So we finally finished building me a forged 347 with a compression ratio of 9:1.

Do I need meth to run 15-17PSI on this motor? Or because I have built it with a rather low compression ratio should I be fine without? I realize there is more power to be had by the lower IAT but do not want to mess with meth really. I wanted to make 700-750 RWHP from my single turbo 76MM turbonetics setup, but wasnt sure if running that boost level without meth would be acceptable. The motor is built with boost in mind, so why not?

 

You live in Florida where you have good 93 pump gas. You can run the 15-17 psi. Its just a matter of how much timing you can get away with. Your going to end up running a fair amount of timing retard and will probably end up somewhere in the 10-12 degree's of total timing. You really out to consider running a meth kit for the simple fact that you may run into some variances in gasoline that the methanol injection will more then make up for. Additionally I'm assuming your running an air to air intercooler. During the hot summer months the intercooler efficiency is going to drop off big time. The added octane and air charge cooling will help ensure this engine stays safe and out of detonations.

Feel free to give me a call directly as I can go over and explain exactly how you can set up your ECU/tune to work as a failsafe. Allowing you to only run the advance timing when the methanol is flowing while also setting up the ECU/tune to reduce the timing in the event the methanol doesn;t spray protecting your engine.

Rodney

 

Good advice. You will be safer and run stronger particularly in the summer.

 

You've gone this far ..... go for the insurance .......

 

Ive got the aem kit already.. just dont feel like filling my bottle all the time At what boost level should I start kicking the meth on? and at what psi should I set it to max? Also which os the three nozzles should I use? theres three different sizes with this kit.

 

I believe the AEM systems works off of a boost signal. How quickly does your turbo's spool up and at what rpm do you hit full boost? Also, what type of mixture are you spraying and do you have the dual nozzle upgrade?

Rodney

 

You should contact AEM for technical on their system. Getting tech from anyone but the kits MFG is wrong. Or contact the shop that installed it for you if you went that route.

As far as needing meth for your setup.. especially with a 76 MM turbo.. you'd be foolish to not run it and take advantage of the headroom it will give you. The 76 is rated over 1k HP..

You can make power with boost, timing.. or both. Octane is what limits you.

 

What if you get 87 octane when you thought you got 93, I used meth on my forged setup for this reason and at the top of 4th gear I would see 20lbs of boost and 16lbs at 6k where I normally shifted on the street

 

I totally agree.. my car broke the sprag on the tq converter and it would spike from 16 PSI to 26 PSI on a shift.

On a centrifugal/sc car its hard to overboost as its related to rpm vs pulley sizing.

On a turbo car.. totally different animal.. as boost is regulated by wastegate and the application of air to regulate it.. as well as load

 

Agreed. AEM should be responsible for providing the customer service on their product after the sale.

Its just unfortunate to see a guy sold a progressive system that I know is based on boost when using a turbo. Not much of a progressive feature if the turbo spools up and hits peak boost at 3800-4000 rpm and the engine is pulled to 6500 rpm. The same amount of fluid is sprayed from 4000-6500 rpm.

Many customers don't realize this and are sold a water methanol injection system based on boost by either a dealer or the manufacture when in fact it should be based on mass air output. This is why we offer MAF based systems for turbo's and positive displacement superchargers.

As for my questions about dual nozzles. LS1 and LS2 intakes are notorious for distribution problems when running a single large nozzle. You'll have some intake ports getting a lot of the water methanol mixture while others are not. We found this out for ourselves over three years ago. The solution is running two smaller nozzles vs one large nozzle. For example, rather then using a single 10 or 14 gph nozzle. We will use two 5's or two 7's. These two smaller nozzles have the same combined flow of a single larger nozzle yet the spray is much much finer mist, then the single nozzle, which is carried better through out the intake. Giving them more equal distribution between cylinders.

I saw this evident after the intake was pulled off an engine in which a cylinder detonated. You could see the staining in the bottom of the intake manifolds runners and could tell the fluid was running along the floor of the intake. This is why all of our C6 Vette systems comes standard with dual nozzles.

Just passing along what I have learned and experienced so nobody else makes this same mistakes. Let me know if you have any other questions or how I can help.

Rodney

Pic below is our stainless steel dual nozzle.



Pic below shows are stainless steel dual nozzle installed.



Pic below shows our dual nozzle installed using the standard nylon hoses for those who can't afford the stainless and are going to use windshield washer fluid or 50/50 mix.

Here's some images of our C6 Water methanol injection tank.








Pic below shows the built in low level sensor. Tank holds 1.7 gallons.



Pic below show's the bottom sump and dual pick ups and option for running two pumps.



Pic shown below with tank installed in left rear storage compartment of C6 Vette. With the lid closed you don't see the tank.



Shown below are some images of our MAF based progressive controller. The gray wire shown in the images gets connected to the output signal on the mass air flow meter. Doing so allows us to based the water methanol injection on the MAF function. This gives the user a true progressive feature across the entire RPM.

 

MAF based is fine as long as the MAF can read the signal. On a C5 Corvette the MAF gets pegged at about 550 to the tire. When your at 700 to the tire.. you lost tracking a long time ago. Same issue with the Buick GN as the MAF gets pinned at 14 PSI boost.. and when you run 27 PSI.. tracking was lost. This is why MAF based cant be used on all applications.

MAF is great for cars like the 03/04 Mustang Cobra. or NA setups. I would argue using it on a C5. Unless maybe if its a maggie. This is also the main reason so many switch to SD tunes.

Only mentioning this because we are in the C5 section of this message board. The C6 uses a different MAF. FWIW, Fastest NA C6 on this forum runs a meth system.

Julio

 

FYI MAF controllers do NOT WORK AT ALL!!!! you need a 3bar map controller....check out devils own with the 3bar map sensor built into the controller itself....talk about easy setup...my writeup i did was for a maf controller and the long and short of it was it didnt work...so i changed two different MAF controllers think they were bad and also two new 2 bar map sensors ....turns out the C5 MAF just doesnt like to provide that low of a signal for say 2psi to 7psi like my setup....once i changed to the 3bar built in MAP it worked right away ill be posting my install with pics but ill be posting that its just a guide and that i changed to the map controller....less wires to mess with as you dont need the 5v reference wire or a ground for the extra map sensor or green wire for the map to controller...as well as the grey wire to controller...so that 4 wires that you WONT have to mess with and really saves on install time...I could install a devils own kit in about 2 hrs with using the stock windshield res. any local IN people im able to help.

 

You pick a MAP sensor based on the boost the motor will make. For those reading this, a MAP is a 0-5 volt sensor that reads pressure on its nipple. A 2 bar sensor reads 1 bar in boost and 1 bar in vacuum. 1 bar is 14.7 PSI. A 3 bar reads 1 vacuum and 2 bars in boost = 29.4 PSI. 0-1.6v is vacuum on a 3bar, 1.6-4.8v is boost. 3.2v is 4.7 PSI. A 2bar is 0-2.4 in vacuum, 2.4-4.8 in boost. So a 3 bar is 1.6v per bar. A 2 bar is 2.4 per bar.

Why do I post this, simple. Its like fitting a tach to your motor. If you spin your motor to 7K rpm's.. then you buy a 8K tach. You dont buy a 20K tach. Why because of resolution. The higher the tach, MAP, etc.. the resolution goes down. Why is this important, easy.. your alky controller makes changes to the way it reads signal from the MAP sensor. So when you run a 3 bar map and only 7 PSI boost. The swing in voltage from 3 PSI when it kicks on to 7 PSI when your running max boost using a 3 bar is .4 volts on a 5 volt sensor. When using a 2 bar MAP, is .7 volts on a 2 bar. The increase in voltage gives the controller a wider range to "control". The output signal is 66% more. Especially on lower boost levels.

If you run anything below 15 PSI.. a 2 bar is the "ideal" sensor. 15-22.5 PSI.. the 2.5 bar is the ideal. 22.5-30 PSI.. the 3 bar is the ideal sensor. Match the sensor to the intended usage. This is why an OEM MFG doesnt put a 5 bar on every boosted app they make. Because of resolution issues.

Back to your MAF deal.. MAF controllers do work. Why your's didnt.. dont know.. you should of taken that up with who sold it to you. Got your money back, figured out the issue, etc.

I dont care if installing a system it takes me 20 hours.. as long as the end result is what I was expecting.. evey minute was worth it. It takes time to properly mount parts, dress wires, dress lines, solder connections, and secure termination. I can hardly jack up a Vette in less than 20 minutes making sure I dont cause damage it. The C5 is a pretty straight forward install. I would say 3-4 hours average.. but every car is different, and you get those vehicles with the "midas". While i'm under the dash midas well clean up the gauge wiring, midas well move this alarm box, midas well fix the connection.. from someone previous.

Good luck.. there is no advertising hype on my end. Just experience from tuning on hundreds of cars with these types of systems.

 

MAF controllers do work. We've been using them for the past 4 years. The controller you used is advertised as a 0-5 volt which works on Ford MAF's. GM is frequency based. So you need a controller that is designed to work with frequency. Our MAF controller has a 4 position switch built into it allowing users to use it with either 0-5 volt MAF's or the three different frequency based MAF's that are out there.

The image below shows what each switch position is intended for. You just have to transpose those values for each dial. One controller that will work with 4 different types of MAF's.



As for boost reference controllers. We offer two versions. Our low boost 0-25 progressive boost controller and our high boost 5-70 psi controller. Both controllers come with built in MAP sensors. All the electronics are sealed in epoxy internally protecting the electronics from weather and moisture. Additionally, the controllers have extensive voltage protection and can be used on 16 volt systems and a separate circuit for using a solenoid over a check valve.

Probably the most note worthy feature for users is the push to connect locking boost port which eliminates the boost hose from popping off and or leaking around the barb under high boost. As well as broken plastic barbs caused by users trying to use a hose clamp to keep the boost hose secured on the controller. Simple, reliable and only $140.00. Compare for yourself and see the difference.

Image shown below is example demonstrating a short boost hose connected to the controller and the fitting we supply for the intake manifold.







Rodney

 

Do I really need to post pix cuz I think your confused. IMO I hate the idea of having to mount any controller under the hood! I prefer to make adjustments in car while driving so say I don't want to inject I just turn both ***** all the way to the right. I domt have to stop the car and pop the hood to do this. Again I do NOT work for devils own just a dealer cuz I've done group buys and sold a lot of kits. I'm just sharing my experiences n not trying to sell anything ESP since I don't get paid to do so. It's interesting you saying GM has different maf freq. But I didn't advertise any certain type of controller. I ordered the chevy corvette maf progressive controller. Are all your kits progresive ? And I agree that a two bar map would be ideal but really my setup and my future plans te 3bar is going to work out just fine and I don't see how it would be any different in terms of being progressive from 2psi to 7psi. My controller reads down to 2psi and Thats when I want it to start injecting and fully inject as I hit max boost at 7psi. I'm fully aware of the resolution in terms of voltage related to psi but again it works just fine. Granted I should have worded my first sentence a little different cuz the controller should have worked but I traced every wire and tested every possible issue and they passed all my tests. I know how to install these kits they are very simple! And yes I too have the "might
as well" touch and fix or clean up issues/connections if I see them. Like the previous owner had some jacked up nasty connections for the boost a pump and I redid the wires and new terminals hopefully preventing issues before they arise

 

..while at it: What controller would take rpm into consideration when injecting? I have a SD tune, so no MAF can be used. I have a PD blower and I'd really like to spray at 2 krpm.

If I spray at 2 krpm triggered for example by 4 psi.. The same psi at 6 krpm needs more meth. The boost-referenced progressive controller won't be able to handle this.

 

Sorry. We don't have anything available to do both rpm and boost. What supercharger are you running and how much boost?

Rodney

 

What are the cons for using pressure and vacuum to control meth injection?

 

If your using a positive displacement supercharger and that supercharger makes peak boost by 3000 rpm. Using a boost referenced controller will not give you a progressive feature across the entire rpm range as the boost signal pegged out a 3000 rpm. With centrifugal superchargers, like ProCharger, the boost will continue to rise the more you rpm it. So using a boost signal will work just fine.

Rodney

 

Maggie MP122 with 9 psi.