GTM Stage 2 S/C on Meth 507whp/357wtq
 

Derek called us up wanting our Stage 2 Supercharger and wanted to get the most out of it on pump gas and keep his beautiful black 370Z reliable. We recommended incorporating water/methanol injection to compensate for the low knock threshold of 91 octane pump gas.

To increase the knock threshold, we decided to do a 5 port injection setup. This entails an injector right before the intercooler, a small injector before each MAF and the main injectors after the MAF sensors. By using very small injectors before the MAF sensors, we are able to lower the intake air temperature the MAF sensors see without dousing them in copious amounts of water/methanol mix. This allows the ECU to advance timing automatically with very little fine tuning. This resulted in an impressive 40whp gain.

The water/methanol system we employed is the Aquamist HFS-3. This is by far the most sophisticated water/methanol injection system on the market. Rather than a simple MAF sensor reading or boost pressure reading, the HFS-3 reads injector duty cycle to calculate how much water/methanol to inject. This means that the car's ECU has already calculated the amount of fuel it will be injecting based on all the sensors it has at its disposal (TPS, MAF, IAT, ECT, RPM, etc.). This not only simplifies the water/methanol system wiring, but it also give it the most accurate picture of what the engine is doing. The HFS-3 also has an ON/OFF switch that enables the end user to decide whether or not to use the system at any given time. While that might sound basic, there aren't many other systems that allow you to just turn it off. The HFS-3 incorporates a failsafe feature that monitors the flow rate of water/methanol through the system to detect leaks, clogs, or an empty reservoir. This gives a warning so the user can take their foot off the gas and switch to a non-methanol map.



To increase airflow to our engine oil cooler, we developed a louvered fender liner to allow air to get sucked out through the oil cooler. This allows for additional heat to be dissipated through the 25 row oil cooler without compromising the front end aesthetics.

:happydance::tup::tiphat::driving:

Love the fender liner, very nice! Are you going to have any videos of this car by chance?

what's that green filter?

meth setup looks awesome!

Pricing for the Meth kit please!

The car's been running great. The install is pretty damned clean. I'm taking her to Laguna Seca on Saturday so I'll let you guys know how she performs.

Impressive car. My question for the GTM guys is what (if any) benefit would you get from injecting water only? That's what I am interested in doing basically to deter detonation and help with cooling the engine. As great as water/meth is, I can get water anywhere, and I am not interested in keeping stocks of meth and water. Since I live in SoCal, I don't really have a freezing issue.


That's the air-filter feeding the SC compressor wheel.

that's quality work

If I'm correct, a stock 370Z is meant to run on 98 octane.

The SC Kits aren't? :ugh2:

In the U.S., premium gas is typically either 91 or 93 octane, depending on the state. A stock Z requires 91. So to answer your question, no.

Interesting. I just looked up the Australian specs and it states:

"Recommended fuel type - Premium Unleaded 95 RON or higher (for optimum performance use 98 RON fuel)"

Anyone know how this impacts on the SC kits if at all?

The US and everywhere else calculate their octane levels differently. I believe that US calcs (e.g. 91) correspond to slightly higher RON numbers.

From Octane rating - Wikipedia, the free encyclopedia: "Because of the 8 to 10 point difference noted above, the octane rating shown in the United States is 4 to 5 points lower than the rating shown elsewhere in the world for the same fuel."

We do not have any videos as we were pressed for time on this project.

We'll be putting together a package and adding it to our website.

Injecting just water will only improve knock resistance. The methanol will lower intake air temperatures more than just water alone in addition to having a higher knock resistance than gasoline. Jordo and I had a good discussion in a different thread that went into more detail.

If you are doing water/methanol or just straight water, you MUST use DISTILLED water! Any dissolved solids will clog the injectors over time! Think about how often you have to clean/replace the aerator screen in your faucets at home...especially in SoCal where we have nasty, hard water that is barely potable. You do not want that dissolved lime and crap in your motor do you?

Like Nix said, we Americans rate our fuel on the conservative side. Our 91 octane is comparable to your 95 octane and our 93 octane is comparable to your 98 octane.

As far as how it would impact the S/C kit, you would run a little richer on higher octane fuel as it would have less propensity to fully combust. Therefore, you would have a conservative tune for your conditions...nothing wrong with that.

NIce, I ran the Aquamist HSF-5 kit on my Evo. Probably the best meth/water injection kit out there. :tup:

You currently have a HFS-3 aqua mist on your website. is it the same?

Great install, nice car and nice pics but that torque is weeeaaaaakkkksauce!

Just to be clear, my understanding is that injecting water should improve knock resistance and lower IAT as well as allow you to (in theory at least) run a leaner AFR since you can replace fuel with water for cylinder cooling. Water has a significantly higher specific heat capacity than any sort of fuel which makes it phenomenal for cooling (as compared to say gas). I definitely understand that you need to run distilled water only, but like I said, that's available anywhere and it's cheap. Meth mixes aren't.

Another consideration is the fact that meth is a fuel so *I believe* you have to tune the fueling more than with just water. With multiple maps this may not really be an issue, but I strongly prefer simplicity.

I do realize that you don't have the added power potential when you run just water and no meth, but my goal with a water injection system would be safety margin, not additional WHP. But that's just me.

In any event, congrats on the awesome build!

Yes, and no. The kit on our website is the basic kit. The one we'll be adding has the additional tees, nozzles, etc.

Yes, injecting water does lower IAT, but meth does it better. True, water has a high heat capacity, but methanol evaporates faster and it's the change of state from a liquid to a gas that absorbs lots of heat (methanol boils at a lower temperature than water).

You don't necessarily *have* to tune for it, but it is beneficial to do so. Anyway, water injection is perfectly fine for what you want.

So, when are you going to be doing this build? :tup:

No arguments with that! Well, I am picking my car up on the 27th. So, after a full break-in and a little financial recovery from the down payment, I will be up there to see you guys. I decided to do the brakes on my car before I even picked it up so there went some of my mod money, haha.

Is water or water/meth injection recommended if one is using 98 RON fuel or is this just an optional extra?

Sweet! I'm excited for you...nothing like that new car smell. :D

It is an optional extra...it is not required. We only recommend it if you are going for gobs of power on stock compression with pump gas. The stage 2 supercharger kit out of the box performs very well and does not need water/meth injection to operate correctly.

I really like what you did with the fender liner. It reminds me of exactly what the inner fenders of my VR-4 looked like. Those were there for the SMIC's though. It makes sence and it works. It looks like a great place in which you could mount a huge oil cooler.

Pretty similar:
http://img.photobucket.com/albums/v3...3/DSC01147.jpg

How much boost are you running ?

Sam told me it was 11psi, IIRC

So you made 466 rwhp @ 11 lbs boost. That seems kind of low. Is your car a 7 AT ?
i thought the UAM car made 507 rwhp. ?

Im making 463ish at 8-8.5 if thats any consolation

interesting, i wonder if it's because of 91 oct. My HR did 450whp at 10psi, so you are not the only one with lower output numbers. Altho that meth injection system is seriously impressive, did not know it can bump up almost 40whp that easily

Not sure about that honestly, Seb at Specialty Z tried a race map with 100 octane and I barely got any improvement ( I do have the largest pulley available though at 96 mm so I am maxed out at boost)

I'm a 6MT. I was running 91. I thought 466 seemed low too...

No idea, hopefully someone from GTM can give us some info.

Haha, i know how you feel, my target was 450+, but i did expect a bit more with the stage 2 and 10psi. When i asked Sam for the reason, he said it has to do with 91 oct, wish i can understand it better to know exactly why.

CA 91 is literally the worst gas in the nation. It wouldn't surprise me if a STG 2 here got 40 WHP less than 93 octane cars in other states.

im hoping that mine will make 500 rwhp before the meth spray. and 540 with the spray @ 11 lbs boost on 94 octane.

Doesn't the meth/water injection interfere or cause damage to the stock MAF sensors? If anything they will be cleaner :p

How much are the IAT's being reduced with meth injection before the MAF and before the intercooler? Which leads into the next question: how much are you able to increase timing from the lowered IAT's?

Have you measured the effect of meth injection on the EGT temps and by how much they can be lowered?

Another great idea from GTM and clean install. When will the kit be availble from GTM?

Zat Zuma,

I haven't measured any temps, sorry. I don't have the equipment. Not sure if an UPREV cable will let me measure temps but GTM never included it with my kit (which is part of the GTM Stg 2 kit) and I've asked for it but they still haven't sent one after a few months. Sam or anyone else from GTM, if you guys can send that over to me, please do.

As for the car itself, it ran well. The oil cooler works. I asked GTM to open up the fake vents up front to allow more airflow and they did that, which is great since the oil cooler sits directly behind that. At the track, I didn't have oil temp issues. The sessions were 20-25 minutes long, outside temp was mid 60's, so while I know it isn't hot out, I was still able to mash it for a long period of time. The highest temps I saw were 240, but most sessions I saw 220.

On the long back straight that leads uphill back into turn 1, I was able to hit 120, and this E46 M3 wasn't able to keep up. He was directly on my *** exiting turn 11 but I was able to pull away. That being said, the driver was pretty awesome and shouldn't have been in my beginner group so as soon as we entered the corners, I waved him to pass. I was definitely slower on this same straight vs a GTR but not by too much. He was definitely faster though. Again, in the corners, he destroyed everyone on the track.

But yeah, the car works, it ran through a ton of meth though. I ran 5 sessions, basically burned through two gallons of meth.

Just wanted to say that the kit works, the oil cooler with the open fang works, the louver behind the oil cooler works...

good to hear!!:tup:

Thanks for the answer Axio :tup:

I was hoping to get some info from GTM though as I'm sure they logged the info I'm looking for.

Mike?

That would be amazing, though isn't 11psi pushing it assuming this is before an engine build.

I see that some of you guys are really confused on the relationship between power, torque, octane, boost, compression ratio, intake air temperature, barometric pressure, volumetric efficiency, air/fuel ratio, detonation, cylinder pressure and ignition timing. As you can see there are a lot of variables to take into account. A number of you get it and some of you look at one or two variables and jump to conclusions with expectations that don’t factor everything in. Then there’s another small minority that over analyze everything.

Ultimately, I have one word for explaining everything here: BALANCE.

Balance between all the variables in the equation for horsepower.

Balance in the analysis of the variables. Don’t oversimplify, and don’t over-analyze.

Balance in the power you make at the wheels on a dyno and power you can actually put to the pavement. Power is nothing without control.

Remember back in elementary school math class when the teacher would say: “what you do to one side of the equation, you must do to the other side of the equation”? Well, the same principal applies to engine dynamics. That’s where the “balance” comes from. Take away octane and you must take away either boost or timing or both (all other things being equal) or suffer the consequences (detonation, blown motor). By the same token, if you add a bunch of octane, but cannot add the boost and/or timing, then you don’t have a balanced equation and you will be limited to the least common denominator. Remember; just because you increased the detonation threshold you are not going to magically make more horsepower. Especially if the ECU is reading high intake air temperatures and is pulling timing on its own…regardless of the fuel octane.

Yes, California gas is horrible. Let me explain how bad it is. A friend of mine tuned his car in New York and when he moved to California, he had to pull 7 degrees of timing to stop detonation! 7 degrees is very significant and depending on the engine and setup can be around 40whp.

There’s another thing I’d like to point out here. We are talking about a supercharger system that generates boost based on engine rpm and pulley size. If you go really big on the pulley, you simply aren’t going to make much boost, and you are going to build boost at a slower rate. If you go really small on the pulley, then you will make more boost and build boost faster. A supercharger system is, for all intents and purposes a “Set it and forget it” kind of system. You can’t just push a button and step up the boost for when you decide to go to the track and put race gas in the tank.

If you want a lot of adjustability and horsepower, then a twin turbo system with a boost controller is a much better way to go. It’s simply a more flexible system.

Here’s the bottom line. If you are going to be doing the Stage 2 Supercharger and running it on 91 octane gas, we recommend a 96mm pulley which will put you at 8 – 9psi and 450 – 470whp.

If you are going to be running 93 octane gas OR 91 with water/methanol injection, then we recommend a 92mm pulley which will put you at 10 – 11psi of boost and 500+whp.

Mike,

I am located in social and I have your GTM stage 2 SC and I have a 96mm pulley, could i use a 94 mm pulley (from what i understand you have one) ? Also can you pm me info on the meth kit.