I see all kinds of stuff for the XKR guys to get 50 to a 100 more ponies and very little for it's little brother XK8.

I would be happy getting just another 10 or 15 HP.

What can we do without being loud and spending a ton of money.

 

Why don't you want to be loud? What's wrong with you?

 

I think that might be an oxymoron

There is only one way, strip about 150kilo out of the car and you will gain about 15bhp , you can then sell what you have taken out and actually make money.


Failing that..... then nothing

 

You can make sure the tension on your throttle cable is adjusted properly. It won't give you "more" horsepower, but if you've never adjusted it your cable has probably stretched and the throttle isn't opening fully when you mash the pedal to the floor.

 

Take your 80lbs spare and tools out of trunk. That's why we have AAA.

 

 

It is possible to double the output of the XK8 engine, although it's going to be expensive and not nice to live with day to day.
If you don't want any noise increase, there's nothing you can do except fit a nitrous system!
Fitting a sports exhaust system, with high flow headers and cats, and a free flow intake system, will free up the very restrictive standard set up. Remapping the ecm can also add a little hp. All this would cost over £3k for at best 30 Hp gain. I did exactly that a few years ago when the standard cats broke up. Superb quality components and much nicer to drive especially when it's opened up a little.
Below are a couple of links to companies who tune the NA AJV8

http://portal.jeengineering.co.uk/new-range-rover/petrol-engines.html

Normally Aspirated
JE are still devoting development resources to enhancing the normally aspirated AJ engine, even though it is coming to the end of its OE use. JE intend to continue using it in the 'JE-35' Anniversary Edition Defender and thus have some exciting developments to offer, notably our big-valve polished and ported heads. Please enquire for full details of these components which give up to 60 more brake-horsepower than standard, with suitably re-programmed electronics. With its surfeit of power for normal use, the AJV8 is particularly suited to LPG modification which gives dramatically enhanced economy. However, the AJV8 engine has been found to be susceptible to valve recession when using LPG due to the valve-seat material used in OE manufacture, and the "dry" nature of the gas with no lubrication additives as found in petrol. JE have developed two alternative configurations to overcome this problem

JAG EXPORTS - FORD JAGUAR AJV8 PERFORMANCE CAMSHAFTS - EC Plaza

New billet ground high performance camshaft sets. Stage I to Stage IV performance levels for both naturally aspirated and supercharged engines. Set of 4 cams for 3.9L to 4.2L Ford/Jaguar AJV8 series of engines.

 

I think the whole point was the quote "without being loud and spending a ton of money"

I mean if you want to spend some money, you can do what I did to my XK8



That will beat most XKRs

 

Lawdy, I had no idea that was an XK8 engine. What's a set up like that go for? Do you have an opening in the hood for that?

 

I guess if I was to do this setup for another XK8.........

The prob you have is the knock on effect, you can't do a setup like that without changing the ECU, well I would not of thought so, as I also fitted much larger injectors. You will probably also notice there is no Tstat tower, no water pump either



They are now both electronically/digitally controlled, I can speed the water pump up if I wish to cool or slower to run hotter, my other option is to just set a temperature and let the control box maintain it.

This meant a stand alone ECU which of course is not going to work with the TCM, so in goes a manual tranny, then you have the instrument issue which there might be a get around if you could duplicate the inputs it needs or you replace the clocks.

Anyway $25K later you wonder where it is going to stop

The air intake is the big hole in the hood



The hood actually acts as the top of my air box, OK it will once I get around to making it

 

This is very easy, most older cars are down on power around 20% due to worn O2 sensors, tired plugs, dirty filters and dirty sensors. If you want this power back, get the injectors professionally cleaned and matched (out of the car), install all new filters (fuel, air, oil, tranny) and plugs, change all oils to all synthetics, replace the O2 sensors, clean or replace the MAF sensor, clean the throttle body, get the latest ECU flash from Jag, and you will have real power that you can use and a car that might even last longer with fewer issues.

 

I will not deny, giving your car a good service will reclaim some lost horses, but this does only apply to a neglected car, if your XK is already in tip top condition, then you will not gain anything.

To get anything above and beyond the so called original spec, takes money