Tune for Fuel Milage?

[JoeyBones]

has anyone tuned a kpro or other EMS more for fuel milage rather than strictly power? If so, how did it turn out?

[RedSiBaron]

Don't quote me word for word on this, but iirc I think people have done it a bit...I mean its the same proceedure as tuning for power, except instead of power you are tuning for efficiency and economy...

Also, iirc someone, mentioned that in kpro you can set up a tune or fuel map for like 0-50% or 75% throttle, then the remaing % -100% tune it for power, that way you can put around not using a bunch of gass, then use the top of the throttle position for power when you need it, but I can't remember where I heard that...

See im fairly certain you can't have multiple switchable maps in kpro...I know on my street 86si when I finish it, ill be on megasquirt and with that I can have switchable tunes that I can run on a switch, so I can have a mild/economy tune, then a balls out tune setup.

[JoeyBones]

that sounds interesting... I should likely go troll through the hondata forums and see whats there, but wanted to just flat out ask first. It seems like it would involve all the same principles as the leaner you run the less fuel you use, blah blah...hell you might get better milage just from switching to kpro with a base map?

[Ctd-fab]

I have messed around quite a bit with my k20a3 and Kpro. After getting 70+ MPG in a 96 civic Hx I had back in the day I tried to use the same ultra-lean burn tuning techniques Honda used on the VTEC-E Dseries engines.

As some of you know the k20a3 has 12-16 valve operation vtec, aka I-Vtec-E. This can allow the engine to run upwards of 25:1 afrs on the low cam. Even on the high cam lobe due to the advanced nature of K series engines and how well they flow I was able to tune up to 18.5:1 afrs cruising at 75mph.

On a 1000 mile road trip I broke out the laptop and started to mess with the fuel tables on the high lobe while cruising. 75-80 mph gave me about 30 mpg on a stock map and my lean cruise map spit out 38-40mpg. I tuned while on cruise control and flat ground to make sure my load cells weren't changing.

Mildly tuned for economy I averaged about 30 mpg city with a heavy foot. Care must be taken when tuning the load range that vtec operates in to make sure you don't push it into knocking.

I'm just a novice with Kpro, I believe a tune from a knowledgeable tuner and a light foot can result in 50+mpgs with small aero and resistance mods.

[talonXracer]

I have a A2/Z3 and put 242whp down at both wheels and routinly get 38mpg at 70-75mph on the highway, all naturally aspitrated.

A stock a3 can not take having such a lean tune for long, again it will work for a short period but it will suffer over time, not too mention the o2 sensor does not like running the higher AFR's. And I highly doubt you could get near 50+mpg. But give it a try as long as you watch for detonation and backoff if there is ANY occurances.

[Ctd-fab]

Thats some pretty good mileage!! Do you have any gearing mods or anything like that done? I was pretty surprised to to see as high as i did from mine because I also had to be hauling at least 600+ lbs of equipment. Mobile fabricator, lol.

As far as knocking goes I never saw any just tuning the low cam map, egt's get cooler at that kind of afr and the worst that happens is you start to miss fire due to being too lean. Interesting enough the performance maps that Kpro has preloaded for the k20a3 made my engine knock so I couldn't run them.

[BlownSi05]

It can be done. When I had my EP3 tuned, my tuner made sure to check and adjust the short and long term fuel trims to get the best gas mileage possible when I was just normal cruising. As a DD, I never got below 29 MPG and it always rated between 29-34MPG. This was a JRSC-R w/ full bolt-ons and no CAT A3. This was better gas mileage than I was getting in stock form.

[heyvortek]

i know a great tuner in sc. go to TopDeadCenter (http://http://www.tdcauto.com/) tell them you know max with the yellow ep3. Hubert is a great tuner. he will do you right.

[AKEP]

i was getting mid 30's on normal afr's. but i drive carefully.

[talonXracer]

Thats some pretty good mileage!! Do you have any gearing mods or anything like that done? I was pretty surprised to to see as high as i did from mine because I also had to be hauling at least 600+ lbs of equipment. Mobile fabricator, lol.

As far as knocking goes I never saw any just tuning the low cam map, egt's get cooler at that kind of afr and the worst that happens is you start to miss fire due to being too lean. Interesting enough the performance maps that Kpro has preloaded for the k20a3 made my engine knock so I couldn't run them.

But just about any highway cruising with the A3 and you are in the high cam table and a fairly high rpm level.

[Deadphishy]

If you have Hondata on a PRB ECU the new Kmanager has a new closed loop Target Lamda setting. So you can now set the AFR you want to ECU to correct to. Hondata also has a little graph that i don't agree with 100% but they have it. That shows what AFR on a k20a2 is the best for economy. I think it was around 15.6:1.

[JoeyBones]

i know a great tuner in sc. go to TopDeadCenter (http://http://www.tdcauto.com/) tell them you know max with the yellow ep3. Hubert is a great tuner. he will do you right.

I met the guys from TDC back when they were first starting things and had my 350Z. Chris seemed like a good guy for sure. I haven't really kept in touch but might give them a call once I get around to k-pro. Also, now looking at your avatar, I see his Supra, and I think i remember seeing your car on their blog?