I went to the Texas Mile as I posted on my other thread. They are adding more things all the time besides the race. This year
they added a car show and a portable Dyno! I have always wanted to get the car on one but never did. This was 3 pulls for $75 which is a steal.

It's a portable unit called a Dynacom.
Dyno Maker

It took several runs to get the car to stay in the right gear and to load the rollers.




The car was making some glorious noise and standing next to it at 200 mph was wonderful. The guy ran it in 6th gear.
Got 530 HP and 540 Ft-Lb of torque. As always every dyno's different so I can't judge any gains from my mods.




Not a copy you can read much on but here is the chart.




It was still going up with every run and I almost ran another 3 as the guy on that last run really knew when to ease into it and then bury the throttle. Hot again as you can see it was 97F.
Car drew a crowd too. Got another Shelby guy excited and he went and got his car to test next!
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Very impressive, but would caution you the the transmission specification for max torque is 516 ft-lb. So either the readout is very optimistic or your tune is taking the transmission beyond design limits.

 

XJsss, would you happen to know what the limiting component would be in the transmission that this is based on? More curious than anything. I have always pondered getting a supercharged XJ and if I do, I have a feeling that I would be pushing it up beyond that point. So, it would be nice to know what I would need to look at in the way of upgrades to keep the car together in 1 piece when max power is applied. Finding the weak link while at full throttle is not a fun way to figure things out.

 

Thermo Here is a link to the Wikopedia page about the transmission (https://en.wikipedia.org/wiki/ZF_8HP_transmission) All the tunes I have seen have not exceeded the max torque of 700 nm or 516 ft-lb but have achieved very high horsepower as much a 700 claimed. ZF makes a higher spec version 8HP90, but ours are the 8HP70. Later XJs may have the second generation 8HP75 and that has a max torgue of 553 ft-lb, but I cannot confirm that Jaguar used the second generation.

 

Since I now have documented speeds at 1/4 mile,1/2 mile and the full mile I really needed an accurate weight to calculate the actual HP.
Went to my local scales and got a total as well as front/rear split. The car is designed very well!

Total weight is 4360 LB. This is more than the published weight and is exactly why I went to a certified scale.
I have 50.9% on the front and 49.1% on the rear wheels with the car sitting empty. Note I removed nothing from the car and it has everything in the trunk and interior except me.

Here is the weight ticket from the certified scale.




Using several online calculators I think my dyno numbers are too low and VERY conservative!




Note I added my body weight back in and this is still too low because I had my helmet and a few electronic devices in the car when I ran the mile. So more weight but I want to be conservative and see where it goes.

The dyno had 530 HP at the wheels and the above shows 621 HP at the engine. Always a guess but with a 15% power loss this would make the 530 HP at the wheels = 623 HP at the crank.
These numbers are very close so I think they are reasonable and accurate.

Not worried about the transmission. The 575 model has 517 Ft-Lb stock so I can't see Jaguar being so dumb as to put a transmission with an inadequate power rating behind their flagship model??
Also note no one has tore up this 8 speed that I can find. Problems yes but nothing from excessive power. I think your numbers are way off.
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Clubairth1 that would support my thought that the later models are equipped with the ZF 8HP75 that supports a max torgue of 553 ft-lb and the 8HP70 was probably fazed out and replaced by the 8HP75 that was introduced in 2014 Question how much fuel was in your XJR when it was weighed.

 

I wanted the most conservative numbers so I had a full tank and a full trunk.
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Congratulations on your new numbers, now all you need is some actual 1/4 mile times.

 

You are so right!
It's on my list and I need to work on my launch.
With a mile race the start is not all that important and I had a few bad ones!
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Ever get those 1/4 mile times...? Nice HP gains as well

 

VAP tune? What mods?

 

No track time as everything is still shut down and I am trying to comply with the don't travel/no crowds stuff too. Plus have at least one more mod I would like to try.
I use VAP as they run sales and seem really tuned into the Jaguar engines. But there are several companies doing this.
Crank pulley and tune with some other stuff.

The 5.0L SC really needs a PVC catch can system properly designed for our PCV system. We also are in dire need of a Meth injection kit.
These are both dirt common on the American muscle cars side of things but we don't have a very big group of people modifying Jags.
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It's better to change PCV valves for a new ones (available in spares), it totally reduce oil usage. Mine XJ have 120000km on a dash and zero oil usage from change to change (i prefer to change oil every 5000km, original Castorl 0w20).
I've opened a SC cover recently and a intake valves was more or less clean, nothing dramatic. On the other hand most of the catch-cans are an additional source of vacuum leaks from mine expirience.

 

Not about oil usage. It's to keep the PCV junk from coating the intake system. Very bad for combustion as oil massively lowers octane level. When I took my old 2005 4.2L SC engine apart to change the under SC hose the the entire intake track and inter-coolers were covered with oil and crud. Took a few hours of soaking and cleaning to remove it. It's surprising what these PCV catch cans pull out of the air stream.

I am grateful that the 5.0L does not seem to suffer much from the dreaded DI back of the intake valve build up. It's funny but more than one tech has said they see this build up much more on the LR side even though the 5.0L engines are identical between Land Rover and Jaguar? Maybe just a lot more Land Rovers out there compared to Jaguars?
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The state of my intake valves when I rebuilt my 5.0 would suggest otherwise:

 

Well Brutal works for Jaguar and see's many 5.0L engines.
Here are his comment about the 5.0L;

Carbon Fouling

This thread has some additional picture of carbon buildup in the 5.0L engine. The most interesting is the picture after the dealer had run some intake cleaner thru the engine.
Still a lot of debate if this type of cleaning does any good?
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My intake valves were pretty gunked up. It wasn't very hard buildup though, more gunky and gooey (maybe due to the CRC GDI intake cleaning). I made them spotless and completely cleaned out the intercoolers, and to be honest didn't really notice any difference in power.

I think using the CRC intake cleaner on a regular basis after you've fully cleaned the valves should do a good job in keeping them clean.