13B-RX3

iTrader: (2)

So i picked up a barrel of M1 today and i was wondering what a/f ratio or lambda would be considered conservative. I had been told once to set it up really rich and lean it out till it stops burbling. I need some kind of number to shoot for or i will continue to lean till it goes from burble to ping I also don't want to have to change the oil every race. Any advice from the pros? I found a good article on reading plugs but i don't know if the same rules would apply to a turbo rotary.

http://www.dragstuff.com/techarticle...ark-plugs.html

Thanks
Allen


Sorry to disappoint you Aaron.

Busted7

Im not the one to get info from but ill fill in till the smart guys give you good answers!

Probely spell it wrong but i think the stoichametric for meth is somewere in the 9's.
I know you need a good hot spark, and you can play with the timing i belive i was running 28 total deg.
I used redline meth premix and it worked pretty good.
I ran straight 50 weight kendall racing oil.
The catch can is your friend and i was amazed at the quanity of meth that would acumulate just playing around.
Oh and about 4 gal's to the quarter mile.

Im done now someone give 13bRX3 some real help.

Lasse wankel

Did some testing back in 2003 on our huge ported 13PP motor on alky. The motor had a Rons mechanical injection and a slide manifold. The engine was set up really rich with exhaust temps in the 570-600 deg Celsius range it made only 250 hp. Then we start lean out the mixture and came up with 728 deg celsius exhaust temps and ignition for leadig 32 deg, it made 313 hp@10050 rpm. First the engine only sputtered and the fumes sticked in the eyes but leaning to a high exhaust temp is the key to good power and it smelled like gun smoke "lol" Can say we first had a Weber 55dco set up on gasoline that made 285 hp. Think Methanol can do as much as 12-14% more power on a PP motor.

/Lasse

61620B

start with 20 deg and work your way up.I have made safe power with 20deg and 25 psi when i first started out.You can run very rich mixtures like equivilent to 10 to 1
witch is around 4.5 to 1 in alky meter.Alky is safer to run with higher timing but you'll suck alot more fuel when you run rich.

Here are some old videos when i was racing with that tune.I ran this engine so many times consistenly,i just added these videos from VHS tapes.
This was back in 98-99 with full exhaust and a T-72 turbo and front mount intercooler.

http://vids.myspace.com/index.cfm?fu...deoID=40103921

RoTaRyBoYz

It's ok Allen, for me any kind of alcohol is good but that 120+ proof stuff you messing with is beyond my level ATM


Rene, thats some old memories there.... Bret Kepner started off with a "73 mazda rx3" but ended up with a "73 mazda r100", I guess he was just to excited

Viking War Hammer

iTrader: (8)

Was ol Kepner in that video? Can't watch it from work............. If so, I'll send this to him

cloud9

iTrader: (4)

I'm for it!!!

13B-RX3

iTrader: (2)

So somewhere in the 10.5:1-10.7:1 range would be safe without being too rich?

I have had several people tell me to run the timing much more conservatively. They say that their is very little power made by advancing the timing but the risk if detonation goes up greatly.

For the record i will probably end up between 35-40 pounds of boost.


Holy ****!1!!1!


Thanks for all the advise everyone!

enzo250

10.5 is a decent start and definitely not to rich..
to little timing is just as bad as too much on a rotary.
try not to go to low..

13B-RX3

iTrader: (2)

What would be considered too low? Below 10?

crispeed

12 injectors = 50psi!

crispeed

Too low is when half of the bottle is missing allready!

enzo250

something to take into consideration is that a/f also depends on whether or not your using an intercooler...

RoTaRyBoYz

Sober up you nut!!! Have you been drinking that M1 again!!!

Allen why is this man being a drunken comedian when we all are trying to learn something important here
Grasshopper you still got that horse riding crop??

13B-RX3

iTrader: (2)

This has to be some kind of code or riddle. Hmmmmm.......12 injectors at 50 psi.........12 at 50.................12.50....................12.50: 1...................12.50:1 at 50............I got it, 12.50:1 at 50 psi of boost. That was a tough one Chris. Thanks for all the info, i will try that today


It is non intercooled Enzo, i would assume you would run a little leaner because of the density of the air?


Thanks again everyone.

enzo250

Actually the other way around.. You will need to run richer.

crispeed

It's very difficult to set an AFR when using methanol/alcohol fuels. Every application is different. As Enzo pointed out an intercooler also makes a difference.
With alcohol due to the volume of fuel involved you can get into major problems if ran too rich especially with too retarded timing. One missfire with all that fuel inside the motor and kiss it goodbye. Same for being too lean also. Some of the times you won't even run into detonation from being to lean but you will burn up a lot of parts when everything gets really hot. EGT's plays an important role with alcohol fuel. For example a friend was running 50psi yesterday on his 13B with a fuel system that was setup to only run about 30psi. He did not blow the motor and it was a half track pass when he realised the boost was just a little too high!
Another example of running to lean with methanol is when sparkplugs come out with the electrodes missing resulting in multiple crack housings but no apex seal damage. Running too rich and you end up with broken/cracked side housings around the intake port side and also dented rotors from trying to compress all that fuel.
Honestly not many tuners are willing to discuss methanol/alcohol tuning secrets. It takes a lot of of time to gain that experience not to mention no one wants to be responsible when **** goes wrong. One of the main reasons why most stick to a particular combination that works for them.
Allen you will be getting a PM very soon.

crispeed

No methanol just VP Import at 55psi!
Actually if you were keeping your eye on me you would have known I've been playing with this getting ready for the DSM shootout next weekend.

rotary8

So Crispeed when are you going to run 55 psi on a 13b .

RoTaRyBoYz

Cris I know what you've been up to, I have xray vision
I'm trying to help a friend get his stroked, Autronic powered Evo VII ready for the long drive to Ohio, but he still having a rich idle problem... Hopefully he pulls his head out his *** and take the **** thing to Enzo asap

This thread has some good info, keep posting guys...

crispeed

That sounds like a logical plan!

rotor_dee

As cris mentioned with methanol AFR meters don't seem to be telling the truth all the time. They become more of a small piece of the info with methanol. You will have to compare your lambda reading to your EGT and make sure they make sense collectively.

ultimatejay

iTrader: (1)

Yes, good input Piston Dee, those will be your best tools. This even applies with gas. Both afr and egt meter numbers will have to make sense together.

crispeed

I had a feeling this would have brought you out of the MS3 cave!

13B-RX3

iTrader: (2)

Thanks for the input Dee. I have a dual channel EGT so monitoring temps won't be a problem. I just need to know what temps to shoot for