The fact you are ignoring is that the "stock" afr is "rich as hell" when the car pulls timing AFTER it detects engine knock, or is reaching its pre programmed IAT/MAT limits that pull timing to prevent potential engine knock.

Thus, the meth, while making the car "rich"... is the lesser of 2 evils... I would rather be rich making full HP and no knock and running cooler, VS, how I would be rich, making 100 to 200 less HP and might have just experienced knock which put me in the rich situation.

Meth's induced richness, is the lesser of 2 evils of richness, and i believe it can be done in a way where the car is "less rich" than when the car pulls timing and is "very rich" with its stock tune knock prevention programming.

So this stuff about protecting the cats, etc, is a moot point to me. The car is already running rich... and making less power. The cats are fine.

And if the cats fail, take it to the dealer, get some new ones under warranty, the end.

And this is why i say, have the meth come on ONLY when a person is hitting these red zones.. that way, you arent running rich at times... when your car would not be about to run rich anyway.

 

Maybe, maybe not. A buddy of mine (who held three "land speed" records before he stopped racing, including one in the "fuel" category when running pump gas), came to the conclusions that straight water injection retarded the burn rate, so timing needed to be advanced to make up for that. I independently came to the same conclusion, using straight water through about ten years of experimentation. I did those experiments, because I found it interesting to see how far I could go with water alone.

On about ten pounds of boost, water injected at about 10 GPH didn't give a "seat-of-the-pants" decrease in power, but it showed up, without advancing the timing, on the engine dyno. Advancing the timing, we could get it all back, without going into detonation.

With nitrous, pushing the horsepower from 840 with the blower alone, to around 1025 with the nitrous, the decrease in timing needed for that level of nitrous turned out to be a good balance for the increase in timing needed for the water injection, so that's where we stopped. The vehicle was already crazy fast, fast enough that I never flat-footed it for more than ten seconds at a time. Or maybe it was more like 8 seconds, or four. Lots more investigation could be done.

 

Good luck getting new cats or any engine warranty with a meth kit hanging under the hood your forgetting this minor detail!

 

I join him and do not see any of your logic! Which is wild and off base 90 percent of the time. Running a meth kit on a stock car with no tune is too FUNNY Then with expecting to get by on warranty while being concerned about no warranty from not tuning? Then the on the break down you have the know your tech EXCUSE???

Great satire you supply to the forum!
Your making no sense.

 

Mike,
See what you are trying to achieve and it makes sense once you figure out the magic ratio. It is similar to those that run E. There is a magic point where if you stay less than a certain percentage, I think 15% you don't need any tuning. In 2012 the Feds/EPA said any vehicle newer than 2001 could use E15, even though most pumps only blend in 10%. Getting back the water/meth usage, I see the IATs as a trigger for spraying but you need a second input. High IATs in and of themselves are bad if you are just cruising down the highway where max HP/TQ is needed. You would need a certain IAT and maybe a MAF/MAP/RPM or throttle position to be set as well. You would not want the water spraying while sitting at idle where it could just puddle in the air intake due to lower air flow needed for the engine. In my set up it kicks in off the MAF, but I am using other mods for my set up. Looking at methanol and premium fuel, obviously methanol has a higher octane or AKI (anti-knock index). Methanol has an octane rating of 98 v. 91-93 for fuel. If the 2017+ Zs that were factory set for 93 octane fuel and you have only 91 available, the extra octane may not be an issue. Remember that octane rating is on 100% meth, it will be even less with water mixtures.
This is a good discussion and we may get somewhere in Mike's quest for the answer.

 

While Mike may not be very delicate in his delivery, he does seem to have an extraordinary level of comprehension for mechanical things. You appear to have neither.

 

Appears that way to you because you have no idea what is going on! Besides a troll needs something to add!

 

Sure! Poor poor pitiful me!

 

Lot of gibberish in a single paragraph. You should stop degrading others postings to for grammar error's and go back to school you have no room to talk! Plus find below is the actual topic of the thread!
[QUOTE=OilfieldVette;1597697811]Quick answer. Do i need to tune my Z after installing math injection?[/QUOTE
..

 

 

 

You have no clue about Meth injection or E85 but yet you still chime in with false facts...

Those were not "informed" facts..LOL

It's probably best for you to read the articles first. The first article does not back up your claims if your running a 50% or lower content of Meth....The second article is for running pure Methanol not water/Meth injection.

So here is some advice.... Educate yourself first before you wrongly educate others.

 

I dont doubt you or your buddys results.
This is an example of one answer doesn't fit all. You or your buddy's results probably are not from running a stock Z06 without any modifications?

I answered the question the OP asked. Which was on a stock C7 Z06 what is the sweet spot (best ratio) of meth to water WITHOUT a tune.

Here is the difference. Your buddy probably had a vehicle that had an optimum tune and then added water. This scenario will of course require an adjustment of the timing to gain any power from just spraying water into an engine that is running optimally.
In other words your buddy's car wasn't reducing timing due to high IATs. In the scenario you presented your buddy wasn't trying to solve an issue...he was looking to add power.

In the scenario presented by the OP we are trying to recover timing in a stock Z06 with a stock tune that the PCM has taken away (or takes away) once the IAT/MAT gets to high.
In this case spraying water is allowing us to reduce the IATs to a level where the original tune allows full timing. No tune required in this scenario and yet power can be recovered or retained on an otherwise stock car.

This is different from your buddy who added water to an engine that was otherwise fine (not retarding timing). In this case, unless he tuned to get additional timing on top of where he begin, (you are correct) he wouldn't see much gain from water alone.
This is because water isn't fuel and brings nothing to the party other than its ability to cool and increase cylinder pressure from steam/vapor created when it is introduced to the hot combustion chamber. Without tuning this could actually lose power depending on how much water is sprayed and other characteristics of his set up. So again you and he are correct. However if he had tuned AND in this process was able to add additional timing he may have seen more power from water alone. If he did this and didn't/couldn't get any increase in power by adding timing then his set up was already optimum (maxed out for timing) to begin with and he didn't need additional cooling to run max timing advance.

This is the key. The purpose of the water is to allow one to run max timing the engine can stand or recover timing the PCM will not allow because the engine is on the threshold of knock based on the IAT/MAT.
If you can run max timing without losing power to high IAT/MAT with extended periods at WOT you dont need to spray water or meth and you dont have an intake charge cooling issue.

The Z06 can run into intake charge cooling issues on hot days or when run hard for extended periods. And therefore CAN take advantage of the 20 to 40* drop in IAT/MAT that water injection can provide.

Your experiences are in line with what has been proven and known for years. However they dont apply to this discussion.

This discussion and my answer is strictly related to what ratio of meth to water is best to use on a stock C7 Z06 to recover timing if you do not want to tune.

And that answer is 100% water.
If you are willing to tune or you are talking about a modified Z06 or another vehicle this may not be the answer.

I have worked with and studied water/meth injection on and off since 1985 (my non inter-cooled 300zx turbo and my friends T type Buick began the saga).

 

The stock AFR is not "rich as hell." Would you care to state your source for this conclusion?
The stock AFR on a Z06 is 12.1 to 12.4 unless the EGT gets hot and COT protection is activated. (which is one purpose for water or meth injection.)
This AFR is within the norm for a factory FI DI engine and isn't considered overly rich. (Technically you should be using Lambda since you are discussing mixing fuels).
Most tuners wont share the AFR where they make the most power on a stock Z06 but you can be sure it isn't far off the factory and some run even richer.
So no the Z06 doesn't run "rich as hell" unless COT is activated or IAT/MAT gets hot.

Which brings me back to the point.
You can achieve what you are trying to achieve without Meth. You can do it with 100% water.
With 100% water alone you can stay out of COT therefore retaining the factory AFR AND keep IAT/MAT low enough to avoid timing being pulled.

I gave you the answer that gets you to your desired result ("making full HP and no knock and running cooler").
You can do this WITHOUT meth (and the added expense) OR a tune OR running richer. The best of all worlds if you want to run the stock tune.
You can probably achieve your goal doing it the way you suggest but there is no need to go through all that trouble if you intend to run the stock tune as you originally stated.
But you will be running richer than if you use 100% water.

 

Jeez, lots of half truths and just plain false information rolling around in here. Just a few comments directed at nobody in particular...

- COT is based on a calculated temperature, spraying meth or water WILL NOT prevent you from going into COT because the computer has no idea what you are doing and it's not based on intake air temps.
- The Z06 will always go into COT within 5-10 seconds of WOT at normal operating temperatures, clearly evident on just about every stock dyno pull if up to temp and it will drop the AFR into the 10s.
- Spraying 100% water will cool down combustion temps and help prevent detonation but without adjusting timing it will also SLIGHTLY drop horsepower assuming no knock or timing retard in the first place.
- Spraying 100% meth will always make more power for the simple fact that it's an ~50 oxygen enriched fuel source and high octane allowing more timing, etc.
- Even a small M5 nozzle on a typical meth kit will drop your AFR a solid half a point to a full point with 100% meth, combined with COT I wouldn't be doing it that's for sure with a stock tune.
- If you are spraying meth, tune your car for it. If you are concerned about warranty, leave your car alone and just drive it you will be fine.

 

Finally someone with some knowledge of tuning these cars day in day out. Thanks NicD!

 

- COT is based on a calculated temperature, spraying meth or water WILL NOT prevent you from going into COT because the computer has no idea what you are doing and it's not based on intake air temps.

1. I am aware of COT being calculated (I think I eluded to that in a previous post). However the prediction algorithm does take temperature into account. Both IATs, both MATs, fuel flow MAF and ECT. If it doesn't how else would you calculate EGT? To calculate EGT you need air density. To get air density you need temperature. So I submit that the PCM does know what you are doing.

- The Z06 will always go into COT within 5-10 seconds of WOT at normal operating temperatures clearly evident on just about every stock dyno pull if up to temp and it will drop the AFR into the 10s.

2. Never said it didn't. All I said is the AFR is not set rich unless it goes into COT. The base AFR in the stock Z06 tune is 12.1 to 12.4 depending on rpm. I will say it takes longer to get into COT on the street than on a dyno and I have made 0-125 mph pulls on the road without entering COT. Admittedly the next pulls where COT all the way.

- Spraying 100% water will cool down combustion temps and help prevent detonation but without adjusting timing it will also SLIGHTLY drop horsepower assuming no knock or timing retard in the first place.

3. This is normally true but not accurate when applied to a Z06. The reason is during high outside temps or after a some time at WOT the Z06 gets hot and the PCM will adjust the timing solution down (pull timing). The introduction of water as you stated "will cool down combustion temps and help prevent detonation". When this occurs the PCM will adjust the timing back to the lower IAT/MAT portion of the timing tables based on the lower temps the water brings them down to. In effect doing as you suggested "adjusting timing" or allowing for more timing to be retained or pulling less timing.
The point is you are 100% correct when you add 100% water to an engine that is not pulling timing or detonating to begin with. But if you add water to an engine that is prone to pulling timing already (running exaggerated IAT/MAT) you will/can recover that timing, up until where you reach the max timing programmed into the timing tables for the IAT/MAT the water brings you down to.

- Spraying 100% meth will always make more power for the simple fact that it's an ~50 oxygen enriched fuel source and high octane allowing more timing, etc.

4. This is not always true. The theory is correct however as you stated when you spray meth the AFR richens. If you spray to much and the AFR goes to rich you can and will lose power.
Point here is you should tune for meth if using meth. If you dont there is no guarantee you will get increased power. Generally if you drop more than 1 point in AFR due to meth you will lose power.

- Even a small M5 nozzle on a typical meth kit will drop your AFR a solid half a point to a full point with 100% meth, combined with COT I wouldn't be doing it that's for sure with a stock tune.
5. Exactly thats why I have said till I am blue in the face. On a stock Z06 if you want to inject coolant AND not tune the answer is 100% water. Water will not have a huge affect on the AFR yet cool you enough to recover the "pulled timing" and power.

- If you are spraying meth, tune your car for it. If you are concerned about warranty, leave your car alone and just drive it you will be fine.
6. Well said.......however many folks want the best of both worlds. Most often we cant eat our cake and have it as well. But there are times when we can have 90% of both. If you use 100% water you can keep 100% of the timing in the factory tune, retain factory rated power, not affect your AFR and possibly not affect your warranty.

 

 

Words to the wise!

 

Ahh, the difference between somebody who has done it and somebody who is guessing. You have no idea at all how CAT TEMPERATURE (not EGT) is calculated in the ECM. On the other hand it's very simple to see when all you have to do is scan catalyst temp on a back to back pull spraying meth and then not spraying meth and see that it doesn't change and it kicks in right at the same time.

What it's set to in the PE table is irrelevant when the calibration guy is handed a MAF table that he has to use and he plugs in whatever number produces the desired AFR in that table. Every single stock one I've seen runs in the mid-high 11s AFR until COT kicks in 5-10 seconds later and then it's buried in the 10s.

Again, the difference between somebody guessing and somebody who has actually done it. The IAT2/MAT is pretty much unaffected when spraying water or meth and it has nearly the same rise even with an M15 nozzle on there. Cooling down combustion temps vs cooling down the IAT2/MAT is the difference and why it applies to the Z06.

Yes it is, it's not theory it's done almost every day. Just today I had a ZL1 1LE on the rollers and after dialing it in without the meth I turned it on and made a pull with NO OTHER CHANGES and it picked up 15+ rwhp and rwtq. Same timing, just down into the mid-high 10s for AFR from a 12.0. When you are spraying something into the engine that is composed of 50% oxygen it doesn't have a choice but to increase in power. Of course if you spray enough that it goes off the chart and floods it you are going to lose power and lose a motor in the process.