Target AFR for Meth tuning?

[blcknspo0ln]

What target AFR are you pump guys with meth tuning for? I'm gearing up to start tuning with an M10 nozzle @ 26 psi on my 50 trim and I'd like a 'base line' AFR to target. Post your experiences

 

[UofACATS]

On a FP Big T28 @ 24psi, the leanest I would ever see is 11.5 to 1, with most of the pull AFRs at 11.0 to 11.2 as a target. In other words, normal pump gas tune.

I didn't run "leaner," I just increased boost and top end timing when spraying meth. Although I wouldn't consider myself a meth guru, the knock would show only 0.4 to 0.7 "blips".

 

[420a-t]

I go for 11.0-11.5/1 afr and run a lot more timing/boost. That's what I did last year. You're going to have to take out a lot of fuel, but do it slowly-it's safer, but I'm sure you already know that. I did a pull last week and hit 20psi on my holset and got a whopping 50-something percent idc with a m15 nozzle.

This is how I tune my car with meth:

1. get the afr right. 11.0-11.5/1afr.
2. boost-how cool do I want to feel when I say how much boost I'm running? 10? no. 15? almost. 20? That will get my rep points with the honda guys.
3. timing

My meth turns on at 6psi btw.

 

[Devilsown]

Most dsm should be running a 3-10 gph nozzle. Nearly stock should be a 3 and one in the 450ish hp range would be around a 10. It does take some trial and error too. But this is the kinda thing that bigger is not always better. To big and you need to pull out lots of fuel to make work. You should be injecting around 10-15% of your total fuel. Any more and your starting to use the meth injection kit as a 2nd fuel system and there not intended for that use. Lots of people do this but i recommend against it.

 

[blcknspo0ln]

Thanks for the responses guys. I just got this back and want to run a dual nozzle system. With my 950cc injectors, what nozzles should I be running? I'm thinking of starting with the larger blue nozzle and then bumping up by adding a green nozzle.

green - 175 ml/min
red - 375 ml/min
blue - 625 ml/min

Anyone know the conversion formula so I can calculate estimated nozzle size? Any opinions on if the nozzle is not mounted deep enough into the TB elbow to spray evenly?

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[ndsti]

Off topic.... but nice welds did you do that?

 

[talonTSIDriver]

Thanks for the responses guys. I just got this back and want to run a dual nozzle system. With my 950cc injectors, what nozzles should I be running? I'm thinking of starting with the larger blue nozzle and then bumping up by adding a green nozzle.

green - 175 ml/min
red - 375 ml/min
blue - 625 ml/min

Anyone know the conversion formula so I can calculate estimated nozzle size? Any opinions on if the nozzle is not mounted deep enough into the TB elbow to spray evenly?

1 gallon (gal.) = 3785.6 mL (4000)

green - 175 ml/min = 10500ml/hr = 2.77 gal/hr = .056gal/min
red - 375 ml/min = 22500ml/hr = 5.94gal/hr = .099gal/min
blue - 625 ml/min = 37500ml/hr = 9.9gal/hr = .165gal/min

Hope my math is still good, its been a few years.

also, depending on your mixture, if you run straight methanol, you can run a larger nozzle than if you were to run a 50/50 mix of water/meth.

 

[absolute_DSM]

EDIT


Info from -
How to convert GPH to CC's for nozzle size - Devilsown Methanol Alcohol Water Injection

Also a handy calculator if youre a member -
Alcohol Nozzle size Calculator - Devilsown Methanol Alcohol Water Injection

 

[jshuman]

I posted the same question on the link forums last week and have not got a response, but this pretty much answers my question.

I have the hyperdrive digital alcohol kit, and it uses a M15 nozzle. It is designed for denatured alcohol and it really goes through it!!!

I am shooting for the 450whp range, so would an 11:1 afr be a good starting point for me as well?

 

[talonTSIDriver]

You tune meth just like you would normal pump gas.

11:1 usually is a safe A/F with pump.

 

[jshuman]

Ok thanks. That gives me a target for when I start tuning tomorrow.

 

[haioku-rocket]

man tune like pump? negative. Almost like tuning race gas. I run the 375ML nozzle about to upgrade to to the 625 on my 50 trim. tune for 11.5 and just go leaner until it knocks then richen it up a bit. I am running 11.8ish range @ 26 PSI getting about 17 degrees of timing on a 9:1 engine with minimal knock with a 50 trim.

 

[JayRolla]

man tune like pump? negative. Almost like tuning race gas. I run the 375ML nozzle about to upgrade to to the 625 on my 50 trim. tune for 11.5 and just go leaner until it knocks then richen it up a bit. I am running 11.8ish range @ 26 PSI getting about 17 degrees of timing on a 9:1 engine with minimal knock with a 50 trim.

You could also be slowly burning a valve that way. Ive seen where a valve was burnt up from running lean on race gas but knock was still not present, same with e85.

 

[talonTSIDriver]

man tune like pump? negative. Almost like tuning race gas. I run the 375ML nozzle about to upgrade to to the 625 on my 50 trim. tune for 11.5 and just go leaner until it knocks then richen it up a bit. I am running 11.8ish range @ 26 PSI getting about 17 degrees of timing on a 9:1 engine with minimal knock with a 50 trim.

Leaning it out till you see knock is not the way to tune.

First off, there are 2 types of tuners (or tunes).

1. Aggressive tune, you will usually you'll see a little bit of knock. this is what lots of drag race guys do.

2. SAFE and Streetable tune. This is what I run, I am no drag racer, I run my car for 10-30 minutes of balls out driving where I am on/off throttle. I do not want to see ANY knock and I don't want to be running high EGT's.

Poor tuning will kill a motor very fast, I have seen it time and time again.

 

[haioku-rocket]

Leaning it out till you see knock is not the way to tune.

Its not real knock genius. Its just a bit of engine noise. People like you flip out over a few counts of knock. I don't. Been running 26 psi daily on a 50 trim for over a year no problems. If you want to be extra conservative which is not needed then thats up to you. The only real way to tune is on a dyno, not off a stupid knock sensor. Knock sensors are just misleading. Only reason I pay attention to knock is because it pulls my timing, thats it. So I do a few logs and if my knock counts read above 10 counts...thats when I back it down. Not because I am "scared" of blowing my engine, because it pulls my timing.

First off, there are 2 types of tuners (or tunes).

1. Aggressive tune, you will usually you'll see a little bit of knock. this is what lots of drag race guys do.

2. SAFE and Streetable tune. This is what I run, I am no drag racer, I run my car for 10-30 minutes of balls out driving where I am on/off throttle. I do not want to see ANY knock and I don't want to be running high EGT's.

Poor tuning will kill a motor very fast, I have seen it time and time again.

Man that is like the most overstated statement out there... ya think!. 11.8AFR is not aggressive on meth. I know people running 12.5. Should read up on what meth/water does to a car and why you are able to run much leaner and be safe.

 

[turboglenn]

Ever engine will want a different timing and AFR value due to it's assembly, age, wear and other variables. 11:1 is a good SAFE target but people can and do run much leaner on meth. I've ran without a knock sensor for years (only using an MSD unit on the dyno ) and by just being smart about what i gave the engine it lasted the entire time. I was able to see afr's as lean as 12.2:1 on pump + meth but by the use of my recently added aftermarket (J&S) knock sensor i could see that the motor didn't like that AFR for extended pulls so i ended up at around 11.4:1 on pump + 70%meth 30% water mix. - Now i just run straight E85...it's-a-much-a-betta

I agree that tuning solely to please a knock sensor isn't the best way to tune, but it is a very safe way for 80-90% of the people out there to tune by. On drag cars you can get a little more aggressive for fast blasts down the 1320, but on road race cars (what i mainly tune) we go a bit more conservative to ensure the motor lasts the track day at the very least (most easily last a season or 2 and then we freshen them up for the sake of it)

Tuning isn't magic, voodoo or witchcraft, but rather a combination of the 3 put together with an attentive ear, a feel for the engine and a general understanding of what a motor wants to be happy while running hard.

With all that said, go out, start conservative and slowly push the limits up until there's either too much knock or you've reached the point of diminishing return for what you're dialing in. Meaning if you're adding timing and seeing 5hp per degree and then you put in 4 more degrees and only see 1hp then there's no need for that much timing and it should be backed down.

The very simple guideline for a tune setup is
A.) set compressor into it's efficiency range and dial in the AFR's on low timing. Then run the motor hard time after time while slowly adding timing.. one you reach "dimishing return" or start to log a lot of knock, back the timing down (or richen up the AFR's depending on where you're at) it's all a balancing act, it's better to have all values fairly balanced and "normal" than to have say timing at one extreme end and then AFR's at the other extreme to try and make the tune safe..

Hope that helps, only time and experience will tell you what your motor wants, and remember, there's no real need to push the envelope on a DD car when even on a conservative tune DSM's will smoke most of what's out there... Good luck and let us know how she runs!

 

[talonTSIDriver]

So I do a few logs and if my knock counts read above 10 counts...thats when I back it down. Not because I am "scared" of blowing my engine, because it pulls my timing.

If you don’t want your ecu to pull timing, just unplug your knock sensor. Yes a few "blips" of knock is ok, but if your seeing 3-4 or even more knock constantly, you wont last too long out on a road course, sure maybe a drag race, but who wants to drive in a straight line

 

[jshuman]

Ok so I am REALLY going to tune in the morning. It rained this whole last week, and I didn't want to try to dial it in on wet roads. I also had to take care of the extreme negative rear camber issue I was having (washers ). But anyways, tomorrow morning I am flushing the antifreeze out and adding water and water wetter for the summer. I plan to start with a 11:1 afr, then add boost, add timing, add alcohol, and remove fuel. I would like to see 27psi with fairly aggressive timing and an afr of something like 11.5:1. We'll see though. Wish me luck
Justin

 

[turboglenn]

Good luck, and on a side note, i'll be in grantsville west virginia this coming weekend for a couple days. I'll be on the lookout for some of our WV members on the highways when driving there!