Doing some tuning today!

[BDC]

I've got a few errands to run today and will be doing some playing around w/ the system. I've currently got 93 octane in and will be doing some 14-15psi stuff; nothing too, too heavy. I'm still running the stock, top-mount IC until we get the A2W intercooler core done (needs piping and water fittings welded on). My plan is to start trimming fuel out and get the alcohol injection curve setup. I am currently running one M15 nozzle in the throttle body inlet adaptor. Since I have an FC, my air intake temp sensor is in the same location so I won't be able to see on-the-fly charge temp differences, but that's changing later this afternoon or early evening when I remove the LIM and put the sensor in there. I'm curious anyways to see what the charge temp differences are given the fact that the turbine housing is parked alongside the manifold and may cause heatsoaking (even though I've got a turbine blanket and a pair of intake manifolds that are ceramic coated.)

I'll get back with you guys to let ya know how things work; hopefully have some datalogs too. For those of you that don't know, I'm one of the (only) two rotary owners who's using Razor's kit. Me and Howard Coleman, author of the infamous "CHART", are experimenting w/ straight methanol injection on the RE w/ Razor's hardware and electronics to see if it's a viable solution to our overall reliability problems. Here's pictures of my installation:

http://bdc.cyberosity.com/v/ProjectCars/BDC/AlkyControl/

Ya know Razor, I think we might be larger than 1gal fuel cell. May have to step up to a 3gal...we shall see. I'll let you know what I wind up with today.

B

 

[Quiky One]

What kind of car is it??

Jason

 

[BDC]

First day - Oh yeah!

What kind of car is it??

Jason

2nd generation Mazda Rx7; one of only two Rx7's that are using Razor's kit.

Got some 1st day tuning data. It's not much as it only amounted to about 15 minutes of adjustments on the Initial, Turn-On, and coarse Gain knob to get the 'curve' in the ballpark. I ran into two problems: One, it's beginning to rain, so the roads are starting to get wet. That nixes the going fast down the highway idea, and Two, I blew an intake hose off at the tail end of my fun. I was inching my way back up to 15psi when I heard something blow off in the intake and then boost dropped down to below 7. I decided to stop there and drive it home, but I've got some data.

First off, this is an alien engine and setup compared to what alot of you guys are doing but nonetheless is proven to work well with methanol in the very limited number of straight-line, drag applications that are out there. There's probably only really a handful of people out there in the rotary world doing it. So, with that, I initially expected to have to jump through a few hoops that you guys don't. Well, I was mistaken yet again. Razor's pre-settings were very close to where they ought to be. Also, his tuning advice was right on the money! Everything he's said has been 100% spot on.

Secondly, this system is mega overkill and I love it! I had no idea it was this powerful. Before my intake whatever it was blew off, I was around 13.5psi of boost about 5500rpm, in 4th gear doing my testing. I had turned the turn-on point down just barely (it's coming on about 4.5/5psi now), turned the initial point up some, and currently I've got the Gain knob set at 3.5. Out of my fuel map from 5psi to 15psi (for any Haltech users out there reading, bar 15 to bar 22) I marked all RPM ranges and lowered it 10%, then 5%, then an additional 11% (a total of about 25% fuel reduction/injection timing). With those controller settings, last time I checked atleast, I was sitting around 10.20:1 AFR's. I didn't get to run the RPM out so I'm not sure if it will remain at those ratios but I suspect it will because it was already tuned pretty well.

I've still got some tweaking to do at the turn-on point as I need to adjust the fuel map to keep it at a smooth transition (it's running lean when I kick the alky on initially; too much reduction in fuel or in the wrong place to start), but otherwise this is working beautifully. My fuel system consists of two 70lb/hr primaries, which run both in vacuum and in boost, and a pair of 160lb/hr Bosche secondaries, which are "staged" at about 3psi of boost along with the primaries. The rotary uses alot of fuel for its size; it's downside for its high power/weight ratio. If this system can sustain a rich air/fuel ratio under heavier loads, then this can potentially change our entire paradigm on the sizes of injectors we use in our cars. No longer will we need these honkin'-huge injectors that already have staging problems nor will we need monstrous fuel pumps for big power. Simply amazing.

I plan on moving my air temp sensor from the throttle body inlet, where I've currently got my injector nozzle, and move it to the intake manifold to get not only a more accuracy charge temp reading but also one that's indicative of the drop in charge temps via the methanol injection prior to it. I'm also going to fix this intake leak. Once I get that work done, I'll report back and hopefully with some more numbers.

B

 

[BDC]

Using Howracer's chart, I did some calculations today to figure what kind of target AFR's I'd like to aim for. One thing that is different about our rotaries from the piston engine is our RE's create alot more heat (on the magnitude potentially of several hundred degree higher EGT's). With this in mind, the (limited) rotary tuning community has generally tuned medium to higher loads, atleast on pump gas, around low 11's:1, to keep the chambers awash in fuel to help with the chamber heat. Even though more optimum combustion is arguably more like high 12's:1 to 13:1 for best power and torque, the notion has been to use our precision-control, fuel injection systems to fine tune for that extra amount of fuel. Both Howracer and I affectionately call this 'the hack job of the decade' or other colourful metaphors depending on where the conversation is going. There's just something wrong about using a very volatile fuel to cool a volatile, heat-generating chamber, while already burning a very volatile fuel.

With this in mind, what I'm curious about is whether or not I should cater my calculations towards a leaner A/F ratio reading because, in this real-world application, methanol is now being used as the chamber coolant and knock deterrant in replacement of fuel. So, would it be wise to create my target A/F ratios based on assuming a leaner mixture, such as 12:1 or 12.5:1 with fuel as part of the 75% equation, assuming I'm using 75% fuel/25% methanol for my overall fuel supply? What do you guys do as far as fuel to methanol ratio? 75/25 or more like 70/30?

Here's what I've got so far:

Tuned for 11.66:1 on 100% gasoline;
- 75% fuel, 25% methanol, for 11.66:1 originally:
- (7.5* 11.66) = 87.45, (2.5 * 5.08) = 12.7 -- (87.45 + 12.7) % 10 = 10.015:1 A/F Ratio

Tuned for 11.8:1 on 100% gasoline;
- 75% fuel, 25% methanol:
- 7.5* 11.8 = 88.5 -- 2.5 * 5.14 = 12.85 -- (88.5 + 12.85) % 10 = 10.135:1 A/F Ratio

Tuned for 11.8:1 on 100% gasoline;
- 70% fuel, 30% methanol:
- 7 * 11.8 = 82.6 -- 3 * 5.14 = 15.42 -- (82.6 + 15.42) % 10 = 9.8:1 A/F Ratio

B

 

[Razor]

Brian you and Howard are two clever guys. If anyone on the planet can do this.. its both of you.

Now one thing that sucks is your not looking at HP data on a dyno or track surface. I understand your dialing her in.. and getting somewhat wet.. but the drenching will help establish your replacement amount.

Whether it be 20, 25, 30 percent.. I dunno.. but if the HP keeps increasing and the EGT's stay stable.. then you hit the nail on the head.

Glad to see your having fun.. I'll pray for some drier conditions to let you play some more. And yes your fuel cals would be correct.. but I dont know anything bout those Alien motors you guys run

 

[BDC]

Brian you and Howard are two clever guys. If anyone on the planet can do this.. its both of you.

Now one thing that sucks is your not looking at HP data on a dyno or track surface. I understand your dialing her in.. and getting somewhat wet.. but the drenching will help establish your replacement amount.

Whether it be 20, 25, 30 percent.. I dunno.. but if the HP keeps increasing and the EGT's stay stable.. then you hit the nail on the head.

Glad to see your having fun.. I'll pray for some drier conditions to let you play some more. And yes your fuel cals would be correct.. but I dont know anything bout those Alien motors you guys run

As far as fuel/alcohol ratios go, what do you guys normally do? I am starting with 25% although I'm beginning to think I can get away with a higher amount of alcohol. Given that our "alien" engines are predisposed to an early death due to the dramatically higher amount of heat they produce compared to their "boinger" counterparts (hah, hah), I am leaning towards putting more emphasis on more alcohol and less fuel. Perhaps it'd be wise to wait until I get a competent knock-sensing system before adventuring out into unknown space like this. One small problem I'm running into is my PLX M-200 wideband displays nothing richer than 10.00:1. Past that point, it says "RICH", which is right at the neighbourhood I would theoretically want to tune for.

B

 

[Razor]

I'd keep it to 20-25% and tune it in the low 10 AFR then work on leaning it out to 10.5.. then 10.7 and see if it picks up power.

At 20% you should be able and throw a lot of boost without issues.

Its not like you can kick a rod out

 

[BDC]

I'd keep it to 20-25% and tune it in the low 10 AFR then work on leaning it out to 10.5.. then 10.7 and see if it picks up power.

At 20% you should be able and throw a lot of boost without issues.

Its not like you can kick a rod out

Hah, that's true, I can't kick a rod out the side of the car, but we do have our own versions of problems. Given the sensitivity of this motor to heat related problems, I think I'll default to 25% to start and watch EGT's as I aim towards your suggestions. Thanks for the tip, Julio.

B

 

[BDC]

Got some more done tonight.

I relocated the air temp sensor from the throttle body inlet (where the M15 alcohol nozzle is located) to the other side of the throttle body in the intake manifold's outer runner surge plenum. My goal here was to get a more accurate reading of the change in air temp made due to the introduction of methanol upstream. After I made sure stuff was buttoned up and leak-free (with no pipe blowing off this time), I took it out.

On my Haltech standalone EFI system, which may operate differently than what you guys use with your Scanmaster software or however it's setup, I have the ability to create fuel and ignition curves on separate map files that I can then load into the ECU at a later time. What I did was basically revert back to my tuned to 15psi street map I had running early this afternoon prior to shaving fuel out of it to add methanol in. I took that map, highlighted the load bars representing all RPM ranges from about 5psi of boost up and removed 25% across the board. So, everything fuel injection wise in vacuum, at the 0"/0psi staging to secondary injectors point, and up to about 5psi remained untouched, then a dramatic drop thereafter in the curves. I left the ignition curves untouched as I figure I want to work with something that's already known-good before I perform exploratory surgery with more advance (I think I'll wait 'til a dyno tuning session w/ a knock sensing system prior to doing that.) Basically, I wanted a clean start from some of the messin' around I'd done earlier this afternoon on the existing fuel map.

Well, I started at around 10psi of boost tonight and worked my way up to about 14.8-15.5psi by the end of it, all 4th gear in mid-high RPM, all to establish the two points for the curve to aim for a consistent air/fuel ratio -- TurnOn and coarse Adjustment. I've pretty much so far got the wideband sitting around 10:1-10.30:1 at 15psi and I'm pretty sure I've got the alcohol curve ramping up right along w/ the fuel curve in boost. Since it was just me in the car, I didn't have an opportunity to video anything or check out the EGT. I was busy watching the road and also the wideband. An Rx7 buddy of mine I'd met at the corner store tonight followed me down the highway for the 15-odd minutes. He said the exhaust definitely smelled different with the alcohol.

So far, my adjustments on the controllers have been:

- Slight lowering of TurnOn point to activate about 5psi (load bar 15 on my Haltech)
- Raised the Initial by about 1/2 turn
- Coarse Adjustment sitting right at 3.

Some datalogged data:

At 5200rpm at 15.5psi of boost (range 11, load bar 21), I'm logging between 3.744 and 3.800ms of injector timing with the two 70lb/hr primaries and two 160lb/hr injectors fully staged. Where I "should" be given it being a fuel-only setup maintaining a low 11:1 AFR is approximately 4.928ms. Big reduction. Looking at a datalog from a couple months ago on the fuel only setup, I should be sitting about 51-52% injector duty cycle. On these logs tonight, those duty cycles were sitting about 31-32% on average overall.

Air temps rose only 9* on the run. I am still running the stock top-mount intercooler for the time being until my air to water core is complete. At this boost, the air temps should be pegged around 275*F but they only went up from 104* to 113* with the sensor located in the manifold. Not too bad.

Here's three screenshots from the last datalog I took in 4th gear. The screenshots are in chronological, page order. Check the right side for time (in sec) of the datalog.

I also wound up using the latter 1/2gal of methanol left in the cell from screwin' around when I installed it. On the way home, I saw the low-level LED flickering when the car hit some bumps so that was a wrap for the night. Hopefully, I'll get some more testing in tomorrow. I still need to smoothen out the transition where the alcohol comes on, especially now that I've got the Initial point cranked up a bit. The car humps a bit when I pull fuel out to stage the methanol on to it'll require some more attention.

I'm very pleased! Having a blast with this system. My neighbours hate the smell, but oh well.

B

 

[norbs]

Interesting stuff, but the question is, is the car making power at the richer a/f or feel like its bogging down.

 

[Razor]

Got some more done tonight.


- Slight lowering of TurnOn point to activate about 5psi (load bar 15 on my Haltech)
- Raised the Initial by about 1/2 turn
- Coarse Adjustment sitting right at 3.

I'd drop the Initial and bump up the Gain to 5-6.. or even 7. That way there is less of a hit when it comes on. And still have the same amount you have at 15 PSI. You shouldnt need lots of alky at 5-10 PSI.. that is why i'm suggesting the drop of the Initial.

Hey your motor is getting cleaned out

 

[BDC]

I'd drop the Initial and bump up the Gain to 5-6.. or even 7. That way there is less of a hit when it comes on. And still have the same amount you have at 15 PSI. You shouldnt need lots of alky at 5-10 PSI.. that is why i'm suggesting the drop of the Initial.

Hey your motor is getting cleaned out

Yep you are right, but my theory here in setting the curve on the Alky system is to match the steadily rising fuel curve I've already got established on my tune, hence the shaving 25% off the top and replacing that 25% with alcohol in its place. I can smoothen out and tune the initial point; I don't have a problem with that. I'd just like to keep it at 25% across the board if possible and make the alcohol injection curve go more aggressively than it needs to be at higher loads (20+psi). Make sense?

B

 

[BDC]

Interesting stuff, but the question is, is the car making power at the richer a/f or feel like its bogging down.

So far it feels the same. I haven't made any adjustments to the ignition curves by running more advance or anything like that. I've kept it the same. Also, I haven't really planted my foot in it in, say, 3rd gear to really see what it's doing. But, the fact that it's holding the air temps (with the sensor located in the intake manifold right near the turbo) and maintaining a good, calculated A/F ratio under load tells me it's making more power.

B

 

[BDC]

I'm not entirely satisfied w/ what the air temp sensor is now reading in its new location. I'm getting the feeling that the manifold it's sitting in is heat soaking due to the exhaust manifold/turbo/downpipe being right below it, possibly making the readings higher than they would be. I'd love to have it on the other side of the engine bay, where it was, but it's too upstream to read the reduction in charge temps when the alcohol starts spraying. Hmmm...

Oh well. I'll deal with that later. I filled my cell back up today and put the spare 1gal jug in the back. I'll do some more testing tomorrow after I get my vehicle registration in order (I'm "slightly" expired). I also think, Julio, that I'm going to go 5% more methanol and 5% less gasoline and go for a 70/30 ratio, no change in spark advance.

B

 

[BDC]

Did some more tuning tonight.

So far, I've got the initial cranked up a hair bit, the Gain is set to 3, and the Turn-On point is just to the right of dead-bottom. I have the alcohol coming on about 2psi. The theory I am currently following is to aim for a low 10's:1 air/fuel ratio on the wideband all the way throughout my target boost (so far 15.5psi), all the time under load. I am trying to get the 'seesaw' of the Initial/Gain pair to accurately replace the 25-28% I've already removed from my fuel curves in boost. With nearly 200 load points in boost alone, it's a little challenging to say the least. So far so good. The motor seems to flood with EGT's at 1100*F and lower with the EGT probe located 4" past the turbo (add ~340* and that's what the EGT's really are under heavy load). I really need a wideband that can read a slightly wider range of resolution. Mine is pegging out at 10.0:1 and not reading any lower.

So far I'm also seeing a drop of nearly 20% in duty cycle along with remarkably lower charge temps on a crummy intercooler. More to come.

B

 

[Razor]

I'm buying stocks in VP Your consumption must be through the roof.

Why not have it come on latter and not displace that much fuel down low?

As long as your injector duty cycle is low..no need to displace the fuel.

 

[BDC]

I'm buying stocks in VP Your consumption must be through the roof.

Why not have it come on latter and not displace that much fuel down low?

As long as your injector duty cycle is low..no need to displace the fuel.

Man Julio, you get up early.

Yep I've got a fairly high consumption right now. I'm still playing with it, but I figure I'll default to the alcohol side of things and deal with the issues of too much alcohol rather than not enough. Remember, I'm dealing with an engine that has a problem early on with heat as well as an engine that runs extremely well with very high octane fuel.

Hey, I was thinking about going 70/30 ratio. What I'm waiting for from guys like you is what kind of ratios you guys have run that have yielded race-gas like results with both timing and what you figure the effective octane is.

B

 

[Razor]

If you pull out 30% fuel.. thats like pumping in 60% alcohol. Takes twice as much alky to make the same as gasoline.. gotta be careful..

Need to have performance numbers to make decisions as to air fuel and timing. The EGT will tell ya if your having any abnormality showing up. So if the EGT is staying in a safe zone.. drop some alky out.. and add fuel. Worry about the high boost high timing areas.. the low boost portion of your map wont create detonation.. no matter how hot it gets.

Cool to hear the motor is a little meth "prostitute"

 

[BDC]

If you pull out 30% fuel.. thats like pumping in 60% alcohol. Takes twice as much alky to make the same as gasoline.. gotta be careful..

Need to have performance numbers to make decisions as to air fuel and timing. The EGT will tell ya if your having any abnormality showing up. So if the EGT is staying in a safe zone.. drop some alky out.. and add fuel. Worry about the high boost high timing areas.. the low boost portion of your map wont create detonation.. no matter how hot it gets.

Cool to hear the motor is a little meth "prostitute"

Yep and the consumption rate with the 75/25 ratio is already pretty high. I'm still thinking about how to do this exactly with this particular system in mind. I understand I won't run into knock at lower boost levels and this is one reason why I'm tempted to shift the TurnOn point back up to the factory pre-set and stave off some of the higher consumption rate; perhaps having it come on at 7-8 psi just above my WG's spring rate.

The other thing I'm wrestling with is to make say a 20 or 25% cut across the top of the entire fuel curve in boost and replace evenly with alcohol, or shall I start out very light w/ a very light Initial point at the TurnOn point then progressively remove fuel (5% at turnon, 15% at 15psi, 20% at 20psi for example) and adjust accordingly on the Gain? In theory, I don't need that much alcohol at lower boost as it's more a function of staving off knock at higher loads...

B