Has anyone removed EGR from a 96 - 97 XJR? If yes, any I'll affects? I personally feel there is no benefit to dumping exhaust gasses back into the combustion chamber.

 

Search terms EGR + Oxides of Nitrogen.

bob

 

Search reveals the smog reduction purpose of the EGR system, but not finding anything in posts about anyone removing system, and if so adverse effects to how the engine performs. Theory is that without exhaust gasses diluting the intake charge it should perform a bit better.
Thinking if the valve is closed when ignition is turned off then simply unplugging it should remain closed when restarted. I do not know if this is accurate assumption as there are a number of reverse acting valves. Another thought is to simply plug the tubing.

 

You will set a bunch of P04xxx DTCs but the valve will stay closed if you unplug it.

bob

 

So yesterday before leaving office I unplugged the valve, started up, and drove home. Could be just wishful thinking, but the car felt peppier. As Bob stated there are now 5 pending codes according to my OBDII scanner:
B30F4 No DTC Definition Found
P13B0 Manufacturer Specific DTC
P0108 MAP/BARO Ckt High Input
P1409 Manufacturer Specific DTC
P1401 Manufacturer Specific DTC

 

I don't think it's doable with a Jaguar but with the GM F-body Camaro/Firebird 3800 V6 we would just use block off plates and remove the ECM code so you wouldn't get the check engine light.

 

Bumping this thread as I’m contemplating doing the same as John.
Has anyone deleted the EGR system all together since this thread started back in 2016?

 

In your quest to be a Jaguar AJ16 engine performance enhancer

By not introducing the O2 consumed recirculation gasses back into combustion chamber you bring the effective volumertic displacement of the cylinder back toward 'the original 100 %

This effective displacement can be say for example 95 % from a ideal 100 %

The EGR valve is closed at idle

Your valve timing or better yet variable valve timing has the same effect of exhaust clearance out for a exchange % ( it's not a perfect draw in / displace pump out process ) out of a cylinder so it can be replaced with fresh air in through the valves to allow a larger fuel charge into the cylinder

Remember there is volume above the piston ( not used in displacement numbers )

This is more pronunced at higher RPMs

The non variable cam in it's installation angle to each other ( overlap angle ) is a comprised version between what is best at low RPMs vs. high RPMs

The early AJ16 engine had a angle of 110 degrees and was changed to 114 degrees bettering idle speed smoothness at the sacrifice of the higher RPM s performance

The number stamped on the cams is a casting # before machining and not a part #

From my understanding the AJ16 engine is a valve to piston interfearence engine so you have to be careful to not hit the valves

03.1-05 (jagrepair.com)

In the end of your combustion process the exit gasses out of te cylinders must l have little O2 left for catalyst converter to keep your nitrate gasses down to a regulatory exceptable amount , NOx being bad

The stoichiometric mass ratio of 1 to 14.7 is not used but less them that say 13.5 so you have little O2 left over

Effect of ignition timing biasing / advancing with a Andy CKPS bracket ( power considerations not considering exhaust gasses.. ).........

Detonation flame front propagation speed and piston position cycle arc timing to extract power from the combustion pressure

This is more of a factor in higher RPMs but the AJ16 engine has a lower top RPM Vs. V8 regulated by the ECU limit toown to 5850 ( given to me off the top of my head ) RPM above the Sport mode shifting point of 5000

This relates to the moment arm of the crankshaft reach length from rotating center and line of force , The AJ16 engine is already a over square engine

Reason for already built into the ECU advancing the timing before TDC





This can be better seen on a graft as you shift the available O2 left over and the conversion to unwanted gasses after the catalytic converter

This is explained in this link

Three-way catalyst l Umicore Automotive Catalysts | Umicore

So in practice to get it to work .................

More simplified gains ( and exceptical exhaust gases ) can be had with a least restrictive air flow ( termed porting ) into the cylinders , Your 2 of 4 valves help with that but the head is still on this engine lacking as it is manufactured , 20 % is a value I have seen in reading

Rewording as I'm not awake yet and can spell better

Some good music to listen to as you think about what is going on with the pounding of the pistons

The Rolls Royce Merline engine of the Spitfire along with the P - 51 is a Hemi but you cant get the same high 145 octane fuel made back then