N/A water injection question

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Turbo231
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N/A water injection question

Post by Turbo231 » Tue Jun 26, 2018 2:23 pm

I am building a stroked LS2 engine (403 cid) for street/strip and want to run 13:1 CR, naturally aspirated. Has anyone used water injection on an N/A engine and been able to run 93 pump gas with that much compression? I can find a lot of info on water injection for supercharged and turbo motors but not anything on high-compression N/A. Any suggestions?

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Re: N/A water injection question

Post by mag2555 » Tue Jun 26, 2018 2:54 pm

13 to 1 on the street with 93 pump fuel?!
You had better put a tow package on the car because you will need to tow a good size swimming pool behind you as you will need the water injection on all the time!

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Re: N/A water injection question

Post by Turbo231 » Tue Jun 26, 2018 2:59 pm

mag2555 wrote:
Tue Jun 26, 2018 2:54 pm
13 to 1 on the street with 93 pump fuel?!
You had better put a tow package on the car because you will need to tow a good size swimming pool behind you as you will need the water injection on all the time!
Cam has long duration and will be retarded to get dynamic compression down to reasonable value.

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Re: N/A water injection question

Post by tresi » Tue Jun 26, 2018 7:24 pm

This is what I was wondering, though not to your extremes, when I started my post that got 7 pages of replies. Thanks guys. What I got out of it and other sources was you'll get a little help on a hot day but not much.

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Re: N/A water injection question

Post by Frankshaft » Tue Jun 26, 2018 7:46 pm

Turbo231 wrote:
Tue Jun 26, 2018 2:59 pm
mag2555 wrote:
Tue Jun 26, 2018 2:54 pm
13 to 1 on the street with 93 pump fuel?!
You had better put a tow package on the car because you will need to tow a good size swimming pool behind you as you will need the water injection on all the time!
Cam has long duration and will be retarded to get dynamic compression down to reasonable value.
Isn't that kind of counter productive? Band aid and take away from one, with the other, and not really taking advantage of either, might wash itself, and you could have ran a more appropriate cam and compression and it could work better. See what I am saying? But it might work. You could try it. Worst case scenario is you switch it over to e85.

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Re: N/A water injection question

Post by stealth » Tue Jun 26, 2018 9:38 pm

Try it....

There is always the E85 option
The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore, all progress depends on the unreasonable man.

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Re: N/A water injection question

Post by user-23911 » Wed Jun 27, 2018 2:04 am

If it's an LS2 then it's already injected.

All you really need is something like an AIC (auxiliary injector controller).
Essentially you take the signal from one of the existing injectors, the box amplifies it and uses it to drive as many extra injectors as you like.Preferably one per cylinder but one or two will do for starters.
Then you need a tank, pump, injector and regulator to copy a normal fuel system but using water instead of fuel.
Then think about long term effects of corrosion.
Also think about how to disable it under low load (TPS input).

Really the only limitation is your imagination.
Apart from the usual haters who like to say it'll never work.

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Re: N/A water injection question

Post by KnightEngines » Wed Jun 27, 2018 2:59 am

Call me an idiot, but I reckon you're ok at 13:1 in an LS with pump swill.
I've run our pump 98 (roughly equivalent to your 93) at 11.7-12:1 with iron heads & carby fed street engines.
They get better fuel for racing, but on the street on street tyres you'll struggle to load it enough to ping unless you like blasting at high speed on the highway - it'll just smoke the tyres.
Knock a degree or 2 out for street driving & run it.

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Re: N/A water injection question

Post by Geoff2 » Wed Jun 27, 2018 4:56 am

Snow Performance should have what you need.

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Re: N/A water injection question

Post by Turbo231 » Wed Jun 27, 2018 8:39 am

Frankshaft wrote:
Tue Jun 26, 2018 7:46 pm
Turbo231 wrote:
Tue Jun 26, 2018 2:59 pm
mag2555 wrote:
Tue Jun 26, 2018 2:54 pm
13 to 1 on the street with 93 pump fuel?!
You had better put a tow package on the car because you will need to tow a good size swimming pool behind you as you will need the water injection on all the time!
Cam has long duration and will be retarded to get dynamic compression down to reasonable value.
Isn't that kind of counter productive? Band aid and take away from one, with the other, and not really taking advantage of either, might wash itself, and you could have ran a more appropriate cam and compression and it could work better. See what I am saying? But it might work. You could try it. Worst case scenario is you switch it over to e85.
I definitely understand what you are saying about it being a compromise with high CR and retarded cam. That's why I am asking these questions. Need other peoples opinions. I have already been thinking about E85. I have several friends with turbo cars running E85 but no NA cars running high CR.

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Re: N/A water injection question

Post by Turbo231 » Wed Jun 27, 2018 9:03 am

While I am asking about my LS2 combo, what is the highest CR that I can safely run with 93 pump gas and not use water injection? I will still be running a long duration cam but not so far retarded. Also, what CR can I run if I go E85?

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Re: N/A water injection question

Post by tresi » Wed Jun 27, 2018 10:30 am

I won't run 13 to 1 on 93 octane, E85 I'd try that on real E85 but not average pump E85.

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Re: N/A water injection question

Post by Frankshaft » Wed Jun 27, 2018 1:12 pm

Turbo231 wrote:
Wed Jun 27, 2018 8:39 am
Frankshaft wrote:
Tue Jun 26, 2018 7:46 pm
Turbo231 wrote:
Tue Jun 26, 2018 2:59 pm


Cam has long duration and will be retarded to get dynamic compression down to reasonable value.
Isn't that kind of counter productive? Band aid and take away from one, with the other, and not really taking advantage of either, might wash itself, and you could have ran a more appropriate cam and compression and it could work better. See what I am saying? But it might work. You could try it. Worst case scenario is you switch it over to e85.
I definitely understand what you are saying about it being a compromise with high CR and retarded cam. That's why I am asking these questions. Need other peoples opinions. I have already been thinking about E85. I have several friends with turbo cars running E85 but no NA cars running high CR.
That is pretty much the only thing e85 is good for in my opinion. The government subsidizes it, and it actually costs more to make than they sell it for. It works great as cheap race fuel. Might as well take advantage of it, since you are paying for the subsidized costs in your taxes. It works great in high commission street cars. Or boosted.

But like said above, you need to check it from the pump. In the summer months, it's usually at least 85%. Some places I have seen higher.

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Re: N/A water injection question

Post by nabx22 » Wed Jun 27, 2018 1:46 pm

We run a 13 to 1 bbc on e85 from the pump it usually test at 75 % we never have any problems

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Re: N/A water injection question

Post by FC-Pilot » Wed Jun 27, 2018 5:53 pm

I have run 13 to 1 in iron headed bbc’s a few times on pump e85 without any problems. If not a daily driver I can’t think of a reason not to run it in your application. But that is just my personal opinion.

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