MB-CLS500

I have ecu tune car made 500 whp with just ecu tune . I am installing custom downpipes with x pipe and muffler delete so its gonna be straight pipe ( no emission laws in my country ) after downpipes they will retune my ecu . AND I want too cool this V12TT engine As much as I can so Do u recommend NOS?? before turbo comopressor wheel? or before thortle body?

SL65MONSTA

im a little lost on the e85, so you mean to say no tune needed or any tweeking other then bigger injectors

ZephTheChef

It's entirely possible that you are correct, with most of the heat having already been pulled out of the air. In fact my calculations in that last post were significantly off, because I forgot to scale back the airflow to a 10-second run. So it actually would have cooled 6x as much as the 12.8 degrees I came up with in that example. I knew it sounded even way lower than I was anticipating, but I didn't stop to redo the math and see why. I will edit the other post with the corrections.

You're absolutely right about me never having done it. I don't like mods that require expensive consumables to operate. Ice and water/meth is bad enough, even being as cheap as it is. I would consider it on the S600 though, since things get real expensive lump sum if you want to make that kind of power any other way.

Overall though, it depends on the HP of the car without the nitrous. I would be very careful with that if your IAT is used at all in the computer tune. If you are seeing IAT drops that low from a 50 shot they are artificial unless we're talking about a car that makes (without the nitrous) 230-320hp depending on what the humidity was during your 50 degree drop. If that sounds relatively close to what you expect out of your car then don't worry about it. Otherwise I would guess a disproportionate amount of that nitrous is evaporating on your IAT probe as compared to within the air stream and it's an artificially low reading. Not a big deal unless your fueling/timing is adjusted significantly based on IAT.

ZephTheChef

You can make it as complicated or simple as you want. I literally put in 450cc injectors and called it a day. On my Buick, which I can actually tune, I went ahead and scaled the injectors and then dialed in the MAF tables based on wideband feedback to get the indicated AFRs I wanted, which allows for significantly larger injectors and a higher HP ceiling than stock. But generally speaking, yes...you can just stick 34%ish larger flow rate injectors in there and call it a day. You can super over-complicate it because the viscosity of ethanol changes a lot more with temp than it does with gasoline, so it will be slightly leaner when cold and richer when warmed up, particularly with a returnless fuel system...but unless you want to go to a full standalone you're not going to be able to fix that anyway.

If you just do it with larger injectors and no tuning, you're still limited to whatever max duty cycle the computer caps fuel flow at. Some cars have fuel cut as low as 80%, some go all the way to 100%. Jerry told me that his tune put the stock injectors somewhere around the low 70s if I recall correctly...so that shouldn't be a problem up to say around 800hp.

ZephTheChef

If the cooling happens before the turbo, you will get higher mass flow through your turbos, as well as the cooling taking place before the efficiency losses in the compressor, which means the 77 degrees F or so of cooling from a 200 shot from the example turns into 102 degree F cooler temperatures at the turbo outlet. But you'll also have an extremely combustible mixture of fuel and oxidizer traveling through the entire intake tract...a backfire would be much more disastrous, and technically speaking your intercoolers will become less efficient due to the lower temperature differential at their inlets and you will probably only end up with very slightly cooler temps in the intake manifold. But the intercoolers will also be more likely to stay at cooler temperatures for longer. So yes, I would probably spray pre-turbo if it were me...50-100 each side.

MB-CLS500

I will go for 50 shot before turbos , Dont want to risk to knock the engine
So Water meth before thortle body and 2 NOS nozles before turbos would be a good setup?

ZephTheChef

It sounds like you're going to have a seriously nice setup, by the way.

ZephTheChef

I had issues with my water/meth in the Y pipe at the throttle body. It caused misfires sometimes, mostly only as I was getting off the throttle. I have yet to see if my new spray bar has fixed that. But I was running what most people would consider a fairly large nozzle. 12 GPH.

Again, it depends on what you're willing to risk/tolerate on your setup. Unless your tuner can set it up in the computer for a dry shot, then a wet shot through the turbos is going to create a pretty serious combustion hazard if you have a backfire, but from a power perspective, that's by far the best way to take advantage of the cooling because it also increases the density at and in your compressor housing which will make those baby turbos flow more air as well.

If you sprayed the nitrous at the throttle body or in the intake manifold you might see colder temperatures in your intake manifold, and increase density at the intake valves, but the turbo output would still be limited by the density at the compressor inlet which won't have changed unless you're spraying pre-turbo. And I'm pretty sure the turbos are the limiting factor here more so than the intake valves so I would focus on that.

MB-CLS500

my tuner recommends meth before intercoolers. I dont want to risk engone at all so forgive for so many question I just starting to learn how meth and intercoolers work in real life if I were to go with only meth injection what the best nozzle location would be before thortle body or before turbo compressor wheel. or may be 1 smal nozzle before thortle body and 2 before compressor wheel?

ZephTheChef

I know you're just looking for a simple answer, but the answer really is, it's complicated and it depends.

With water/meth it's all about what you want that water/meth to achieve as far as where you put it. It can be used for charge air cooling, or it can be used for in-cylinder cooling as knock prevention. As far as charge air cooling, pre-turbo will be the biggest BTU impact on charge temperatures. However, like I said, it will also make the intercoolers technically less efficient due to both the lower air temp as well as the increased humidity (humid air takes a lot more energy to cool/heat). *some* of the cooling from the water/meth is wasted if it happens prior to an intercooler. A nozzle after the intercooler will result in most of that cooling taking place in the charge air, however, it can puddle or have uneven distribution if your charge temps are quite cool already after the intercoolers. Remember, under pressure the boiling point of water/meth goes up quite a bit so it will be less likely to vaporize at lower temps than in atmospheric air (however, the air will also hold more of it before becoming saturated). It also can possibly work its way into the throttle body electronics and cause issues. I haven't had that problem on my S600, but I did on one of my other cars and had to replace multiple throttle position sensors before I figured out what was causing it.

The other option is direct-port or in the manifold with a spray bar like I did on my car. This ensures that distribution is even and additionally, some of it may still enter the cylinder as liquid and act as a cooling agent during the compression stroke. Heating during the compression stroke is really the primary cause of knock/detonation. Charge air temps are just typically the way people indirectly address this issue. Obviously the cooler the air going in, the less it is heated during compression so cooler charge temps mean it will be less likely for the temperatures in the chamber to exceed the autoignition temperature of your fuel.

To put heating during compression into perspective, you know how hot air is coming out of a turbo, right? Really, really hot. Around 300 degrees F before intercooling at 16psi. Well your turbo is operating at a pressure ratio of around 2.0. Your engine's compression ratio is what, 9:1 (I've heard various figures)? I won't get into the math, but the heating during even ideal compression is tremendous compared to the intake heating from the turbo. I mean the ratio is over 4x higher, so that easily explains how temps approach autoignition temps of gasoline at 1200 degrees plus if you don't have good intercooling. To add to this, the turbo can be intercooled, the compression stroke cannot. Normally the only cooling you have in-cylinder is fuel that is still vaporizing, so it is of huge benefit in my opinion to use the water/meth for additional in-cylinder cooling vs using it to cool the charge air. The charge air can be cooled with intercoolers/ice box, and other means...it's much more difficult to figure out cooling during the compression stroke. So that's why I put my nozzles as close to the intake valves as reasonably possible with my spraybar without spending the money for and figuring out how to fit 12 actual direct port water/meth nozzles.

MB-CLS500

So where did you put your nozzle after the thortle body or u did direct injection? I read a lot about how water meth works and I my goal is what you said to cool cylinder inside . I was thinking about direct injection I have some pictures of intake maniflod and I think nozzles can be installed near fuel injectors . A good IC with HE and high GPM rate pump + will keep IAT down. And to my mind Direct water/meth injection will keep engine cool and prevent that heat soak . I wanna do direct injection . What r ur thoughts on this . You mention that your engined misfired when u sprayed before thortle body . Will missfire happen if u do direct injection?

ZephTheChef

I am a cheap *** so I built my own spraybar using garden misting nozzles at 50 cents each instead of buying nozzles for $30 each, plus holders and tubing, fittings, etc. There is an extremely short video of it spraying before I welded it into the manifold in my build thread in the regular W220 section. I will try and repost it here as well.

I haven't put enough road time on my car since switching from the single nozzle to tell you much about whether or not it solved the misfire issues (which I suspect was due to unequal distribution). I think the injection quantity and activation pressure are going to determine whether or not it causes enough charge dilution or increased spark voltage requirement to initiate a misfire. Also, the smaller the nozzle the better the atomization/droplet size so I'd rather have 12 tiny nozzles than one big one. The smaller the droplets the more surface area they have, the more surface area they have the faster/better they will vaporize.

ZephTheChef

Here's the video. I didn't really take any pictures of anything because it's not real pretty or anything special to look at. Basically I drilled holes in the manifold and inserted my spray bar and then welded it back up. It's fed by a 1/4" aluminum tubing so water/meth quick-connect fittings go directly onto the bar.

MB-CLS500

But does this garder mister sparys direct pressured mist ? It looks like that it just disipates in the air . After this mod u did not had any misfire issues? I aksed speedriven ane they told me that coz intake manifold is a short runner it has very uneven distribution to place nozzle before thortle body . They said best place is before turbos. But i want in cylnder cooling and I defenatly wanna go with direct injection wich size do u think is best for direct injection and from where to take signal EFI or MAP ?

ZephTheChef

Yes, they are correct, the single nozzle I had before the throttle body had terrible distribution. These nozzles spray a fine mist and are lined up with the intake ports. True direct port would probably be even better, but this setup cost me like $30 plus some work...and it would have been like $700 and a lot of lines and fittings running everywhere for all the stuff to do it with traditional water/meth nozzles. These misting nozzles are essentially the same thing as water/meth nozzles, but they are just a lot lower flow rate than most water/meth nozzles and aren't threaded on the outside like you'd need for a typical direct port setup. I haven't done a flow test to determine exactly the flow rate at the pressures my system are running but they are stated as .5 gph nozzles and I have 1 per cylinder basically spraying at the port entrances.

I do not have a progressive setup, so I don't have a MAP or TPS or injector pulse signal or anything fed into a controller, the pump is just on a relay triggered by a boost switch. So basically I can adjust the boost pressure that it activates at, but I can't really adjust the flow rate (except by changing the pump bypass pressure). That's probably at least part of the reason why I had a misfire. My injection rate didn't have any kind of ramp at all, it was just full blast once it came on so if it activated too early it might have caused a bit of a stumble. Poor distribution would magnify that effect.

If you have plenty of money, by all means, I would go with a progressive controller of some sort and direct port with actual water/meth nozzles if you think you've got room to plumb them in without any interference with the fuel injectors or rails or intercoolers or other things that might be in the way. The alcohol injection systems kits use the smaller tubing and fittings that are easier to work with. They have recently changed their name and have a bunch of new products coming out. Not everything is functional yet on the new site and their old site has been broken for some time. They still sell through ebay though. Here is the new site: http://prometh.com/

There's no reason you can't spray both pre-turbo as well as direct port.

MB-CLS500

I am sure there is some room to place true direct injection setup but I need to find out what cc nozzles I will need for it. what do you think what about size of nozzles? wich size would work best

ZephTheChef

Honestly, there are so many strategies you could go with there that it's hard to make a recommendation. Nozzle flow is going to vary significantly depending on pump pressure, and whether or not you have some kind of progressive control on it. Larger nozzles you might have to wait to a higher load to activate to avoid stumbling/misfires. Smaller nozzles are a safer bet, but you may not be getting the absolute most cooling you can that way.


I have 3gph nozzles in my Buick, one per cylinder. However, that car was making at least as much power as the Benz on half the cylinders. I think 1/2 to 1 gph per cylinder would probably be a good size. Using the standard recommendation of 12-25% of the fuel flow, that matches up with that figure.

MB-CLS500

I think nozzles will fit on these Red spots in the intake manifold?
I agree with you about small nozzle size. But It may have misfires still with Direct port injection?

ZephTheChef

I don't think there's anywhere near enough room where you've indicated. The nozzles with holders are quite bulky, especially the straight ones like you linked. The fuel rail also sits very close to that area. If you are going direct port, I think it would have to be at more of an angle in the side of the port. Like to the left of where your red dots are in the picture, tucked up in the little cavity between ports. The injectors and rails and wiring will make it tough, as well as the engine support bracket that goes over the rear of the manifold (the piece the intercooler filler bolts to)...it takes up a lot of real estate. Overall, I think it's difficult to near-impossible to do with the bulky 1/8" npt nozzles and fittings most water/meth vendors sell.


You might be able to figure something out if you have it out of the car but you're going to want everything mocked up like it is in the car because there are a lot of things that could interfere. The intercoolers for example didn't clear my fuel injector wiring adapters so I had to get different ones. Everything is very tight in that region.


If you wanted me to build an internal spray bar setup like mine, I do have a spare manifold that I bought for that very purpose so I could have it ready to go in advance of tearing the car down, but I decided to just do it all at once and didn't end up using the spare. It was a low parts cost but I probably put 8-12 hours of trial and error fabrication/welding to get it working and the spare manifold itself wasn't cheap so I'd probably want $500 USD plus shipping to make one. I really can't comment on the long-term performance of my setup yet though, and I don't know about arranging shipping to Georgia, though (since I'm assuming Tbilisi is not in the U.S. state of Georgia, lol). At that kind of pricing you're probably not saving much money over trying to fit the regular 1/8" npt nozzles externally anyway...but at least you'd know that the fitment works.

ZephTheChef

I'm actually replacing my radiator tonight in the S600 so I will be able to take it on some longer trips and get you some feedback on how the new nozzle setup is working. I don't think there will be misfire issues with a direct port setup or spraybar with small nozzles, but it kind of depends on what size they are relative to the airflow through your engine, and what your activation point is. I mean obviously if I turn my pump on at idle, the car almost dies (and would die if it was more than just a fraction of a second test spray). However, if I don't turn it on until 15psi, you probably wouldn't even notice when it comes on. Smaller nozzles you could turn on earlier, larger nozzles you may have to play with the turn-on pressure or go with a progressive controller depending on how your car reacts.

ZephTheChef

That's the downside of an internal spraybar...it's not serviceable in any way. I can't experiment with different nozzle sizes because I can't get at the nozzles, it's a permanent installation. They could potentially be changed through the ports if you had the manifold off, but I epoxied mine in for extra safety...I didn't want them working loose over time and popping out and going through the engine and destroying it.

MB-CLS500

Thank you for so much info on this . I will try to find 1 small L shape nozzle to find out if it will fit between fuel injector and manifold if not I will spray it str8 to the compressor wheel . Speedriven sprays directly to the compressor wheel now I understand why but anyway im gonna try to fit if there will be room for L shaped small nozzle there wiil be plenty of space to run tubing ontop of manifold
Yes I live in Republic Of Georgia it borders Russia , Turkey, Black Sea

ZephTheChef

That sounds like a good plan. Spraying into the compressor wheel definitely has huge benefits, especially on hot days. You might want small pre-turbo nozzles as well even if you do get a functional direct port setup.