can i do damage?

[GTO]

sorri for the nub question guys, but i recently purchased a alky injection kit off of ebay. i didnt find out about this site until after i bought the kit. anyways my real question is can i do any damage to my motor? i have a data logger for the car and this set up will be used in a 1994 3000GT VR-4. im just curious, if the system can spay to much water/alky into the intake charge, and hurt the engine.

oh btw its not a progressive kit, it just has a boost switch, after a preset boost is reached it just activates.

thanks for any help and again sorry for the nub question

alex

[hotrod]

The answer is yes and no to be honest!

Anytime your modifying a high power car, some risk of mucking things up exists. Some are better at anticipating risk than others so its hard to say without knowing how you approach problems.

A quality kit that will not leak huge amounts of water into the plenum when shut off, will not hurt the engine by spraying too much water. The amount of water a running engine can digest is simply beyond most peoples comprehension. Pratt and Whitney Aircraft ran "flood" tests on those WWII supercharged aircraft engines and they could dial the water spray up to the point that liquid water was pouring out the exhaust headers and the engines continued to run without problems (although making only about 1/3 the normal rated power).

The only reasonable risk you have for "too much water" and damaging the engine is "hydrolocking" the engine by having a system that is layed out improperly and will siphon large amounts of water into the intake when shut off. Some early systems used engine vacuum to pull the water in, and under some conditions they would set up a siphon action and drain the entire water reservoir contents into the intake when they were parked. That would fill the first cylinder to open its intake with a slug of water and "munch" bent rods and broken pistons followed quickly.

When tuning remember to use the most conservative approach, ie before you pull out water, back off boost, timing or add fuel so you always start from a safe side of opreation and work your way up to a more agressive tune.

The guys with the Grand Nationals and other home brew systems that were developed before all the fancy tuning electronics used a very simple and pragmatic approach.

First they gave the engine a good tune on just gasoline and found the line they could not go beyond on their normal fuel. They would then start adding WI with no tuning changes until the engine felt "soggy" ie it lost its edge and didn't have sharp throttle response due to excess water for the tune. Then they would gradually add timing advance, lean the mixture or add boost (doing only one at a time) until the engine cleaned up and started to pull hard again. They would keep pushing the tune until they begin to see signs of problems. then they would work the cycle again, by adding more water etc.

Doing it that way is a slow methodical process but will get you a razor sharp tune if you do it right.

A dyno is nice but not necessary.

Remember there is only one proper ignition timing for a given tune, where rather large changes in fuel mixture do not change power all that much when your near peak power. (there is only a couple of % change in power all the way from the high 11:1 AFR ratios to the low 13's on NA engines)

Find a mixture that is a good solid starting point, - usually around 12.5 for a NA engine, - find the best timing on that mixture for max power. Be slow to add timing, fiddle with mixture and boost first, then tweak the timing every now and then. As you add water spray rate the engine will nearly always want just a couple degrees more timing, but not a lot 3-4 degrees is about all the extra advance you are likely to need.

use the least ignition timing that will get you within about 1-2% of max power. That is the safe side of the tune, over advance gains you very little except very high cylinder pressures, blown head gaskets, and beat up bearings. Make most of your power with boost and leaning the mixture if you are on a forced induction system. On NA mostly lean it out and then add ignition advance as a last step.

If you give it a chance the engine will tell you what it wants.

If you add 2 degrees of timing and nothing much happens your probably already too far advanced. If you pull timing and power is basically unchanged you are almost certainly too advanced. If you pull a couple of degrees of timing and you just begin to see a drop in power you are very close to best timing.

On fixed single stage (non-progressive) systems, most of us trigger boost somewhere near 10-12 psi. Pick a boost level that has the engine under good load but a couple psi below the lowest boost that can cause detonation on your engine /setup. If you trigger too early it can bog the engine. You want to have enough load on the engine that it can use the water but could get by without it if it had to.

Larry

[GTO]

hey thanks alot man, i was pretty much worried about doing damage to the motor by using to much water/alky. btw this is the kit i bought.

http://cgi.ebay.com/ebaymotors/WATER...QQcmdZViewItem

seems like a pretty ok kit, i dono well see, ill be using a 600cc nozzle.