Technical Staggered | Pre-turbo Methanol Injection

doublespaces

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Oct 18, 2016
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I don't run meth on my car, but I am interested in this concept. I made a post about this on e90post 8 years ago, and the task was more complex given the twin turbo landscape.

With a single turbo car, however, it would seem that getting a pre-turbo nozzle in the intake pipe wouldn't be so hard anymore. Nevermind your general opinions about methanol, lets discuss the benefits of a pre and potentially post turbo injection setup.

Many of the parts we put on our cars have a limited life, they are wear items. Racing teams are happy to get a season from their engines, and some are happy to get a single race. Assuming we were willing to subject the compressor wheel to a degree of abuse and be happy to get X miles out of it, what possibilities could we realize with such a setup?

Picture for motivation:
RZJhsr1.jpg
 

The Convert

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If you put the nozzles closer to the filter on a bottom mount kit with an inlet tube, you probably wouldn't shorten the life at all. Just one more reason to go bottom mount.
 

dyezak

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You don't want to inject pre-compressor. I know that from experience. Turbo compressor wheels are made of aluminum, and spin at tens of thousands of RPM's. When liquid hits aluminum at that speed you get erosion. The picture you posted was of a cosworth turbo from the LOLA XB powered champ car (it's a very famous picture of a turbo hahaha). That turbo has a forged titanium compressor wheel. Even with a forged titanium compressor wheel I wouldn't expect it to survive for tens of thousands of miles that a streetcar would see. I'm sure it was fine for a Champ car that would get new turbos every few races and only accumulate about 1000mi total before they were replaced.

If you've never seen compressor wheel erosion here's an example picture:

30.jpg


That's about what mine looked like on my 1g AWD DSM after a year of injection. I don't have any pics of mine in particular, but this is a good representation. The finer you get the injected liquid to atomize the less of an issue this would be, but it's always going to be a problem. I was doing this back in the late 1990's, and let's face it, our injection tech back then was a 20psi pump pushing through what amounted to a nitrous nozzle. Not exactly great atomization.

I think what you're looking for is volute injection. I had never heard of volute injection until recently, and I've never tried it, but this is an example:

volute_methanol_injection_stage_1_6_1024x1024.jpg


This eliminates all the erosion problems and gives you most of the benefits of pre-compressor injection. You don't get the compressor efficiency bump from the wetting action of the meth creating an internal seal in the compressor. But all the other benefits are there.

NOW your question is going to move to pre intercooler vs post intercooler injection and what problems could you introduce via injecting liquid (no matter how finely atomized) before an intercooler.
 
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doublespaces

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If you put the nozzles closer to the filter on a bottom mount kit with an inlet tube, you probably wouldn't shorten the life at all. Just one more reason to go bottom mount.

And this would be incredibly easy to do, at least on every kit I've seen except the FFTEC.

NOW your question is going to move to pre intercooler vs post intercooler injection and what problems could you introduce via injecting liquid (no matter how finely atomized) before an intercooler.

The pre turbo portion was really what had me the most intrigued. I've heard of volute injection seemingly once before, I'll take a deeper look.

Is there any reports of someone doing this to a garret or precision compressor housing?

This is why I've heard of this before:

https://bmw.spoolstreet.com/threads/volute-methanol-injection.1845/