factory made harness. If you can wire your own harness, you can save a grand.

http://www.honda-tech.com/zerothread?id=1003169

That is an M4 (older DOS-GUI programming). To use it for Trac. Cont. you would have to buy a multiplexer. And I would add the datalogging module. The 6 hours tuning thing is dumb. You will be making changes on a race car and will need to log stuff forever.

BE CAREFUL buying used ones. If it is STOLEN, it will be useless to you, as the owner can lock up the software with a password. And report it stolen to Motec so customer support is non-existent (serial number based).

There are more economical choices out there for engine management. I don't know what they all have to offer, but I would do research if I were considering it. Haltech, Accel, AEM, Electromotive, MSD, DTAfast, EFI, Autronic, Link, etc. all have useful stuff, but I don't remember the individual features of all of them anymore. Bosch is back in aftermarket/motorsport ECU sales, too.

If you want to learn about EFI/engine mgt. and some of the different systems, the Kinsler catalog is a good place to start. Go here http://kinsler.com/Cat_31_Whole_PDF/0201234_screen.pdf
and scroll to pg. 67 and start reading for the next several pages. I bought my first Motec from Kinsler.

If you want to do it on the cheap and have a computer science degree and know a lot about engines, crack open a megasquirt and see if you can start adding inputs and connecting it to a programmable logger. I think you will spend WAAAY more time than it's worth, tho.

Choosing a system would depend a lot on the car, too. If you are running a 5.0 Mustang engine in an XR, you would do well to go with an economical Accel as they are cheaper, there are tons of experts who have maps for every engine configuration, and your typical Mustang/drag dyno shop will know how to use it (if you need help tuning).

I chose Motec because I needed an aftermarket ECU, Motec had already done a turbo Mazda3 project car, and they knew what all was involved, I have a tuner that I trust whose primary knowledge is with Motec, all the other Mazda race teams (drag, World Challenge, etc.) use Motec, and the folks at Mazda had a good relationship with them.

To get a car to run on a Windows based M400 that has an entirely new engine configuration (not just another 10:1 V8 or bridge port rotary) can get quite expensive when you figure in dyno tuning time.


btw, all of the motec software is free on their site www.motec.com if you want to download it and see how it is to use. Pretty straightforward once you get the hang of it.

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Lurch
Eric Burmeister
The west coast...of Michigan

Lurch Wrote:
> Choosing a system would depend a lot on the car,
> too. If you are running a 5.0 Mustang engine in
> an XR, you would do well to go with an economical
> Accel as they are cheaper, there are tons of
> experts who have maps for every engine
> configuration, and your typical Mustang/drag dyno
> shop will know how to use it (if you need help
> tuning).
>
> I chose Motec because I needed an aftermarket ECU,
> Motec had already done a turbo Mazda3 project car,
> and they knew what all was involved, I have a
> tuner that I trust whose primary knowledge is with
> Motec, all the other Mazda race teams (drag, World
> Challenge, etc.) use Motec, and the folks at Mazda
> had a good relationship with them.

Two most important paragraphs above when thinking about engine management. Megasquirt is cool and I suppose it's neat that there's a cheap solution for street cars, but I'd never put it in one of my rally cars. Too limited on the software and tuneability. It's become quite the hit in non-rally forums though, mostly due to low cost.

It mostly comes down to what you know or who you have access to knows or what you're willing to learn. For the Merkur, I'll likely run either Haltech or AEM Stinger. Haltech I have experience with in an Audi and a Rabbit and maybe soon in a Focus. The AEM Stinger I'm familiar with the software already and someone's making a fairly inexpensive plug and play solution for the Merkur.

Is engine management allowed in Spec Focus? I didn't think it was, but Weber makes an Alpha ECU kit for it. Get a catalog from Burton Power in the UK.

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Grant Hughes

http://www.carmodifications.com/

http://www.elementtuning.com/main.htm

Don't know a hell of alot about tuning it myself but use it, like it. We use ALS, launch control, H2O spray control and eventually H2O injection control. Plugs into the factory harness.

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Gone fishing



Edited 2 time(s). Last edit at 06/05/2007 09:09PM by david amor.

Yeah, I run my watersprayers timed off of intake charge temp sensor thru Motec, too. Developing new sprayers for Pikes.

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Lurch
Eric Burmeister
The west coast...of Michigan

Stand alone engine management is not allowed in Spec Focus. However the after market flash tuners have completely reverse engineered the factory ECU. So you can buy software and a device that will let you change every parameter in the factory unit by connecting into the OBD-II port under the dash.

That is good but you don't get data logging or any a system that is as flexible as the Motec.

The reason I asked is more out of curiosity or if I ever decided that Spec Focus was too slow for me and wanted to build a faster motor and move into G2/M2

Duratec 2.3 out of a Ranger with a 2.0L crank and long rod setup. Direct to head ITBs from SBD and Weber Alpha Pro engine management. 210-215 hp and 8000-9000 red line. Brilliant.

In the future I want to build a Group 2 Festiva with basically that setup. The new generation is supposedly coming here next year.

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Grant Hughes