Go Back   waterinjection.info > Injection Applications (making it work) > Competition Specific

Thread Tools Display Modes
Old 22-11-2003, 06:57 AM
Forum Admin Forum Admin is offline
Senior Member
Join Date: Oct 2003
Posts: 127
Default High water flow - high EGT applications?

I have never done this but I have heard of some drag racers tuning by setting flow of water/methanol high to bog the engine, pulling back a little then leaning to the point of some pretty high EGTs. Of course this is only for 10 seconds but always sounded kind of aggressive to me. Also does not sound like it is for the meek. Just curious whether anyone here has done this or if there are any other specific drag race tuning applications that wouldn't apply in other situations.
Reply With Quote
Old 22-11-2003, 11:59 PM
AKWRX AKWRX is offline
Join Date: Oct 2003
Location: Juneau, Alaska
Posts: 32

Yes, this has been a common technique that has been used for many years on very, very high HP street and drag applications with alcohol, or a water mix injection system. It is about all that can be done when using an after market fixed map piggy-back chip. The turbo Buick and super charged Ford applications come to mind. With no programmable engine management, or data logging capability, it is about the only way to tune for max power. Crude compared to what can be done with more current electronic management hardware, but effective none the less.
Reply With Quote
Old 09-02-2004, 09:03 AM
hotrod hotrod is offline
Senior Member
Join Date: Oct 2003
Posts: 307
Default slow and methodical

Just like folks can road tune an ECU rather than do it on a dyno, if you take your time, and methodically make small incremental changes you can over time dial in a very agressive system.

You description leaves a bit out though, its not just a single pass process.

Basically you start with a stable tune and gradually make small additions/changes while closely monitoring all the available information.

Remember until recently, people did not have the luxury of buying affordable wideband O2 monitors or even logging engine operations. They had to pull and read plugs, watch drag strip times, use their butt dyno sense of how the engine was running, did it have snap, or was it a bit flat. Get knowledgable friends to listen to the car as it went through the traps and then make sense of all the little clues.

Come up with a best guess of where they were, make a small change in the direction they wanted to go, and then do it all again. For folks who didn't live at the drag strip it might take a full season of tinkering to get the system dialed in to 90% of where they wanted to be. Then another season to get that last 10%

The system is much like the basic process of dialing in a new engine and carburator or distributor before all the magic diagnostic resources were availble.

From the basic safe street tune they added water until the engine sounded and acted "soggy" fiddle with the turn on point a bit to find where they "needed" the injection to come on, and where the engine "liked" it to come on.

Then they started adding boost in small increments. If the added boost cleared things up, then when they got close to detonation, they would add a bit of timing or subtract a bit of timing, or subtact a bit of fuel or add a bit and see if things improved or got worse. If the move was good, then they would add or subtract a bit more. They would basically baby step their way towards an agressive tune. First adding boost, then changing ignition timing, then tweak the air fuel a bit. When they were to the point the could make no more improvements, they would start over adding more water. If they developed a flat spot or other rpm dependent problem they would then fiddle with the turn on point or jet location of the injectors. Some times going to multiple staged injection, where one set of jets came on at one boost level and another came on at a higher level.

One of the advantages of this process is you learn how the car behaves if it has more ignition timing or fuel or boost than it wants, so you become better at reading the behavior when all other means of diagnosis fail.

Reply With Quote
Old 01-05-2004, 08:34 AM
Super Diesel Super Diesel is offline
Junior Member
Join Date: May 2004
Location: Westminster, CO.
Posts: 2

Hey hotrod, I will be running a (yes I said it) hotroded diesel this summer at the drags with water injection and N2O. I can't add any extras like methonol because my timing is already so far advanced. It will predetonate, so i'm using it for cooling. Any suggestions? Super Diesel
Super Diesels on Biodiesel, need I say more?
Reply With Quote
Old 02-05-2004, 02:56 AM
hotrod hotrod is offline
Senior Member
Join Date: Oct 2003
Posts: 307
Default NO experience

To be honest with you I have no experience with how diesels behave with W/I. Since a diesel is always over supplied with air and the throttle occurs on the fuel side, I'm not sure how much effect intake charge air cooling will make a difference, or how much water they can accept. My impression is that the tractor pull folks use it mostly to hold down EGT's.

This paper implies that the presence of water may delay the ignition event slightly, although this is an experimental direct injection model of the combustion process, it may be useful.


This page also comments on direct injection for emissions control and suggests a water / fuel ratio of .4 - .7

This web page has a guy who says he pits for a tractor pull and will explain how to set up a water injection system. It might be useful to touch base with him and pull him into this forum for everyones edification.


I'll keep looking around and see what else I can find.

Reply With Quote
Old 08-12-2006, 08:30 PM
Prometeus Prometeus is offline
Join Date: May 2005
Location: Zelo Buon Persico
Posts: 50
Default Tractor pull

Hi all,

in tractor pull were used to prepare mixt up to 70% of Methanol.

Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT +1. The time now is 10:25 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2022, Jelsoft Enterprises Ltd.