Since a Chevy 350 swap will be quite more expensive than this idea. Ive found that it would be very fun to plop a turbo in it so here is what I have in mind.

anti-surge 62mm-Turbine/57mm Comp Turbonetics Style turbo with a 7psi 38mm waste gate. The psi to the engine will be more about 5-6psi keeping the same effective CR as the XJR6 and a manifold merge as I don't want twins.
330-400cc Injectors small change from the 223cc injectors to borderline a Good AF while maintaining smooth idle without flooding or having to remap an impossible ecu. Hks ssqv type BOV. Air to Air intercooler mounted in front of the radiator.
so with that and other small pieces and small adjustments to how it behaves I believe it should output anywhere from 350-400hp let alone the sweet sounds of BOV.

 

We are curious, yes...

 

The 120deg firing interval of a 6 cylinder engine really lends itself to a twin turbo installation, as the std 242deg period cams will give complete pulse separation for each turbo, on a twin turbo engine.


The std injectors on the XJR6 engine are 5.125g/s = 307.5g/min = 410cc/min with the std 3bar regulator. The XJR6 mass airflow sensor will read up to 1018kg/hr. The pistons on the XJR6 at 8.5:1 compared with 10.0:1 on the naturally aspirated AJ16 engine.


If you turbocharge a std AJ16 engine and leave it with a 10.0:1 engine you are going to have rely very heavily on the knock control system to stop the engine detonating. This would probably still be the case even if you ran it on fuel that was much higher octane than the 95RON on which it was mapped.


Also the XJR6 a fitted with twin 80litre/hr fuel pumps. The naturally aspirated XJ6 only has a single pump, which will not supply enough fuel to achieve your 350-400bh target.


In my opinion you should fit all of the following parts from an XJR6 to your turbocharged AJ16 engine if you want it to stay in one piece;-


pistons
injectors
airflow meter
ECU
fuel pumps and controller


Good luck with your project. I know that the AJ16 engine is mechanically capable of producing >400bhp if all the correct changes are made.

 

Well the only problem is just a MAF from a xjr is 380-500 US dollars same with an ecu. What I was going to do was run a Single performance fuel pump capable of running what I require aswell as custom 350cc injectors that way when the MAF freaks out due to the boost and will naturally richen the mixture by longer pulses(i assume) giving me a better A/F. For the pistons aswell, with the amount of boost ran it will have at or below the same effective compression as the xjr has as the actual true boost would be about 5-6psi. correct me if any of this is not true or workable.

 

If you just fit higher flow rate injectors, the closed lop fuelling adaption will just try to correct the fuelling control back to normal, thereby cancelling out the effect of the bigger injectors.


I don't understand your statement:-


For the pistons aswell, with the amount of boost ran it will have at or below the same effective compression as the xjr has as the actual true boost would be about 5-6psi


As I previously advised a naturally aspirated engine has a 10:1 CR and a supercharged engine has an 8.5:1 CR. I don't know how you can equate a 10:1 CR NA engine running with 6psi boost with a 8.5:1 CR SC engine running 10.2psi boost.

 

Hmm? Effective compression is compression plus boost so with the XJR running 8.5:1 plus 10-10.5 psi would equate to around 14.5:1 Effective compression and a 10:1 engine with 5-7 psi is equated to 14.3-14.7 effective. and how will it revert to normal fuel levels? It wouldn't be running rich nor lean with stock injector pulses, as boost is a part of it. so how would it see it as over fueling what sensor would do that?

 

A larger injector with the same injector pulse width will give more fuel, so in open loop mode it would be over fueling. In closed loop, when controlling to the O2 sensor, you will see a negative fuel trim value as the ECU brings it back in line.

I'd wager your problem will be exceeding the max range of the MAF at high flow and you will either get an error or, worse, the signal will be clipped and the ECU won't know that it should be adding more fuel.

There are programmable MAF meters you could use to "cheat". Essentially use injectors that are 20% larger and then define a transfer function in the MAF the is 20% lower and lie to the ECU about how much air is coming in.

Has other risks because load and thus timing is also based on MAF input, but you can get the fueling right in this way.

 

Yes I can see the MAF as being a slight problem but ill see how the MAF deals with air amounts if it goes to just a high or goes to a default setting. as with the fueling since o2 controls A/F adjustments I see it as being fine with about 20% higher than stock injector as it should correct the pulses to get a good mixture and everything is fine and dandy on that end, but yes I agree with your statement I hope in my case the MAF will just stay with a high reading under boost and let the higher flowing injectors deal with the rest. I will look into it when the time comes.

 

Anything ever come of this? Is there a snarling turbo AJ16 cruising the streets of Maryland???

 

Me too, just curious to know how it did go.
what about the AJ16S engine ? isn't it a turbo charged version of AJ16 ?
is it difficult to modify a AJ16 into a AJ16S ?

 

sadly being the in between'er of technology it would cost quite a bit of money to rewire the AJ16 with a programmable ecm that could run larger injectors, and the AJ16S was supercharged with an Eaton twinscrew. While it most likely will not see a turbo on the lovely I6, I've very much planned out either a V12 swap or an Aluminum LS as there's actual performance parts for both engines respectively. I would have looked deeper into keeping the I6 but the trans is dead and I don't feel like rebuilding it since I'm already building a trans for my camaro and id rather have something making 500hp in it anyway.

Also to modify the base I6 to the s version i believe you'll need the MAF sensor and ecm and obviously the supercharger. I know the v8 XJR had twin fuel pumps of the same model but I'm unaware if the AJ16S had larger injectors or the twin pumps.