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 Thursday at 02:56 AM 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

 

[jeffer949]

This is the one ive been looking at. https://www.siliconeintakes.com/front-mount-intercooler/water-to-air-intercoolers-p-213.html

I believe i have room on the intake side right by the strut tower to sneak it in . 

 

I'm not doubting that its working well.  And the fact that your not seeing those spikes is due to the thermal mass of the intercooler and antifreeze thats in it soaking up the heat from the charge temp.   I guess my thinking is when is a colder IAT not a good thing?  And what are you trying to avoid by having it run all the time?  If its noisy and it bugs you. Sure, I can understand that.  Its only pulling a few amps and I just dont see a downside other than maybe noise from the pump.   With that said. Ill leave you alone to your decision.  I dont run megasquirt currently but it seems that the simple way would be on off with a relay that you could tie  into which ever data point you want. There isnt going to be one right answer for this.  When autocrossing I would want it on 100% of the time.   

 

On your turbo setup.  How do you like that turbo? When does boost come in? That turbo has been on my radar for the future. Im not looking for a hp monster any more. I want 300 ish hp to the wheels on my wagon. Its a cruiser not a drag car!  What i want is power lower in the rpm range. I wont be getting the protunerz manifolds. while nice i know i just wont spend the money on them. But I may be convinced to go away from my 2nd hand cheapskate tendencies to get a nice turbo for once. 

[Datsunpowers]

The first engine was a stroker turbo engine where I had hopes of big power with the ProTunerZ manifolds. I wanted a turbo capable of high boost. This was is where the GTX3071R Gen II came in. Well having the wastegate hoses switched and a speed contest with a Toyota Camry TRD and to rich of a tune scuffed two of the six pistons. This toasted engine one, an expensive lessons learned the hard way.😆 It was dam fun to drive at 20 Psi! So Engine number two is a stock setup with 10 Psi and I finished the final intercooler design. Engine three and two years later is another stroker turbo with 88mm JRE forged pistons that I hope to finish the next two weeks. Its finally out of machine shop hell. The plan is to unbolt all the good stuff and move it over to this new engine. I hope the third time is a charm! I tell you all this to say the turbo has been one of the best parts so far it just works and works well at high or low boost levels. Its definitely a quality piece, but wasn't cheap. I did purchase it from Full-Race Motorsport Black Friday sale. I think it was 20% off. 

 

I enclosed a chart with several second gear full throttle pulls. Hope that shows you what your looking for. I also enclosed the compressor map from Garrett Boost advisor at 375HP.

 

 

                                                                                                                           Garrett Boost Advisor GTX3071R Gen II Turbo 375HP

 

I know when I first started trying to fit an air-to-water intercooler. I could get a smaller barrel intercooler to fit with the stock turbo and manifolds by replacing the J-Pipe and placing the Intercooler in its place. This would leave room for the stock AC compressor if it had AC installed. The reason I didn't go that route as its only rated for a max of 290HP. What you don't get from product description is a lot of tech specs about its cool capacity, so I passed one this one. 

 

When I went to the larger turbo and manifolds. I didn't have the room that I did with the stock setup. The compressor housing is bigger on the GTX3071R and this moved everything out against the shock tower. I wasn't a fan of cutting up my new compressor housing to weld a short 90 degree elbow on it. This is where I came up with the current design to pipe it down and up to the larger Intercooler to handle the heat of the higher boost levels. I just didn't have the room with the larger 600HP rated core between the strut tower and the engine. My recommendation is to mock the one your looking at in carboard and see if you have enough room between the engine and the strut tower. 

 

Good Luck!

[jeffer949]

Thabks for the info. I'm pretty sure I have a bit more with in my engine bay than a s30 does but yes I like the idea of making a cardboard mockup. Or maybe even 3d print one.  

 

Sorry to threadjjack. But thanks for the info