Octane boost from Meth
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
no what is done is that a temp sensor is placed post nozzle (the maf has a temp sensor but the maf would get messed up from the methanol) the temp sensor is thus seeing the iats with meth and if they go up (in the rare event of system failure) will pull timing. Once the system is operational the timing maps will return to normal. This works very similar to the way our cars are programmed to handle 87 octane in the event that the wrong gas is filled
Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Also your question "Once it pulls timing, do you need a retune" indicates that you probably didn't realize that this is a dynamic event; it pulls timing isntantly once it sees that the IAT has climbed, it brings the timing back up once the IAT comes back down. This is driven by a table that simply co-relates ignition timing to intake air temperature.
Melting Slicks
Joined: Feb 2008
Posts: 3,400
Likes: 3
From: Gboro/H-point/Reidsville NC
Ignition timing and Air/Fuel ratio are two independently controlled variables.
Also your question "Once it pulls timing, do you need a retune" indicates that you probably didn't realize that this is a dynamic event; it pulls timing isntantly once it sees that the IAT has climbed, it brings the timing back up once the IAT comes back down. This is driven by a table that simply co-relates ignition timing to intake air temperature.
Also your question "Once it pulls timing, do you need a retune" indicates that you probably didn't realize that this is a dynamic event; it pulls timing isntantly once it sees that the IAT has climbed, it brings the timing back up once the IAT comes back down. This is driven by a table that simply co-relates ignition timing to intake air temperature.
But you hear all over this board,dont tune with meth.Use it only for safety reasons.If the car will pull timing in the event of a failure,why would you not use meth?
Thread Starter
Burning Brakes
Joined: Oct 2009
Posts: 1,231
Likes: 1
From: Paramus NJ
So can I tune with a 100% meth tune, and still have this as a safety device? Where it pulls timing in case of a pump going south?
But you hear all over this board,dont tune with meth.Use it only for safety reasons.If the car will pull timing in the event of a failure,why would you not use meth?
But you hear all over this board,dont tune with meth.Use it only for safety reasons.If the car will pull timing in the event of a failure,why would you not use meth?
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
There are 3 tune styles:
1) no meth my car now makes 650rwhp @ 10lbs
2) tune using meth only to further add timing and lean the mix beyond what pump gas can achieve, if your pump fails your car lowers timing to prevent knock and save the motor, I can bump my setup to around 680 with this method
3) full meth dependant tune, now in addition to the timing we increase boost to say 15lbs, and make 750-800rwhp on my car (take off my restrictor plate, AA kits swap pulleys) the motor has no way to adjust boost, all it can do is pull timing to prevent detonation, the motor won't blow but doing this a few times can't be good for longevity. This is how ecs tunes and has only seen 2 failures on hard driven cars
1) no meth my car now makes 650rwhp @ 10lbs
2) tune using meth only to further add timing and lean the mix beyond what pump gas can achieve, if your pump fails your car lowers timing to prevent knock and save the motor, I can bump my setup to around 680 with this method
3) full meth dependant tune, now in addition to the timing we increase boost to say 15lbs, and make 750-800rwhp on my car (take off my restrictor plate, AA kits swap pulleys) the motor has no way to adjust boost, all it can do is pull timing to prevent detonation, the motor won't blow but doing this a few times can't be good for longevity. This is how ecs tunes and has only seen 2 failures on hard driven cars
Melting Slicks
Joined: Feb 2008
Posts: 3,400
Likes: 3
From: Gboro/H-point/Reidsville NC
The gain in HP you are going to see by using meth is actually because you are not losing HP from timing being pulled during higher IAT's. That is where your benefit from meth is. When you hear "tuning for meth" that means tuning for the additional bump in octane you will receive. If your car is tuned to run on meth and you have a failure you certainly run the risk of grenading your motor. Keep your tune for 93 octane and enjoy the benefits on lower IAT's from the meth.
Speedy
Joined: Mar 2007
Posts: 6,109
Likes: 931
From: Tn
2024 C8 of the Year Finalist - Modified
Melting Slicks
Joined: Feb 2008
Posts: 3,400
Likes: 3
From: Gboro/H-point/Reidsville NC
Gotcha! Sorry for all the questions this is my first boosted Vette. So adding timing = more power. So can you add a ton of timing and have your A/F spot on?
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Le Mans Master
Joined: Oct 2007
Posts: 6,149
Likes: 11
From: Greater Detroit Metro MI, when I'm not travelling.
Racer
Joined: Jul 2005
Posts: 420
Likes: 14
From: California
Sam, how long does a fill up on Meth last you? It sounds like you are saying you have to fill it frequently. I have gotten many tankfuls of gas (probably 10 or more) on a single fill up of Meth. Now I probably dont lean on my car as much as you do with yours but I do usually get 1 or two WOT pulls in 2nd/3rd gear every time I drive. It is interesting when I hear of people having to fill their meth frequently. Sometimes I wonder if maybe my meth is not spraying as much as it should.
Your meth sprays when you are under boost, and in direct proportion to how much boost you are making. I.E. The harder you drive the car, the more methanol you will use.
A high HP car on street tires will see the methanol last almost for ever as going into high boost is completely pointless. I have the traction to use full boost and I drive my car very hard, so I can go through my 1.7 gallon tank in 4 fillups. Conversely, when I drive in cold or bad weather it lasts almost indefinitely since I can't lean into the boost as much.
I.E. It depends entirely on how hard you drive the car.
A high HP car on street tires will see the methanol last almost for ever as going into high boost is completely pointless. I have the traction to use full boost and I drive my car very hard, so I can go through my 1.7 gallon tank in 4 fillups. Conversely, when I drive in cold or bad weather it lasts almost indefinitely since I can't lean into the boost as much.
I.E. It depends entirely on how hard you drive the car.
