SPRAYED 01

iTrader: (22)

Im new to tuning and methanol. My setup is a forged 9.5:1 370,comp midframe 88mm,80lbs injectors. The car is currently fully tuned to run on 93 up to 10ish psi and I run a 109/93mix at 20psi.

Its a proven setup that runs well. Everything is the same except I just installed an alky control dual m15 nozzle kit with 100%meth.

The purpose of the kit is to be able to run 20psi without race fuel. I still plan on adding race fuel at the track but would like to tune for just 93 and meth. Race fuel is just for a back up and on track days only.

I use hp tuners, currently im at a max of 18 degrees timing and have been logging 11.4 afr. Im thinking of leaving the timing alone and aiming for 11.0afr with meth.

Thoughts on that plan? Any one see any issue with my goals?

SPRAYED 01

iTrader: (22)

Also any tips or advice on tuning with meth in general would be great. Im thinking of having it come on at 5psi and keeping the fueling the same untill about 3600rpm, then lean it out for the meth. Its a very fast spooling car so it won't take long to get above 5psi.

LS1 240sx

iTrader: (1)

here,

https://ls1tech.com/forums/forced-in...e-cracked.html




Also keep an eye on your IAT and I would knock timing down abit to 15*, you can always raise it down the road when you got everything working right, but for tuning process keep it abit low for forgiving errors.

denmah

iTrader: (2)

with the cars i have tuned on 91 and methanol i run 22lbs and around 10-16deg of timing, depending on how the car responds to each degree on the dyno

25deg on motor then tapering down to those numbers at high boost

9sectruck

iTrader: (9)

11.2-11.5 afr start out at 10deg, and work up on timing.
Afr in the 10s can pop ring landings

denmah

iTrader: (2)

i am not trying to be an ***, but can you explain how a rich afr pops ringlands?

i throw 10.6-10.8 AFR at my high boost cars (over 20lbs) and they love life.
140+mph

what exactly happens when its too rich and lifts a ringland?
just wondering how that happens or what goes on in the combustion chamber?

TurboAv

iTrader: (6)

He's talking about rich knock I believe. More happens in the 9's to low 10's. Some cars can tolerate a richer mixture though.

98Camarod

iTrader: (43)

Overly rich conditions can cause you to "wash the cylinder". Meaning fuel is used as part of the lubricant in the cylinder for the rings vice oil. This in turn causes ring to wall contact which kills the ring life. Then you'll have the ol' blow by. I'm not certain if this is what you were referring to, but this is what I've researched as far as what an overly rich condition causes to the engine.

denmah

iTrader: (2)

i think he means too much fuel in the cyl will actually detonate inside the ringland? and annihilate it?

9sectruck

iTrader: (9)

I dont know what it actually does but have seen engines with popped landings with low timing and had 10.0-10.5 afrs when they got hurt

SPRAYED 01

iTrader: (22)

Thanks for the replys. I set up my timing to start reducing after 104 iat. I have it start out at pulling 2 degrees and it ramps to pulling ten over 135ish. Any thing wrong with pulling to much timing? I would hope it it got that high id see it (iat gauge in car) and let out.

WSLN 6

iTrader: (3)

Shoot for high 10's to low 11's. Been running straight meth a pump for years with great results. Stoich for meth is much lower than gas, so compensate accordingly.
Warning to those who live in a cool climate....keep your IAT's above 65F. Meth will not flash off at much below 70F and tends to stay liquid. Under high cylinder pressure it will ignite when it wants to, causing a sweet blowtorch effect....
Hopefully the LS intakes that draw from the top will prevent these puddling issues.

Forcefed86

iTrader: (4)

So this is what I picked up over the years, feel free to disregard all of it. It’s just my opinion.

Pump gas has a very narrow peak power and detonation window compared to alcohol fuels. (aka it’s a sucky race fuel!) Most people aren’t monitoring each cylinder so you can have #1 cyl running at 11.5 and the #7 running at 12.8. Air/fuel distribution and injector flow rates all vary a shyt ton and gets worse the more cylinders you have. Since pump gas is so touchy the #7 cyl may blow a hole in the piston and the #1 cylinder is happy at 11.5. Most don’t tune on the edge with pump for this reason. The window or “happy place” where the motor makes peak power is so tiny you can have issues cylinder to cylinder. So in general I’d have to agree that error on the richer side of things (within reason) is the “safe” route to go.

I always shot 11.3-4 range with pump. Running 10:1 AFR’s on pump is crazy far out of the peak power window and not very efficient and you will drop power (not that I think it will destroy anything). Cyl washing and rich detonation from what I’ve seen happens at much richer AFR’s than 10:1. Too many people think that additional fuel cools the cyl. That’s not really the case with pump gas, the volume of fuel being sprayed in the cyl between 11.5 and 10.0 isn’t enough to “cool” much. (alcohol is a different story) With pump gas the additional fuel is mainly slowing the flame front. (Very similar to retarding the timing) I would suggest nothing richer than 11.0 and dropping timing back to slow the burn instead of adding retarded amounts of fuel.

With Meth inj, the more Meth you spray the more it opens up your peak power window. So you can get away with richer mixtures. I replaced 30% of my WOT fuel with meth. Tuning on a gas scale wideband my I liked about 10.8 or so on meth injection.

As always with timing dial it in last. I’d start out with a overly low 8*-10* or so on pump. Dial in your boost and AFR, then bump it up slowly watching the plugs VERY closely. Pump gas is very sensitive to timing.

LS1 240sx

iTrader: (1)

plugs as in spark plugs?

SPRAYED 01

iTrader: (22)

How do you guys check plugs on a turbo car? I know you have to shut down right after a hard pull, any one worry about cooking the turbo?

Forcefed86

iTrader: (4)

I wouldn't worrie about it to much. It's not like your doing it all the time. Shutting down the car immediatly after a run is more for ground strap heat range reading and fuel curve reading. Detonation speckling will show up clearly even if you don't shut down right after a pass.

Basic info on ground strap heat range reading (i like the very first image for heat range.)

http://www.wallaceracing.com/plug-reading-lm.html

And this is what you don't want to see... anything resembling small specks are usually signs of detonation. This is a pretty bad plug. Hope you never see this much on a plug! I picked up some bad gas in my car and this was the result.

Ferocity02

iTrader: (60)

I run 91 octane and a 50/50 mix of water/meth at 15 gph. I'm currently at around 0.78 lambda (~11.1 AFR) and 14 deg of timing. Mightymouse's spreadsheet says I should be around 10.5 AFR which seems kinda low. My tune is in no way optimized. I started very safe and slowly added timing and leaned it out. I feel like it's pretty safe, I don't want to do too much more without a dyno.

driven87

iTrader: (1)

As i stated in my PM to OP i run my car at 11.2 AF and 15 degrees of timing on 19-20 psi and have been 9.2 at almost 154 at 3700lbs. gonna try some different timing numbers on dyno and see. even with this pt88 at my weight i think all squared away ill get an 8.7ish and 157ish out of it on 93 and straight meth with dual nozzles

denmah

iTrader: (2)

same thing i run on alot of cars

TR6 plug, gapped 24

91-93 and prestone washer fluid (close to 50/50 mix) large single nozzle
20lbs of boost, 11.0 AFR, 10-16 deg depending on how it makes power on the dyno.

put cars into the 9.70-9.90 range at 140+ easily and safely, even on a gen3 motor with stock 862 heads

SPRAYED 01

iTrader: (22)

Im tuned on tr8 plugs. Any issue with being too cold?