Welcome to the North American Subaru Impreza Owners Club Wednesday May 22, 2019
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Go Back   NASIOC > NASIOC Technical > Water/Methanol Injection, Nitrous & Intercooler Cooling

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Reply
 
Thread Tools Display Modes
Old 04-07-2019, 05:34 PM   #26
blurred
Scooby Newbie
 
Member#: 47143
Join Date: Nov 2003
Location: Toronto
Default

I run water/meth as a safeguard/buffer. AEM, 125cc above 10psi and I think 3500rpm. Using turbo power washer fluid which is 50% methanol, pump mounted near the oem intercooler spray tank in the rear fender and using the oem tank for the fluid.

Personally I'd never trust a meth kit to operate as a secondary fuel system
* Registered users of the site do not see these ads.
blurred is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-07-2019, 06:01 PM   #27
TurboCarnage
Scooby Newbie
 
Member#: 477613
Join Date: Nov 2017
Location: East coast
Vehicle:
2017 Wrx
Wrb

Default

im using mine as a safety measure also. im not looking to get crazy power with it but i want it to keep things safe since im upgrading to a socal v3 turbo. thats why i wanted the map switch. with aem off ill still have fun. but with meth on ill feel much better in higher revs
TurboCarnage is offline   Reply With Quote
Old 04-07-2019, 06:09 PM   #28
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

I used to feel the same way about it, only using as a backup.

But with the (new to me) option to map switch I can't see the risk anymore. Enlighten me.

If the meth flow is hooked up to IDC, and the failsafe is based on a lean AFR, how is it so different from filling up with e-85 one day and e-10 the next?
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 02:14 PM   #29
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Crickets.... Lol

It was a serious question. I can't see what I'm missing but..... That sometimes doesn't mean much.
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 04:31 PM   #30
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Not really different at all.

Only thing is, is coming up with the failsafe based on AFR. That I am not too sure on. A turbine flow meter would be easier to do I think.

If you come up with something that would failsafe on AFR please post it or PM me I would be very interested.
Delphi is online now   Reply With Quote
Old 04-08-2019, 05:30 PM   #31
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by Delphi View Post
Not really different at all.

Only thing is, is coming up with the failsafe based on AFR. That I am not too sure on. A turbine flow meter would be easier to do I think.

If you come up with something that would failsafe on AFR please post it or PM me I would be very interested.
I was thinking flow meter too, but then nurp mentioned reliability issues with his AEM. That got me thinking that there is no failure to AFR beyond a failure that show itself everywhere vs. isolation to the meth system itself.

The AFR failsafe i use is this - Innovate PSB1 https://www.innovatemotorsports.com/products/psb1.php

Manual - https://www.innovatemotorsports.com/...SB1_Manual.pdf

It will need a relay arrangement just like yours as it's setup to cut the boost solenoid on overboost and/or lean AFR.
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 05:37 PM   #32
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Interesting.

I thought about this.
https://sirhclabs.com/product/water-...l-flow-sensor/


I do have this sitting on my bench though.
https://www.amazon.ca/gp/product/B01...?ie=UTF8&psc=1
Delphi is online now   Reply With Quote
Old 04-08-2019, 06:07 PM   #33
blurred
Scooby Newbie
 
Member#: 47143
Join Date: Nov 2003
Location: Toronto
Default

Quote:
Originally Posted by PDXREALTOR View Post
Crickets.... Lol

It was a serious question. I can't see what I'm missing but..... That sometimes doesn't mean much.

Just compare the hardware, software and sensors you have to run your actual fuel system to the wmi hardware, software and sensors.

I would simply run e30-e40 at your power levels for a level of safety.
blurred is offline   Reply With Quote
Old 04-08-2019, 06:16 PM   #34
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by Delphi View Post
Interesting.

I thought about this.
https://sirhclabs.com/product/water-...l-flow-sensor/


I do have this sitting on my bench though.
https://www.amazon.ca/gp/product/B01...?ie=UTF8&psc=1
I came across that first one, and also considered it. The one on Amazon is good find if you could narrow the voltage down to 0-5v (sure there's a way with some know how).

There is also the Snow Perf. flow meter with a boost cut feature https://www.maperformance.com/produc...EaAiUYEALw_wcB

Quote:
Just compare the hardware, software and sensors you have to run your actual fuel system to the wmi hardware, software and sensors.

I would simply run e30-e40 at your power levels for a level of safety.
That was kind of my thought process for running an AFR based failsafe. The entire failsafe (ARF gauge) is taking it's reading off all those sensors you mention.

I have no ethanol beyond 10%. I've been using TORCO for ~ 100 octane but 1) it's a waste when cruising, and 2) it's a PITA to measure out 3 oz per gallon at the pump..., especially given we don't pump our own gas here in oregon.
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 08:42 PM   #35
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Quote:
Originally Posted by PDXREALTOR View Post
I came across that first one, and also considered it. The one on Amazon is good find if you could narrow the voltage down to 0-5v (sure there's a way with some know how).

I think I could.

Max flow (1gpm) would be no Jet and the line just free running. At rest it would be what ever it reads.

Measure the voltage with a DVM and see what it comes in at. Supply voltage would be from the other TGV.
Delphi is online now   Reply With Quote
Old 04-08-2019, 09:19 PM   #36
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Another update for you guys. Here is the system functioning!

https://www.instagram.com/p/BwBBnM8F..._web_copy_link
Delphi is online now   Reply With Quote
Old 04-08-2019, 09:44 PM   #37
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

That's awesome .... now run that thing WOT and flip the switch.

I ordered my controller today...... right behind you!
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 09:50 PM   #38
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Quote:
Originally Posted by PDXREALTOR View Post
That's awesome .... now run that thing WOT and flip the switch.

I ordered my controller today...... right behind you!
I wish, the weather is so nice out but the dyno day is in May. Plus I have some boost leaks at the injector seals. Got new ones on route. Leaks at 30 psi
Delphi is online now   Reply With Quote
Old 04-08-2019, 09:59 PM   #39
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Quote:
Originally Posted by Delphi View Post
I wish, the weather is so nice out but the dyno day is in May. Plus I have some boost leaks at the injector seals. Got new ones on route. Leaks at 30 psi
It's going to be a long month. Injector Dynamics o-rings?

How, or where, are you doing the boost leak test at? Do you rotate the engine so all the valves are closed?
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 10:22 PM   #40
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Quote:
Originally Posted by PDXREALTOR View Post
It's going to be a long month. Injector Dynamics o-rings?

How, or where, are you doing the boost leak test at? Do you rotate the engine so all the valves are closed?

Going to be a crazy long month, good thing I am busy until then mostly

Just on the coupler off the turbo. I didn't worry about rotating the motor off since my air compressor can keep up. I just spray soapy water at every connection on the car.

And yes ID o-rings. Getting new OEM ones.
Delphi is online now   Reply With Quote
Old 04-08-2019, 10:32 PM   #41
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

do your ID have those little aluminum buckets that sit in the rails?

Mine are the ID 1300s and they have the buckets with super thin o-rings. those pop in the tgv housing and always pinch. I suggested ID include some spares given they are an odd size and likely a viton .... frustrating.

I need to boost test mine.
PDXREALTOR is offline   Reply With Quote
Old 04-08-2019, 10:52 PM   #42
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

No my are OG ID1000's so I dont have the caps, uses oem style orings.
Delphi is online now   Reply With Quote
Old 04-08-2019, 11:13 PM   #43
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Lucky...
PDXREALTOR is offline   Reply With Quote
Old 04-15-2019, 10:52 PM   #44
Nurp
Scooby Newbie
 
Member#: 383782
Join Date: Mar 2014
Location: Winnipeg
Vehicle:
2014 WRX STi ST
SWP

Default

I think I had 3 issues with my AEM Flow Gauge.

1. always read 250cc/l more than the rated nozzle. Sent back to AEM and they said it was working fine so no idea what was going on.
2. had a slight leak from the sensor after about a year but I put some teflon tape around the threads and never had a leak after.
3. would not turn on when very cold. This was usually around -25 to -30 degrees celsius. If it doesn't get that cold where you are then you probably won't have the same issue.
Nurp is offline   Reply With Quote
Old 04-29-2019, 07:42 PM   #45
Kingtal0n
Scooby Newbie
 
Member#: 97370
Join Date: Oct 2005
Location: florida
Vehicle:
1995 240sx
blueish. kinda. **** idk

Default

I've tuned a bunch of setups. 93, E85, methanol, all of it.

Some common misconceptions are abound every forum.

First, the methanol/water is not intended to be an IAT cooler. It should not be a reliable source of intake air charge temperature cooling. Please see my references below.

Next, the water component is an tuning element all by itself. The properties of water are quite different than methanol, gasoline, and Ethanol. Water will not burn, so there is no increase to EGT when it evaporates. Instead, it pulls heat out of the combustion reaction, which slows it down. Water also cools the combustion chamber volume, including piston surface, and valves, which make it useful to limit thermal expansion (seized piston rings / ring gap issues at high boost). Neither methanol nor any actual fuel will do this.

You can use 100% distilled water in these systems for cooling the CC. Methanol is only necessary when the additional octane is welcome. Octane rating is inversely perportional to power content. i.e. 87 octane > 93 octane > 100 octane > 110 octane, etc... in terms of potential energy trapped in the chemical bonds. That means when you hold A/F ratio constant (say, 12:1) and go up in octane rating, the power output (potential for power output) will decrease. e.g. Switching from 93 to C16 on a combo which was running fine with 93, will typically result with a drop in power.


The beauty of the methanol/water system is that you can keep using 93 octane gasoline (cheap fuel) and only use the "good fuel" when you need it. The system turns on only when required. It allows you keep a tiny 5/16" fuel line (which supports 750hp on gasoline but NOT E85) so- no fuel system upgrades will be necessary ($$$) with just this one additional system. The methanol raises the octane of gasoline significantly so it allows you to increase boost pressure.


I would not use the methanol system as a way to increase engine timing for power increases. This is because residual cooling of the combustion chamber in the event of methanol system failure will allow time for the operator/driver via a number of safety features (i.e. a/f warnings, wideband, flow sensors, etc...) to become recognized several seconds after the failure occurs, thus allowing the operator to save the engine by letting off. However, if additional timing is invested into a strictly "methanol" tune, and the pump fails, there is NO TIME for the operator to lift. The engine will instantly explode/blow a head gasket/chunk a piston because the additional timing doesn't care about residual cooling- it was OK when the octane was HIGH, but the octane suddenly drops back to 93 (on the very next combustion chamber event, which at 6000rpm happens in like .002 seconds or something) much faster than a human can respond. And also typically faster than the computer can get a handle on it. You really need about 3-4 second window to lift, to give the computer and sensors a chance (if there are any) to recognize the pump has failed. And you just don't have that window when additional timing was invested in the tuning.


A word about pump failures- the methanol/water pump is a WEAR item, they last perhaps 1-4 years and then like any other wear item, they need to be replaced before it fails. Think of it as a timing chain or oil pump or whatever, they wear out eventually.

I can say MUCH more but I think the post is long enough, please see these references I collected over the year for addl info, and then please ask any questions as I love questions....

https://www.corvetteforum.com/forums...post1599255680

https://www.corvetteforum.com/forums...post1599233451
When meth hits an IAT sensor it causes the sensor to read falsely low. Meth/water injection does very little to change IAT. I will follow with references because i know how crazy it sounds.

This is used as a safety feature i.e. readings return to normal if the meth fails. On with the refs/reading:



Lets look around the internet at people who use the systems regularly. Articles and For sale ads are trying to sell you something, will often simply repeat what they read on the company website or for sale ads.
Do not trust those ads. Instead, read what the users of such systems have to say

https://www.miataturbo.net/methanol-...3/#post1149921
Quote:
The hype about "chemical intercooling" is BS. To really cool your intake air, you need a heat exchanger.

https://ls1tech.com/forums/showpost....43&postcount=3
Quote:
Quoting this post just for emphasis. Unless you have extremely high IATs, pure water will likely cause a loss in power.

evaporating in the intake tract causes a loss in power, because as a gas it takes up space
https://www.svtperformance.com/threa...#post-13194241
Quote:
you are introducing methanol particles and water which takes away oxygen from the combustion cycle, without any additional tuning you may actually lose some power since you are losing some of the energy of proper combustion.


the info is even 'hidden' in the faq
http://www.alcohol-injection.com/en/faq
Quote:
Yes, By increasing the boost pressure you should be able to increase the horsepower.

leaning on 100% meth is risky
https://ls1tech.com/forums/showpost....5&postcount=26
Quote:
Except if there is any problem whatsoever when running 100% meth. Reduced flow, dodgy pump, whatever. You will destroy your engine. IMO there is less of a cushion when you are replacing lots of your normal fuel, with methanol.

IAT reading while on methanol are bogus
https://ls1tech.com/forums/showpost....8&postcount=44
Quote:
I would not go by what the IAT reads. most of the time, these big IAT drops are happening because the mist/droplets are touching the IAT sensor. Thus skewing the reading.

bogus iat reading
https://ls1tech.com/forums/forced-in...l#post18973099
Quote:
You really don't. Just let it do it's thing. You'll know by the change in your AFRs.


meth isnt for IAT cooling
https://ls1tech.com/forums/forced-in...l#post18973619
Quote:
Cooling the air charge is a slight side benefit IMO. You aren't cooling the charge air by much as a whole. The major benefits are in the CC. I'd think an EGT probe would be the best way to measure Aux inj. temp drops.
Quote:
The charge temps aren’t largely effected by aux inj. Compare the amount of fluid injected to the amount of air ingested per minute. It’s easy to see that the aux inj fluid can’t effect the air temps much as a whole.
Quote:
This is easily seen by the "too good to be true" IAT temps some of these guys report. The temp drops reported aren't physically possible. If the reported IAT's were accurate, then none of us would need intercoolers. Yet an intercooler will make more power than aux inj alone every time.
Quote:
The small amount of extra charge cooling does not need to be compensated for IMO. The actual change in the overall charge temp is tiny. Figure a 6.0 at 6000 rpm and 85% VE flows roughly 15,300 liters of air per minute. So 242,510 gallons per hour. Compare that to the typical 12-15 gph worth of Aux INJ. nozzle.(.002%) It’s like pissing into a hurricane and expecting a big temperature shift.
----------
need to add boost to take advantage of aux injection
https://forums.nasioc.com/forums/sho...28&postcount=7
Quote:
but you need to be able to increase boost enough to take advantage of this characteristic. If you have a limited max boost pressure that is below waters maximum allowable boost curve, you will see no significant benefit to adding alcohol to the mix.
------



cliffs...
-meth/water injection doesn't cool the intake air temperature as much as parrots and for sale ads would have you believe
-100% meth is dangerous and foolish to consider in a majority of applications and should not be considered here because of its invisible flammability
-100% meth is also dangerous because it replaces too much fuel with an aux system that relies on an external pump with a service interval
-water component of injection will reduce power because it absorbs energy and has a high heat capacity

-extra boost pressure is the ideal way to compensate and take advantage of any water/methanol injection system



More reading:

https://ls1tech.com/forums/showpost....0&postcount=27

Quote:
All those saying that pure meth is the only way to go are EXTREMELY foolish.

Pure meth is perfect for a forged piston setup with safe ring gaps.

Water cools far more than meth could ever hope to, and guys on stock cast pistons and stock ring gaps would benefit a great deal from using water to keep combustion temps down. Spraying pure meth might keep detonation at bay, but its not going to help keep those rings from butting together or a ring land from breaking. Water WILL.

Pure meth won't corrode your aluminum or your silicone couplers anytime soon. You would need to run about 50 gallons of pure meth through there before you will be able to even see any signs of use.

https://ls1tech.com/forums/dynamomet...l#post17542483
Quote:
Now if we turn the smoothing on and zoom in on the curves a bit more, you can still see the bump down low, but I'm actually losing a few HP up top with the meth.

https://ls1tech.com/forums/dynamomet...l#post17542512
Quote:
So all that water is doing is to help put out the flame so to speak.
-------
Quote:
We messed with water and meth percentages on my boosted car on the dyno and my car held cooler IATs with the 50:50 water meth mix than straight meth.

Quote:
Meth will NOT give you more power. It allows you to run more timing and stay away from detonation. As the OP just proved, even adding the timing it's not a significant amount of power increase. It doesn't matter how much meth you are spraying. You won't add more power by spraying more meth. More meth will not always give you the better setup over a meth water mix.
Quote:
. Biggest reason meth is good for boost is you can up the boost.

https://ls1tech.com/forums/showpost....7&postcount=61
Quote:
What I found at the end of the day was that my car went the fastest mph it's ever been at the boost level I was running it at with a mixture of 85% M1 methanol and 15% water ....

...the highest MPH came when using a little bit of water in there with it.


https://ls1tech.com/forums/showpost....1&postcount=21
Quote:
...we had problems with the water putting the flame out back at the old shop on different builds....


https://ls1tech.com/forums/showpost....8&postcount=33
Quote:
So I took my car back to the original dyno where i put down 452/425 max (2.8 pulley and volant intake) and was only able to best 423/436 (2.6 pulley and 50/50 meth)
----------------
https://ls1tech.com/forums/forced-in...l#post16473165
Quote:
Originally Posted by ZNix View Post
Straight methanol is the best at cooling.
response
Quote:
No, it's not. It evaporates quicker, so yes, it will give you a lower reading at the IAT sensor, but once it hits the combustion chamber and ignites, it adds to the overall heat in the chamber. Water on the other hand, cools as it evaporates, which is slower at ambient temps, but once it hits the chamber, pulls out considerably more heat, and since it doesn't ignite, it doesn't add anymore heat back into the piston/chamber like methanol does.
---------------



bottom lines:
-water puts out fires
-methanol is a high octane fuel (a 'race' gas) e.g. As octane rating of a fuel goes up (ex. 87 -> 93) energy content of that fuel goes DOWN
-mixtures over 51% methanol will BURN and are NOT recommended for street cars
-water is better at cooling that methanol, because methanol BURNS and ADDS HEAT to the reaction of combustion
Kingtal0n is offline   Reply With Quote
Old 04-29-2019, 08:59 PM   #46
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Good read.

And yes I strongly recommend not using a jet before the IAT as well.

I am using Meth because I have no access to e85 where I live and want to take full advantage of the turbo I am running. I also incorporated a failsafe system for map switching. Which should be instantaneous with the subaru system going to completely different fueling, timing, and boost maps.
Delphi is online now   Reply With Quote
Old 04-30-2019, 02:42 AM   #47
PDXREALTOR
Scooby Specialist
 
Member#: 468393
Join Date: May 2017
Location: PDX OREGON
Vehicle:
2017 STI

Default

Very good read, though I'll admit I skipped most of after the cliff notes.

I know one thing for sure from experience - I used -20 wiper fluid with a nozzle that caused a .4 afr drop (which I raised right back up to compensate) for the sole purpose of stopping detonation in the 5k rpm and above region when the turbo is shooting out the hottest air. It worked, and I added 2* but that's not enough to grenade a motor that's not tuned to the hilt. Is it? Cooling or not, it worked great and was not jacked up enough to where if something failed I'd be out of luck in seconds.... i don't think.

I think tuning with conservative timing (maxing boost) is an excellent strategy and I read about and talk to people who do the same. As someone once said - timing is not a volume knob.

Since I've been tuning my car over the last year, with a few different turbos and a lot of plain old playing around to learn...... I've always held to the keep timing down and boost high strategy.

What are your thoughts on the map switching and its ability to map switch quick enough to save a motor with timing sky high? Will the cob flex maps switch quick enough on a 5 volt to 0 volt signal?

One more thing to add- the SNOW pumps are beefed up, and used in OEM vehicles. I wouldn't think they're replacing pumps every 4 years.... could be wrong though.

I'm off to go play with my guns. My car is in the body shop, the motor is F'd, and a side from intriguing conversation I could care less about that damn thing right now.

ARs and sub guns is where my brain is....
PDXREALTOR is offline   Reply With Quote
Old 04-30-2019, 10:23 AM   #48
Kingtal0n
Scooby Newbie
 
Member#: 97370
Join Date: Oct 2005
Location: florida
Vehicle:
1995 240sx
blueish. kinda. **** idk

Default

The issue is the speed with which things are happening at 6k 7k 8k

When engine frequency is very high, it will be sensitive to very small changes/conditions. For example a variance of at least 1-2% is common from cylinder to cylinder due to Helmholtz resonant effect of pretty nearly any individual runner intake manifold due to the shape of runners and the dispersion to each cylinder. This is why we see taper manifolds with short runners on high rpm, high boost engines. They design the manifold to eliminate the water hammer effects of closing valves, which sends positive pressure wave pulsing back into the plenum where it interferes with the air charge for adjacent cylinders, causing the next one to run lean, then rich, and so forth, which can result with a blown motor over time. At 6k rpm the effect can occur several times within the space of 1 second, gradually warming the cylinder which keeps getting the extra dose of air due to being only ever so slightly lean. It can be seen on an individual EGT analysis, but obviously not a combined EGT read, which means if you are tuning by EGT and shooting for a 'perfect number' with a longer runner manifold of almost any kind, it usually means 1 cylinder is getting hot and 1 is cool, and they are averaging. Lets see, 6k rpm is 100RPS, in 1 second if you have 100 revolutions for a 4-cylinder that is 200 combustion events in a single second. So lets say on event number 2 the meth shuts off. After approx .005 seconds now your cylinders are getting lean and hot. And it isn't just 1 of them, its all of them. When combined with the fact that most people are not running individual cylinder EGT to begin with, the motor probably already has a 1-hot cylinder, so its just getting hotter after .005 to .02 seconds later, and maybe around .1 to .2 seconds total its ready to spike in pressure and do some damage to the engine. This is where conservative timing is very important. The engine should be timed with these issues in mind, and many 4-cylinder engines produced since the 80's will tolerate a lean condition on mediocre fuels (93 solo) very well, that is, without any issues, so long as the timing is in check. Lets take a closer look at what I'm saying,



Notice that pressure is climbing rapidly before the spark occurs, and how high it gets near TDC. Let that sink in: Because torque is a cross product at the perpendicular distance of a lever arm, when the piston is near TDC and cylinder pressure is very high, there is no torque production at all, or very little with only a few degrees ATDC. It isn't until the piston moves down a bit and the rod generates a nice angle with the crankshaft arm that the torque production starts, and that is where you want the fuel and air to expand nicely in time with the moving piston and expanding volume to keep giving you torque along the way. What high temperature does in a gasoline application is, it shortens the distance from left to right after a spark, making the spike higher and higher as temp climbs, eventually giving a big enough spike right around TDC to pop the head gasket (you hope). If you've upgraded the HG then that was a big mistake, because now your weak link is the piston. I would never use a NON-OEM HG on a cast piston engine for this reason.
Next this might be a little strange to think of, but we need to consider that engines are slowing down between combustion events. Consider a 1-cylinder engine for a moment, like a lawn mower. The cylinder fires and torque is made, rpm rises. But then the piston has to go back up, and down, and up again, which means it is gradually slowing down the entire time until another event occurs. We say that the rate of change of engine frequency is negative between events, and going positive during the period of torque production events.
Now with that in mind, look again at the graph above. As the cylinder is compressing fuel and air it is slowing down, while pressure is increasing, even before the spark occurs. Let's say a spark never happens, will the engine stop at TDC? Trick question because it depends on the rotating inertia of the engine we are examining. If the rotating assembly were mass-less, or very very low mass, the engine would reverse direction before it reaches TDC because there was no momentum to keep it going through TDC. This concept is extended through the idea that our timing and fuel quality need to match the engine's own internal rotating inertia in such a way that it keeps up with the rate of change going positive through each gear, where each gear has it's own rate of change. In other words, since the engine rate of change is gear dependent, so then is the timing. But our timing maps don't have a vs gear option, you cant command more timing in 1st gear where rate of change is high, and less timing in 5th when the engine is accelerating only slowly. That means we need to find a 1-size fits all timing number that works for 5th and 1st. Also, heavier vehicles accelerate more slowly, which means the dyno roller you are accelerating isn't going to simulate the same rate of change condition as the actual road will, which is why it is common to hear that "I've never seen a max power dyno setting that performed equally as well while actually racing or driving" (or something like that). So by searching for a peak number by using timing on the dyno, you are really just doing that: finding a peak power setting for the dyno. Once the vehicle hits the actual road, loaded in various gears, the timing setting from the dyno is almost useless due the myriad of conditions the engine will endure, especially if racing without significant cooldowns (drag racing vs road racing). As a conservative tuner, what we want is to use the minimum timing necessary to keep the engine 'happy'(defined shortly) while it is heating up in the final gear (say 5th or 6th) for as long as it is used (amount of time at WOT per each gear), that it will ever be used in (If you never race or run the car to 200mph in 6th then don't worry about 6th, etc...).

Remember it only takes .005 seconds at 6k for an accident to start a chain of events which may lead to 'detonation' (using the term loosely, i.e. E85 fueled engine can pressure spike without detonating), and it only takes 1 good spike to ruin the engine, and there are 200 opportunities per second at 6k rpm (nevermind 7k 8k) for this to happen.

So now, what is 'happy'


Notice the EGT begins to rise rapidly once timing is reduced past a certain threshold. That is because the flame is "chasing" the piston, as the rotating momentum of the engine is causing the piston to run down the bore away from the flame, the fire winds up in the exhaust and raises EGT. This of course means you are also heating up the cylinder, everything is getting hot.
But then also notice that the 'cold' setting is even more dangerous. If the rotating weight is very low (an extreme example: rev the engine in neutral) then a pressure spike may only serve to increase the torque output, no damage is done. However, if the rotating weight is 'heavy' (4000lb car accelerating in overdrive at WOT) and even more so if the engine is at a low frequency (2k-4k rpm) then the small pressure spike will grow large quickly because the piston cannot 'move out of the fast enough'. The expansion rate is exceeding the rate of the change of the engine.

To prevent a general catastrophe, time the engine such that the piston is mostly past TDC when any potential spikes might occur. Usually this is in the range of 7 to 9* BTDC(for 18-28psi boost pressure typically, JDM engines after 92+) of ignition timing. It is early enough for most turbo 4-cylinder engines using gasoline at reasonable compression ratios to keep from being on the "EGT RAMP" displayed above, and late enough that in the event of a hot cylinder or a lean A/F ratio (for whatever reason) the momentum of the engine has already brought it far enough through TDC to keep the pressure spike from going too high. It is also worth mentioning that with some fuels and conditions, especially on a lightweight dyno roller, an engine will typically keep gaining in torque even while the pressure spike is getting dangerously high and the engine is under unnecessary stress. In other words, pressure spikes add torque, is common to see additional torque from a poorly timed engine over one which is properly timed, because its literally a spike in pressure which may help shove the piston once it gets to the right rod angle. This can be seen on a dyno chart with smoothing:0 usually as little jagged spikes in the torque curve, which is why I always use smoothing:0 for dynojet plots. Examples:

2.0L dyno (not my tuning)

In this plot you can see a variation in torque, but this was hopefully due to poor boost control feature. If not, it is a timing issue.
It is worth looking at because you can see such a large variation even with smoothing:5. I wonder what it really looks like? I'd be worried if the boost log shows a straight line, that means the torque oscillation is due to the rapid increase and decrease in the rate of change of the dyno roller at high frequency; In other words, speeding up and slowing down the speed of the engine as intermittent pressure spikes create portions of increased torque for a brief moment, spread out over time so that it is not consistent. Dynojet rollers work by measuring the rate of change of a known weight roller in the floor; from this they measure work/time, or power. Then working backwards to get torque if you have the engine frequency clamp connected (spark clamp).

next is mine, in a car from 2008,
50trim vs 60-1 turbo on 2L, smoothing:0

Notice nice and smooth torque curve indicates no pressure spikes. That doesn't mean ignition timing is ideal; it just means the engine is not experiencing any difficulty/pressure spikes while rate of change is positive, and obviously that boost isn't wandering much if any. A smooth application of increasing power to the dyno roller. I was likely using 9* btdc for all curves, perhaps 10-11* for the 15psi run. Another good sign is that the curves 15psi vs 18psi take on a similar shape. If the 18psi run was jagged or differently shaped, it would be warning us of a problem. This is why I like to perform low boost runs first: it gives you an idea of the VE curve of the engine, that is, the torque curve. Cylinder VE is directly related to torque when the engine is properly tuned for the supplied fuel.

Next, I found this random from google image for this example:

Even with smoothing:5 you can still see a jagged output curve. Imagine what it really looks like.
IMHO they are pushing too much timing, trying to get a peak number out of the dyno. Notice the highest number will be taken from that one tiny peak in the power curve at 5700, which you should be able to clearly tell is a 'false' peak. No engine should randomly create an extra 10-20 horsepower for an instant at some random rpm;
If you keep pushing timing, these little spikey oscillations create false peaks, the dyno will read the highest number even if its just a momentary peak as the "max output" and that is what everyone wants to see, the highest number.

Last edited by Kingtal0n; 04-30-2019 at 11:03 AM.
Kingtal0n is offline   Reply With Quote
Old 05-09-2019, 03:19 AM   #49
badaily16
Scooby Newbie
 
Member#: 469025
Join Date: Jun 2017
Default Anyone still using meth/water injection?

Quote:
Originally Posted by Delphi View Post
Another update for you guys. Here is the system functioning!

https://www.instagram.com/p/BwBBnM8F..._web_copy_link


Hey just a suggestion. If I was you I would change the Accesstuner flex fuel ethanol sensor calibration smoothing factor to 1.0 and ethanol sensor calibration sampling rate to 1. This will allow your map switch failsafe to happen instantly instead of incrementally going to zero. This will ensure minimum amount of damage happenes if the failsafe needs to activate. Heres my video for example.

badaily16 is offline   Reply With Quote
Old 05-10-2019, 10:05 AM   #50
Delphi
Scooby Specialist
 
Member#: 239335
Join Date: Feb 2010
Chapter/Region: W. Canada
Location: Edmonton, Alberta
Vehicle:
2011 WRX
WRB

Default

Quote:
Originally Posted by badaily16 View Post
Hey just a suggestion. If I was you I would change the Accesstuner flex fuel ethanol sensor calibration smoothing factor to 1.0 and ethanol sensor calibration sampling rate to 1. This will allow your map switch failsafe to happen instantly instead of incrementally going to zero. This will ensure minimum amount of damage happenes if the failsafe needs to activate. Heres my video for example.

https://youtu.be/2mmF0dyI4k8

Thanks,

I will be sure to mention that to my tuner if he doesn't already know. It was more just a proof of concept that I was doing and making sure the systems work before I trailer it down to him.
Delphi is online now   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -4. The time now is 01:16 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2019 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.