Tunable X300 ECM ?
#3
#4
#5
#7
I was referring to turbocharging the AJ16,not using a supercharger. Turbos are more efficient and have the potential to produce more horsepower than a supercharger. Usually your limitations with a turbo is due to fuel injectors,fuel,pump,ecm tune and a few other issues. You can easily double your horsepower with a turbo and the right mods,just as long as the engine can handle it.
Trending Topics
#8
#9
Turbo supercharging and positive displacement engine driven units will theoretically produce the same result. The problem with the crankshaft driven unit is the parasitic draw on the engine itself.
It takes about 60 HP to drive the Eaton M112 compressor on a 4.0 XJR/XKR for max output.
If you NET 370 BHP then the engine might produce 430 IF it did NOT have to use that power to drive the compressor.
The Turbine driven compressor takes time to 'spool-up' the compressor so you have to wait for the power to be delivered to the powertrain (trade-off).
In an engine that uses a constant RPM, the Turbo is the way to go (aircraft, farm or commercial tractors, generators, ground power units etc.). If you demand power almost instantly with varying throttle, then the mechanical supercharger is the way to go (DRAG RACERS!!!!!!!!!!!!!!!!!).
If you wanted to convert the XJR to Turbine driven compressor, then you have all the base components already there. The ECM is ready to accept the boost, the engine is configured for forced air induction and charge air cooling!
LETS SEE SOME PICS OF THE CONVERSION!!!!!
I'm in!!
bob
It takes about 60 HP to drive the Eaton M112 compressor on a 4.0 XJR/XKR for max output.
If you NET 370 BHP then the engine might produce 430 IF it did NOT have to use that power to drive the compressor.
The Turbine driven compressor takes time to 'spool-up' the compressor so you have to wait for the power to be delivered to the powertrain (trade-off).
In an engine that uses a constant RPM, the Turbo is the way to go (aircraft, farm or commercial tractors, generators, ground power units etc.). If you demand power almost instantly with varying throttle, then the mechanical supercharger is the way to go (DRAG RACERS!!!!!!!!!!!!!!!!!).
If you wanted to convert the XJR to Turbine driven compressor, then you have all the base components already there. The ECM is ready to accept the boost, the engine is configured for forced air induction and charge air cooling!
LETS SEE SOME PICS OF THE CONVERSION!!!!!
I'm in!!
bob
The following users liked this post:
someguywithajag (09-26-2018)
#10
If the turbo system is designed right and tuned right,there is almost no noticeable lag on a current turbo system. Turbo lag is becoming a thing of the past if it's properly sized for the system. It's also a matter of getting the fuel delivery programmed just right and having the proper parts to deliver it to the engine.
#11
The limitation of the standard engine management system is the airflow meter. The version on the XJR6 can only read about 1018kg/hr. If you want to build a turbo version of a naturally aspirated AJ16 engine, and exceed this airflow, then no additional fuelling will be added, assuming you have already transferred the airflow meter, injectors, twin fuel pump and ECU from an XJR6. I can reprogramme the fuel map to add more fuel. I have a long term ambition to build a twin turbo AJ16 engine of about 600bhp. I intend to use the airflow meter to only measure half the airflow and then reprogramme the ECU to double this value. The bottom end is extremely over-engineered, so 600bhp may well be possible. However, I would plan on adding piston cooling jets, and much increased coolant flow rate. The cylinder head gasket will probably fail before the bottom end.
The following users liked this post:
someguywithajag (09-26-2018)
#12
So basically what your saying is that your going to trick the ECU into thinking it's only getting half the airflow coming in. What would be the need for twin turbos? I would think a properly sized single turbo would be able to get to 600hp assuming you can keep the engine from detonating. What do you think the maximum boost level that a naturally aspirated 4.0L can handle in stock form? What about a thicker head gasket or doubling up the head gasket to lower compression ratio? Do you think it would be able to handle somewhere between 10-15 lbs of boost and still have a sufficient air/fuel ratio under boost? What about running a water/alcohol injection system to cool the cylinders down. How well can you alter that ECU?
#13
People who talk about turbo lag have never driven a car with a modern turbo with ceramic ball bearings instead of the old sleeve bearing type of turbos. This makes a WORLD of difference in the responsiveness of the spool time of the turbo. Modern turbos are way better than the old technology turbos from the 1980's - 1990's
#14
Two smaller turbos will provide much better response than one large turbocharger. Response is still an issue with state of the art turbochargers, even with GDI engines with VVT that can run higher levels of valve overlap. Anyone who has seen a constant engine speed response test on an engine dyno in which torque, manifold pressure and turbine speed are all measured couldn't argue that even a well matched turbo can take around 2 seconds to spool up at low engine speeds. I wouldn't pressure charge a "naturally aspirated" AJ16 without replacing the stock 10:1 CR pistons with something much lower. The pistons from the supercharged engine are 8.5:1 which would be OK for 400bhp. If you want more than 400bhp, I would be tempted to go lower, or restrict operation to higher octane fuel say 98RON (93 pump octane). I wouldn't recommend fitting two head gaskets to try to lower the compression ratio. The gasket is already likely to be a risk at high boost pressures, so fitting two of them won't make it any more reliable. The supercharged engine peak boost pressure is only 7PSI. If you run 10PSI you will certainly be saturating supercharged airflow meter and significantly reducing the level of over-fuelling. This will increase the risk of detonation. Water injection would help. I can reprogramme the engine ECU to artificially enrich the fuel map to compensate for the air that is not measured once the airflow meter is saturated. For my twin turbo project I plan to modify the software to double the measured airflow, but only measure half of it with a standard airflow meter from a supercharged engine. This will effectively double the airflow measurement range of the engine management system. I haven't built a test intake system yet to split the airflow in half, so I haven't been able to prove out the system yet.
#15
What about a different MAF?
Definitely an interesting topic, especially if successful, reliable and it could one day be developed into a step-by-step "kit" that others could follow.
The performance options for the X300 drivetrain are so limited in the aftermarket, it would be great one day to collect "kits"(in concept, not to buy from a vendor) into a list based on cost, difficulty, performance and reliability that owners could then choose and save on research and frustration.
So this avenue will prove interesting to watch over time.
Andy, given your expertise I'm sure you've already considered if a different MAF could be used with the OEM ECU that could accommodate a higher intake airflow rate.
So I'm curious what you've discovered that would keep you from using a different more modern higher capacity MAF versus the somewhat complex method you've described of using the OEM MAF, dividing the airflow and then multiplying the value by 2 in the ECU.
.
The performance options for the X300 drivetrain are so limited in the aftermarket, it would be great one day to collect "kits"(in concept, not to buy from a vendor) into a list based on cost, difficulty, performance and reliability that owners could then choose and save on research and frustration.
So this avenue will prove interesting to watch over time.
Andy, given your expertise I'm sure you've already considered if a different MAF could be used with the OEM ECU that could accommodate a higher intake airflow rate.
So I'm curious what you've discovered that would keep you from using a different more modern higher capacity MAF versus the somewhat complex method you've described of using the OEM MAF, dividing the airflow and then multiplying the value by 2 in the ECU.
.
#16
I think putting a turbo kit together would be great. The only downside I see is how many people would be willing to invest to purchase a kit that would probably be approx. $2K-$3K,and the dwindling amount of X300 cars out there. I'm sure they would have sold well when the car was just a few years old but now they're all hitting 20 years.
#17
#19
Do you have the tables for fuelling and ignition maps? It might be easier to use an aftermarket ECU like Megasquirt if you already have that data; as those tables are the difficult part to generate.
#20
There are literally thousands of pieces of data in an OEM ECU such as Lucas / Sagem 6.2. Many of the functions that they control would not exist in an after market ECU. Thousands of man hours (many of them my own) went into calibrating this system, I don't intend to throw it all away. A twin turbo installation would lend itself to twin MAFs anyway. It is just that I will use the signal from one of them, and will need to try to balance the flow between the two.