can water injection help heat soak issues?
 

After searching/reading up on WI; I don't believe that WI can be used to solve my heat soak problems; please correct me my thinking is wrong:

My problem seems to stem from track operation past approx 15 mins; my intake air temps begin rising to the point that the ECU stats pulling timing, then the engine is power is reduced for the last half of the race.

While there is no question in my mind that WI will reduce detonation and make the engine run cooler, it wouldn't seem to help out my problem of heat soak causing high IAT readings, as the WI is not injecting into the heated air stream that the IAT sensor is reading. Further, it doesn;t seem that cooling the engine would have any effect on heat soak of the intake stream, as this is mostly a function of heating from the compression of the intake air; independent of heating of the engine.

As the threads I've encountered all say that you need to inject the water/meth right into the throttle body, this seems to do nothing to lower the temps of my IAT sensor; which is upstream from the throttle body.

When I began to look into injecting further upstream (with the hopes of cooling the intake stream prior to the IAT sensor) it seems that no one was doing that. I suppose it either didn't work, cooled the sensor too severely, water came out of suspension/pooled in the inter-cooler, or some other such problem.

If WI will not help, then what other solutions do all of you use to cure heat soak? I've got a large barr/plate intercooler, placed and ducted into clean air.

what sort of AITs are you seeing? where is your AIT sensor exactly? you do have a FMIC?

No. Your ducting is broken.

If ur IC is the right size it should work.

Water injection is best when u have a seperate fuel and timing trim for when it is spraying. And a failsafe when not.

If you spray water on top of the tune you have now without trims or retuning, you will lose power.

Myself. I would not use WI on track. Another thing to go wrong. Just pay the price for some race gas and you should be safe from det.

You still need to redo ur ductig thoough.

And. How are u sure your IATs are climbing? Your AITs have to rise a LOT to pull say 3*.

Oh and what brain is gettin at:

Expose your AIT sensor bulb to the airstream. Sometimes they sit in a crappy little metal weld on sleeve that gets hot and messes up readings.

well I've never had that issue, so I'm surpirsed it's heat soaking during driving, on the trakc or not. I need more deets.

In all fairness, I am just assuming that it is heat soak. The symptoms are that I am down on power after 15 mins of track time and the cars I used to hang with are pulling me on the straights.

Next event is at the end of the month and I'll come prepared with an air intake temp gauge.

Here's a pic of my intercooler. The ducting seals up the nose pretty well.

I did relocate the IAT sensor into a steel inlet pipe with a steel threaded sleeve, from the OEM rubber inlet elbow. Good point that the underhood heat might be heating the steel tubing/sleeve which might be effecting the temps that the sensor is seeing. I see that some of you have moved your IAT sensor to the cold side pipe of the inter-cooler; perhaps for this reason? I'll look into this.

Thanks for your quick responses. https://www.miataturbo.net/attachmen...ine=1342039148

Move your IAT to the coldside of the intercooler right after the exit. You do not want it up in the engine compartment.

wait.
what?

We have AIT sensor on cold side because THAT'S THE AIR THAT'S GOING INTO THE ENGINE. Because that's how the ECU works, ideally, you want MAP and AIT sensors at the exact same location but that doesn't always work out for other reasons.

I can only assume that air temp on hot side is something retarded like 300F....

The factory location for the intake air temp sensor was on the cold side, but right up at the elbow that feeds the throttle body. On the forum's recommendation I'm going to relocate this to the cold side outlet of the inter-cooler.

Other Forum threads have elluded to the 120-130+ degree mark as to when the ECU starts pulling timing. Are you in general agreement with this range? Do you have an opinion as to how hot is too hot for an intake air temp?

no logging??? what is the point of having a damn ems?????
bleh

There is no agreement. It is a fixed table in the EMS.

Actually. What is your EMS?

Also it pulls like 1 crappy degree at 120*.