EFI Amazement!

[81xsproject]

MegaSquirt has go leaps and bounds (IMHO) recently with MS Studio's VE Analyze Live which actually adjusts your tables as you ride to reach your specified AFR's. It has been a great couple of days on Megathrust. Today I decided to check my mileage. So, I topped off (paying careful attention to the 'full' fuel level, and went for a run down the highway. Hwy 101 is no Minot, SD. It's got plenty of turns, hills, and so forth. I tried to keep it between 60-65 +/- a few here and there. I also exited once, stopped, and got back on the highway all while trying to be pretty light on the throttle (no easy task for me ). When I finally got of at a town with gas, the tripometer said I had gone 51 miles since I topped off. When I topped off this time, the pump read 1.006 Gallons! EFI...having your cake and eating it too!

[Ken Talbot]

Now that's simply amazing. You sure you're not running it on Canadian gallons?

Have you tried it out with this setup when you're giving it lots of hard twists and "bug 2.0" sort of speeds. It would be interesting to hear how it stacks up performance-wise.

[3Phase]

Man, that might be worth the switch to fuel injection!

[81xsproject]

Have you tried it out with this setup when you're giving it lots of hard twists and "bug 2.0" sort of speeds. It would be interesting to hear how it stacks up performance-wise.

I forgot to mention. On the way home, I did 70-80 on the Hwy. I had a very heavy hand. I took a 15 mile scenic alternate through Avenue of the Giants (twisty). I stopped about 10 times to review pics I was trying to take will riding through corners (sounds like a potential Darwin Award , right?). When I got back and topped off, it was 54 miles on 1.4 gallons. 38.6 mpg is 5-6 better than my best attempts at economy with my old carbs.

...

I just spent 15 minutes trying to figure out how to post my Picasa slideshow of the pics I took but no luck. I think it can be done because my buddy posts his in his Chevelle forum.

[XS1100 Newbie]

Is it really enough improvement to warrant the cost, or is it just for fun?

[CatatonicBug]

Is it really enough improvement to warrant the cost, or is it just for fun?

Well, since it's possible to get upper 30's with the stock setup, and low 40's with some fine tuning of the carbs, and he got 38.6 with the FI.... I'd say it's just for fun. Although if you could get that 51mpg under "regular" riding conditions, with enough miles it might be worth the cost.

[DGXSER]

I'd say if you can consistantly get upper 30 mpg range while being heavy handed on these machines, your doing REALLY good. When I get in playful mode, my mpg drops to low, low 30s. like 30-32. I avg 36 with alot of highway miles. If all highway, no fun miles I have gotten into the 40 range.

So, depending on how much the FI system cost, and the price your paying for fuel in your part of the world, just for fun could mean the fun you get to have with the fuel cost savings.

[81xsproject]

If I had to guess and hypothesize , had I not stopped and been driving on a straighter, flatter road, I could have gotten up around 55. And, yes, I EFI'ed for fun and learning. I haven't YET (but I am confident I will) squeezed any more WOT power out of it than my carbs made. However, the motor runs unbelievable smooth, I have low end power I could never get with my carbs, I don't ever have to remove ANYTHING to change tuning, and I have a fully programmable timing curve. My only dependability issues have been brought on by mistakes I have made during the actual process of tuning. From my best recount of parts and what I paid, I am into the FI for around $700. However, I sold my carbs for around half that.

[XS1100 Newbie]

That sounds like good fun, and it ends up with little cost. The last hot rod i built was a couple bucks more than that. Probably 10 times that. At least you are not sacrificing mileage to get better performance, and hopefully reliability is ok.

[crazy steve]

...I haven't YET (but I am confident I will) squeezed any more WOT power out of it than my carbs made. However, the motor runs unbelievable smooth, I have low end power I could never get with my carbs, I don't ever have to remove ANYTHING to change tuning, and I have a fully programmable timing curve. My only dependability issues have been brought on by mistakes I have made during the actual process of tuning. From my best recount of parts and what I paid, I am into the FI for around $700. However, I sold my carbs for around half that.

There may not be too much in the way of WOT power to be had, as carbs are at their best efficiency at WOT. But the smoothness and low end grunt is a hallmark of EFI over carbs due to the much more precise fuel delivery and better fuel atomization that it offers. If heavy-handed throttle use is netting you mid-to-high 30s, that's a very nice improvement. From what I can tell, the MSII you're using is batch-fire injection, so there should be more gains with using a sequential-injection MSIII controller (of course, probably more $$! ). Another thing that might be interesting to try would be a common-plenum intake with a single throttle plate. Individual-runner intakes are notorious for poor low-end torque. This should work much better than a comparable common-plenum carb setup as you don't have to worry about fuel distribution. Food for thought...

With the issues of bad carbs/ignition parts (that will only get worse as the parts supply continues to dry up), this is a very viable alternative...

[81xsproject]

From what I can tell, the MSII you're using is batch-fire injection, so there should be more gains with using a sequential-injection MSIII controller (of course, probably more $$! ).

From the reading I have done, the power gains from sequential are very small not to mention the incurred need for a cam position sensor. Fitting the crank sensor was headache enough. I can't imagine trying to get a sensor on the cam somewhere. The real headaches are fuel delivery (HUGE PITA), coolant sensor, and crank wheel/sensor in that order. Well, if you're on a budget anyways. I am going to try replacing the Busa fuel pump with an MSD inline pump and reg. With my through flow fuel rail adaptation, I am hoping the MSD won't self-destruct from low flow rates. This is all to try and get the stock airbox back on.

As far as WOT, I don't think the FI can do too much more. The real gain offered to the XS by MS is the programmable timing curve. From my recent reading, the potential to really squeeze out hidden power is in the ignition timing. The problem is that the only real way to tune for optimal timing is on a steady state dyno ($$).

[crazy steve]

I would think that the only major benefit of sequential EFI would be an increase in fuel mileage, and it may not be that much. Does the MSII fire all the injectors with each plug fire, or are they 'paired' to the coils? If the latter, I doubt if you would see much gain. And I'm sure it would be a pain to get a cam positioner in there.

As to timing, yeah, that's where the real 'fine tuning' takes place. Out of curiosity, does the MS accept external inputs for altering the timing with multiple curves? If so, there's probably a bunch of mileage to be had with a 'vacuum switch' to change curves under light loads, using manifold vacuum as the source. This would be the same deal as the ignition on the XJ. Harley uses the same deal, but uses a stand-alone switch rather than having it built-in to the box. Theirs can be adjusted too, with roughly a 4 to 10 "hg range.

Maybe you could have the first 60+ mpg XS11!

[XS1100_OEM4ME]

$$

MegaSquirt has go leaps and bounds (IMHO) recently with MS Studio's VE Analyze Live which actually adjusts your tables as you ride to reach your specified AFR's. It has been a great couple of days on Megathrust. Today I decided to check my mileage. So, I topped off (paying careful attention to the 'full' fuel level, and went for a run down the highway. Hwy 101 is no Minot, SD. It's got plenty of turns, hills, and so forth. I tried to keep it between 60-65 +/- a few here and there. I also exited once, stopped, and got back on the highway all while trying to be pretty light on the throttle (no easy task for me ). When I finally got of at a town with gas, the tripometer said I had gone 51 miles since I topped off. When I topped off this time, the pump read 1.006 Gallons! EFI...having your cake and eating it too!

How much does it cost to change to EFI

[DGXSER]

How much does it cost to change to EFI

Taken from post above by 81XSProject (not trying to make a point of it, the site made me put some text of my own in and this what my pea brain came up with)

From my best recount of parts and what I paid, I am into the FI for around $700. However, I sold my carbs for around half that.

[81xsproject]

I would think that the only major benefit of sequential EFI would be an increase in fuel mileage, and it may not be that much. Does the MSII fire all the injectors with each plug fire, or are they 'paired' to the coils? If the latter, I doubt if you would see much gain. And I'm sure it would be a pain to get a cam positioner in there.

The MS will fire the injectors a user specified number of times per cycle at a user specified point in a cycle. I fire my injectors 2 times per cycle

As to timing, yeah, that's where the real 'fine tuning' takes place. Out of curiosity, does the MS accept external inputs for altering the timing with multiple curves? If so, there's probably a bunch of mileage to be had with a 'vacuum switch' to change curves under light loads, using manifold vacuum as the source. This would be the same deal as the ignition on the XJ. Harley uses the same deal, but uses a stand-alone switch rather than having it built-in to the box. Theirs can be adjusted too, with roughly a 4 to 10 "hg range.

Maybe you could have the first 60+ mpg XS11!

No external, additional equipment needed. My MS is set up to us Speed Density fueling algorithm. So, both the fuel tables and the spark tables have manifold pressure taken from the MAP sensor on the Y-axis and RPM on the X-axis. So, it can be tuned for all loads including deceleration. I currently have the table set up to have up to an additional 16 degrees of advance as the load lightens.