How tune for alcohol injection?
How tune for alcohol injection?
How do you compensate for alcohol injection? Assume an engine already with bigger MAFS and injectors and an ECU tune. When adding alcohol, do you just increase the max boost and tinker with the spray point, or do you need to alter the fuel and/or timing maps?
You account for alcohol with timing. First get a tune without it and then turn the spray on. The alchy will take a lot of your power away at first... I found my 50/50 methanol/water mix really put out the fire: dropping power almost 100 horses at certain points. Once you get the spray going, start adding some boost pressure and timing across the board. You will be able to get much more timing without hearing knock-- to the point where you will get your power back and perhaps exceed it. Keep a sharp eye on knock volts and take small steps. You might also be able to lean the gasoline out a little bit but I just kept it where it was for my tune.
Careful man, good luck!
Careful man, good luck!
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Structure240sx
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Anthony is right, its the extra octane from the alchy that allows you to add timing and boost. Think of alcohol as a knock-retardant, not a power adder. Alcohol burns just like fuel does, but there is no additional combustion or anything like that... it just burns slower allowing for a more efficient and complete combustion (AKA higher octane).
Cool. Fiz, I was surprised that you said "The alchy will take a lot of your power away at first... I found my 50/50 methanol/water mix really put out the fire: dropping power almost 100 horses at certain points...You will be able to get much more timing without hearing knock-- to the point where you will get your power back and perhaps exceed it." Isn't the whole point of setting up alky injection to DEFINITELY exceed the amount of power you could run on pump gas alone? I know that it can give you more reliability by reducing the chance of knock to almost nothing, but still...who wouldn't try to get more power if they had the ability to avoid knock with much higher boost? And where the heck is WD? I'm shocked that he hasn't chimed in yet
Alchy is not a power adder... What it does is give you a little bit of a cushon when it comes to knock. Yes, it allows you to increase the boost while using pump gas -- this is where your extra power comes from -- but just alchy + timing at a given boost level will not differ all that much from pump gas + regular timing. There is a chance you will get extra power out of just the timing alone at a given boost level, but it all depends on how agressive you want to be. What I did was add timing pretty much to the point where I got my regular power back, and then I increased the boost some. Granted, I tuned my car with a large cushon and I could have certanly pushed it much farther... but I like my car where it is. The power is very good and I dont have to ever worry about knock or bad gas. There are other ways to use alchy of course... depends on what you want to do and how much you want to press your luck.
I'm looking into it to be able to run around 350 whp on a stock block occasionally without it blowing up. It can handle this power, but the margin of error is slim...alcohol will help out. This is research way in advance though; I won't have another car until next spring at the earliest. Just trying to learn as much as I can in the meantime
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WDRacing
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Sorry I'm so late, my parents are in town visiting.
Alcohol will generate a little more HP then pump gas when burned, so will methonal.
There are a ton of things to account for when adding alky, water, methonal...etc.
You really should make a choice though, add boost or add timing. I wouldn't do both. If your running low boost, say 15 psi, then you can add alcohol or methonal at about the 8-10 psi mark and not have to retard timing which will yeild quite a bit of power. Or you can crank up the boost while keeping the same timing retard which will again add hp.
When I first started using alcohol, I used a on/off type kit. Boost activated and pump speed was controlled via a rheostat in the cockpit.
I simply figured out when my car was running out of fuel, or where knock would begin and used 2 psi before as a starting point. Mine was at 15 psi. So the pump came on at 13psi, this type of kit is harder, due to the over rich condition you hit at first, but boost comes on hard and fast when your at 15psi and beyond levels. So you won't make peak power until you hit full bost, but you make a ****load once you're there.
So heres my easy safe recipe for adding alky. Pick your turn on point. Start with enough alky to bog your motor down, then add enough boost to where it doesn't bog much when the pump comes on. You will encounter a slight bog at the onset of alky everytime unless you have a variable injection type of kit.
If your a DIY guy you can build a two stage kit for about $200 total for a decent 2 stg. This way the bog goes away and you have two points for injection enabling alot more boost or timing to be run.
Water will drop your EGT's the most, then straight methanol, the a 50/50 mix of water/meth then denatured alky, but alky is expensive.
There is aslo propane, but thats another type of kit entirely.
My thoughts on the whole alky injection are this, everyone should use it. At the very least water or alky will allow your car to run stronger without the worry of blowing up. Not to mention allowing you to push your motor to the limits alot safer.
Use enough pump gas for your motor's WHP level, but add alky/meth to cool the EGT's enough to avoid knock.
Eventually you'll be where Fiz and I are. I'll be removing fuel on the fuel injectors side and adding methanol for increased power.
Hope that makes sense.
WD
Alcohol will generate a little more HP then pump gas when burned, so will methonal.
There are a ton of things to account for when adding alky, water, methonal...etc.
You really should make a choice though, add boost or add timing. I wouldn't do both. If your running low boost, say 15 psi, then you can add alcohol or methonal at about the 8-10 psi mark and not have to retard timing which will yeild quite a bit of power. Or you can crank up the boost while keeping the same timing retard which will again add hp.
When I first started using alcohol, I used a on/off type kit. Boost activated and pump speed was controlled via a rheostat in the cockpit.
I simply figured out when my car was running out of fuel, or where knock would begin and used 2 psi before as a starting point. Mine was at 15 psi. So the pump came on at 13psi, this type of kit is harder, due to the over rich condition you hit at first, but boost comes on hard and fast when your at 15psi and beyond levels. So you won't make peak power until you hit full bost, but you make a ****load once you're there.
So heres my easy safe recipe for adding alky. Pick your turn on point. Start with enough alky to bog your motor down, then add enough boost to where it doesn't bog much when the pump comes on. You will encounter a slight bog at the onset of alky everytime unless you have a variable injection type of kit.
If your a DIY guy you can build a two stage kit for about $200 total for a decent 2 stg. This way the bog goes away and you have two points for injection enabling alot more boost or timing to be run.
Water will drop your EGT's the most, then straight methanol, the a 50/50 mix of water/meth then denatured alky, but alky is expensive.
There is aslo propane, but thats another type of kit entirely.
My thoughts on the whole alky injection are this, everyone should use it. At the very least water or alky will allow your car to run stronger without the worry of blowing up. Not to mention allowing you to push your motor to the limits alot safer.
Use enough pump gas for your motor's WHP level, but add alky/meth to cool the EGT's enough to avoid knock.
Eventually you'll be where Fiz and I are. I'll be removing fuel on the fuel injectors side and adding methanol for increased power.
Hope that makes sense.
WD
Well, do you think its worth the hassle of installation and keeping the reservoir full to run around 350 whp on a stock block? I would probably go the first route, staying around 15 psi but adding timing compared to a setup without alky. Most people running 15 psi from decently sized turbos seem to make around 325 whp, so I would think that with the additional timing I would be around 350 whp with no additional detonation risk. How quickly do you go through alky?
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WDRacing
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I'm doing a dual stage setup until I get the motor built. I'm planning on a 8 psi injector and a 12 psi injector. This should kill any detoantion I have and allow me to run 15-18 lbs of boost without any timing retard. With no timing retard your looking at 15-20 hp per lb of boost instead of 8-10.
Alky and water ingestion will all depend on how much you spray. I'm using water until I swap in a built motor, then I'll be running all methonal.
WD
Alky and water ingestion will all depend on how much you spray. I'm using water until I swap in a built motor, then I'll be running all methonal.
WD