116 octane tuning

[LETZRIDE]

Been doing some reading as of lately. If you spray meth 49/51 mixture on 91 pump gas you get approximately 116 octane similar to the race gas- How much timing should you add to the car if you are tuning for the methanol?

I think methanol is slower burning than gasoline, so... I know I read that for nitromethane which is also slow burning, guys bump timing right up to 60 degrees. Our cars generally like about 28* on regular gas, Can we go up to 35-40*s on meth? Would the car make power?

[Gutless]

Re: 116 octane tuning

I run -40 window washer fluid on both my forced air cars. It really helps my turbo 6 and I run it in my l67 bird. I run a Comp G timing table witch is more aggressive than the stock one and am able to run 89 with 10PSI and no knock.

I dont see why you would do it on a NA car. I suppose you could. The main reason you run alky is to absorb excess heat from the charged air. A NA motor doesnt really have a high air charge temp so your not going to get much.

[LETZRIDE]

Re: 116 octane tuning

I disagree. I've read about N/A guys who have tuned for the meth get up to 20rwhp. I see a number of benefits running a meth setup N/A

- Cooler/consistent intake temps- I rememeber when I was cam only I could fluctuate between running 14.4 and 13.8 just based on weather. Having a consistent intake air temp that makes the air denser should at the very least insure you always consistently run your quickest times regardless of weather.

- Steam cleans the motor ensuring you never get carbon build up

- Can be mixed with Nitromethane to start getting some interesting power gains

- Finally, the people who don't see gains are the ones that simply install the meth but don't tune for it. Meth is a fuel, if you lean the car out and up the timing, you'll see more than just a gain from "cooling". The trick is spraying meth before you IAT sensor so that you can build a safety into your tune so that if you pump fails, you don't blow your motor to pieces

[ssms5411]

Re: 116 octane tuning

I would run it at 28 degrees timing. Someone a long time ago did a test and turned out to be 28 degrees was the best running more didn't do anything more on our cars.

[LETZRIDE]

Re: 116 octane tuning

but thats on regular fuel. When you start introducing slower burning fuels and higher octane I feel like that changes everything?

[thebeewantsboost]

Re: 116 octane tuning

it may work well in your situation. what's scary, especially with forced induction, is if you lean out the tune, using the iat sensor as a failsafe. you're probably still effed if the methanol system fails. because of how lean you'll be running. i've been debating on how to go about using my methanol kit.

[LETZRIDE]

Re: 116 octane tuning

it may work well in your situation. what's scary, especially with forced induction, is if you lean out the tune, using the iat sensor as a failsafe. you're probably still effed if the methanol system fails. because of how lean you'll be running. i've been debating on how to go about using my methanol kit.

why? if when you spray meth you are between 30-50*F temp (lets just say) then you have an aggressive tune...after 50*F you tell the car to just dump fuel and cut spark down to like 10*

The car should just bog out with no power. The result would be instant...faster than you could even take your foot off the gas.

[Gutless]

Re: 116 octane tuning

Compression ratio?

I know a stock motor will pick up quite a bit switching to E85 and bumping the timing, but Im not sure if alky does as much. Im not saying it wont work, just wondering how much you pick up vs a small ~50 shot of nitrous.

[thebeewantsboost]

Re: 116 octane tuning

Correct me if im wrong but i dont believe we have the capability to adjust fuel vs iat.

[LETZRIDE]

Re: 116 octane tuning

Correct me if im wrong but i dont believe we have the capability to adjust fuel vs iat.

No you're right we don't...I thought we did, but I didnt have my laptop open at the time.

We do have an IAT spark table though...so why can't you use it to add spark only in the say 30-50*F range when you know the meth is spraying, but when it drops out of that range pull immediately down to 10*. This is how our spark limiter works as well as cutting injectors...so if your fuel injectors were still working and you cut to 10* that shouldn't cause damage should it?

[thebeewantsboost]

Re: 116 octane tuning

I guess it really just depends on how much gas you are replacing with methanol. There are a few spots in my FI tune where I'm running single digit timing. The fueling is good on my tune and that's without methanol injection @ 10 psi. But n/a and forced induction are different animals. I guess the best thing to do is setup a tune with your 10* of timing and roughly what fueling you'll be at it, go easy on her and see what it does.

[z34phoenix]

Re: 116 octane tuning

you would also want to relocate the IAT as i dont think it would be a good idea to spray ahead of the MAF sensor.

also even if they setup does help to lower the intake charge and add more fuel, it still will not level the effect of cooler or hotter weather temps. on a cooler day you will have more oxygen in the air. the meth setup will work to further cool that air but will not change the amount of O2 in it. same thing goes with high or low pressure days.

I just looked in tiny tuner and yeah there isn't much mapped for 96 camaro's.

the best way to find an ideal timing would be a dyno. but if that isnt an option and you have a wide band O2, then just scan the wide band and compare the injector flow rate/pulse width to the wide band and the amount of spark you are commanding. if you are commanding more timing and you go richer then you have past a sweat spot and are not burning all the fuel. same goes for injector pulse... if your AF stays the same and its commanding less fuel then the timing isnt working.

the ideal situation to see is more timing causes the AF to lean out and the injector pulse is longer. that means you are spraying more fuel and using it completely.

[LETZRIDE]

Re: 116 octane tuning

the cool air charge should make the air denser. There is never more O2 in the air just because it is cooler out, but because the cool temperatures makes the air denser therefore allowing more O2 to enter the engine per volume of air.

Same thing applies to fuel, which is why they sell fuel coolers. The cooler your fuel is, the denser it is and you can actually richen your car up just by chilling the fuel

[z34phoenix]

Re: 116 octane tuning

Well yes the ratio of oxygen is always the same but on a cooler day you will still have more oxygen per unit of volume then on a cooler day. One reason for the fuel chillers is also to lower combustion temp and reduce the chance of detonation.

In any case it will be interesting to see your results. I know meth inj does help with boost. The only issues I have seen and heard of were that it was very hard to keep a consistent af ratio. It might just be better to try a cold can for your fuel and run larger injectors if you are close to runing them static

[thebeewantsboost]

Re: 116 octane tuning

"Vehicle speed must be greater than this before starting to enrichen the airfuel ratio and retard spark to limit vehicle speed."
this was in the tiny tuner notes for the mph speed limiter. looks like it actually adds fuel and pulls timing. not completely relative to what we are talking about but reminded me of this thread.