Injecting into turbo.....anyone try it?

AnArKey

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Joined
May 23, 2001
I already know its a bad idea with a intercooled car. But I'm doing a little testing without a intercooler, to see if I can get cool inlet temps with a 70/30 methanol mix, or maybe pure methanol (not sure yet).

Now I have read both sides. #1 it will destroy or wear away the compressor blades. BUT, some have asserted it's a matter of how well you mist the injection. That those who did cause damage to their turbos, did so because they were using injection nozzles that made a stream more than a mist. That makes sense to me.

So has anyone tried alcohol or water injection into the turbo inlet, but with fine misting nozzles (aquamist, SMC/McMaster)?
 
derek, I have not tried that method. Over the years of testing various systems I have found there is a definate benefit from better atomization. However, I do not believe it is necessary to subject the turbo to a potential erosion situation in order to achieve this.
Also, w-a injection, in theory, should act as a highly effective, virtual IC. IOW, you *should* be able to have an effective heat reduction mechanism without resorting to an IC. "throw it away!"
PS is the street car scene still going strong in my 'ole stomping grounds?
 
alky

I tried this on my hot air car a few weeks ago. One --1mm aquamist nozzle before the throttle body. Could not get the boost up to where it was prior to the nozzle install. Removed the nozzle at the track, next run, boost was back up. Haven/t given it enough thought to figgure as to why this happened
 
Re: alky

Originally posted by Lee Thompson
I tried this on my hot air car a few weeks ago. One --1mm aquamist nozzle before the throttle body. Could not get the boost up to where it was prior to the nozzle install. Removed the nozzle at the track, next run, boost was back up. Haven/t given it enough thought to figgure as to why this happened

Well by injecting water and/or alcohol, you are cooling your air charge by some degree, which gives you a denser air charge. Maybe your turbo just can't flow any more air. You can get 30-40% increase in mass air just by dropping the charge air temperature. If anything, the boost dropping is a positive indicator.
 
I'm thinking we should preserve heat energy to drive the turbo and worry about cooling the output, not the input.
 
Doesn't quite work like that. By cooling the in and out temp of the turbo, we won't be subtracting the heat energy that's driving the turbine. Seperate sides of the turbo.

A given amount of injected liquid will have a given amount of BTUs of heat it can (hopefully will) absorb. Just a matter of vaporization. If you get 100% vaporization, you WILL get a certain temperature, given a certain mass air flow.

By injecting pre-turbo, you will get a certain amount of cooling from vaporization before the mixture ever hits the impeller. That is true. But you won't have 100% vaporization, probably less than 20%. Why? Because with 100% vaporization, you would have -20F inlet temps. Just not gonna happen (the colder the air gets the slower vaporization occurs).

So all the left over finely misted but still unvaporized mixture hits the impeller, and gets mixed like crazy, DRASTICALLY increasing the vaporization rate. As the impeller compresses/heats the air, the mixture is already there, cooling at the same time the impeller is heating. The result should be sub-intercooled turbo outlet temperatures.

Injecting pre-turbo is the best bet when you don't run a intercooler, as long as it won't cause damage to the turbo. That's the unknown I am hoping someone can answer. I do know many older turbo applications exist where a carb was placed before the turbo. They were sucking gas into the impeller, I see no obvious reason why methanol/water mix should be any different.

I may just do this incrementally. Inject one nozzle pre-turbo for a little while, constantly checking the impeller blades for any sign of wear.
 
alky

Derrick, I talked to 2 different turbo builders before I tried this. Both told me if I mist the alky it will not hurt the turbo. I guess the droplets are what SANDBLAST the impellor. I was using a 1 mm nozzle. Next time I will try a .5 mm nozzle--BTW I agree with you.
 
Let me bring up this old gem.

Is anyone injecting water or alky into the inlet (compressor) of the turbo?

I asked Precision Turbo about this. They said an intercooler is preferred, but injection will not hurt the turbos.
 
"Those sites has some good discussions, but not a lot of data. Lots to think about though."
Guess it's comes down to "try it, and see" time.

I have my system set up to run dual nozzles, currently in the up pipe. {Pump to a manifold, split into 2 lines.} I can re-route to the turbo inlet. I also have multiple temp sensors in the system, logging w/ the Holley Dominator controller.
Pump 93, M1, no cooler. {I may try some E85, race gas, additives, Avgas 100LL. System has a multi tune capability.}
This is a LS based system, so the data may not be "valid".:devil:
We'll see.;)
 
"Those sites has some good discussions, but not a lot of data. Lots to think about though."
Guess it's comes down to "try it, and see" time.

I have my system set up to run dual nozzles, currently in the up pipe. {Pump to a manifold, split into 2 lines.} I can re-route to the turbo inlet. I also have multiple temp sensors in the system, logging w/ the Holley Dominator controller.
Pump 93, M1, no cooler. {I may try some E85, race gas, additives, Avgas 100LL. System has a multi tune capability.}
This is a LS based system, so the data may not be "valid".:devil:
We'll see.;)

Please let us know what u find out. Your data might be even more useful since the LS engine is larger.

I'm doing something similar with an RB25 engine.

The few people that have data for pre-turbo injection show all good results. I wander if ice water injection could get IATS below ambient. If so, then the mechanical intercooler could be removed.
 
I injected pre-turbo on my Carbed Turbo V6. Did it for years and yes, it did erode the impeller blade. I was using the McMaster Carr mist nozzles. I believe I got too aggressive with it. I was running a lot of water/ethanol. Too much. I was using dual nozzles, a size 10 and 15 (the biggest they have).

I plan to try again, and not get carried away this time. I should have been adding more fuel through the carb and injecting way less alcohol.


These are the nozzles:
https://www.mcmaster.com/#spray-nozzle-misters/=1cys2zs
 
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