I recently installed an MP122 in my 2000 ECSB Z71. I have a 2.8 inch pulley and it makes 13-14 psi currently. Got it tuned and it runs good but the IATs seem consistently 40-60* higher than ambient. The setup has the 90mm J-tube and 90mm TB and a 4 inch CAI that picks up air from outside the engine compartment - the filter is down in front of the passenger side front tire below where the stock airbox was. No MAF, running SD. I am spraying 50/50 meth with a snow kit and a 10gph nozzle - nozzle is about 8 inches in front of the TB. I have it set to come on at 4-5 psi and max around 12. The truck makes full boost just off idle so it sprays a LOT of meth. I also have a Canton 2 gallon tank for the heat exchanger as the tank that came with the kit seemed small. Running water wetter and enough antifreeze to keep things from freezing. Running 17.5* timing and pulls one degree when IATs get above 113. Pulls more as IAT gets higher.

With temps like they have been around here - 30s at night and 50s daytime - I usually see IATs around 90-100*. If I cruise on the highway for a while they may get down to 80-ish. The meth doesn't seem to make any difference in the IATs. The first 5 minutes that the truck is running the IATs will be 20* above ambient, but I guess once the intake heats up the IAT sensor gets heat soaked?? The sensor is in the intake.

If I go WOT the temp climbs instantly to the 120-130 range. It will recover fairly quickly. The water in the heat exchanger tank never really gets above about 100*. I am wondering if the 80-120* range is just normal for these setups due to the heat soak. I haven't had this setup installed in the summer, so if it will keep things in that range when it is 90*, I will be ok with it. I had a side mount whipple before and in the summer the IATs would get crazy. But the meth seemed to help a lot more on that setup.

Any input will be appreciated. Maybe this is normal for these blowers?

 

I can't speak to the 122, but my 1900 stays about 15* above ambient. 40-60 sounds high.

How big is your HX? Have you checked to verify that there is plenty of fluid and that the pump is working properly?

 

Your cruise temps seem a bit high but 30 degree rise on WOT is not bad. Is your reservoir plumbed before or after the heat exchanger? 100* reservoir coolant temps after the hx in 30-50* ambient air suggest an upgraded hx could help.

 

I am using the HX that came with the kit. It is about 10 inches tall and 22-24 inches wide, maybe 1.5 inches thick. Circulation is good. If I open the top of the tank the water is swirling around good when the pump is on. Water goes from the tank to the HX to the intake and back to the tank. There is about 3 gallons of fluid in circulation through the HX - way more than if I had used the small tank that came with the kit.

Thanks for your input.

 

Is the IAT sensor before the meth nozzle in the intake tube?

 

With the location & style of IAT sensor in the MP112 and MP122 Maggies, everything the OP is describing is very normal. You can get pretty aggressive with the IAT spark tables and still be okay.

What are your IAT's at the end of a run?

 

I forgot where the IAT sensor was...is it post rotor in the intake manifold?

 

Yes, it's in the front & top part of the manifold, where it doesn't get a lot of air flow across it.

 

This may sound silly but are you sure your plumbing of the cooling system is setup properly? Pump lower then reservoir, pump after reservoir pushing fluid into the heat exchanger, then to the blower and returning from the blower to the reservoir?

Those IAT's are really high for the 122 when its suppose to be more efficient and not have as bad of IAT problems as the 112. It might be worth it to have a larger heat exchanger built up. Another option is going with the RDS phenolic spacer to get the blower to stop getting heat soak from the engine. I will be taking that plunge soon bc I am trying to get all that I can out of my 112.

 

Yes that is exactly how it is setup. Sounds like I may need to pay less attention to the IAT numbers and get a little more aggressive with the tune. At the end of a run the IATs are between 130 and 150 with the weather like it has been. Don't know about summer temps. Depends on the ambient temp, humidity, etc.

I don't think it would be a good idea to move the IAT sensor to the air intake tube, pre-blower, would it?