Are you guys triggering something via IATs?

Cause my experience is an IAT map is a fuel trim that leans fuel as IATs rise (less molecules air per volume) right?

I havent understood how a fast acting AIT sensor is a reliability mod.

Or do you de-linearize your IAT correction table so it doesnt correct for air density over a preset high temp.

Or do you just want to know what your IATs are in the logs with less lag?

 

For me specifically, my tuner has the car go into a “limp/safe” mode if IAT gets too high to prevent any (possible/further) damage.

 

@Howard Coleman I just remembered that during my last dyno tuning session, we realized my IAT sensor was not working right. The shop I rented the dyno from had a GM IAT sensor that they welded into the intake pipe right before my Greddy elbow. I remember my tuner saying he prefers the GM Fast IAT sensor over the one I got from LMS. Is this sensor still thermistor based?

Sorry…my memory is a little hazy between work, the three kids, and I think my brain trying shut out the PTSD of this car…

 

Yeah it's still a thermsistor. It's super nice to have thermocouples. But, for the record. There's plenty of reliable single turbo setups using the stock IAT sensor.

 

ya its a thermister. im actually currently running 2x IATs
gm open element right after ic core and a triumph "fast reacting" in stock location. running ai so the stock location one kinda helps to see the temp difference. i am curious in this thermocoupler sensor for stock location though

 

The triumph is the one LMS sells. It was acting wonky during my last tuning session and way slow so the GM one was welded into my intake pipe. I like the idea of two but I’m out of inputs on my Haltech to be able to use two.

With AI, I guess I’ll need the injector before my IAT sensor. Not sure it’s a great location. I think I’d want the injector closer to the TB but I probably want my IAT post injector

 

while it might be helpful to you, you probably don't need to change your IAT to a thermocouple. if you do wish to use IAT as a "Failsafe"... as Nelson set in your map... you would need to use a thermocouple as it is the only sensor that will accurately and, more importantly, not be so laggy as to report a 200+ IAT should it occur. . there are other "Failsafes" that will help your motor should something malfunction... boost and AFR.

i operate in the 500/600 area and do need to know my IATs as well as find ways to lower them. not so much in the 400 area. i did some calculations, which i won't bore you with, and just as an FYI come up with about 145 for you around 400.

as to apex seals, i would use whatever your builder feels is a fit. apex seals have not been your problem other than the OE seals which lost their tips due to detonation. the warping has been due to excess combustion chamber heat and your AI will cool things down a bit. we all have our favorites, ask 10 of us and you will get 10 diff answers. system setup is the key to happy seals.

 

is the 145 with or with out AI?
and is that max temp BEFORE you should get into boost? I try not to get into boost at above 120f

I might still be willing to do a thermocouple in uim, was looking at m10×1.25 to npt adapter

 

i find temp outputs from turbos to generally be between 300 and 500... in boost.

since the 8374 is a "modern" efficient turbo and you are in the lower end of the boost scale i picked 350 F to do my calcs.

really good intercooler cores are around 67% efficient.

general engine bay temps around the area where the air filter is are 125 F. considering your air filter is located in the exhaust stream from the radiator and near the IC it is probably inhaling air at 150.

i decided to split the range and used 137.5.

350 F minus X / 350 F -137.5 = 67%

X = 142.3F assuming the IC is 67% efficient.

water as injectant will not significantly impact IAT. Methanol will lower IATs by as much as 40 F. water has more of an impact within the combution chamber.

 

@Howard Coleman just making sure you aren’t confusing me with @AlexG13B. I’m likely going to stick with my current IAT sensor. I know my tuner has other failsafes in place. Getting my combustion chamber temp down is the #1 goal right now.

 

One thing that bugs me about the WI systems like AEM is lack of RPM input. So, at higher RPMs you're getting less water per combustion cycle. Seems backwards.
Anyways, it's way better than nothing.

 

I have heard the controller is now progressive so you say the boost you want it to come on and the max. I assume that’s better than nothing. When I’m at high boost, 99% of the time I’m at higher rpm

 

"at higher RPMs you're getting less water per combustion cycle. Seems backwards"

since maximum cylinder fill (peak combustion chamber pressure) is at peak torque, not peak rpm or power, this isn't a big deal. any properly tuned fuel map has a slight downturn in fuel flow from peak torque to peak rpm.

AI can be very delivery specific if you wish. control the flow using your ECU. requires adding a solenoid, easy to do but not necessary for most.

 

I think you guys may be over-thinking it a bit. Yes you can basically set up a water injection system like a full fuel injection-type setup, I know Howard has done that, with a full 3d injection table and everything. If you do that you have to tune for it and set up a lot of things for it.

The AEM setup is very basic - run a vacuum line to the controller, set your start boost and end boost, and go. I have mine set to come on around 7psi and max out at 14 psi.

Guess what? My air temps drop like a ROCK when it's running, my 15 year old motor is solid and makes great compression, and I haven't touched or messed with that system since it was installed. Just poured in more windshield washer fluid. Which, FYI, doesn't go down that quickly.

Just use the medium-sized AEM nozzle, put it in the TB elbow, set up the controller, and enjoy life.

Dale

 

Thanks, gents. I was thinking the new ECU's could comfortably control the AI mapping, and that would be an improvement.

 

100% agreed. My AEM v1 kit worked flawlessly for a whole decade. and it is now on a different car working fine. The only reason why i got rid of it is because i have the pdm control my water injection system now, so all i needed was a pump.

In some cases though that huge change in temperature might be a false reading because the water (or methanol) in this case goes right on the sensor. It all depends where everything is placed. I am not saying that yours is like that but i have often encountered this problem with other setups.

@Djseto
I read the last few pages in one sitting to get an idea what's going. other than reading the last few comments
Do you have any of the logs to share here? Sorry i dont think i saw them reading through the pages. My apologies if they have been posted
How much vacuum is the car pulling on idle (and what rpm) ?

the heat is mentioned a few times. what kind of EGTs were you seeing? Where are the probes located ?

I am very curious to see that. In my 10 year old setup i would often see 1000+ C (even 1100C) from times and i never had an issue where the seals wouldnt hold.
I switched setups now, and my EGTs have dropped but the engine is still the same and still running strong..

at 14psi i highly doubt that your issue is not running AI despite all the benefits you get from using one.

 

@R-R-Rx7

• I do not have sensors for EGTs. In hindsight, I wish I did that with my Haltech setup when I was having my harness made.
• I do have logs from my dyno pull with iRotary and my last dyno session with the current Rotary Aviation Seals. What specifically do you want to see or do you want the whole logs?
• Looking at my logs...I idle around 1000rpm and my manifold pressure at 1087RPM is -15.3 inHg

 

you dont need to integrate the EGTs in the harness , but if you are planning on using the Haltech can TCA2 (or TCA4) all you need to do is hook up the the EGT amplifier the can network directly and then straight on the manifold.
I personally went with the TCA4 (4channel as opposed to the 2channel of the TCA2) so i can use thermocouples in other areas. In my previous setups, i had 3 EGTS, 2 pre turbo and 1 post turbo but i felt that this was an overkill so on my newest setup i didnt use a post turbo one.
EGT sensors often fail, i would have a separate "harness" for them. I have destroyed more EGT sensors that i can count.
so switching the sensor from the manifold all the way to the amplifier is the right way to do it if you are asking my opinion. I have added an EGT connector half way to make it easier (as mine is RHD) but on the LHD it should be a lot easier without any connections.


I am not saying that the EGTs will prevent all the engines from blowing up but at least you will have data and a sensor that will detect that something is wrong. They are pretty fast to react

-15inHg is pretty decent. is this the current vacuum or was that pre dyno? How has this changed pre-dyno vs post dyno ?

 

@R-R-Rx7 it is the current vacuum. I'd have to check the logs for what it was pre-dyne but I know Nelson watches all log data like a hawk so if my vacuum levels weren't good before we started the dyno pulls, he would have called it off.

 

Technically your current vacuum is good this is what makes me wonder

 

"I have destroyed more EGT sensors that i can count." i was in the same boat but think i found the cure:

https://www.rx7club.com/single-turbo...-will-1154841/


"What specifically do you want to see or do you want the whole logs?"

i would like to see your timing lead and split at your target boost.

"your current vacuum is good"

yes

 

ok. What are that metrics typically called? These are the metrics my tuner setup during logging.

 

not on the list, normally called ignition angle

 

Gotcha. Let's assume for now that my tuning is good given Nelson's reputation for not blowing engines up and Haltech telling me the tune looks fine, aside from AI, anything else I should check? Could adding water via AI help clean up the internals and possibly free up any stuck springs or side seals that perhaps is contributing to my low numbers?

Those RA Super Seals have also been Cryo treated according to Bryan at Rotorsports and given I've not pushed anything more than 14psi, I can't imagine they've warped. When I spoke to RA, they said 14psi isn't remotely near the pressure that would cause these seals to malform. Now, I know heat certainly can change things but short of a new engine, I want to make sure I explore every angle.

 

i would personally do it the other way around, assume that Nelson has no reputation and you want to see what the hell is on your map. While i do understand that his map is his "intellectual property", when there are issues like what you are experiencing you need all the information you can get.

Dont take this as an "attack" at Nelson. I know Nelson personally and he has tuned my car in person a good decade ago and i didn't have any actual tuning issues with the timing. I would still want to see what's on my map to rule out the tuning from the root cause.