E85 Powered VR4?

[runner4053]

Originally Posted by vr4_rider

I get 10 mpg...tell me I can't get better...hahaha.

No matter how I drive and at what psi, I always get the same gas mileage per tank. I always put in 5 gallons exactly, and I always get about 49-52 miles before I refill another 5 gallons.

When my boost was set at 14 psi, I was getting 10mpg. It's set to 6 psi and I still get 10mpg...what the hell.

You may have a rich idle.

I get the same thing, but 15 mpg

[vr4_rider]

I rich idle can affect the whole spectrum?

[runner4053]

Well, when else are you supposed save gas? Cruising at 14.7. idleing at 15.0-16.0. And decelerating.

I have a rich idle I can't tune out. I got that 15mpg the same time I got the Maft-pro, big injectors, and an aftermarket FPR.

Not to mention that when you step on the throttle, the car adds a 'squirt' of fuel extra to ease the transition from idleing/cruising to accelerating. So it could carry over that way.

I'm just throwing a place to start looking out there. I don't know any more than you do. I still get shitty mpg.

let's get back to the topic though.

[a2j]

Originally Posted by vr4_rider

I get 10 mpg...tell me I can't get better...hahaha.

No matter how I drive and at what psi, I always get the same gas mileage per tank. I always put in 5 gallons exactly, and I always get about 49-52 miles before I refill another 5 gallons.

When my boost was set at 14 psi, I was getting 10mpg. It's set to 6 psi and I still get 10mpg...what the hell.

you are talking about ford? or vr4? I don't think psi will increase/decrease your mpg. but its just IMHO.

[vr4_rider]

Ford is a member on the forums..I have his old stealth. I am talking about my vr4.

PSI will cause your mileage to change..more air=more fuel, right?

I changed my settings a little bit, so we'll see what I get now

Trung

[eldos1]

Points to remember when converting to E85.

-You need 30% MORE fuel for the same engine tune on E85.
-Converter boxes will increase the injector pulse about 20%. The ECU will add the other 10% compensating for the lean condition.
-The stock TT fuel pump can't handle the 30% more fuel demand.

Great resource on fuel pumps. http://www.stealth316.com/2-fuelpumpguide.htm

[vr4_rider]

-Converter boxes will increase the injector pulse about 20%. The ECU will add the other 10% compensating for the lean condition.


Can you elaborate? Thanks.

[eldos1]

The E85 injector boxes will increase the injector pulse time about 20%. This will let about 20% more fuel into the system. When your ECU sees that the A/F ratio is lean, it will add more fuel into the system. When it is rich, it will shorten the pulse with and put less fuel into the system. Most fuel systems can +or - 10% to 15%. from the base line. If you add 20% to the base line you get around +35% to -5% from the old base. This will let you run E85 +30% to unleaded at 0% and still let you have + or -5% for other conditions because of the ECU. This will take about 1/8th a tank to adjust.

Remember you are still increasing the duty cycle of the injector and you can max them out sooner.

Notice also that these boxes do no connect to the o2 sensor. The only thing they connect to is the injectors and a ground.

Another way you could increase the fuel to the system is to add bigger injectors and tune with a piggy back fuel computer like a SAFC or even a piggy back ECU like a greedy blue or ultimate. To get a better tune, you will want to be able to adjust the timing curve also.

450cc injectors are about 20% over stock, so in theory you could use 450's and a bigger fuel pump and run it that way and be in the ball park or the +30% with the ECU compensation, but I don't think you could win at the track, but it should work around town. I would not attempt without a good data logger or A/F gauge.

I notice you have 675's, but this gives you the idea over stock levels.

[Telefonica]

Originally Posted by runner4053

Well, when else are you supposed save gas? Cruising at 14.7. idleing at 15.0-16.0. And decelerating.

You can lean it out way more than that! I cruise and idle at ~18 afr with no problems. Also, after leaning it out, try increasing the ignition advance to help pick up some power. I consistently get ~30 mpg on this set up.

Of course, however, when I boost my AFR drops to ~11.5:1 to be safe.

[runner4053]

Originally Posted by Telefonica

You can lean it out way more than that! I cruise and idle at ~18 afr with no problems. Also, after leaning it out, try increasing the ignition advance to help pick up some power. I consistently get ~30 mpg on this set up.

Of course, however, when I boost my AFR drops to ~11.5:1 to be safe.

Wow, I didn't know you could do that. Will do.