I have done every performance mod to my 2015 xkr convertible.
1. Tune and pulley
2. 200 cell cats full racing exhaust
3. Hi flow air filters
4. Car has been lowered
5. 305/30/20 pilot super sport rear
6. 265/35/20 pilot super sport front
7. New wheels that are forged and lighter.
Anyone know of any other modifications including engine work? Wanting straight line performance.

 

Methanol injection, E85 conversion, nitrous, headers...

 

Jahammer I can't find any company that makes the headers. Do you know of one? Maybe I can have them custom made. Anyone do dyno work to establish what type of hp it adds?

Thanks

 

https://www.jaguarforums.com/forum/x...eaders-173453/

Also I believe VelocityAP may have some.

 

Throw away the Michelin Pilot SSs, use anything (literally) else.

 

An overlooked mod (I think) is boring out the throttle body. It is most effective with "suck through" intakes like your Jaguar, as compared to "blow through". Maxbore.com throttle body boring service and repair is the man to do this. Made a noticeable, but minor difference on my '07 XK (N/A).
Anything you do to materially cool intake air temp is very beneficial. Do research aftermarket intercoolers. You will probably have to do your own research - don't expect someone to offer you a "kit", but if they do it will be very expensive.
Nitrous is a great mod for the street - it is cheap and unobtrusive. It is there when you want it (keep the bottle full); and produces a wide powerband.

 

Unfortunately Cee Jay had a very bad experience with his tires. I have had almost every brand of tire including multiple Michelins and so far the PSS has been the stickiest for the money and I have had no issues with them. Since he had those defective tires, there have been reformulations.

 

Rey please elaborate for me in regards to your experience with the bored out throttle I'm on the quest to get my e.t down with the n/a

 

Here in the UK I had my 2011 XKR tuned top pulley filters and mapped by Viezu it ran 503bhp standard on there Dyno then 560bhp after .They do a further tune bottom pulley and charge I/C sports cats tweak the map 650bhp .

 

In oz we have a type of fuel called e85 which is roughly 105 Octane with a decent custom dyno tune I wouldn't be surprised if one could picked up another 35-40whp

 

We have that here too, power gain is a bit higher than that but because the specific gravity is different from gasoline, you would need larger injectors and a more powerful pump plus a PCM map to account for fueling, etc.

 

Ok, so it's not a performance mod, but you've got a convertible and if you don't have 'theJagWrangler.com' Remote Top and rear window controller, you're missing out on the best 'Wow' factor for your car, when you're not on the track.
A little plastic box, weighs probably less than a pound, but man does it perform!
If you're concerned about the weight, just skip the burrito before track time.

 

See post #2

 

Info. The Science Behind How Michelin Made Its Best Tire Even Better

 

Steve K - Answer to my experience with bored throttle body. The bore of my stock throttle body is 82 mm. Www.maxbore. com did the boring to 85 mm. Cost now is $125 and MaxBore turn around is about 24 hrs.
Larger throttle bodies are an easy hp gain. I wonder if Jaguar/anyone has produced a larger bore throttle body that will interchange with ours?
Had a '05 Cadillac CTS-V with stock 75 (aprox) mm throttle body. Went to a 90 mm aftermarket from TPIS, but this required also a new manifold mount. OEM manifold is a plastic compound, and new mount was glued onto manifold. I think Jaguars would be more complicated.

 

Sorry to steal your thunder didn't see your post ! ☺

 

Yes your correct think it burns roughly 30% faster so pump and injectors would need to be upgraded along with ecu

As you and i know both chasing extra hp is quite an expensive

 

Rey did you conduct any test prior to the larger throttle installation ?

If you have an ODB11 scanner you can take the maf lb/min reading to determine whether your mod has increased airflow

 

Steve, no testing before/after throttle body boring. My Jaguar is the n/a base model. I was interested in a bit more top end power for high altitude driving, with no driveability/gas mileage loss.
The electronic throttle body control acts much like a constant velocity carburetor, so there is no bogging at low rpm/high throttle opening with a larger bore. You can easily "do the math" to measure overall throttle plate area before and after. Bore area will only tell the absolute maximum potential airflow. Read somewhere (cannot find the quote) that "suck through" throttle body supercharged motors like Jaguar are much more responsive to throttle body bore size than "blow through", like Paxton.

 

I know it has been mentioned before, but how about a wet Nitrous Oxide "Cheater" kit?