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This is my understanding. I've tuned both petrol and methanol before. I'm open to feedback maybe I've done it wrong. The displacement/ BPC in 12P is a calculation of injector size and engine capacity fuel type is not factored here. You then target different AFR's depending on your fuel type. As in where stoich for petrol is 14.7 E85 is 9.8. That's where the extra fuel comes from.

In a recent V6 methanol with 60lb injectors I done I ran a kinjflow of 0.045 (from memory) but with methanol based AFR tables and cranking fuel table to suit eg, 5.4AFR at 100kpa (12.5 petrol) and 6.8AFR )14.7 petrol) for stoich (figures from memory)

The injector opening time is calculated against VE% desired AFR kinjflow and other enrichments etc. So targeting the different AFR's for ethanol will increase the amount fuel injected.

Dylan, that 5.4afr at wot is a little lean for methanol, it produces best hp at 4.8(.73/.75 lambda), probably get away with it on the strip, but for circuit or speedway things may get a little hot.

With the pressure regulator. If cutting the rail and I would assume new threads is going to be a hassle fit a banjo fitting and then use a Ford regulator. They use a tail fitting for in and out and can by put anywhere that is convenient.

Regarding the use of alcohol. If you have to use 4.8:1 against say 11:1 (turbo assumed) for petrol wouldn't you have to add more than 100% more fuel or is my mental maths missing something? So I would think you would double your kinjflow to be somewhere near a good starting point then trim in the VE tables after that. Maybe there is something too simple I am missing.

v6bucket wrote:Dylan, that 5.4afr at wot is a little lean for methanol, it produces best hp at 4.8(.73/.75 lambda), probably get away with it on the strip, but for circuit or speedway things may get a little hot.

Thanks for the tip mate I did end up at 4.8 anyway.

Charlescrown wrote:Regarding the use of alcohol. If you have to use 4.8:1 against say 11:1 (turbo assumed) for petrol wouldn't you have to add more than 100% more fuel or is my mental maths missing something? So I would think you would double your kinjflow to be somewhere near a good starting point then trim in the VE tables after that. Maybe there is something too simple I am missing.

You are adding at least double the fuel with the target AFR. For every 4.8 bits of air you are injecting 1 part of fuel compared to every 11 parts of air 1 part of fuel. With the sprint car I done the kinjflow of 0.045 I could run that motor on petrol with the same 60lb injectors and not alter that. Just revert back to normal petrol AFR's and all will be good.
As the motor is unchanged the engines VE (amount of air it flows or displaces) won't of affected.

So Dylan am I right to assume that if my injectors were big enough I would double the kinjflow number to be close to the mark? I know VE wont change but all said and done it's just another number in the calculation to get the right amount of fuel.

No if all you're changing is the fuel type just change the target AFR's. kinjflow is just a calculation of injector size and engine capacity. Don't forget about the post start enrichments they will need altering as well.

Dylan

Not only the target AFR's need changing but also " MAP A Run A/F Param: Stoichiometric A/F Ratio" setting. Are you changing this?

Yes thanks mate I did. Although the methanol car I did was a race car I flagged open loop but I did..
Holden202T was knd enough to send me a stock bin set for methanol for an example. There's lots of little changes.