frcefed98

iTrader: (16)

Well I made the jump from meth/water to straight meth. I tuned the car to 11.5-11.6 on the meth/water mix.

Now that the straight methanol is in there, my a/f has dropped even more than it was on the meth/water mix...is this normal? Now my a/f@WOT is 10.5-10.6 with straight methanol.

About how much fuel@WOT did you have to remove to run meth, from a no meth boosted tune? I'm suprised at how much I have to lean out the WOT areas of my VE table to accomodate the straight methanol....definately don't want my meth kit to fail when I'm on the meth tune This stuff is freakin nice and insane at the same time. Quite a jump up from the meth/water mix when it goes WOT

I know I can up the boost and timing now and it'll probably lean it out on its own, but I rather dial it the level of boost i'm running now.

I'm running the meth tune for the track and just running a safe street tune for 91 pump and no meth for every day use.



Any help or pointers, throw em my way
J

MIGHTYMOUSE

iTrader: (59)

i have my bs3 pull out about 20% of my gasoline when the meth comes on, 11.3 target AFR

frcefed98

iTrader: (16)

COOL Dave, I was waiting for you to chime in. Looks like i'm on the right track then. I was kinda freaked at how much fuel I was pulling out. I'm going slightly leaner to 11.5-11.6 in my tune. Get that inline and then up the timing/adjust fuel to see how much she'll take before she knocks. I'm running a weak 13 deg WOT for safety right now.

Then i'll start all over again when I push the boost past 15+psi. Right now its around 14psi steadily.

Thanks again Dave,
Jeremy

frcefed98

iTrader: (16)

Dave are you running straight meth as well or a mix?

MIGHTYMOUSE

iTrader: (59)

str8 mef yo

Steel Chicken

iTrader: (3)

you could start mixing the meth with water, so you dont have to lean your tune out. this would be a safer solution. water wont cool as much as meth, but it does slow the combustion process down, and in a different way decrease the likelyhood of detonation

frcefed98

iTrader: (16)

I was running 35% meth to water and it was bogging the car real bad. So I decided to try out the meth by itself and it doesn't bog, but man did it make the car go rich.

Dave Thanks homie...don't steal my car...please.

Damn hoods

Leaned her out some more, still too rich towards my shift points, but nearly have the rest of the areas in line.
J

Draco

Wrong. Water has a much higher latent heat of vaporization then methanol and will therefore remove more heat from the rest of the air/fuel mix as it evaporates.

Draco

At 5200 RPM and 8 PSI, my boost VE table values are down around 80%. If I wasn't running methanol injection, they'd be around 120-130%. I target an AFR of 11.3:1. Depending on how aggresive you spray, you will have to pull SIGNIFICANT amounts of gasoline from your tune.

I use ~ the same amount of gasoline now at WOT @ 8 PSI compared to when I was stock .

speedz06

Try going to a smaller nozzle with the meth before leaning your tune.I'm thinking that I would want to see at what AFR you are making the most power and if it looks safe also the cooler air and detonation resistance from the meth acting as an octane improver may not require you to run as rich as you think.I'm still messing with mine but I get to do it every day so I see how the changes effct performance

frcefed98

iTrader: (16)

Draco, i'm definately on the right track then as far as my tune goes. But on to the next discussion point....

Speedzo6, me and my Dad were discussing this today as well. Why go with a larger nozzle if a smaller nozzle can provide the cooling/KR resistance you need without having to take so much fuel out of the tune.

Being a mile high I also don't know if that is playing a big role in my meth/fuel needs as well( a hunch says it does ). We just don't have much air to burn, FI or not. So like injectors up here, smaller will usually work nicely.

I've been messing with this all week and really have the tune going great, taking small steps tuning wise so I don't blow a HG or two.

I'll be installing a smaller nozzle tomorrow. I couldn't get it finished today which sucked.

The smaller nozzle will probably get my a/f into the range i'm shooting for 11.5-11.8 without reducing my tune much further....be a great experiment.


Can't believe I have almost burned through 2 gallons of meth so far doing tuning and testing

Oh yeah, a in car WBO2 is a must, logging software also a good idea, EIO enhanced even better idea. Makes dialing in a tune a snap.
J

Blackbird

J- thats how I do it. IMO your on the right track.

I run as little meth as possible to get the job done.

I definetly don't recommend relying on it as a major part of your fuel system.

stevieturbo

Do you trigger this upon actual injection of meth, or simply from a signal indicating that meth is supposed to be being injected ?

ie from a pressure switch in the meth line, or from a signal from power to the pump ?

First would ensure methanol is actually being injected, second would rely on the fact the system is working.

wicked_95z

iTrader: (8)

By no means am I an expert, but I would think you would want to turn the gain on your meth down to get to your target AFR. That way you are not relying so heavily on the meth if for some reason your pump quits working and you go lean real quick

MIGHTYMOUSE

iTrader: (59)

the more meth you spray = more boost = more hp

why would you ever want to limit that?

-stevieturbo

bs3 pulls the fuel based on wideband 02 so it relies on the fact that meth has been injected and is allready in the tailpipes

Draco

This is a good point, and it can be taken even further.

1. Cooling the air will increase its density. This will allow you to pack more air fuel mass into the cylinders at what will appear to be the same boost pressure.

2. Methanol is a more potent fuel then gasoline. Comparing stoich AFRs, Meth will make more power then gas thanks to its higher energy content. The problem is you need 2.5x as much Meth by volume to get to a stoich mix of around 6.4:1. However, since you have this new, supplemental fuel system - why not take advantage of it?

I take this approach - inject alot of Meth and pull alot of fuel. I will be pullying up shortly to see how far I can take this little S-trim on a stock bottm end.

Blackbird

I don't think J is building an all out car. Different goals for different folks. I am guessing he would rather leave some psi and power on the table for a setup that if the meth stopped flowing he had a prayer of keeping his motor together. J can correct me if I am wrong but I bet thats what he is thinking. The meth is more of a saftey net. I know at least for me thats my way of thinking and thus my comment I felt he was on the right track.

RW99

Draco, I just want to make sure people don't misread what you've written... Methanol does have a higher octane rating than gasoline, but it carries less energy per unit mass... so while less risk of detonation occurs with the use of methanol, there may be a limit to the amount of alcohol you can effectively spray into the intake charge to try to replace the higher energy content of the gas that you're injecting directly.

It's a good idea to remember that while the octane rating of methanol is higher, it is not comparable to a very high octane gasoline... because there's less energy available for the combustion event.

But that's not to say that spraying more can't give you more power... up to a point...

wicked_95z

iTrader: (8)

That is my line of thinking, especially with my luck

frcefed98

iTrader: (16)

Right on track Heath, just wanting a good margin of safety aswell as a cheap form of racegas. I never ran the car at the track without a tank of racegas, it was "cheap" insurance.

Now racegas went to 7.50 a gallon at our track, costing me about 75 bucks just to make a couple passes at the TNT sessions...

Now I can get 5 gallons of meth that'll last pretty long because i'll be using it as a track only fuel, at 2.70 a gallon.

My car does fine on street pump 91 and 12-14psi, no meth on the street tune.

When it comes time for a few passes at the track, flip two switches, meth and the high boost setting on the BC, load up the meth tune and have safe fun then drive it home when i'm done.

I'm just going for a 10.99 pass and whatever it takes to get me there. But it is nice having a good system in place if I do want to take it further if I wanted.

I tried the water/meth mix and just didn't like the bog when it hit. The meth is much more fun when it hits

Didn't get a chance to test the smaller nozzle today It'll have to wait till tomorrow.
J