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Originally Posted by 86saleen13
I have an '86 Mustang 5.0, Speed Density, SN89 SC w/6 psi @ 5700rpm. I have NO monitoring equipment at all - actually I just ordered my boost gauge. I put a coolingmist 150psi kit on my stang a couple days ago and ran about 64oz of water through it. The WI starts injecting at 2750 rpm. Today I mixed 50/50 Meth and water and put in.
I have no knock alert on the car. I am getting some detonation at about 4300 RPM in 4th gear/ with 12 deg. of timing. I have backed the car down to 10 deg and will drive it again later.
Now as for tuning - where do I begin? I read alot of posts and its all strange to me. I dont have any idea what all your terms are (EGT, AFR...) I am going to order the MSD Knock Alert and a timing retard - this should help out. And what about spark plugs and MSD ignition boxes? Will these help detonation? I read about cooler plugs - can I get at autozone?
I could ramble on for along time about this - so confusing :shock:
HELP!! :?
Ed
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In order to get the best out of an engine, you need the two following conditions:
1) good air/fuel ratios (afr) - too lean afr will make the car misfires as the mixtute is not easy to ignite.
2) Accurate ignition timing. Too advance will make the engine ping and too late will loose power.
I suugest you to tun the car wothout WI first and then trim the above two again after the introduction of WI.
Since the Coolmist kit only makes its delivery to boost pressure without the referenece to RPM, then you may need to put more work into tuning both afr and tiimng since the WI is not related to fuel delivery (easier to predict). Nevertheless, it can be done.
Adding methanol will make the matter slightly more involved as methanol is also a fuel, tuning for accurate afr requires more work especially you are coolmist does make its delivery to fuel flow.
Here is some help regards to tuning with WAI:
The following charts are calculated based on:
10Kg of air, Gasoline's latent heat capacityof
350KJ/Kg
Water's latent heat capacity of
2256KJ/Kg
Methanol's latent heat capacity of
1109KJ/Kg
Injection water at different ratio to fuel at 100% water and 75% Water/25% Methanol. You can see the at 100% water injection, only 3% of w/f fuel ratio is enough to replace 2.5 point of a/f ratio (dotted line). As soon as 25% of Methanol is added, the a/f ratio is dropprd to 12.0 - loosing some cooling capacity
Each of the following chart show a 25% percent increase in Methanol concentration of the mix.
lastly, just methanol is added and no water. The chart on the right is 100% water
The two charts show (first and last) that you will require to inject twice the amount of methanol to equal the latent heat of water alone. Methanol is relatively low cost and very effective as a coolant so what is the problem?
When higher concertration of methanol is injected, you need to lean your engines a/f ratio to accomendate the extra fuel or your engine will bog down and loose power. Consequentially - one runs the risk of putting the engine into heat stress if the supply of methanol is suddenly interrupted. Injecting water does not affect the a/f ratio. It appears that 50/50 mix has the best of both worlds.
In either cases, having a good w/a injection system with reliable "system fault" diagnostic capability is essential especially if you are running a high concentration of Methanol.