locospl

iTrader: (3)

I'm looking to move my IAT to the intake manifold just behind the throttle body. My IAT is currently about 8" before the TB and leaves no room to install the meth nozzles between the BOV and IAT.

Anyone running their IAT in this location on a LS3 intake? If so did you do anything other than drill a hole and thread it in? Any cracking or boost leak issues?

89ROC-Z

iTrader: (11)

I'd like to know as well.

Slow94Formula

iTrader: (18)

I put mine in the hole where the MAP sensor is supposed to go. Just drilled it out and tapped it for the sensor. Threaded it in carefully and it was good to go.

JAX04

iTrader: (17)

Curious about something, you bring up the BOV placement in relationship to the Meth nozzle, what about people spraying pre-compressor?

toytech93

iTrader: (2)

water/meth vents into the engine bay when the BOV open, sounds messy

blake b

iTrader: (11)

I measured the width of the IAT threads, found a drillbit slightly smaller and drilled a hole. Then I used the IAT as the tap and just screwed it in. I did put some thread sealer on the IAT threads. I used the Indian Head stuff that seems to be resistant to every chemical.

I sold that intake and have to do the same thing to my LS7 intake...

Forcefed86

iTrader: (4)

You don't want your IAT sensor post meth injection.The sensor bulb gets saturated with alky and evaporates causing false cool IAT readings. Defeats the whole purpose of the IAT sensor. Esp. if the sensor feedback controls timing/fueling. IMO leave the IAT in the piping and run the meth post IAT sensor.

The 50% or less water/meth mix (by volume) isn't flammable. Thats what most distributors suggest. (for that reason IMO) I spray 2gph pre-turbo and 14gph at the TB. I've never seen a trace of fluid on or around my BOV. Never found any fluid in my IC either. I believe it flashes to steam pretty quickly in small amounts pre-turbo at decent boost levels.

Ping King

iTrader: (20)

I see what you're saying as far as the false readings, but isn't having the IAT sensor post meth a way of confirming that the meth is indeed being injected? This allows an IAT correction in the ECM to provide more timing/less timing?

Forcefed86

iTrader: (4)

I played with meth for many years back in my turbo buick buick days. I replaced roughly 30% of my WOT fuel with 100% methanol inj. And that did require timing changes.

Here is my opinion on most LS guys I’ve seen using it.

1.) Most don’t spray enough meth to require additional ign lead.
2.) Most do more harm than good trying to add timing with it. Add boost leave timing alone, watch the plugs.


I’d suggest an LED wired to an inline pressure switch if you wanted to confirm 100% when/if meth is being injected. I just wire an LED to my meth pump, or watch the progressive controller on the nicer kits I’ve used. Not full proof, but I never had a problem.

Ping King

iTrader: (20)

Makes sense to me.

denmah

iTrader: (2)

stock ecu + IAT sensor in the intake = major tuning issues with drivability

the stock PCM can sway fueling completely lean or rich if it wants to just because of the IAT temp and its difficult or near impossible to fix

i used to install them in the intake, well i still do with megasquirt, but if its stock pcm i just use a 4.7k resistor (57f)

rotary1307cc

iTrader: (5)

I definitely wouldn't be taking that advise

dmaxvaz

iTrader: (1)

which advise is that? soo many people drifting in rt and lt field regarding this question

locospl

iTrader: (3)

Thanks for the replies and pics. I understand the differences in spraying meth pre and post IAT. I am not going to use meth to help with fueling as my system is more than capable for my HP level. Meth will be sprayed just to cool IAT's to prevent timing retard on hot summer days. My car is a driver so it sees some long drives and will be heat soaked quite often.
I am going to put my meth nozzle between the BOV and IAT in the charge pipe or move the IAT to the intake. Meth will still be injected pre-IAT.

locospl

iTrader: (3)

What would cause the difference in fueling with the IAT in the intake Vs the Charge pipe? My IAT is currently about 3" in front of the TB. Is it heat soak inside the intake when the TB is closed?

What are you using the resister for? Is it just to fool the reading to the PCM?

Blown06

iTrader: (32)

This is dumb. Meth should not be spraying while the BOV is open. The BOV valve should only be open in a vacuum situation. Always closed while in boost.

locospl

iTrader: (3)

Meth would still be in the charge pipe when the BOV opens as TB closes. During the transition from boost to vac meth is blown out the BOV.

danieloneil01

I drilled a hole behind the TB on top of the intake (LS6) and used a rubber grommet to push the IAT sensor into. It doesn't need to be threaded.

rotary1307cc

iTrader: (5)

I mean on deleting the IAT and making it inactive as probably some of the dumbest advise i have ever heard

making driveablilty and fueling better in different conditions by taking the IAT out of function...... brilliant

cylinder airmass doesnt change with air temperature variance does it

I can start my car at 20* or 100*, and make a pass with 80* IATS or 200* and fueling is money

I would suggest anyone who is deleting an IAT sensor to maybe take a look at cylinder charge temperature bias

Forcefed86

iTrader: (4)

Wish I had more experience with HPtuners trying to understand it all myself. I want to use it on the next build. Could be totally wrong here but From what little I’ve seen...

The problem lies with uneducated folks using HP tuners and the GM NA IAT trim table with forced induction. The AFR/Timing jumps around too much doing this. I’d think it would really throw things off if you change map sensors as well? Or does HP tuners scale the table to the new map sensor?

As said you need to adjust the IAT trim tables for the IAT input to function correctly, makes sense to me. Though If you don’t know how to do this properly, your probably better off disabling the IAT trim table (or adding a resistor. Same thing really). To me it seems more “idiot proof” to lock the timing value to the main timing table with no IAT input/trim. Then let the WB02 trim the fuel tables for minor changes. Not ideal, but not as likely to melt an engine if you don’t drive in extreme opposite temperatures. Again I could be totally off here Just trying to learn.