mstansbury0704

Have a higher compression ls1 that appears to just not want to let go so im going to drop a few pulley sizes. procharged, heads cam car. makes 10psi at 6k and close to 11 at 6500. Running 15 degrees of advance. I will be dropping from a 4.38 to a 4.13 so hoping to see eh 12 or so..

Been just piddling around with the car waiting on stuff to come in and decided to maybe revisit my meth setup and possibly go to a dual setup. Snow kit, right now im running a 12gph or 757ml/min nozzle spraying 50/50. I found an old post by I think aquamist saying to multiply total CC of injectors by 15-20% for a 50/50 mix. That seems like a LOT of nozzle compared to other peoples setups. I did find this nice little calculator but it too suggests a very large amount of nozzle. https://www.customperformancesolutio...injectioncalc/

Ive searched a bit on this and most people here are ***** to the wall running massive nozzles on 100% so info is few and far between but this 1100ml/min according to aquamist math comes out to an 18GPH nozzle. This is a lot more nozzle than I've seen the few people running water mix suggest in the past.
Thoughts on this?

Full Power

My limited experience, plus a lot of 'reading' suggests that there is a world of difference between straight Methanol and 50/50 Windshield washer fluid.
50/50 Washer fluid will bring down IAT, and allow greater manifold pressure about the same degree as a cold winter drive versus a hot day in dense traffic (heat soaked air intake).

Straight Methanol is FUEL, with about 130 Octane. Methanol stoich is somewhere close to 6 to 0ne AFR, and will make power down to 5.8 to one. Methanol is half oxygen by molecular weight, so you can push a LOT of it into a cylinder.
My point is that you need to decide if you are JUST providing a cooling MIST, or if you are essentially going to run a DUAL fuel engine, if you dump a serious (stoich) quantity of Methanol you'll both have to accomodate that into your fueling tables IN the boost region, ie LESS gasoline AND your tune will be 100% dependent on the METHANOL tank being full, and the pump working, or you'll melt pistons.
Let me state that another way:

IF you run straight Methanol , and TUNE for it... You're HOOKED on it.

mstansbury0704

I tune myself. My VE table looks like a bowl up top because of the methanol. Without the water in it this car would probably not have cyl 7.. If E was closer and more available I’d consider that. I have the fuel system for it and would just need an injector swap.

Back to the topic, it’s odd if you go by snow’s chart it suggest a super small nozzle compared to what I see recommended and used by some here. And then calculators are on the other end of spectrum and recommend way more nozzle even for 50/50 along with aquamist. What gives? I thought I was running a decent sized nozzle already for my setup but am now finding conflicting info on it. Should I really be running 18gph of 50/50 for 11-12 PSI on a centri?

Right now on the meth im around 70-80% IDC on boost ref’d at 4 bar base.. I don’t feel any bog but I have the ramp in setup early and it’s on full duty before peak torque. I have 4.11s so you wouldn’t feel much of a bog anyway lol. Hopefullly will be sending my rear to MWC to get some 3.70s and a refresh this year. 4.11s were nice when NA but constantly blowing drag radials at 60mph and having to shift like mad isn’t exactly optimal. I just find it odd that the proper meth nozzle sizing is all over the place depending on who you ask. I’ve got a message into nitrous express asking them the same question as well

GMCGreg

Can only say this , I run 1000cc/min of home made 50/50 all in at around 4-5 psi on my turbo 6L , no bog and haven't blown up the SBE in 31,000 miles ( only added the the extra 375cc/min maybe 2000 miles ago in preparation for more boost ) 15.5 currently on 91 octane. Hope this helps

mstansbury0704

that helps a lot. You’re on 1,000cc at 15.5 lbs? Stock compression? I have prc 225 62cc heads but im running the ls9 gaskets now so probably just a touch less than 11:1 now. Sounds like we have a similar mentality on the meth injection. I think I have mine start at 3 PSI and all in at 5 or 6.. I use boost juice though just for ease. I have about 6 gallons left and once I run out I’ll probably go get 5 gals of m1 and mix myself.

GMCGreg

Yes , stock compression LQ4 so 9.4 :1 . Pretty easy to add a bit of meth to -30 blue WW fluid and get appox 50/50 mix very cheap

91 Z28

iTrader: (3)

I'm running an AEM setup with dual nozzles spraying 1500cc with boost juice on my 9.3:1 forged 370 pushing about 17 psi right now. It's a progressive controller and I start at around 6psi and all in by 15psi. I'm also running 91 pump gas. Gonna start creeping up to 20+ right away. My nozzles are about 18 inches from the TB and before the IAT sensor. I run a Holley Dominator ECU and have just been letting the ECU take care of the fueling. No bogging out and plugs look good

mstansbury0704

Damn this making me think I’ve been under spraying a little vs what I could get away with compared to what you guys are doing. I ordered two 8gph nozzles so I think will be around 1000cc

91 Z28

iTrader: (3)

Hopefully Forcefed86 chimes in. He's been playing around with stuff for a long time. I made a thread about this stuff a little while ago and he gave me a lot of good info

mstansbury0704

it would be nice. Like I said I tried to search and damn I feel like a tadpole in a big pond around here lol. I don’t make 4 digit hp numbers like these fellows on here do. Maybe someday when this motor lets go I’ll get closer

91 Z28

iTrader: (3)

Well until Forcefed86 chimed in I was spraying barely anything at all. I'd be spraying almost 2000cc but can't find the 1000cc pintle for my nozzle

mstansbury0704

yea I kind of just got trickle down info on it and went with something I saw on here. It’s definitely not a real adamant answer on here with everyone’s setups all over the place! But either way, more meth nozzles in my garage the better I guess for the future plans.. Next course is deciding on what rear gear I want to swap too. That is a toss up as well between 3.70s or 3.5 when on a stock 26” tire.. I still have 4.11s and they are pretty horrible with the FI setup. Might as well forget you have 1st and 2nd cause all they do is make a bunch of noise.

91 Z28

iTrader: (3)

I've got a 4l80e with a 3.25 rear gear in my car with a 26" MT drag radial. It's got a Circle D converter in there but it kinda makes it a bit of a dog off the line. I either need to work on the tune more or just get rid of it cause it's not doing it for me and get an FTI converter

mstansbury0704

haha I’m sure you make 2x the power I am making, I bet the 3.25s with a good stall would be amazing on your setup. My car is mostly a street car but with it being 100+ degrees out like every day of the week I don’t even wanna drive it lately.. Plans were when it finally pops to get a forged unit and I know I’ll want the 3.5s then but at this rate it will last another several years lol. Just really unsure how much of a change it will be going from 4.11s to 3.70s. 1st is useless and 2nd gear rolls are good until it starts to build boost and then blows the tires. Honestly I feel the car is faster just taking off from 3rd instead of 2nd at the same mph. It doesn’t spin and I don’t have to make a shift. Been playing around on the TREMEC gear calculator and 4.11s to 3.70s don’t really seem to be a drastic change. I fear I’ll have the same problem.

GMCGreg

FWIW, 4.10s to 3.70s is very close to a 10% change in rpm and torque multiplication, I think of it as 10% less torque at the wheels, about 17% for 3.50s . Don't have a centi but this is a good reason for boost control on a turbo . I run 3.73s with a 29.6"tires in my 4400 lb + truck and without lower boost for street driving would be impossible to hook up , mathematically that's the same as 3.25s and 26 inch tires

mstansbury0704

those are my thoughts too, idk how drastic the 3.70s will be in the car. I’m a bit torn. I don’t want 4th gear to be a turd but then again I feel like the 3.70s will put you in a weird spot where they don’t really do anything good, you’ll lose that sweet 3rd gear passing zone the 4.11s put you in and you’ll be in a weird in between gears situation and you’ll still blow 1st and 2nd with DRs. I don’t think I’ll ever get close to needing 3.5s 140s trap speeds currently, however it’s been a long time since I cared enough to run the 1/4. If I recall a long time ago when I had my NA cam boosted before my morel lifters ate one of my lobes that I geared out the 4.11s before or at 1000’.and I was a bit younger then so I think I had my spark cut box set to 7grand lol..Getting older making me more cautious ..I make a few lbs more and have a custom cam now but don’t rev it out that far anymore.. maybe the move is to plan on 3.70s and if it’s too short move to an easier to hook 28” tire?