EFI for TR5/6?

[FatJon]

4 hours ago, unclepete said:

I've already got a distributor so why lose it? Also what would drive my tacho?

If I fitted a crank position sensor, wouldn't I also need a Coil pack etc?

Is one system better than the other?

By the same logic you’ve already got a fuel system.

 

Unless you want sequential you don’t need to know cam position, and a modern coil pack ignition is a much more energetic spark than an old style coil, cap, rotor arm, points etc. Sequential offers no advantage unless you are trying to meet modern emissions standards, which you will never achieve on a TR6 engine. 

 Also with only one pulse per cylinder event you get very inaccurate timing while the engine speed is changing during deceleration/acceleration, especially so during cranking when the speed can vary wildly over the stroke. A 36 tooth crank sensor arrangement is easy to fit, accurate and mechanically simple. Simple usually means reliable. All of the above are the reasons modern engines did away with distributors many years ago. EFI is only half the job done if you still rely on a distributor and a lucky guess on crank angle/timing. It’s actually easier to do the whole job too as you don’t need to lock up the distributor advance or modify its internals, just put it in a box and forget it.

 

Edited December 3, 2022 by FatJon

[CK's TR6]

Hall effect from DIY Autotune. The distributors are actually two pot metal? pieces pressed together. Broke off the bell, turned the remainder down to a cylinder, then 3d printed a prototype housing. The plate with the pivot pins was ground down to effect a tooth. If my 3d printed had been upgraded to print chopped carbon fiber polycarbonate filament (on the todo list), I wouldn’t have hacked up a piece of aluminum. Tach drive is as always.

As for ignition timing, MS3x will drive individual LS coils. Design a nice holder and send it off to SendCutSend and you are there. I had a legacy EDIS6 setup so kept that.  I suggest you read up on optimizing MaximumBrakeTorque MBT for each operating condition (MAP x RPM) and the benefits therein. As for ignition timing stability, crank fired ignition is dead steady. Try that with a distributor and changing RPM. ie dynamic crank accelerations per rotation resulting in same in camshaft.

Batch versus sequential injection. Methinks each person will vehemently defend their choice as best. Whatever. I would leave that up to someone who has done multiple installations utilizing each technique, preferably on the same vehicle and lived with it for awhile. Having said that, a MS3x supports the LS coils directly and has sequential. Why not use sequential then? A cam sensor is butt simple to do. 

[JochemsTR]

5 hours ago, CK's TR6 said:

Why not use sequential then?

Too much effort for no significant change. One seems to forget, these are 50 year old engines. I would love to see the Dyno Curve with and without sequential. 

[unclepete]

On 7/31/2022 at 8:21 PM, marki said:

I’m also running an idle air control valve, starts just like a modern. You don’t even have to get in when it’s cold to start it.

Marki

Looking at your idle control valve and the 6 take offs to the throttle bodies, it looks like you are using the balance screws on the throttle bodies? I thought these were for fine tuning the air flow across each body, or is this not important?

[unclepete]

5 hours ago, JochemsTR said:

Too much effort for no significant change. One seems to forget, these are 50 year old engines. I would love to see the Dyno Curve with and without sequential. 

Hi Jochem

Dyno Curves - Are there any out there? There are some ECU's with a 'Self Learning' feature, seems ideal to me, not wanting to plug the ECU into a laptop every 5 minutes? 'Switchable Mapping' some ECU's have this feature enabling an engine to run completely different maps ie. one for road use and trackability, another for a snorting beast on a track day and maybe another for somewhere inbetween?

Edited December 4, 2022 by unclepete

[JochemsTR]

Pete, self learning or closed loop do not have anything to do with sequential or injection angle. I am surprised, reading here on emerald and their rolling road, that no one here has tried and activate the sequential or injection angle. Since these can ONLY be optimized on a rolling road. 
Setting up your basic VE Table may be done on a cross country road, in my opinion it will give you a 97% solution. For many amongst us, sufficient. I did my basic installation on a rolling road. 

[CK's TR6]

In "Designing and Tuning High Performance Fuel Injection Systems" pages 38 - 40, Greg Banish describes the pros and cons of batch vs. sequential. As for how complicated sequential (and the requisite cam sensor) is, it isn't very difficult. 3 wires and hack up an old distributor. Software changes are easy, especially compared to some other functions of TunerStudio. Several of us in the states use sequential, and there all kinds of old cars on the MS forums that have done it. Like I said, most people have a vested interest in their particular approach.   

[JochemsTR]

The sequential injection requires carefull consideration of the injection angle. Not something to be taken lightly. As I mentioned before, I have yet to see any hard evidence, this bringing any benefit to a TR6 engine. Noticeable maybe in Idle and Cruise Consumption, again, I doubt noticeable on a TR6. On acceleration, all Pros are gone. But please show me otherwise. My video shows how smooth an Idle can be done, even with a race cam.

 

My advise to @unclepete start easy, work yourself into the matter, upgrade as it goes. Trust me, with EFI you will not be dissappointed.

 

Edited December 5, 2022 by JochemsTR

[CK's TR6]

Here is a quote from Rick Baines re sequential angle on his Spitfire, “ “You keep changing the angle on the ECU settings at idle until your (sic measured) AFR reads about 1 point richer - then you know that’s where the fuel is mixing best, and then you lean it back off to get your target AFR”.  

Or you can use the angle that Emile determined for his TR6 and then adjust from there.

As for the benefits, who knows? Subjective would be my guess. And, according to Banish, the intent would be to spray onto the hot backside of the intake valve just prior to opening. This essentially eliminates the issues of wall wetting of the intake port. 

In my opinion, if you aren’t injecting directly into the port (ie as close to the backside of the intake valve as possible), say because you are injecting via a throttle body that is mounted on stand-off manifolds, there is no point in sequential. Which is a different argument for not doing it. ie, if the point is to reduce the effects of wall wetting, but you have 5” or more of wall wetting, then don’t bother.  

Rick Baines simply bolted a sensor to the side of his distributor using an existing hole and triggered off the existing rotor shaft.  So, one bolt, 3 wires, and the above programming. He apparently triggered going low where the shaft is cut away for the distributor rotor. If a person can’t handle a bolt, 3 wires, and a couple of settings in TunerStudio, they should evaluate whether a turn key system is more appropriate for their needs.

 

[marki]

On 12/4/2022 at 9:17 AM, unclepete said:

Marki

Looking at your idle control valve and the 6 take offs to the throttle bodies, it looks like you are using the balance screws on the throttle bodies? I thought these were for fine tuning the air flow across each body, or is this not important?

Hi

 yes that’s correct they would control tick over air, that’s now controlled by the IACV. 

[unclepete]

14 hours ago, JochemsTR said:

The sequential injection requires carefull consideration of the injection angle.

Hi Jochem

Surely Injection angle is fixed via the throttle bodies? Or am I misunderstanding you?

[FatJon]

Injection angle is the starting crank angle at which the injector opens. Of course this changes with the fuelling needs of the engine in different conditions.

It’s not really very critical, I have swung it around by huge amounts with no significant change in output power. It can be used to fine tune matters at very short injection times like idle and cruise but at higher outputs the injector will be open for most of the cycle. The only way to overcome this is to use huge injectors which is problematic as they become very non linear at the extremely short durations necessary for big injectors at idle speed. If you were to try to inject only when the inlet valve is open you would need very large injectors to get enough fuel in that short duration. It’s impractical and no engine has this. then there is the delay between fuel leaving the injector and reaching the back of the valve to consider. Again this time is variable with engine speed, that’s why modern engines have injectors very close to the valve. That is also a luxury we don’t have with the TR6 engine as the manifold is always wet. This negates any benefit of sequential injection in this particular application. 

[CK's TR6]

The end of my injectors is within an inch of the head, but it is a bespoke manifold.

[FatJon]

1 hour ago, CK's TR6 said:

The end of my injectors is within an inch of the head, but it is a bespoke manifold.

That puts a different very complexion on the question. Well worth a sequential setup in this case. 

[CK's TR6]

I have most likely gooned up the math:

For one revolution of the crank:

Assume 270 degree cam, take out lash and all that to get valve at 0.010" open yields about 250 degree duration which is 0.7 of a revolution and rounding for clarity

1000 RPM is approx 60 MS per rev, 0.7 of that is 42 MS and my pulse width is 3.4 MS 

2500 RPM is              24 MS,                                    17 MS                                       8.9 MS

4900 RPM is              12 MS                                      8.4 MS                                     16.2 MS

If my math is correct, then if I squirt at idle somewhere around 310 degrees, the squirt will end just prior to valve opening. Assuming the cam is symmetric etc. I believe TunerStudio just gives the one input for sequential timing without regard to RPM. At 2500 RPM, the squirt will end about 10 MS before the valve closes. At 4900 RPM, a lot of intake port wetting occurs ;-)   If any of this is remotely correct, then sequential MAY yield some benefit at idle and cruise but none at higher RPM.

[JochemsTR]

on higher RPM/Load you want the injection angle changed towards spraying on a closed intake valve. so you need a RPM/Load/Angle Table.

The best calculations are worth nothing if you cannot verify this on a rolling road and have someone experienced looking over your shoulder. This type of tuning is not something to take on lightly. There is no room for subjective interpretation.

For a TR6, too much effort and time.

Edited December 6, 2022 by JochemsTR

[unclepete]

The following is an extract from the 'ClassicFuelInjection' website;

"During self learn the CFI system continually monitors the exhaust gasses and uses these results to correctly calculate the correct amount of fuel required at any given time.
To initially calibrate or map the system all you need to do is connect your laptop and run the software and then drive the vehicle.
It will then monitor the fuelling and automatically adjust the fuel maps as required, all you need to do is drive.
The 3D tables allow you to specify 100's of individual values of spark ignition timing and fuelling based on engine speed, throttle angle, manifold vacuum etc.

Normally after just a few varied driving trips the system will have learnt all it needs.
At this point you no longer need the laptop and you can just drive the vehicle as you would normally."

How does this system differ from the Megasquirt or Emerald systems or is it just a more advanced system?

[FatJon]

3 hours ago, unclepete said:

The following is an extract from the 'ClassicFuelInjection' website;

"During self learn the CFI system continually monitors the exhaust gasses and uses these results to correctly calculate the correct amount of fuel required at any given time.
To initially calibrate or map the system all you need to do is connect your laptop and run the software and then drive the vehicle.
It will then monitor the fuelling and automatically adjust the fuel maps as required, all you need to do is drive.
The 3D tables allow you to specify 100's of individual values of spark ignition timing and fuelling based on engine speed, throttle angle, manifold vacuum etc.

Normally after just a few varied driving trips the system will have learnt all it needs.
At this point you no longer need the laptop and you can just drive the vehicle as you would normally."

How does this system differ from the Megasquirt or Emerald systems or is it just a more advanced system?

Exactly the same. The MS system uses Autotune which is just like you describe.

[CK's TR6]

I stand corrected.......re the MS3x sequential injection algorithm.  "TunerStudio MS Lite Reference", James Murray (2018) page 88, gives one the choice of angle specifics, that is: end of, middle of, or beginning of squirt. Therefore, if set to "end of squirt" one can end the injection pulse exactly when they want it in reference to the intake valve timing (each cam has specifications on duration and timing in reference to the crank). It seems Rick & Emile have empirically hit upon a good timing that stays the same in reference to the intake valve movement. One software choice, one software inputted angle, one bolt and 3 wires; C'est tres simple. IMHO deciding that each cylinder will get squirted at the same point referenced to the intake valve movement is less risky than batching and having 1 or 2 cylinders way off from that perhaps even squirting halfway through the compression cycle.  However, if you have a bunch wall wetting going on because the injector isn't right up near the head, then the fueling at intake valve opening can rely on evaporation off the wall rather than the specific timing of the squirt, so batch is fine.

Since we are well into a rabbit hole of thread creep, I suggest reading Banish (previous title) pages 48-52, "Performance Fuel Injection Systems" Cramer & Hoffman pages 110-111, 117-118, 121-126 "How to Tune & Modify Engine Management Systems" Hartman pages 118, 130, 142, 146. And of course, YouTube channel "EFI University" for the reading impaired. The essence is that you want peak cylinder pressure to occur at the best mechanical advantage crank position without encountering detonation. This results in peak MBT (maximum brake torque) at some particular operating condition. You want this at all operating conditions if possible. AFR affects it, but ignition timing is the real determinate. So, for a particular operating point, you would increase ignition advance until MBT is achieved. This requires a specific kind of dynamometer, a load control (aka steady state) that can measure torque vs an inertial dynamometer. The dyno holds the engine RPM constant, the operator holds the load constant (say MAP if using speed density) and then you vary the ignition advance while referencing the engine torque output (MBT). And you do it ad nauseum to fill in your ignition table.  So, what kind of rolling road and what you are trying to achieve matters. 

HP is a mathematical function of RPM and Torque. Torque is a function peak cylinder pressure (VE) and when it occurs. 

I didn't do EFI for the sake of EFI, I did it so I could have dry manifold design flexibility. I have no desire to have it look all too cool like some old style Hillborn racing system or a stack side throat Webers.  

[unclepete]

That is a whole lot of information!

One more question again.

6 Throttle bodies or just 1 ?

[FatJon]

1 hour ago, unclepete said:

That is a whole lot of information!

One more question again.

6 Throttle bodies or just 1 ?

6 is optimum for a performance tuned engine but can get expensive. 1 is fine for most cases, cheaper and easier to tune but limits ultimate power of any given engine, especially high rpm applications.

6 is actually easier daft as it sounds as you can convert the PI existing TBs or get off the shelf aftermarket bits.

 

 

 

[CK's TR6]

One problem with single TB is tip in response. If the TB is large enough to NOT restrict airflow at WOT and high RPM, then tip in response maybe more problematic for day to day driving. Which begs the question, since ultimate power is also a function of ultimate RPM,  what is your driving style or intended driving style? If it is a track car, then WOT all the way up to the RPM limit just below self destruction. With proper balancing, lightening, Racetorations steel crank etc, that may mean something above 7000 RPM. Tip in response is not applicable. If a fast road car, then day to day driving is more important, but again, will you routinely take it above 5500 RPM? I have a single TB that is quite large but has a shaped blanking plate riveted to one side (OEM did this), this permits very good tip in response while having a large throat. The blanking plate doesn't effect the WOT throttle flow much at all. But, I don't drive much at all above 5000 RPM. See previous post re manifold, my manifold was to increase VE (torque) down low and it restricts flow at high RPM. And, I have soft and hard shift limits programmed in the ECU too. I do hit them once in a while. 

The first question is, what are you going to do about a manifold? Is it wet? How much fabrication are you willing or even able to accomplish? What about idle air control? Answer those and you will have your answer. Again, procure the previous referenced books and educate yourself on the sections about your question.

[unclepete]

1 hour ago, CK's TR6 said:

One problem with single TB is tip in response

What is 'tip in response' ?

[RobH]

 

Throttle 'tip-in' is the change from from cruise to acceleration. The response is how linear the % of acceleration is in relation to the % of throttle pedal movement,  i.e how progressive the throttle feels. 

 

[CK's TR6]

It is also the response coming off idle. You are stopped at the light and just need a few hundred RPM as you let the clutch out, imagine that a slight tip in of the throttle is a big change because the single TB lets in a lot of air. Makes daily driving a challenge.