As title says, i know intercooler is always best option. But I wanna try spraying meth pre-turbo
before i go adding weight and make front end changes. Anyone have experience with it and like to share how well or bad it worked? My basic setup 1/8th mile car 5.3 billet s480 e85 cam 3200lbs th400, turbo inlet is ram air setup with short 4" up pipe etc etc.

Im thinking run biggest nozzle possible 100% meth using a controller to ramp in... Wanting to run a decent amount of boost and get into the 5's.

Anyone have good success? Lets here some opinions...

 

 

Pre turbo can help, but not as much as post turbo. If I had to choose one or the other, it would always be post turbo, but as the above poster mentioned, some use both. Without any form of intercooler, I would run 100% meth, but your components need to be up to spec. You don't want leaky fittings or pumps in such a scenario.

 

Reposting.

 

The one benefit to pre-turbo is that it’s also injecting pre-intercooler. Unless your IC is grossly undersized, the IATs post-cooler won’t be hot enough to change the state of the water to get the phase change cooling pre-engine. Hell, the boiling point of methanol at ambient pressure is 173F and that only goes up with boost. Post-cooler IATs are unlikely to be even high enough to boil the meth either. By spraying pre-turbo, you can effectively get a denser charge.

It’s hard to quantify any results because spraying meth and water before the IAT sensor can give false low readings as the liquid evaporates off of the sensor element. BUT water/meth provide a huge benefit in combustion chamber. Under pressure and heat, the water/meth change state in the chamber, sucking out heat and reducing the chance of predetonation. In my opinion THIS is why people can push more boost and make more power on pump gas + water/meth. Injecting straight tap water, I was able to push 30psi on pump gas (through a Mazda rotary!) with zero issues.

 

After really thinking about it last night im leaning towards just getting the cxracing a2w intercooler. I dont really want the weight, lines, piping etc. or have to deal with buying ice constantly but im trying to make as much power as possible. Hell i might even do both if money allows. After seeing that the intercooler setup will cost about the same as some reputable meth kits Im kinda leaning towards going IC.

I mean i doubt it, but would spraying meth pre, and post turbo be more effective then a cheap w2a IC setup? Its an 1/8th mile car and i wanna be as light as possible and have killer 60ft times. Keep in mind i would be mounting this IC underhood so spool wont be effected really i guess. This is probably a no brainer to some but i got hear some opinions on the matter because i feel like everyone chooses ic because everyone else is doing it. Ive read and read many many articles and thought i would post up before making a decision on what to do as im wanting to go to dyno very soon and see what my setup will make. Part of me wants to try just meth only and see for myself, other part wants to do whats been proven.

 

A good A/W intercooler setup is going to cool better and make more power than a meth kit.
Its also far more work to maintain.

 

 

Instead of a large nozzle have you looked into direct port? I run the prometh (used to be AIS) direct port kit and progressive controller. I have a taller intake and put the nozzles high in the runner near the plenum.


Agree I run 100% M1

Since OP mentioned weight, A/W adds a good bit of it. Factor in the A/W core, reservoir, pump, lines from reservoir to pump to core and back, and water add up, often close to 100lbs. Most setups have 50lbs of water alone just cruising around. Guys add 20lbs of ice at the track to a normal 5g reservoir to get them to work properly.


I run a good air to air as well as direct port meth, I can make tons of back to back pulls and not have IAT issues, no need to drain reservoir add ice, etc..

 

I had whatever A/W core Shearer uses, think its a Bell and it worked fine with just water. But compared to a Garrett A/A core the temps are about the same to factor in a similar price point. Comparing a Precision to a Treadstone is laughable.

 

 

I ran 50/50 water/meth with no IC for years. It added 60rwhp on pump gas at low boost, would be worth more at 30psi. That was injected about 12" before the throttle body. Now I run 2 jets, but they come in later and now I run a big front mount IC as well - but that's because I need to run under boost for longer periods. For drag racing I would not have added the IC unless I had to do back to back runs in quick succession. Both water and Meth help cool the AIT but water provides IN-CYLINDER COOLING, The small power increase from the high octane meth does not compensate for the benefits of water. So - if no IC run 50/50 water/meth. If you add an IC then you could inject 100% meth

I would NEVER run pre-turbo injection except as a secondary input and I'd keep that jet small. Research by many experts has shown that adding jets between turbo and TB is best by far - i.e. right before the TB but back around 12" to give it time to atomize better.

 

A2A is simple and never fails.

Simple is good.

 

We dyno tested pre/post turbo meth injection like 10 years ago using an AEM kit. Same size nozzle, same volume of 50/50 being sprayed.
EGTs were noticeably lower with the nozzle near the throttle body. It was a clear indication that detonation resistance was higher post turbo.

The pre-turbo nozzle did lower IATs, and EGTs to a lesser extent, but most of its cooling capacity was wasted on all of the hot aluminum it came into contact with before reaching the engine.
Once the water/meth mix changes state to gas, its basically useless for cooling. Don't waste its cooling capacity trying to cool down your piping.

 

Very nice discussion!

 

What if you were to do both? Ive got a max effort centri setup that Im contemplating not doing a ic in favor of pre blower/post blower (tb) meth injection.

 

See what JoeNova said.

If you focus on the pre-throttle body setup and nail that - adding a pre blower jet will not add much - if anything. In fact, there is a max water/meth fuel loading and beyond that you gain nothing, go too far and you will hydraulic. Better to get the flow to optimum in the 1 place that works best, adding more at that point will go backwards. Spend the money saved by having just one location doing something else like an electric water pump

 

 

I dont' agree with what is being said at all.

Pre-turbo is the best option IMO. (for non intercooled setups) The issues with the tests being done is that not enough volume was sprayed. I can see all of the meth flashing in small volumes. Basically being "used up" before it's past the TB. But in no way is it "wasting" the energy by cooling the turbo.

Cooling the charge as it's being compressed ups the efficiency of the turbo. An intercooler can't even do this. The more you spray, the more it shifts the compressor map to the right. Also pre-turbo vaporizes the mixture better. The key is to spray huge volumes... Most kit pumps only support about 30-50 gph at 100psi. And at the rated 300psi they can't even keep up with 10-15gph worth of nozzle most run. Key is to drop the pressure way down on the pump so they spit out alot of volume and max out the pump progressively. Atomization is great, but it's not as important pre turbo and 100psi is more than adequate with most nozzles to prevent turbo damage. Also meth isn't as hard on blades as water in general.

Water has totally different draw backs and benefits and can't be run in huge volumes. But is certainly beneficial, esp in small amounts. you could mix 1-2% or so in your meth and spray 50gph or so for a max effort deal with the good pump. The big boys spray 100gph+ pre-turbo. I've got the equations used to calculate temp drop and approx. nozzle size on a max effort deal if you know your HP level. Idea is to target 150* (boiling point of the fluid) and calculate how much meth is required to drop your current temps that far. The more power you make, the more fluid is required to drop the charge temps to that magic 150* point. A single pump may not cut it for large power setups.

That said I have friends running 28lbs on S480 5.3s non-intercooled with no water/meth in the 1/8th doing 5.40's at 2800lbs. So you probably don't need it at all for your goals and the typical no brainer kit would be fine for a little extra insurance. Just depends how far you wanna go with it. The more effort you put in, the more benefits can be had.

Another consideration is safety. A good back fire through the intake with 50gph worth of meth flying through 1000hp worth of air is a flammable AF ratio. Basically a bomb. You'd need some sort of relief on it to be truly "safe" IMO. Burst panel, or a large BOV with a spring set to slightly above your max manifold pressure and not connected to vac/boost. Then there's fire risks if a line or fitting fails. Should be treated like a fuel system IMO. No push lock fittings or nylon hoses.

 

I was very impressed with what pre compressor did for my setup that was non intercooled, details are here: https://ls1tech.com/forums/forced-in...x-results.html

I still prefer a Garrett cored A2A though, that cant be beat for simplicity and working like magic.