Pre turbo water injection

[chuntington101]

has anyone tried this pre turbo water injection idea? i have heard some VERY intresting things about it. sounds like you have to make sure you run LOTS of presure and spray as fine as you can.

Anyone got any coments??

Chris.

[annodomini2]

I would have thought you would want it post turbo, to cool the charge.

Otherwise you are compressing and effectively heating the water along with the air.

[Huff]

I'd think it would be rather hard on the compressor turbine, too.
No personal experience with it though.

[chuntington101]

Thanks guys. Yes that was my initial thoughts and from what I have seen used before. However from what I have heard injecting the water pre turbo helps absorb the heat as the air is compressed inside the turbo. This results in a lower temp after the turbo. As the air temps are lower the turbo work much more efficiently, thus taking less exhaust gas to produce the same pressure.

Some people are using this in conjunction with a conventional methanol injection system and these results in very low intake temps.

Also by injecting water as apposed to say methanol, commonly injected after the turbo, you run less risk of damaging the ally comp wheel.

Has anyone tried this or seen anything about it?

Cheers

Chris.

[GreenV8S]

There was a thread about this a while ago on the ERL forum. The expected advantage is that by absorbing the heat as it is generated during the compression process (rather than afterwards), the compressor sees lower gas speeds and pressure differentials (for a given mass flow), is more efficient and can cope with higher flows/pressures.

The main concern was erosion of the impeller blades due to high speed impact with water droplets, and to avoid this they were injecting the water in a narrow cone aimed at the spindle. I guess that the problem of erosion would vary hugely from installation to installation and might not be an issue for some people anyway.

[CNHSS1]

might be worth searching for the late Tom Hammond as he did something similar on his ex works Pikes Peak spec SWB quattro hillclimb car. think i read about it in an old Cars and Car Conversions car clinic article, possibly by Simon McBeath or Gerard Sauer?
if you get no joy, let me know and i will venture into the loft with the dust and spiders and see i i can find the article

[Boosted LS1]

I used to squirt into the compressors and didn't have any problems. It was a very crude arrangement to

[Otto]

Boosted LS1 said:

I used to squirt into the compressors and didn't have any problems. It was a very crude arrangement to

You just redirected one of your windscreen washer nozzles didn't you

[chuntington101]

Boosted LS1 said:

I used to squirt into the compressors and didn't have any problems. It was a very crude arrangement to

i have heard Bike guys simply tapping of the boost presure and then spraying through a cheap nozzele! lol guess is mean you dont need a hobs switch! lol

think the systems now run very high presure pumps 9250psi) and very fine nozzles.

Did it work for you mike? has anyone got any logs of temps before and after spraying?

Cheers

Chris.

[Boosted LS1]

It was a high pressure pump operated via an edlebrock vara-jection unit which has some flow adjustment functions. It also had a vacuum sensor so switched on with the arrival of boost. The injectors were 'welding nozzle tips' lol. So no atomisation there then but I hoped the compressors would take care of that. It worked a treat and intake temps dropped very quickly when the water went in. I never saw anything wrong with the turbo's and being a simple set up there wasn't anything to really go wrong.

I'll use something from Snow Performance next time and probably inject into each intake runner.

[Wedgepilot]

I looked into this a few years back, and I'm pretty sure the best place to spray was just after the intercooler. The finer the spray the better, so powerful pumps running high pressure are the order of the day.

The water lowers the temperature, plus the presence of water itself helps delay pinking/knock by slowing the flame front.

It's very common in diesel tractor racing in the US (I kid you not), and IIRC, the RAF did some research into it back in the 40s for their supercharged engines.

[Boosted LS1]

Nowadays you can buy nozzles which atomise the water which is far more efficient then my simple bodge.

[toohuge]

Wedgepilot said:

I looked into this a few years back, and I'm pretty sure the best place to spray was just after the intercooler. The finer the spray the better, so powerful pumps running high pressure are the order of the day.

The water lowers the temperature, plus the presence of water itself helps delay pinking/knock by slowing the flame front.

It's very common in diesel tractor racing in the US (I kid you not), and IIRC, the RAF did some research into it back in the 40s for their supercharged engines.

Yes, the RAF did experiment with it. I think that the Subaru 22B used water injection as well, just a hunch.

[theshrew]

Lad i no had one on his R5 Turbo a few years ago. Im not 100% certain but im pretty sure his went into his inlet manifold.

If i see him soon i will ask him for you.

[350Matt]

If you contact aquamist they make a very nice little mount to support one of their atomising jets so that it sprays at the centre of the turbo and so preventing blade wear due to erosion. It looks like the sign for radiation if you can picture it with three spokes and an outer ring which is clamped into position inside the inlet pipe to the turbo.

[chuntington101]

Thanks for all the coments guys.

I am intrested in PRE TURBO injection only. i am aware of the benifits to injecting water after the intercooler.

Boosted or anyone else thats tried it, i dont suppose you have any temps before and after injecting that water do you? also did you use water or meth or a mix? is there any advangtages to using either/a mix?

Matt, thanks for that i'll take a look on their site!

Cheers again,

Chris.

[chuntington101]

Wedgepilot said:

I looked into this a few years back, and I'm pretty sure the best place to spray was just after the intercooler. The finer the spray the better, so powerful pumps running high pressure are the order of the day.

The water lowers the temperature, plus the presence of water itself helps delay pinking/knock by slowing the flame front.

It's very common in diesel tractor racing in the US (I kid you not), and IIRC, the RAF did some research into it back in the 40s for their supercharged engines.

WW2 aircraft actually used a 50/50 mix of alky and water from what i have read. Red dragon (P51 Mustang with a Griffin engine) ditched the original aftercooler and ran pure water/meth injection to cool the intake. also you have to remember that they ran a MASSIVE carb PRE turbo. wonder what effects that had on temps???

Cheers

Chris.

[900T-R]

When Saab did a simple pre-turbo water injection kit for the early Turbo's (basically a second washer/bottle pump, a nozzle and a box full of relays) it was said to be incompatible with having an intercooler - I think the reasoning was the water droplets/mist would condense to in the IC core again.

I'm sure the rationale behind pre-turbo water injection was mostly getting the compressor blades to atomise the water properly instead of needing a rather high pressure differential (=expensive, heavy water pump, especially back in 1980) to atomise the water into small enough droplets through a water injection jet (ERL specifies a minimum differential pressure of 3 bar with their jets). Of course, given the propensity of the purely oil cooled bearing housings to coke up the engine oils that were used at the time, anything to lower the temps inside the turbo would have been a bonus, too.
As mentioned, the downside of this simple water injection method was erosion of the compressor wheel blades.

[Boosted LS1]

chuntington101 said:

Thanks for all the coments guys.

I am intrested in PRE TURBO injection only. i am aware of the benifits to injecting water after the intercooler.

Boosted or anyone else thats tried it, i dont suppose you have any temps before and after injecting that water do you? also did you use water or meth or a mix? is there any advangtages to using either/a mix?

Matt, thanks for that i'll take a look on their site!

Cheers again,

Chris.

Hi Chris, I didn't log temps back then but I could feel the difference when the water was injected. The engine became much smoother and quieter, oh and it went quicker. I used water alone but a meths mix would be better imo and that's what I'll use next time around.

[annodomini2]

chuntington101 said:

Wedgepilot said:

I looked into this a few years back, and I'm pretty sure the best place to spray was just after the intercooler. The finer the spray the better, so powerful pumps running high pressure are the order of the day.

The water lowers the temperature, plus the presence of water itself helps delay pinking/knock by slowing the flame front.

It's very common in diesel tractor racing in the US (I kid you not), and IIRC, the RAF did some research into it back in the 40s for their supercharged engines.

WW2 aircraft actually used a 50/50 mix of alky and water from what i have read. Red dragon (P51 Mustang with a Griffin engine) ditched the original aftercooler and ran pure water/meth injection to cool the intake. also you have to remember that they ran a MASSIVE carb PRE turbo. wonder what effects that had on temps???

Cheers

Chris.

The merlin and griffon are Supercharged, but the effect is the same.