Injection amount vs E85
 

Ive recently got my twincharged ( m90 and 69mm gt45 ) 2jz running again. This time around its got 10:1 compression on 25psi boost. Ive been tuning it on 98 and 50/50 water/methanol.
Total 98 flow is around 1500cc to 2200cc depending on rpm ( 5000 to 7000 ). I started spraying 1800cc/min, 1500cc direct port and 300cc pre turbo but still had slight signs of sparkles on the plugs ( no audible, well by ear ), so I upped it to around 23-2400cc by adding a second pre turbo nozzle and upped the pressure a little which has seemed to work.
It had me thinking how much you would have to inject to keep up with E85's knock limit. As at the moment I'm injecting technically M30, M40 plus the water. Or over 100% water/meth to fuel.

http://i966.photobucket.com/albums/a...pscvjujiug.jpg

https://www.youtube.com/watch?v=awHJHKUOx_g
Cheers

Re: Injection amount vs E85
 

If you run it at a petrol equivalent indicated AFR of 10.2 or about lambda 0.69, you run way too rich in my opinion. That will even promote knock.
Is the 50:50 by weight?
Running so rich in the presence of water reduces burn speed a lot. It costs power.

I'd retune it to lambda 0.78-0.85. No need to run any richer on so much mix.

One of the reasons you might experience more power on e85 is its higher burn speed compared to your current super rich mix.
The ignition timing numbers will not directly be comparable due to the different burn characteristics.

Re: Injection amount vs E85
 

I understand what your saying but the way I look at the afr is there is approx 50% methanol to 50% fuel going through the engine. The afr target for a boosted methanol engine is around 8.0 or 0.55 lambda, gas target is 11.0 or 0.75. So I figure running an afr in between these would be correct, so around 9.5afr or 0.65 lambda at 50/50 meth/fuel. So Im at around 9.8afr to be the same so 10.5 is still leaner. I tried leaning it out to 11.2 at the track with no gain in et or mph so I richened it back up. Also the plugs lost there fuel ring which scared me a little lol. I understand the water does its thing but at some stage you would have to go richer than a lean gas scale reading. Cheers

Re: Injection amount vs E85
 

Bullshit!

Have you ever run an engine with proper knock control before you posted this?
I have many times and I can tell you first hand across lots of different set ups that there is direct correlation to excess fuel ration and WM50 rate that shows greatly reduced knock levels as you get more petrol in there. I've run these down to 0.670 L.

Re: Injection amount vs E85
 

Unless you want to pick up parts off the road or track keep it with 40% to 45% excess fuel mate, real world always trumps theories and performance validation is king.

Re: Injection amount vs E85
 

Hello Peter,
Ears, a TurboXS knocklite and later a J&S Safeguard plus gauge.
No Motec or Syvecs capability, but in a early Elise you can hear it knocking pretty well as there is no sound insulation and the engine sits close behind your head.
Now at least my puny SC Rover K made less power on rather rich AFRs and knocked with less advance. Could be exhaust valves getting hotter or whatever. Lot's of nonlinearities.
Maybe I was all wrong and should have drowned that bugger in fuel despite it performing rather poor.

You also posted similar observations on way rich not being any good in the past.
You advocated AFRs of 11:1 and higher.
I can dig out a few examples from you, but can't be bothered on a ipad.
From: http://rotarycarclub.com/rotary_foru...p/t-10423.html
"*At full boost pressure* The AFR on average is 11.3:1 with the current WI setting, it only goes towards 11.4:1 at revs past 7400rpm to stop the power from falling off where I need to hold rpm to say 8300rpm to save making a gear change be it on a straight or hold out 5th gear for 200+mph top speed as my car is geared for too :). Lower boost pressures (0.5bar to near 1.0bar) the AFR is around ~12.0:1 setting (more so because any more excess fuel is not required, especially with water injection or even without) Anything with more excess fuel really takes away allot of power. My EGT was always around 980 deg C or so with the correct ign timing, this set fuel mixture, and WI rate. Anything outside of these settings results in lower power, too high an EGT, misfire, or and less measured performance (< too over cooled *fuel or combination of fuel and water*, or not enough ignition advance especially) in my standard 90-140kmh testing I do."

"Default Re: Injecting water into a rich a/f mixture is not a good id
Quote:
Originally Posted by Richard L
Not so long ago, a user of our WI system has lost some 40+ WRHP during a dyno tuning session, not surprise to know that he was quite disappointed. Only after a few months later and have discovered that his engine is tuned to run an a/f ratio of around 10.5:1.

I would really like to hear from anyone if they have suffered the same experience?
Great thread Richard !

I have seen this in my own current car, but I put it down to non audible misfires. When I have had a super strong ignition system on various other cars I have done I have not seen losses in that magnitude but they def do exist.
__________________
http://www.riceracing.com.au
RICESP > F40 > Zonda > ZR1
Water Injection Specialist
"Can't be defeated!, don't know the word!, shoulder to shoulder!, we'll fight the world!, WE CAN'T BE BEATEN!!!""


In the end, it won't matter as long as you can extract the most from a given set-up. :-)
You have also worked on lower boost levels at the time you posted you observations.
Could very well be that at 30PSI and higher things look different these days.
I went NA for 2018 :-)

Re: Injection amount vs E85
 

Would you agree that the only reason for a richer mixture is due to the volume or percentage of methanol used in relation to fuel flow? I wish my wideband actually went lower than 10.0 lol. Cheers

Re: Injection amount vs E85
 

Miss fire and knock are two different things, so not much point quoting that really.
Was just talking about your statement as its opposite to what I have see these days, using the only knock capable ECU that is proven at places like LeMans (Life Racing/Syvecs).

I've got allot of cars running with much higher energy CDI systems than back then, all on WM50 and regardless of engine type, they will show lower knock with great excess fuel (I have only tested to ~9.5:1 AFR). Each one of them will take more ign timing and make more power when running this with WM50 than they will if run at 0.730L or 0.760L or higher...

Thus I pretty much default to 0.700L myself, this is for cars running 8.2:1 to 9.0:1 CR, petrol and WM50, like the poster here I can't see difference in performance on these combination run to 3500mB (MAP), but do see lots of reduction in thermal stress on the engine and turbo shown by EGT sensors. Only negative is increased fuel use, but given on these cars it makes up less than 1% of time on load then its meaningless to a 'street car' that is raped on road.

Other question is it the meth that needs it?
It's just what the engine demands........ use anything other than a Life Racing/Syvecs engine management unit and you are doing nothing more than guessing as I have not seen anything else (used them all) that can actually run an engine at the knock limit all the time like these systems have proven to do when it counts (in professional endurance racing) not paper/web page or hobby racing series. :)

Re: Injection amount vs E85
 

Mine is but one experience though :)

All of this has been covered at length ~80 years ago anyway, where engines were run to knock limit with every permutation of excess fuel and WM50 ratio from 0.2 by mass to 1.5 all of the information is out there and the testing is comprehensive.... much better than anyone has shared on gagtube or on-line and lets not forget it was done by people who held relevant qualifications in the said topic too, not wikkipedo Goolaged knowledge for Generation nobodies that proliferate today via blogs etc etc.

More often than not lack of ignition energy is the #1 culprit towards people (including myself back in the day) making wrong assumptions about the merits or otherwise of water injection and the many ways it can be set up and run.

Re: Injection amount vs E85
 

Your work on ignition has been greatly appreciated here and elsewere.
Sounds reasonable that in certain conditions and suitable hardware more fuel can work well.

I am aware of the WW2 literature and have read it as well. It is just not all directly applicable in a given car engine set-up. Your ignition issue is one of them.

Could be that my experience of rich not performing well is fundamentally casued by ignition onset delays or other related issues.
One aspect that made a bigger difference for the power I was able to extract was proper mix distribution and that the fine mist actually makes it into the cylinder. Modern curved plenum runners of dry flow manifolds are a major obstacle for central injection systems.
You method is one of the ways to deal with droplet aggregation, make them very small to begin with.

Cheers
Marko

Re: Injection amount vs E85
 

Been using allot of Richards systems recently (direct port) as per your finding and others works well, but I dont know everything, never will.

Anyway yours and everyone's contributions is what its about here and why its a good place, always fun to go back and re read some of the stuff from many years before too :)

Re: Injection amount vs E85
 

Because I have got a state of the art LT10s microtech which has no knock sensors, I have to read the plugs after each tune change, which Im happy to do. Ive never once heard my setup knock by ear but its showed on the plugs, although I have heard it knock just before the water turned on before but never once its on.

So just out of curiosity does anybody check the plugs? Or does everyone rely on knock sensors etc? Only reason I ask is I was always under the assumption that knock sensor wont show pre-ignition or at least not fast enough? Not that a plug check can help once the damage is done lol.

Here is an interesting read, unless Ive missed it I could find it on this site. Once it loads its a little down the page. Cheers

https://www.sciencedirect.com/scienc...7661021502648X

Re: Injection amount vs E85
 

Preignition is usually a consequence of knock.
Unless you run extreme compression ratios or get boost spikes that woud result in instant preignition, Diesel comes to mind, it usually starts with "plain" knock. Knock tends to increase local temperatures of chamber components such as spark plug electrodes as the combustion becomes irregular and overall faster. As pressures rise faster than anticipated, chamber temperatures rise rapidly.
The longer it knocks, the hotter bits get until they are so hot they ignite the fuel before spark occurs. You have pre ignition. It is a run-away process. It starts with light knock changing to heavy knock until kaboom, you get preignition. This commonly ends in engine destruction. The entire process can at times take less than a second given enough boost and heat.

If you have a very fast knock control system, it will retard ignition within one revolution preventing the worst. My J&S safeguard worked that way. I have tried it when my priming pump of the old Aquamist race pump failed. I spit huge flames out of the exhaust of my Elise in concerto with big misfires. The J&S pulled 10 deg timing out of all 4 cylinders at once. The TurboXS knocklite also shows single and faint knock events below the audible treshhold. At first I thought it was indicating artifacts, but pulling 2 deg of timing in these spots reproducibly removed the indication.

You can data log the output of the J&S, but commonly there are only a few spots you need to correct under full load.
I have also used it to generate a suitable IAT ignition compensation table for water methanol injection on my engine.
The base settings were mapped at 20-30C IAT with short squirts of power.
The temps up to 50C were evaluated with longer and repeated pulls or during hot weather. The range to about 70C intake air temp, the highest I ever managed, then on track.
Without data logging, you cannot really do this conveniently.
If you push on without active knock controll, you'll eventualy run into trouble.

Modern ECUs have sophisticated knock control.
But for less sophiticated systems, the J&S is a viable add-on for high boost applications. I'll safe your engine eventually. I doubt that you can pull your foot fast enough of the throttle at 25PSI of boost when heavy knock occures. A small drop in fuel pressure due to starvation is all it takes to blow an engine without protection. Same for bad fuel, failing IAT sensors, etc. My Rover would not have survived it without knock controll. I have cracked a liner during a fueling issue at the bigging of mapping it myself. There wasn't more than a slight power fluctuation and it blew liters of coolant at 6000 rpm in seconds though the exhaust. It was the biggest cloud I have generated in my entire life. The fuel pump was not up to the job feeding the bigger jets leading to pressure issues. The wideband lambda sensor data together with the injector duty cycle showed this nicely. I then added a fuel pressure sensor to confirm.

Re: Injection amount vs E85
 

See the table set in my many Life Racing ECU customer cars, take note of title ;)
NOTHING in the world is more fragile than a rotary engine!!!!
And with stock standard apex seals you can not break the engine due to knock, once set up correctly with a Life Racing F88 ECU.
I record every single engine cycle (all the time on load) and the ECU has always controlled this so each firing event of the plug each event of signal from the knock sensor is recorded but more importantly acted on INSTANTLY by the ECU.......... nothing in the world I have seen works as well, the other real racing quality ECU's I personally used and owned inc Pectel MQ12 and Bosch MS5* series ECU, shit that costs $20,000 for a control unit FYI :) no Mowreck or Microwreck need apply LOL.......
https://i.imgur.com/Bz9z6Jj.jpg

Re: Injection amount vs E85
 

So it looks like not many people bother checking the plugs lol. You forgot microjunk and microwreck haha. Cheers

Re: Injection amount vs E85
 

I pull them once in a while to check uniformity and look for absence of oil contamination, but if you push boundaries it might be worth doing it more often.
Otherwise the knock sensors, ears and wideband lambda sensors tell me what is going on.
For a turbo, you need at least EGT.
If you really want to know what is going on, add a turbine rev counter and pre and optionally post turbo pressure probes.
On the intake side, measure preturbo IAT and pressure. together with post turbo temp and pressure, you can see where you are on the compressor map.

If you run charge cooling, you could measure water inlet and outlet temp plus air inlet and outlet temp. This allows to calculate CC efficiency and figure out where the bottle neck is.

Re: Injection amount vs E85
 

To actually hear knock from in the car, how bad does the knock count show? My car has 4 mufflers so its pretty quiet:).

Re: Injection amount vs E85
 

In a early Lotus Elise of the first series, you hear everything.
Can make you nervous after a big rebuild or power increase.
You can literally hear the injectors ticking at idle from the driver seat.

There is virtually no sound insulation, aluminium tub chassis, open top, mid engined. The "firewall" consists of a 3mm thick glass fibre sheet and you sit right in front of the engine for a RHD car and gain some extra 30cm distance in a LHD car. Seat mounts are short, seat padding is pretty thin, engine is partly mounted to the same alloy tub as the seat.
The engine/boot lid has big grilles to let the air out though the top. Noise also passes well. The lid is made from thin aluminium sheet and has no insulation material attached. High frequency noise easily exits the engine bay.

With a hard top or soft top fitted the cabin noise actually gets louder.


I have a radio installed, but past city speed it becomes pretty much useless. This is with a quiet muffler with its valve closed.
https://youtu.be/h-898etjgx0

Re: Injection amount vs E85
 

I am not sure what the delay is from sound generation inside combustion chamber then in air, then through various parts to your inner ear, process in your brain, then motor skills reaction and muscle movement to your leg but I would say well over 150 cycles of the engine would have happened at full revs before you can react.

Never mind that the audible knock/detonation event is much more intense that what I class a a pre ignition event trigger in the Life Racing ECU! So all up on some engine types you can say with 100% accuracy that is you are using knock ears or your own ear than that is about as archaic a method you can employ as a caveman to club a woman over the head for sex in his rape dungeon ............ sure you get the woman but she could be stone cold dead! some I guess it does not matter? :)

Many more minor events typically happen *unless you are totally wrong in calibration* or have some other part failure well before you get to pre ign or audible detonation, and the whole idea of well set up professional knock control is exactly that, you CONTROL it prior to it becoming a problem.

Never lost an engine on LR or Syvecs with my set up knock control, irrespective of root cause, loss of fuel pressure, poor fuel, some mechanical issue. Even this forum specific like latency of WI delivery say in 1st gear on a car capable of pulling 1.5g acceleration! with huge crank rpm acceleration rates and transient turbo response as per a light switch.

All of these things make it imperative that you run a proven ECU with correct knock control set up well, just my 2 cents on the topic.

Re: Injection amount vs E85
 

Here is a little sequence of events on time line to show you what I verbally described.
Keep in mind the ECU triggers instantly on register of knock despite what visual log threshold is set too, (in this cars case 300Hz is enough to capture the sound resonance through the block) even at 7500rpm on 4 stroke engine, you can see cycles recorded and event trigger of ign being pulled which instantly within one cycle of engine reduces knock........

All of this needs to be managed correctly to not allow run away knock and then pre ign from getting a foot hold and it happens so fast that there is no way in hell someone using knock ears will EVER catch let alone stop engine damage, the only reason they get away with it is the engine is either low stressed or is strong, its got nothing to do with skill or understanding (quality of equipment LOL) in them using 'knock monitoring' while tuning/fucking your engine and guessing what is happening to it under their supervision ;)

https://i.imgur.com/Q1xg9rs.jpg

https://i.imgur.com/HIOPakS.jpg

https://i.imgur.com/Tg59xpA.jpg

Re: Injection amount vs E85
 

I must be reading your graphs wrong but it looks like it starts knocking then pulls 3deg but the knock keeps going up even with the timing pull? How much knock have you seen to actually put aluminium on the porcelain of the spark plugs in a piston engine? Cheers

Re: Injection amount vs E85
 

Yeah you are reading it wrongly, so instantly it takes out timing then it re introduces it after a certain amount of non knocking cycles, then if it knocks again, which it did then it takes out again and it repeats.

Once you do allot of these as I have you can see that once knock starts the engine is 'hot' and it wont really like the introduction of normal levels of timing but each time it varies! so this is why the ECU manages it.

On most cars I do I let the LR take the engine up to its knock limit, its an automatic process and the ECU does a fantastic job of running each chamber to its limit ALL the time :)

Re: Injection amount vs E85
 

Peter,
as I mentioned before I was running a J&S knock controller on my Rover K. Like your ECU, it can pull up to 10 (20 is an other setting for some slow burn chambered motors) of timing within one revolution.
It does this for individual cylinders independent of the other cylinders.

The initial retard is computed from the knock intensity. Ignition timing is then reintroduced by some 2 deg every 10 revolutions or something along the lines.
You can watch this on the gauge. So again, similar to what your ECU does.
I can hear the knock and also hear it disappearing.
Can I react fast enough in case of a catastrophic lean event with my foot? No.
The J&S did that for me. Same for your ECU.
I slowly build up timing and at some point I can start to see knock on the gauge and hear it. Due to the timing regulation of the knock controller, the ticking sound become irregular. It happens, then disappears and then returns. if the timing pull is rather large, you can also feel the power fluctuating. This is then a clear indication that I need to have a look at what's going on.

My ECU did not have all those features integrated, so I added an aftermarket system that provided that functionality.
I for example had fuel starvation in Spa on track with massive misfires. This a typical Elise issues on track once fuel levels drop below some 15l .
Sounded like a machine gun. The J&S did its thing and protected the engine. The gauge lit up like a night club.
Without closed loop knock control, I might have blown the engine.

Overall I am all with you. Ears and feet are not fast enough. Still, I can hear it confirming what the gauge tells me. This not a bad thing.

I know the requirement for fast intervention for a long time and have acted accordingly.
I am not using your particular ECU, witch sounds like it is a nice unit, but a stand alone solution available at the time.
It is not as sophisticated as your ECU, but does its job. No caveman and club to get women here :-) Closed loop fueling (100% of the map) and closed loop knock control.
Never blown an engine since installing the J&S.

Re: Injection amount vs E85
 

J&S is a good thing > http://www.riceracing.com.au/Photos/page%204.4.JPG

Re: Injection amount vs E85
 

I know this is an old thread, very interesting.

I am nowhere near as technical (or smart) as you guys but I have to agree with Rotrex.

I have put my EVO X (4b11T) through it's paces over the last 6 years. It has had two engine builds, 4 different turbos etc etc. Now running Motec M150, 9174 twin EWG, 4" downpipe and exhaust valve, direct port meth (been using this for over 5 years).

We target 0.9 lambda (approx 13.2AFR) measured at the 02 sensor (and also in the exhaust pipe).

I run 1600cc/min in direct port plus 150cc pre turbo and 250cc pre throttle (6 jets). At 2.4bar it runs @ 100% flow (upgraded 300psi pump and line pressure >170psi under max flow).

We tried to add more fuel and make it richer but we lost power. It has been running 0.9 lambda for >4 years now and is very happy healthy engine.

This is 700awhp on mainline and full time attack car.

also I'm runnin 9.0:1 CR

edit: forgot to mention this is on pump fuel 98 and we also use det cans while tuning also. Worth mentioning we run 28deg timing and rev limit is 8,800rpm. we increased ignition timing to 30 degrees, it didn't make anymore power but it didn't knock also.

Re: Injection amount vs E85
 

Mate ^ sounds good, I also completed a 4B11 set up not too long ago, we have each cylinder set to maximum (runs Syvecs). If you want I can post some things here after durability testing is completed

Re: Injection amount vs E85
 

Wow! You are using a lot of water/meth! Probably more than 70% of the fuel injected. Did you try using less water/meth like around 1200cc/min to see if you coud still reach your power goal?

Re: Injection amount vs E85
 

http://www.riceracing.com.au/rides/M...SST_Justin.htm

Another

Re: Injection amount vs E85
 

Why not E85 + water meth? who would be crazy enough to do this? surely it cant make more power and be more durable? imagine indeed kuntz !

Re: Injection amount vs E85
 

So sorry for the delay, I missed this.

Yes! I have been forever upgrading my meth system as we hit it's max flow. I have personally run 5 different flowing jets in my DP setup as I chased more power. The last change was stage 3 cams and 4" downpipe resulting in the need to increase jets again (which is what I am running above). Looking at the logs (and seeing power drop) is very obvious we were running out of jet. upgraded jets solved the problem, we even started them on lower flow rates but had to quickly turn them up to make top end power.

Rob

Re: Injection amount vs E85
 

Later in the year I intend to run my existing setup and an E40-E50 mix. I'm keen to see the difference.

The only thing I'm still on the fence about is an upgraded intake plenum, I just haven't seen or heard concrete evidence on this upgrade.