L28ET Air-To-Water Intercooler Pump MegaSquirt Configuration Help

[Datsunpowers]

Hello HybridZ folks, I need some recommendations on my 1971 240Z Turbo on how to drive my Bosch Intercooler water pump with my MegaSquirt V3.57 ECU. This is the first time I have setup an Air-To-Water intercooler. What I really like about this setup is the cooling ability of the Intercooler and the very short intake track from the turbo to the manifold. My question for the forum is how to drive the pump as I don’t know how the OEMs do it. The Bosch pump (0392022002, flows 317 GPH, and pulls 3.2 amps) is used on Ford supercharged Mustang Cobras. I could use an On/Off setting or PWM configuration. It doesn’t make sense to leave the intercooler pump on all the time. Currently I just have a switch on the console to turn the pump on and off.

 

Possible MegaSquirt configuration options to drive the Intercooler pump is (On/Off or PWM). Configure the Water Injection option (Pump Output) to turn the pump On/Off at an air temp of 90 degrees. The MegaSquirt will provide a ground to the Intercooler Pump relay.

 

1.        On/Off Control: Configure the Water Injection option (Pump Output using Inj G) to turn an external relay on to turn the Intercooler Pump on with the MegaSquirt below.

 

2.        PWM Control: Configure the Water Injection option for PWM (PumpOutput using Inj G and Valve Output Inj Bank 1). Pump Output controls the external relay on and Valve Output supplies PWM ground for the Intercooler Pump. Setting the Valve Speed to fast will pump to operate properly I hope. I found this setup on the MSEXTRA site from "Prof315" controlling a Water injection pump not an Intercooler pump.    

System Diagram

 

Here are some pictures of my design that changed over several months. From a performance standpoint I let it heat soak until the intake air was 100 degrees and turned on the pump and it cooled the intake air to 55 degrees in 10 seconds.  It seems to work very well and has a quite operation.

 

 

 

 

 

 

 

 

 

Edited 9 hours ago by Datsunpowers

[A to Z]

Most car companies are going to have a switch operated off of intake temperatures is my guess.  If you want it basic, you can put it on a toggle switch and then turn it on and off as needed and maybe add an intake temp gauge to the cabin somewhere.  Another option is maybe tee off of the electric fan and let the fan operation also turn the intercooler fan on and off?  Call Godzilla Raceworks in Texas and ask them what they think.

[calZ]

I think PWM control based on intake temp would be the best, but I'm assuming you don't have an intake temp sensor? 

[jeffer949]

Hey. Ive been toying with running something similar as I dont want to cut up the front of my car (84 maxima).

 

My question is why dont you think it needs to be running all the time? Per your testing you state that it takes 10 seconds to bring the temp down from 100deg to 55 deg.  So your driving along(in mexico) and the intake temp is 75-80 deg and a car pulls up and you have a competition on who is faster.    Your intake temps are going to spike well above 100 deg right away then your pump kicks on and 10 seconds later(if not longer as i doubt that test was done under boost) your intake temps get under control.   

 

Any delay in the cooling will a hurt performance. My car currently has no intercooler and at a low 7psi my intake temps can go into the 160-170 deg in well under a second of boost.  An intercooler isnt there to remove heat after the fact like a radiator.  Its there to remove the heat before it goes into intake. sure use the MS to trigger a relay but id keep it on any time the car is running. 

 

 

[jeffer949]

On your setup, What size is your core and how much hp are you making?  What size of heat exchanger out front?  Like I said i like the idea. Id have to position things differently as yours is right where my ac compressor is and thats not going anywhere!!! 

[Datsunpowers]

Calz: Thanks for the Recommendation. I do have an Manifold Air Temperature (MAT) Sensor between the Intercooler output and the Throttle Body input that is connected to the Megasquirt ECU.

 

Jeffer949: My current engine is a stock L28ET set at 10 Psi and 440CC injectors operating at 6500 feet. The big upgrade was the Garrett GTX3071R Gen II ball bearing Turbo and ProTunerZ Intake and Exhaust manifold. It was a nice upgrade from the stock setup with very minimal turbo lag. I don’t know the HP level, but it’s been very reliable and fun to drive. I am almost done building my Stroker Turbo engine with 88mm JRE forged pistons and MaxSpeed Rods. I was thinking of turning up the boost a little more, but not to crazy as I daily the car to work if the weather is good.

 

Let me clarify my Intercooler testing. I heat soaked the Intercooler with several boosted passes over 30 seconds to heat it up to 100 degrees with the pump turned off. I then turned on the pump to see how fast it would bring the temperature down to see how efficient it was at removing the heat out of the air stream. This is where the temp went from 100 degrees to 55 degrees in 15 seconds. Now to be fair I did this testing last month when it was 50 degrees out. How well it performs when its hot at the autocross is yet to be determined. I will say before the Intercooler I would see very high temperature spikes under boost and I am not getting that now with the Intercooler filled with Antifreeze. I enclosed a datalog that shows the RPM, PSI Boost, and MAT. You can see how the Intercooler is working under boost.

Since I am not seeing big heat spikes under normal driving that’s why I want to turn off the pump until its needed. I have several choices to turn on the pump in Megasquirt.

1.        TPS % position

2.        RPM

3.        MAP (kPi)

4.        MAT Temp

I am thinking TPS could be a better choice vs. MAT Temp to turn on the pump.

 

Data log: The RPM is 6085, MAT is 69.7 degrees, and Boost is 9.9 Psi in a 3rd gear pull.

 

I agree with you about the Intercooler blocking the AC mount on the left side of the engine. Being the car is a 71 240z it doesn't have AC, but my thought is to use an original 240Z right side AC bracket and convert it to use a Sanden compressor.

 

Here is the link to the Intercooler and Radiator I used for the build.😀

 

https://www.siliconeintakes.com/front-mount-intercooler/long-flow-style-water-to-air-intercooler-p-219.html

https://www.siliconeintakes.com/electric-radiator-cooling-fans/air-to-water-radiator-p-1063.html