Where did you put your sensors at?
- Thread starter jonny87turbo
- Start date
Does any one know if meth injection will mess with my air temp sensor if its to close? Does any one know how far away I need to put my air temp sensor from the meth injection nozzle?
Install your AIT sensor just upstream from meth nozzle. If you spray meth on sensor it will read too low air temperature.
MAP sensor better installed remotely, don't screw it on intake manifold, can get erratic signal. My MAP sensor was installed on the bottom of manifold and alky injection destroyed it in ~ 1 year
MAP sensor better installed remotely, don't screw it on intake manifold, can get erratic signal. My MAP sensor was installed on the bottom of manifold and alky injection destroyed it in ~ 1 year
mk3ukr;1378560 said:
Read this from an SF post: I am just relaying this these were not my words but think about it. The whole point of the AIT is to tell you the temp of the air entering the motor right? Well if the meth cools the temp by 30% and you are tuning to 30% hotter temps your tune will be wack. I run my meth nozzle just after the IC exit and will be running my AIT about 16-18" upstream from the nozzle just before the TB. I would love to run it at the very back of the manifold to read the hottest temps going into a cylinder but I hear stories of terrible heatsoak after shut-down leading to lean start up and initial running. But needless to say here is a chunk to read from a very knowledge EMS and meth guy over on SF:
Hey R.K. thanks for turning us onto that thread great information and Ben is a great help!
The thread backs what I was explaining about the IAT being after the spray to me sure the IAT reads the true temp. Also as Ben points out it can be used as a failsafe using a load vs IAT temp map to make sure the temps are below a certain temp otherwise timing is pulled and such. Here are some parts of the thread:
"Intake air temps and combustion temps are greatly reduced actually. Expect your IAT's to be at or under ambient. We have monitored this and seen a huge drop. Naturally this varies on how much your spraying and at what PSI pump pressure but it is extremely noticeable.
Intake Air Temps are drastically reduced when spraying methanol. This is obviously one of it's great attributes. Most stand alones that are worth there salt monitor and map by IAT's. If you carefully read and log your IAT's before and after you can see exactly where the air temps should be sitting when spraying. If for ANY reason the spray fails, pump dies, line gets cut, nozzle clogged, tank runs empty (although you SHOULD have a light on your dash to tell you when your getting low), meteor strikes your control unit, whatever... then your IAT's are going to shoot up fast. Any good IAT sensor is going to see this faster then you can think it, or monitor a gauge. You adjust your mapping so that the car basically falls on it's face should this happen. Dump fuel, yank timing, etc. You can't miss it when it happens and you know to lift instantly.
Also flow devices and gauges have a hard time working properly if say a line get's cut or some other issue that allows your meth to flow unimpeded.. but possibly NOT into the nozzle... Free flow, or cut line that is spraying, what ever, use your imagination. So by mapping using IAT's that is one of your safest ways to go. You can still use all your "fail safe devices" to monitor what you wish, but I would not rely on them for safety. Anyone who tries to tell you otherwise is attempting to sell you something.
IAT placement should be in the intake itself, not the intercooler piping ( I have seen that done before) and middle of the intake is probably your best bet for accuracy. You can do it in the intercooler piping but your readings will not be the same.
IAT compensation is mapped so that under normal driving conditions (no or very low boost) all is fine. The real heat is created under boost and depending on the EMS you can map by IAT Vs. any factor you choose. I understand some systems are more limited then others.
In this particular car the IAT is on top of the manifold near the 5/6 cylinders.
Your IAT shouldn't suffer from heat soak really. It should always monitor at least close to accurate when in use. IF not that would be a pretty inefficient sensor I would imagine. Especially considering your mapping is dependent on it (at least with better stand alones) and that mapping would be affected with even a 15-20 degree variant.
In the case of the Supra pictured above we were seeing 20 degree or more changes in IAT within less then second when under load."
Ben seems very knowledgable in the meth area and I learned alot just reading the thread! I can't wait to get a standalone going and take real advantage of spaying meth all the time!
Link to the thread:
http://www.supraforums.com/forum/showthread.php?t=550320
HTH,
Seth
Idea to place AIT sensor after nozzle and use fuel and ignition compensation as failsafe is excellent.
If sensor placed before nozzle - reading will be higher then actual air temp.
If sensor placed right after the nozzle - reading will be lower then actual temp. because of the liquid alky evaporating from the sensor tip
Practically in the end everything in the right tuning.
I am not sure too many people even bother to change AIT compensation tables for fuel and ignition in AEM. In mk3 base map fuel correction is not exactly correct, ignition correction table zeroed out.
If sensor placed before nozzle - reading will be higher then actual air temp.
If sensor placed right after the nozzle - reading will be lower then actual temp. because of the liquid alky evaporating from the sensor tip
Practically in the end everything in the right tuning.
I am not sure too many people even bother to change AIT compensation tables for fuel and ignition in AEM. In mk3 base map fuel correction is not exactly correct, ignition correction table zeroed out.