zero maintenance supercharger?

[dcmdon]

Too many short trips. If I bought a diesel, it would carbon up and break. Know your vehicles needs before you buy it.

When I first retired from the AF, I was a shop maintenance manager for Caterpillar and then Detroit Diesel. Long haul trucks do great, but I saw a lot of pickup trucks with carbon problems. Don't even get me started on Generators. We would need to take a load trailer out yearly to get them warm enough to burn out the carbon. The places that went cheap and didn't the units would always fail when they were needed.

A friend of mine used to own an oil company. He paid 20% more than new to buy late model low mileage old tech trucks to use for oil trucks.

The particulate filters are a nightmare for oil trucks. They tool along at low speeds doing their deliveries and never get hot. Then they idle for 10 minutes at each delivery so the engine can turn the oil pump.

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[Griepp06]

i have someone that locally is selling the Hamburger stage 1 kit after trading in his gladiator and putting it back to stock for that trade for $4K. i am considering it but that's why i am seeing what the long term dependability issues are for these kits.

 

[DAVECS1]

i have someone that locally is selling the Hamburger stage 1 kit after trading in his gladiator and putting it back to stock for that trade for $4K. i am considering it but that's why i am seeing what the long term dependability issues are for these kits.

Would be happy to work on a tune for that setup. I have looked at some of the data and there are a couple of changes that should wake it up down low. It will require datalogs and testing.

 

[ShadowsPapa]

You guys eat Meow Mix too?

You should see those guys party!

 

[Griepp06]

How does elevation change effect a custom tune? I spend most of the year at 900 feet but I try and visit my brothers in Denver at 5000 feet and then we go snow boarding at 13000 feet and I may or may not be pulling a 4000lbs trailer which is the big reason I am looking at boosting the 3.6.

 

[DAVECS1]

You should see those guys party!

Kind of more like this

 

[DAVECS1]

How does elevation change effect a custom tune? I spend most of the year at 900 feet but I try and visit my brothers in Denver at 5000 feet and then we go snow boarding at 13000 feet and I may or may not be pulling a 4000lbs trailer which is the big reason I am looking at boosting the 3.6.

There is an option in the setup to theoretically calculate VE instead of using the MAP sensor. Jeep sets it up from the factory to do this for most of the load range. VE is directly affected at Altitude as it significantly changes manifold pressure.

I have enabled real MAP sensing and VE, and the fueling needed with it.

 

[dcmdon]

There is an option in the setup to theoretically calculate VE instead of using the MAP sensor. Jeep sets it up from the factory to do this for most of the load range. VE is directly affected at Altitude as it significantly changes manifold pressure.

I have enabled real MAP sensing and VE, and the fueling needed with it.

I would think it wouldn't change a thing. It measures MAP. Key word is ABSOLUTE pressure. So it doesn't matter if you have -8in Hg, with wide open throttle at one altitude or partial throttle at another altitude.

What am I missing?

 

[DAVECS1]

I would think it wouldn't change a thing. It measures MAP. Key word is ABSOLUTE pressure. So it doesn't matter if you have -8in Hg, with wide open throttle at one altitude or partial throttle at another altitude.

What am I missing?

Your missing the fact that jeep does not measure map until 98kpa in your factory tune. I have seen aftermarket tunes that raise that number even. Thus absolute pressure in VE is not done based on sensor data but calculated airflow through the throttle body

 

[dcmdon]

Your missing the fact that jeep does not measure map until 98kpa in your factory tune. I have seen aftermarket tunes that raise that number even. Thus absolute pressure in VE is not done based on sensor data but calculated airflow through the throttle body

So you are saying that until you are at wide open throttle. (essentially 98 kpa??) its deriving based on some kind of mass airflow sensor? (hot wire sensor?)

 

[DAVECS1]

So you are saying that until you are at wide open throttle. (essentially 98 kpa??) its deriving based on some kind of mass airflow sensor? (hot wire sensor?)

Not even that, that would be more ideal. It is calculating based off an array that tells the system when the throttle body is opened by a certain voltage, this is how much air it is capable of delivering at a given RPM.

 

[dcmdon]

Not even that, that would be more ideal. It is calculating based off an array that tells the system when the throttle body is opened by a certain voltage, this is how much air it is capable of delivering at a given RPM.

So just a throttle position sensor??

 

[DAVECS1]

So just a throttle position sensor??

So just a throttle position sensor??

Nope, just this table right here

 

[ShadowsPapa]

Not even that, that would be more ideal. It is calculating based off an array that tells the system when the throttle body is opened by a certain voltage, this is how much air it is capable of delivering at a given RPM.

OK, but what about pumping efficiency? Some engines can actually reach about 130% pumping efficiency, meaning even naturally aspirated, the valve timing, overlap, LSA and other factors allow it to actually pull in more air than what fits in the chamber at normal atmospheric pressure.
In other words, at BTD, it's got more air in the cylinder than 100%
A DOHC engine can easily pull in more than 100% At BDC you have more than atmospheric pressure before the piston compresses it.

 

[DAVECS1]

Volumetric efficiency calculation is based on available intake air VS power level and load. Most tables have their axis stop at 102kpa naturally aspirated.

Many supercharger companies if not all, change that table I posted, including me. It allows you to trick the engine into thinking there is more capacity to the engine to be had at a given throttle position, as the internal code has airflow limits based on engine size. These are not adjustable. The problem is then VE is way off. At WOT it uses a strategy closer to Alpha-N fueling so no biggie and why most superchargers for this engine are setup to work when the throttle is floored. The problem is part throttle suffers as VE fueling, load, spark, and cam timing are all based on a false airflow now and the claculated torque is way off. Thus the weird throttle oscillating and power surges.

I digress, sorry to start a thesis in the thread.

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