I'm curious if the following is possible and correct me if my understanding is wrong or misinformed.

- while idling or cruising lets call it highway driving, the ecu uses the stock a/f, boost, etc maps.
- while driving hard lets call it track driving (if you have done a reflash ie: bushur, ams, etc) it goes to the modded maps

Is it possible then to tune an evo for both occasions using the same ecu since the maps aren't used at the same time? ie: leaner for better mileage on the highway and a bit richer for the increased boost, etc that is used during "track driving"?

Just curious. Thanks,

 

You want the ability to have multiple Maps?
I don't think its possible in the way you are describing

 

Theoretically yes, there are aftermarket ecu's that allow you to switch between mulitple maps. (Typically they do this to account for pump fuel or race fuel) However, they aren't available for the X yet.

The bigger problem is that the stock X maps are richer than the tuned ones, so what is the benefit of using it? you could have 2 different tuned maps, one for low boost, one for high boost, but I don't think the stock turbo can handle enough boost for this to be useful. I suppose you could still have a map with more aggressive timing, and slightly more boost. But I doubt it would be worth it until you've got a lot of mods.

so yes, possible but no plausible.

 

You will need to wait for CObb tunning's Accessport. Can hold lots of maps

 

The correct answer is that the maps are based on several things: Engine load, throttle postition, RPM.

Many tuners do not change fueling when the car is cruising. This is at low load where the car is mapped to be much leaner at those points, or as close to stoich as possible, which is 14.7:1. At higher load or higher RPM, the ECU is richened because there will be boost (or more boost) in the equation.

Same exact thing with timing. At low load, the car runs a ton of timing, particularly as the revs climb. In high load, it runs substantially less.

The things that are typically changed by tuners and stay departed from stock are the Mivec maps and the boost maps. The difference in the boost maps is nonessential when cruising and using no boost, but the Mivec maps tend to be advanced more even in lower load in tuned maps.

A good tuner will manipulate the entire map to be superior to stock in every way possible: Fuel consumption, drivability, and power.

So what I am trying to say to you is that a correctly mapped is not something that is undesirable or one dimensional. It is something that should be front to back better and everywhere in between. I hope I explained this in a good way that makes sense to you.

 

The only time you would want multiple maps is when you are tuning for completely different things. One of these would be if you have a dedicated race gas map for super high octane.

Another would be a valet map if you have a lot of other people driving your car and you want to severely limit your boost or RPM potential.

But for the purpose of your original question, you only need one map for whatever octane you run on every day. Just get someone to tune your car that you trust and know will do a good job.

I have one flash (which of course contains several different maps for different parameters) and have spent a lot of time getting it perfect. This stock turbo doesn't benefit from race gas like a big turbo, so racegas or meth is lost on me. I also don't care about a valet map, because I don't let anyone I don't trust drive my car.

 

+1, I want vallet map when going to dealship I dont trust them.

 

The dealership hasn't seen any of my three Evos since they left the lot and don't again as long as I own them.

 

Using an Autronic SM4 standalone I had my Evo 8 running 16.8 while cruising on the highway and 11.8 while under and we've had ton of other cars doing the same for many years with zero issues . I have not use the current flash for the X but I have learned that the set-up pretty much replaces the stock map with its now and it does not actually read off the stock ECU and since we haven't used it yet we do not know its limitations . We're working on writing our own program which actually writes to the stock ECU and that will allow us to run a lean mix at cruise and richer mix under load . For you like more info contact John at Jestr Tuning , we'll have it ready soon .

 

Not to get off topic but my side skirt keeps falling off so I keep having to bring it to the dealer to get it fixed. I just now talked them into ordering an entire new peice so I will have to bring it back again. Thats why I have to keep going to dealer. Everthing else is done at home if I can.


On topic, If you want to change maps around for different occasions I say wait on Eccuflash or Accessport you can flash away at your ECU with maps.

 

Noize,

What you say makes sense. If I'm going to take my car to someone and spend money for them to tune it, well it'd better be a hell of a lot better than stock (and what I'm reading about AMS, Bushur, etc it is). You hit the nail on the head of my original very miss-worded question, why not mod the lower engine load portion of the map for a bit leaner mixture? If my understanding is correct, anytime your on the throttle and in higher load / rpm / throttle position areas it will run off the high load portion of the map that could be tuned like a tuner normally would for more performance. Then anytime your crusing or daily driving in low load situations, it reverts to a bit leaner mixture than 14.7:1 for the low loads.

I guess this just seems like an untapped area for those that want the best bang for the buck of better gas mileage on the freeway (5th gear, low load cruising) and much better performance than stock. Seems like a tuner could sell more maps based off mileage increases than performance I mean the mileage increase would pay itself back in $ while the performance increase pays itself back in and

Just a thought, feel free to comment.

 

Shoot, its dial a map. They could set it 17.5:1 if you wanted them to. I have no idea how the factory knock sensor will react to it in anything but the lowest load settings, but if you're wondering for science... That said other post above aside, I would **never** map my turbocharged car at 16.8:1 cruising.

A little more understanding for you is in order. For the basics and to get going, read this: http://en.wikipedia.org/wiki/Air-fuel_ratio

Talk to your tuner before your car is custom tuned. Tell him what you want, what you expect, and ask him if he is comfortable running the car leaner than stoich in closed loop and cruising situations. Get his take before you make the final call.

Mapping a car is like starting work on a painting. There is a blank canvas and you have a lot of options. Some will procure great results, some disasterous ones.

 

Noize,
I appreciate the responses. Unfortunately no Evo X yet, mainly trying to do some research and the engineer in me keeps wondering why the evo guzzles the gas. I've been reading up on stoich, A/F, proper mixtures, etc prior to posting and what made me think of this was reading the Evo tuning for Noobs guide in the Ecuflash forum. In there I believe the author said the highest mileage came around 15:1 or somewhere around there. A lot of it would be very dependent on quality of gas, weather conditions, driving habits, etc as you already pointed out. I'm sure a good tuner could come up with an excellent map and / or compromise to the solution. Thanks again for the helpful info.

 

No sweat man. There is a really simple reason why the Evo guzzles gas. It needs a sixth gear! Fifth gear is a .87 gear going through a 4.53 final drive ratio. I don't know what the speed limit is in your part of the country, but this means that the car is turning just over 3700rpm at 80mph. That coupled in with the fact it weighs 3500 pounds is definitely why is gets crappy fuel economy.

Realize that for 2008 models, companies were all forced to change the way they show fuel consumption per mandate. So that had an effect on it too. Using cruise control and exercising restraint when commuting will go a much longer way for your fuel economy than leaning the heck out of the mixture IMO.

Good luck, and I hope you end up with an Evo.

 

6th gear FTW! Yeah I've read a lot about the differences between the MR & GSR for most of the years and it's unfortunate that there isn't a true "overdrive" gear. Unfortunately that's how it goes sometimes, maybe for 2009 we'll get a better 6spd manual tranny? And the EPA thing yeah, I see that a lot when I'm out window shopping on car lots. It's great they did the change to make the test more realistic but sucks to compare new vs. older used vehicles because of the different methods of testing. Oh well... thanks again.