Water injection and race fuel?

macaws · 10-19-2005, 04:13 PM

Does anyone know what gains if any can be expected from water injection with say 100 octane fuel ? I know the position with 91 or 93 octane but does the same apply to higher octane fuels?

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bboy · 10-19-2005, 07:54 PM

Not a whole lot with something like c-16 which basically does not detonate. Remember there's no more energy in race fuel than pump fuel, just less likelihood of detonation.

offset · 10-19-2005, 09:52 PM

Quote:

Originally Posted by bboy

Not a whole lot with something like c-16 which basically does not detonate. Remember there's no more energy in race fuel than pump fuel, just less likelihood of detonation.

Any chance it could help lower EGTs at all (sorry if that sounds really stupid, just haven't thought it through)?

offset

Phil Jr. · 10-20-2005, 08:20 AM

aquamist says its will greatly help in-cylinder cooling. The only other thing that can do that is dumped fuel I think. My guess is better in-cylinder cooling = lower EGTs?

n2xlr8n · 10-20-2005, 08:21 AM

Quote:

Originally Posted by offset

Any chance it could help lower EGTs at all (sorry if that sounds really stupid, just haven't thought it through)?

offset

Definitely. It will lower EGTs, because one is forced to run more ign advance.

...and bboy...VP C16 will allow detonation, I promise.

S.

Davenow · 10-20-2005, 08:24 AM

Quote:

Originally Posted by bboy

Not a whole lot with something like c-16 which basically does not detonate. Remember there's no more energy in race fuel than pump fuel, just less likelihood of detonation.

You would still see benefits from reduced intake charge temps. Remember, cooler charge=denser charge. Denser charge= more power

dudical26 · 10-20-2005, 08:27 AM

I asked this question of Richard L, the guy from aquamist, and he said that it will help in cooling the intake charge and EGT, but that is about it when used with race gas.

Uncle Scotty · 10-20-2005, 09:19 AM

.....d0000ds....there is a B-I-G difference between 100 and c16.

W/A and 100 should be da bomb, if tuned properly.

Phil Jr. · 10-20-2005, 09:21 AM

should be expensive

hotrod · 10-20-2005, 10:12 AM

It depends on how much boost your setup can run. If your turbo can generate enough boost to reach knock limited power output on 100 + WI you would be making some serious power. It should be close to C-16 or possibly better.

If you are turbo limited so you do not need that sort of octane to reach the limits of your turbo, then it would be a waste of effort.

Larry

macaws · 10-20-2005, 10:57 AM

Thanks for the replies. My tuner does not believe in WI at all. Perhaps someone can do a dyno test on 100 octane fuel with and without WI-- if you chaps are right the results should convince him.

PS the turbo I have in mind is 700bhp capable--- certainly enough to test the limits of det on 100 octane fuel.

offset · 10-20-2005, 01:09 PM

Some tuners will never warm up to WI. I have developed the impression that it can have great results on Subies. Especially for those of us who do daily driving on pump gas for sure.

offset

DonkeyPunch · 10-21-2005, 12:08 AM

Quote:

Originally Posted by offset

Some tuners will never warm up to WI. I have developed the impression that it can have great results on Subies. Especially for those of us who do daily driving on pump gas for sure.

offset

It's the shizzle

DP

macaws, are you using just water, or running a mix, and what mix if you don't mind me asking. I am using methanol/water at about a 40/60 ratio. I love it much better than Denatured alc.

DP

Davenow · 10-21-2005, 01:25 AM

WI rules.
I am running SMC's setup 50/50 water/alchy.

Figure on in the area of 30whp on a "stage 2" STI once tuned.

Phil Jr. · 10-21-2005, 01:27 AM

Dave did you install that kit yourself....if so how difficult was it?

macaws · 10-21-2005, 02:58 AM

[quote=DonkeyPunch]It's the shizzle

DP

macaws, are you using just water, or running a mix, and what mix if you don't mind me asking. I am using methanol/water at about a 40/60 ratio. I love it much better than Denatured alc.

[quote]

I'm running nothing yet. I have a Rigoli Racing 2.35 short block on the way which I will run with race cams and the HKS T04Z turbo. Here in South Africa 100 octane leaded race fuel is the best one can get without importing special fuels at ridiculous prices--hence my question about WI specifically on a highish octane setup.

hotrod · 10-21-2005, 03:18 AM

WI needs to be used in a manner that is suitable for it. If you just throw WI on a car and make no tuning changes, you will likely see a small drop in power unless the car is already running hard enough that detonation is a problem and the ECU is pulling timing to protect the engine , simply adding WI will yield a small power gain.

There are basically two approaches to using WI ( with lots overlap between them).

First you can run it to add a cushion of safety from detonation and make little if any tuning changes. In that case your probably better off with an alcohol injection setup or at least a high alcohol content mix of water and alcohol.

Don't use more water than you need to give you a safety factor and your good to go. Add too much water and you are absolutely guaranteed to lose power due to the overcooling of combustion, especially if you are already running a tune that has a rich AFR.

If you lean the mixture out toward 11.5 - 12:1 you will see some advantage to the WI and still have a moderately safe tune if the WI quits on you.

The second approach is to use WI to raise the maximum cylinder pressures you can run without getting detonation. To do that you MUST tune for the WI. Typically you will add a couple of degrees of ignition advance and lean the mixture to a point that would be unthinkable without the WI.

This is the boundary that many tuners simply cannot accept or will not even attempt.
If done carefully you can lean a WI system to mixtures that would melt pistons on gasoline only and run safely and with much greater power on lower octane fuel PROVIDED the WI never has a problem.

If you lose the WI due to a clogged nozzle or failed pump or hose while under heavy load and boost it will very quickly kill the engine. Failure of the WI under light load and this sort of tune will still give you time to recognize you have a problem.

So bottom line you must decide how much risk you are willing to accept for how much power gain. WI tuned agressively will allow boost levels that can achieve a 50% to 70% increase in engine power. No that is not a typo!! but that is a very risky setup for the average user.

Most do a compromise between the two. They tune a bit more aggressively than usual as if for a fuel octane 10 or so octane numbers above your normal fuel. (ie a 100 octane tune on 91 octane), and take reasonable measures to prevent WI failure.

Some especially folks that live in very hot environments like the desert south west of the U.S. add WI and hardly change the tune at all. That gives them a car that runs like it is always a cool spring day, but if the WI fails they will probably not kill the engine.

It all depends on where you fit in that range of acceptance of risk and hunger for power.

Larry

DonkeyPunch · 10-21-2005, 05:46 PM

Kinda what larry said, you are effectively making say 91 or 93 octane fuel about 100 octane on a conservitive safe tune, that if you have a failure, you can either,
A. Not drive the car hard until you fix the problem.
B. Use a UTEC, and have a constigency map that runs with out WI or AI.

I have my normal no WI VF22 maps on slots 1 and 2 and water injection maps on 3, 4, and 5. That way if I lose the pump or whatever, I can disconnect my pressure solenoid that kicks on the pump, and just run without WI on the regular maps. This has already come in handy as I had a leak that took a while to track down.
I gained 30 HP and 30 Ft lbs on a dynapack on a EJ205 with a VF22, and am pushing 23 lbs of boost in 5th. That is about as far as I want to go pressure wise with this block and internals. So yes if you use the higher octane stuff with alcohol or methanol, you will effectively make the octane level that much higher. Be careful with leaded race gas as it will eventually ruin you 02 sensors.

DP

10-19-2005, 04:13 PM	#1
macaws Scooby Newbie Member#: 58433 Join Date: Mar 2004	Water injection and race fuel? Does anyone know what gains if any can be expected from water injection with say 100 octane fuel ? I know the position with 91 or 93 octane but does the same apply to higher octane fuels? * Registered users of the site do not see these ads.

10-20-2005, 10:57 AM	#11
macaws Scooby Newbie Member#: 58433 Join Date: Mar 2004	Thanks for the replies. My tuner does not believe in WI at all. Perhaps someone can do a dyno test on 100 octane fuel with and without WI-- if you chaps are right the results should convince him. PS the turbo I have in mind is 700bhp capable--- certainly enough to test the limits of det on 100 octane fuel. Last edited by macaws; 10-20-2005 at 10:58 AM. Reason: error

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10-19-2005, 07:54 PM	#2
bboy Scooby Specialist Member#: 56468 Join Date: Mar 2004 Chapter/Region: NWIC Location: Seattle, WA Vehicle: 04 Improved STI Dirty White	Not a whole lot with something like c-16 which basically does not detonate. Remember there's no more energy in race fuel than pump fuel, just less likelihood of detonation.

10-20-2005, 08:20 AM	#4
Phil Jr. Scooby Specialist Member#: 62221 Join Date: May 2004 Location: Montana	aquamist says its will greatly help in-cylinder cooling. The only other thing that can do that is dumped fuel I think. My guess is better in-cylinder cooling = lower EGTs?

10-20-2005, 08:27 AM	#7
dudical26 Scooby Specialist Member#: 37934 Join Date: Jun 2003 Chapter/Region: Tri-State Location: Northern NJ	I asked this question of Richard L, the guy from aquamist, and he said that it will help in cooling the intake charge and EGT, but that is about it when used with race gas.

10-20-2005, 09:19 AM	#8
Uncle Scotty * Banned * Member#: 16200 Join Date: Mar 2002 Vehicle: OK buy Nates beans westcoastroasting.com	.....d0000ds....there is a B-I-G difference between 100 and c16. W/A and 100 should be da bomb, if tuned properly.

10-20-2005, 09:21 AM	#9
Phil Jr. Scooby Specialist Member#: 62221 Join Date: May 2004 Location: Montana	should be expensive

10-20-2005, 10:12 AM	#10
hotrod Scooby Specialist Member#: 14141 Join Date: Jan 2002 Location: [email protected] @ 5800 ft on 13T Vehicle: 2002 Impreza WRX	It depends on how much boost your setup can run. If your turbo can generate enough boost to reach knock limited power output on 100 + WI you would be making some serious power. It should be close to C-16 or possibly better. If you are turbo limited so you do not need that sort of octane to reach the limits of your turbo, then it would be a waste of effort. Larry

10-20-2005, 01:09 PM	#12
offset Scooby Guru Member#: 32636 Join Date: Feb 2003 Chapter/Region: MWSOC Location: Dayton, OH Vehicle: 2004 Impreza STi Silver/Silver	Some tuners will never warm up to WI. I have developed the impression that it can have great results on Subies. Especially for those of us who do daily driving on pump gas for sure. offset

10-21-2005, 01:25 AM	#14
Davenow Scooby Guru Member#: 23676 Join Date: Aug 2002 Chapter/Region: NESIC Location: de_dust and Orgrimar Vehicle: .	WI rules. I am running SMC's setup 50/50 water/alchy. Figure on in the area of 30whp on a "stage 2" STI once tuned.

10-21-2005, 01:27 AM	#15
Phil Jr. Scooby Specialist Member#: 62221 Join Date: May 2004 Location: Montana	Dave did you install that kit yourself....if so how difficult was it?

10-21-2005, 02:58 AM	#16
macaws Scooby Newbie Member#: 58433 Join Date: Mar 2004	[quote=DonkeyPunch]It's the shizzle DP macaws, are you using just water, or running a mix, and what mix if you don't mind me asking. I am using methanol/water at about a 40/60 ratio. I love it much better than Denatured alc. [quote] I'm running nothing yet. I have a Rigoli Racing 2.35 short block on the way which I will run with race cams and the HKS T04Z turbo. Here in South Africa 100 octane leaded race fuel is the best one can get without importing special fuels at ridiculous prices--hence my question about WI specifically on a highish octane setup.

10-21-2005, 03:18 AM	#17
hotrod Scooby Specialist Member#: 14141 Join Date: Jan 2002 Location: [email protected] @ 5800 ft on 13T Vehicle: 2002 Impreza WRX	WI needs to be used in a manner that is suitable for it. If you just throw WI on a car and make no tuning changes, you will likely see a small drop in power unless the car is already running hard enough that detonation is a problem and the ECU is pulling timing to protect the engine , simply adding WI will yield a small power gain. There are basically two approaches to using WI ( with lots overlap between them). First you can run it to add a cushion of safety from detonation and make little if any tuning changes. In that case your probably better off with an alcohol injection setup or at least a high alcohol content mix of water and alcohol. Don't use more water than you need to give you a safety factor and your good to go. Add too much water and you are absolutely guaranteed to lose power due to the overcooling of combustion, especially if you are already running a tune that has a rich AFR. If you lean the mixture out toward 11.5 - 12:1 you will see some advantage to the WI and still have a moderately safe tune if the WI quits on you. The second approach is to use WI to raise the maximum cylinder pressures you can run without getting detonation. To do that you MUST tune for the WI. Typically you will add a couple of degrees of ignition advance and lean the mixture to a point that would be unthinkable without the WI. This is the boundary that many tuners simply cannot accept or will not even attempt. If done carefully you can lean a WI system to mixtures that would melt pistons on gasoline only and run safely and with much greater power on lower octane fuel PROVIDED the WI never has a problem. If you lose the WI due to a clogged nozzle or failed pump or hose while under heavy load and boost it will very quickly kill the engine. Failure of the WI under light load and this sort of tune will still give you time to recognize you have a problem. So bottom line you must decide how much risk you are willing to accept for how much power gain. WI tuned agressively will allow boost levels that can achieve a 50% to 70% increase in engine power. No that is not a typo!! but that is a very risky setup for the average user. Most do a compromise between the two. They tune a bit more aggressively than usual as if for a fuel octane 10 or so octane numbers above your normal fuel. (ie a 100 octane tune on 91 octane), and take reasonable measures to prevent WI failure. Some especially folks that live in very hot environments like the desert south west of the U.S. add WI and hardly change the tune at all. That gives them a car that runs like it is always a cool spring day, but if the WI fails they will probably not kill the engine. It all depends on where you fit in that range of acceptance of risk and hunger for power. Larry

10-21-2005, 05:46 PM	#18
DonkeyPunch Scooby Specialist Member#: 18987 Join Date: May 2002 Chapter/Region: NESIC Location: Griswold, CT Vehicle: 2014 Forester Dark Grey Metallic	Kinda what larry said, you are effectively making say 91 or 93 octane fuel about 100 octane on a conservitive safe tune, that if you have a failure, you can either, A. Not drive the car hard until you fix the problem. B. Use a UTEC, and have a constigency map that runs with out WI or AI. I have my normal no WI VF22 maps on slots 1 and 2 and water injection maps on 3, 4, and 5. That way if I lose the pump or whatever, I can disconnect my pressure solenoid that kicks on the pump, and just run without WI on the regular maps. This has already come in handy as I had a leak that took a while to track down. I gained 30 HP and 30 Ft lbs on a dynapack on a EJ205 with a VF22, and am pushing 23 lbs of boost in 5th. That is about as far as I want to go pressure wise with this block and internals. So yes if you use the higher octane stuff with alcohol or methanol, you will effectively make the octane level that much higher. Be careful with leaded race gas as it will eventually ruin you 02 sensors. DP