RazorLab

iTrader: (8)

You do indeed need to do more homework. Alot of evo owners have set cruise to leaner than 14.7:1 with the narrowband, even before this ecuflash tweak, via zietronix, with many many miles on the motor.

I would say the max you probably want to go is 15.6 or so, anything more than that you are pushing it and losing already very coarse narrowband resolution. Imho of course.

veta

OK, if only American can be smart enough, you can learn from Ben Strader http://www.efi101.com/



I am sorry try to save you money for a new engine.

nothere

iTrader: (23)

There is a proven line of thought that an engine will cruise safely at 15.xx. Best done with motors that were designed from the factory to do so. but not limited to those only.
Seems somehow the discussion has switched to the merits of narrow band tuning.
We can agree that the use of a wideband, and cruise in the 15's is acceptable?

I personally haven't tried it yet, I'm trying to cut back on my flashing.

I have been reading a number of forums where the discussion has been about lean cruise.
http://www.innovatemotorsports.com/f...ead.php?t=7337
is one, you could limit your reading to two posts from Klatinn.

lastly, no need for an aftermarket emc to run other than 14.7. The stock ecu can be flashed to run your choice of afr. One way is to change the area the ecu runs closed loop.

RazorLab

iTrader: (8)

haha dropping the Ben and a tired thought about American mentality.

So what makes you think nobody in this thread has been to Ben, hasn't put tons of miles on a car like this, or is a properly trained tuner?

tmaxxman21

i also get 28-29 mpg. tbe, intake, boost controller, fuel pump and tune

Smike

iTrader: (8)

I think I have it now also. I had to change my OPL1 and 2 to 30 TPS. Logging I saw that it bounces from 30-60 (ave was 40-45). So the TPS was going in and out of open-load. Now it seems to be working. Hit 90mi at 3/4 and I have over 180 and I am not even at half tank.

Jeff_Jeske

iTrader: (66)

I think I would air up my tires to 50 psi and do some weight reduction before running the car leaner than normal at cruise. Thats just me though.

At partial throttle with aggressive mivec my car seams to instantly boost and I love it. I'd rather toss a few extra $$$ at the gas bill than stay out of boost.

Inprogress

iTrader: (30)

But couldn't the same be done with a leaner cruise? I mean, you could still enjoy the instant boost and fun with a leaner then normal cruise right? I'm not implying anything, just simply asking. No offense intended.

Jeff_Jeske

iTrader: (66)

I don't know if I buy off on this leaner cruise stuff. Going for 14.7 to 15.5 in terms of fuel used really isn't anything. It certainly isn't going to account for 3-4mpg improvements.

Most people could benefit more from zeroing in there fuel trims.

I understand wanting to get the best fuel mileage you can get but you shouldn't be looking for 20% better mileage than listed on the sticker. The only way to really get better mileage is to not make the engine work as hard.

Decrease drag, weight, speed, and throttle adjustments.

Smike

iTrader: (8)

just about there - tires at 32f/36r, weight reduced as much as I can go without taking the interior out, and I have front aero and now the VG out back...given they are not for MPG...

I drive 55+ miles to work. Well over 500 a week. So wanting slightly better MPG kinda works for me. I got 23-24 MPG pre mod which isnt bad for the car. Getting 26-27 would just be a little bit better.

Jeff_Jeske

iTrader: (66)

And all I'm saying is that's less than a 3 gallon per week change.

Probably cheaper to tune the car to run on 89 octane and save $9 that way!

juyanith

iTrader: (7)

I'm not quite sure what you don't like about getting better gas mileage, Jeff. Sure, it's not earth shaking but I went from 21-22 to 24-25 mpg which works out to be a 10-15% improvement. (And, if you think about it, going from 14.7 to 15.5 is approximately a 5% change. The rest of the benefit, for me anyway, is that my car was dipping below stoich frequently when cruising on the interstate.) If I were to switch to 89 octane, I'd loose the power when I feel like playing.

Anyway, the car hasn't lost any performance and there is no change in how I'm driving so I don't see a downside. I fill up approximately once a week; that's 5 tanks I'm saving a year which is around $200 at current prices. The change to my fuel table cost me nothing and I'm saving a little money. What exactly is wrong with that?

JohnBradley

iTrader: (30)

Czechs do beer/lager/ale very well in addition.

To the subject though.

Veta no one is using a narrow band to tune the lean cruise. The 5% change in fueling ends up as more than 5% fuel saved. All you need to do is watch the vacuum gauge on the highway at 65 and see. Before all of this I was running at anywhere from 5" to 0" of vacuum to maintain speed. I now regularly run in the 9-10" vacuum range which equates to less load and less fuel. Another trick I have done and may have forgot to mention is add timing.

The changes in fueling during tip-in happen so fast (since the car is already in open loop) that I have never seen it be dangerously lean. The accel enrichment table that works of TPS as well, sees to it going rich (12.5-12.8) almost instantly and then drops to your tuned AFR.

JB

veta

Yes for best millage you need to go leaner than lambda, anything like 15,2-15,6 will be the best. But why do they think they can tune car using narrow band lambda ?
I always see some pseudo "tuners" trying tune car using narrow band, and they cant hear me until they kill engine.
So sorry if i am too hard by trying to help, trying to explain that narrow band lambda cant be use for tuning another value else 14.7:1 what is she designed for.

veta

Thanks... it is a while ago i sell my Supra MKIV.... but i can remember my MPG on T67 charger + stock ecu, and after installing AEM EMS. It was inatantly double. Most of stock ecus are using MassFlow meter as a refference to calculate engine load. It is very easy to tune, but it is very inaccurate in transient situations (by building boost, on throtle response, decell, accel etc.) in oposite to SpeedDensity, that ist always at right value (if correctly tuned), because the load is calculated from boost in intake manifold. I think that S/D ecu can be tuned better for performance, response and also for better millage.

My personal record in EVO IX GSR is 325mil on one single tank. I am going to install AEM EMS in near future (waiting in my garage) and i am looking forward for the result.