mooreboost

iTrader: (6)

Does the AEM unit have any feature that could save my engine in the event that my alcohol kit stops working, like the new XEDE?

racegate

iTrader: (1)

Yes, there are many ways to skin that cat using an AEM if you use a pump with a pressure switch. Drop boost, remove timing, add fuel, or all of the above.

kcevo

iTrader: (11)

AEM EGT sensor is another, if the meth/alcohol isn't spraying what it should your exhaust temps will show this and you can set it up to dump fuel.

propellerhead

iTrader: (3)

The problem with relying on EGT is that it's far too late to prevent detonation damage by the time EGT rises enough to be noticed. An EGT based fuel trim should be configured right along side a coolant based fuel trim and knock detection, regardless of using injection or not.

Really the safeguards this guy is looking for need to be a part of the injection system, whether it be spraying methanol or water. A decent system will detect a failure with the flow of alcohol and will have an outout to trigger a relay. The relay can be used to simply dump boost back to wastegate levels or in the case of the Xede, switch maps. The AEM can be configured to dump fuel, pull timing or both.

An example of such a system would be the Aquamist 2D. Upon detection of an interruption of waterflow, pump overrun or the water level in the spray reservoir dropping below a prescribed level, the Aquamist system will trigger a relay. This can be used to activate the "anti-grenade" measures described. While the Aquamist system is probably twice as expensive as the other popular kits, I haven't seen any of the other kits offer the fault detection that the Aquamist does. They may offer something but I just haven't seen it.

kcevo

iTrader: (11)

Already checked with my local aqumist dealer and the switch you are speaking of will be outflowed by most of the kits on the market besides the aquamist kit. The EGT sensor is keeping it simple w/o having to use elaborate gadgets, believe me I was trying to get fancy and spent an hour or so on the phone with the owner of alkycontrol.com and he convinced me the best way to was to use an EGT. With the system running at optimal flow your EGT's will be in the range of 700 degrees celcius, if at all a clogged line, low pressure at the pump, etc. it will show in the EGT's and you can dump fuel to the point the motor will bog like hell. No sense in getting to elaborate, sense the system very rarely fails to begin with.

racegate

iTrader: (1)

If you are using an alkycontrol kit, or any kit that uses the shurflo pump, that functionality for a saftey pressure switch is already there. You just need to wire it into the AEM, and configure the inputs/outputs. I've been setting up alky kits with 100% safteys and AEMs for 2 years now. Works flawlessly. Just ask Knyght on this board.

Using EGT is kind of a hack...the alky system itself needs to notify the ECU that it isn't spraying or is faulted.

kcevo

iTrader: (11)

The way the AEM can be set up using the pressure switch on the pump is nice, but what if there is a clog at the nipple where it is spraying? I may wire mine up like I have seen many people in the Supra community do with Anarkey's kit, but to say the EGT is kinda of a hack is far from it. If the meth injection is not working as it was intended to do, it will show in the EGT's no matter what. If the AEM had a timing correction table for the EGT's as it did for fuel now that would be sweet, also most people don't control boost thru the AEM so that is one variable that would not be controlled.

VTECH8TR

iTrader: (70)

Chad,

Long time no talk.

Racegate highly recommends to use a boost solenoid of some type to control boost through the AEM, in the event you have a pump failure you can lower the boost as he explained it to me. He is very knowledgeable in the AEM and been tuning them for years now. Hes my new best friend. hehehe

Racegate the person above mooreboost has a kit installed from me.

racegate

iTrader: (1)

What you do is couple the pressure switch on the pump with an AFR trigger. Pump needs to have pressure AND AFR needs to be above a certain lambda to remove fuel / timing / add boost. That covers all failure scenarios, including a clogged nozzle.

kcevo

iTrader: (11)

But, if there is a clog at the nipple where it sprays into the engine then it will not be picked up by the pressure switch at the pump. A pressure switch in between the pump and the nipple would be ideal, like a hans pressure switch, but personally that is getting too elaborate. The EGT sensor is showing me what the meth/water/alcohol did in the combustion chamber, if there is any slight hiccup in the system it will show in the EGT's. Don't get me wrong wiring up the pressure switch into the AEM is a great idea in case the pump fails, but it doesn't cover all scenarios.

propellerhead

iTrader: (3)

I think you're referring to the DD2 which is a dashboard display for monitoring waterflow. While that would work that's not what I'm referring to. The 2D doesn't require any add-ons to detect flow faults. It does this by monitoring the water/methanol injector duty cycle to the the pump duty cycle. If the pump duty is higher than expected, then you've got a leak. If the pump duty is lower than expected than you've got a clog. A simple float switch is used to detect low fluid conditions.

racegate

iTrader: (1)

No...my solution does cover all failures. The AEM will not make any fuel boost mods unless the pressure switch tells the AEM that the alky is "on", AND the AFR is rich enough to indicate the nozzle is actually spraying. Trust me, I have tested it by removing the nozzle completely and letting it spray onto the ground. Pump says "i'm spraying"...but the AFR doesnt go rich because the nozzle is not connected, so the AEM says "sorry...no dice, I'm keeping the stock maps." The key is coupling the pressure switch wtih an AFR switch in the AEM....your AFR won't go rich without alky actually in the motor. Requires some simple circuitry to latch the AFR condition after the alky comes on, but its nothing compared to the cost of a motor lost due to a alky failure. Works very well.

kcevo

iTrader: (11)

Personally, I feel the aquamist kit has all of the safety features you could ever want from a system. But, the system is limited to a 500cc flow valve, not nearly enough for what most people are doing. Not compatible with alcohol/methanol I believe. And way to expensive. If you wanted an aquamist kit to flow as much as say an alkycontrol kit you would have to buy 3 or 4 total systems.

kcevo

iTrader: (11)

Based on this scenario you are not doing anything more elaborate than using an EGT sensor like I was saying, only thing you have added is the fact that if the pump fails then the AEM will recognize this and not add boost if and only if the AEM is controlling boost.

racegate

iTrader: (1)

The problem with the EGT sensor is that it is quite slow reacting. AFR change is very instant when the alky stops spraying and gets caught right away. In the EGT scenario, the alky stops working, then the knock control needs to pull timing, and then the EGT goes up. EGT will not directly go up that much with the alky just not spraying. Detonation itself does not raise EGT that much that you can look at it to determine if the alky is on or not. Timing pull is the biggest contributor to EGT, and if you wait for timing to be pulled as the motor is at 13.5-14.0:1 or leaner, it may be too late. The AFR on the other hand is -instant-. As soon as teh alky stops spraying, the AFR goes lean, and the EMS does its thing regardless of what the pump says.

In other words I just feel the EGT would be too slow reacting to really rely on it as a saftey. I have monitoed EGT with fixed timing, and for a full AFR point swing EGT only changes by roughly 30deg C. Usually by the time you see the EGTs are too high, its too late, thats why I suggest AFR instead. With AFR say run 12.0:1 on Meth...you can trigger on something as low as 12.5:1 to catch the motor "on its way" to leaning out. That will work 100% faster than EGT, and provide better results.

[EDIT: Chad- I did not mean to take an arrogant tone and critcize the use of EGT. Re-reading my first post, I may have came across that way, sorry. I just feel its not very adequate in saving the motor for the aforemntioned reasons. I'm always up for a good tech. debate! ]