Unreal

Why not just put IAT sensor in pipe before TB. I use a push in grommet IAT and never had an issue, even with 25psi.

I see 130F after Meth. Premeth, who the hell knows or cares?

Streetk14

I mounted the CTS-V IAT2 sensor right behind the throttle body in the manifold on my LS3. I'm sure there is an accessible place for one on an LS7 manifold.


Agreed. While having pre-meth data is interesting, I want to know what's going on inside the plenum. Being able to tune the IAT/spark tables are also a big plus.

Turbo-Geist

Here is what I am understanding from this thread:

1. The IAT sensor is in the MAF and the meth is being injected downstream of the IAT sensors and just before the throttle body.

2. IAT temps are being read from an IAT sensor that is in a pipe which is being subjected to hot air coming from the radiator fans and engine compartment heat.

3. The actual temperature drop due to the methanol ijnjection is unable to be logged as a data point and therefore making a determination on whether the engine could use additional methanol is hard to determine.

I know it sounds like the IAT temps are high, but they are not out of the realm of what would be expected post intercooler at 20 psi during a half mile pull.

OEM factory turbocharged cars routinely see 290 def F temps before the intercooler and experience a 120 deg F temperature drop. This puts their IAT temps at 170 deg F prior to the throttle body.

Have you ran any of the data for this project through a flow simulator to determine if the system is functioning as designed?

schpenxel

Your understanding seems correct to me.

I would think adding an IAT after meth (either in intake or at least further downstream in the charge tube) would be your best bet

The current setup is not giving the ECM accurate info on the temperature of the air actually going into the intake.

Turbo-Geist

Here is what some of the analysis data would look like:

Given
Inlet air temperature: 90 deg
Ambient intercooler temperature: 90 deg

Compressor efficiency: 75%
Manifold boost: 20 psi

Intercooler efficiency: 70%
Pressure drop: 1 psi

Methanol injection rate: 1000 cc/min
Methanol temperature: 90 deg

Find temperature at each point

Temperature at compressor discharge: 294* F
Temperature drop from intercooler: 177*F
Temperature at intercooler outlet: 152* F
Temperature after methanol injection: 95*F

I left out some of the parameters to keep the post simple, but in this scenario, the system starts out at 294* F leaving the compressor and after the intercooler and 100% meth injection the IAT is 95* entering the engine.

This depends on giving the methanol injection enough time to properly mix and cool the compressed air.

Obviously, in order to dial it in for this combo there are some key items that need to be known:

Compressor efficiency (located from compressor map)
Intercooler efficiency
Methanol injection rate
Methanol injection temp

This would allow an analysis of the system, a comparison of what is occurring in the field and adjustments to deliver desired performance.

grocerygetter

Show me a picture and part number for the sensor for this please. It can be via pm if you choose. Thanks man!

Unreal

Look at my 10 different build threads. No idea on part number. Got it from ECS with my kit.

chuntington101

Finally! Someone that finds the issue before trying it rather than tryng to fix what may not be the issue!

You don't need a flow simulator to find out if were the issue is. Just monitor temps around the system and see what is changing. If turbo out temps remain the same at 20psi no matter the length of the race then you know the turbos AREN'T the issue. If the temps constantly rise post intercooler, but not post turbo, then you know the intercooler is to blame.

If its the turbos and you bolt on a larger intercooler then yes you will see lower intake temps. But you are not solving the problem.

schpenxel

Call ECS, they have them. 609-752-0321

Also, you can use sensor part number WT382 (this would be one that screws in, not the rubber coupler pop in type Unreal mentioned)

Streetk14

This may not be correct, but I remember being told that the typical "push-in" IAT sensor couldn't be calibrated to read accurately -- at least on an E38 car. That's why I went with an LSA/LS9 sensor. I haven't really looked into this myself, but the info came from a reputable source. Just an FYI to everyone before ordering a sensor.

schpenxel

Haven't heard that, but would be good if someone could confirm/deny. I've never used one, so I just assumed they could be made to work properly

I do know a WT382 sensor can be calibrated properly for whatever that's worth

I set mine up wrong to begin with and had IAT's about 10 degrees under ambient there for a bit, lol

Unreal

Push in works fine on my car and calibrated just fine. Reads ambient when car is off from 40-120, so unless something is strange outside those ranges, it is perfectly accurate on my car.

BLOWNBLUEZ06@RKT Performance

^^^ FWIW, that's a Borg Warner part# from a 95 ZR1

WHITE_SHARK

I think before any major changes or upgrades you do to IC, as advised, please just relocate the IAT sensor before the TB/Post meth. I think you will not check this thread again lol.

I bet no one in this forum suffering from IAT as me, usually I see between 250F-270F at the end of 1/4 mile, running dual nozzle spraying before the IAT sensor, running the procharger race A2A intercooler with F2 procharger (heat generator) at 24psi with 4l80e tranny. For my case, the cure is to switch to A2W or add a 50 NOS shot or switch to more efficient unit like F1X (which I will do it again as last trial with supercharging my vette)

EX1

Nitrous from my experience does very little to help IATs unless you are running a very large shot. My car only saw a 10* difference in air temps from a 100 shot. I bet you would see very little from a 50 shot.

Rkreigh

I'd really like to see what a direct port meth system could do to help this situation

the ttix intercoolers are pretty good but as you hold boost for a long time they are going to heat up and not be able to keep you out of detonation

use the meth as your intercooler and get the car tuned for it.

it will quell those high IATs and provide chemical intercooling and better distribution all of which should keep you out of detonation.

to go much bigger on the TTix you'll need to do some fairly sizeable frame sectioning to get the clearance needed and modify the manifolds to support a bigger T4 turbo

all of which are pretty tough to do, a better manifold that is fitted similar would be better

also consider the champion 3" down pipes. the TTix chokes off at high boost and running dump tubes would also help your back pressure issues quite a bit

nice ride!

I'm going to try e85 on my car to see if I can get some advantages out of the cooler running and higher octane fuel.

neverstop

crazy, surprised to hear that much of a shot did that little. I think SloPoc was seeing like >50* drops in IAT off a 100 shot at the ~940whp level (with nitrous). I have seen some pretty big IAT drops on the kenne bell cobra crowd with just 50 shots so I'd think a 100 shot would do wonders

schpenxel

Where were the temps being measured at and where was the NOS being injected at? I would bet those two things are the differences.

Xtremespeed

#12614717 is the screw in style iat sensor if you still need one.

Turbo-Geist

Spray the nitrous or meth downstream of the IAT sensor and you aren't going to be able to datalog the temperature difference.

Anyone that thinks nitrous doesn't cool, talk to the Czar.