Alky injection location -pre/post carb?

[ShawnR]

I was puttering around this evening and got around to reading the manual that came with the AEM alky injection kit. It says to put the nozzle before the throttle plate.

I was planning on sticking it right at the post-turbo "foot" since there is already a fitting there for it, but now I am looking at pre-carb locations.

Anybody done this already and care to throw out some advice?

Shawn

 

[WarWagon]

Pre turbo injection has it's place and I'll say this is not one if them. The stock draw through configuration already has a wet flow mixture, the fuel in the mix is reducing temps already. I'd suggest the foot injection point if your going to do it. That is the next best opportunity to help reduce intake charge temp while keeping the mixture distribution even. If it weren't a draw through setup it could benefit from the pre turbo injection. Too much liquid and especially a water/alky mix that is poorly injected will erode away the compressor wheel.

 

[pacecarta]

if you put it after throttle blade you are putting nozzle in a high vacuum area and it will pull the alky out of the tank all the time the engine runs
you can do it but you need a high pressure check valve ( cracking valve ) to prevent alky draw from vacuum

 

[ShawnR]

The kit did say that it has a check valve in the nozzle. Sounds like I'll just go with the original plan and stick it in post-turbo at the foot.

Thanks.

 

[b4black]

I run it pre turbo & carb. That way you're not fighting pressure or dealing vacuum. Plus I felt it would be better atomized going thru the carb. I did erode my comprssor impeller, but I got way to carried away with the alcohol (and it took years).

In the compressor foot, I worried about even distribution. Plus you need to run high enough pressure to overcome the boost pressure (which your AEM set up likely is OK for).

http://www.beforeblack.net/alcohol.htm



With the alky, you will be upping the boost and I suggest getting a good boost controller. I've run up to 19 psi. I plan to try the hallman boost controller.

 

[b4black]

The charge cooling comes from alcohol's higher heat of vaporization. It shouldn't matter where it is injected. Water it even better. I run a 50/50 mix of ethanol and water (E85 is a cheap source of ethanol).

 

[ShawnR]

I have E85 available locally. Methanol is a lot harder to come by. You run 50/50 E85 and distilled water?

 

[b4black]

Yep. Mix the two, shake (careful, it will build a little pressure) and the 15% gasoline in the E85 will separate and float to the top.

Remove the gasoline - it gives the E85 vapor pressure, making it dangerous under the hood. The 50/50 mix is much safer.