I have just joined but have been visiting as a guest for some time now, I have just finished putting an xjr6 into a MK2 and would be interested in buying a bracket from you and sending my ecu, how long do you need the ecu for?. Also I see you changed your M90 for an M112, I have just bought one to modify and install, will this change the way you upgrade the ecu?

 

For most of the audience on Jaguar Forums, the boost in fuel economy is just icing on the cake. The real benefit is in sharper throttle response and improved performance.

For your own baseline testing, you might try a complete reset of your trip computer and a reset of your ecu. That way these are your numbers only and not mixed in with previous history.

 

Johnnyb60,
If you have poor fuel econmy it can be a sign of a failing lambda sensor. The fuelling adaptions can be checked with a a scan tool.

The fuel economy benefit of my bracket varies depending on how the car is driven, but I would expect it to be better than 1mpg(imperial)

pn4sure,
I can reporgramme AJ16 engine ECUs, but one of my brackets is a more cost effective way of modifying the igniiton timing. Remapping the ECU is more appropriate for owners with specific requirements resulting from changing engine hardware.

 

Hi Andy,

Nice piece of engineering! I have just read the whole article and all its posts and I am very interested in fitting one of these on my jag. I will certainly drop you a mail. Thanks for the work!

 

Thanks XJRengineer, for the response. Do you think it could be lambda sensor even if the thing just passed California smog test? And by lambda sensor do we mean the ones stuck in the exhaust pipe? Does my car really have 4? I can see 2 of them easy enough... Sorry I really haven't dug around under the hood much at all yet. It's a shame how Christmas gets in the way of us playing with our toys.

jb

 

Hi Johnnyb60,

Lots of good advice given in response to your post, but IMO the best place to start is with the simple stuff. My trip computer ('97 X300) showed only slightly better fuel consumption than yours when I bought it. I now get equivalent to 22MPG (we measure in Liters/100km in this country) combined, and in the last few months it has been used mostly for urban driving, so on a long trip I'm laughing.

All I've done to achieve this is: 1. Drive it without pretending it's a McLaren, 2. Changed the oil every 6 months regardless of mileage, 3. Complete flush of transmission fluid and replaced with full synthetic, 4. Replaced all filters & I now ride with a K&N air filter, 5. Fit Andy's bracket, 6. Keep tyre pressures at 37psi all round. Result of this effort is a much better pull, super smooth ride and as I said, much better fuel economy.

I didn't reset my trip computer but I reckon after the first 12 months I purged it of the previous owners driving habits. Next on my list is to replace the old Champions with equiv. NGK plugs. I've acted on many comments, guidance & advice on the forum which has been excellent, but am a strong believer in tackling the simple things first, then the more complicated if still not happy with the results. My dad always taught me, if the car won't start first check you have fuel in the tank!

 

Hi Andy,
Okay I will get one of your brackets, have you calculated the HP increase with the bracket and supercharger upgrade to M112.
pn4sure
64 Jag MK2/XJR6
06 XKR

 

Johnnyb60,
If your car has just passed an emission test, then unless you lambda sesnors have failed since passing the test, this is probably not your problem, if indeed you have one. Fuel consumption depends massively on how the car is driven. It is almost imposasibel to compare result other than at a std test condition. When I say std I mean the fuigures being compared between cars need to have both been measured with AC off, at the same kerb wieght including fuel mass. The only comparible test is a constand cruise on a level road with a fully warm engine. Reset the trip computer during a long interstate journey and then see what you get. This is really the only figure that you can compare with other people. As you are in the US you also need to calirfy that whether you are quoting US or imperial gallons, as they are different.

Your car will have 4 lambda sesnor, two upstream of the downpipe catalysts and two downstream of them. The downstream ones do the fclosed lop fuel control and the upsram ones provide referecne signals for monitoring the conversion efficicency of the catalysts (this arrange is the opposite way raound to almost ebvery other OBDII compliant car ever built)

Jagent,
I think NGK make great spark plugs, but for some reason they don't seem compatible with the on-plug ignition coils used on AJ16 engines. I really recommend that you don't fit them.


pn4sure,
Another owners posted here that he measured a 20bhp increase in power output when he fitted my bracket to a naturally aspirated AJ16 engine.

I have not dyno tested my XJR6 with the Eaton M112 supercharger. However, I would estimate that it makes between 380-400bhp. It outperforms an XJRV8. It was still accelerating on a runway when it was measured at 158.48mph using elapse time measurement between two lasers 5m apart on the track.

 

Just had one of the brackets delivered to New Zealand. Not fitted yet but it's worth having it sit on the kitchen bench awhile as we enjoy our summer if only to enjoy the excellent quality of the machining.

 

Hi all,
I bought my bracket about a year ago but I didn't fit until last week, the reason for this is that I have had several running issues.

Some people wonders how much difference the bracket makes.

- A couple of days before I mounted the bracket I had traction problems around 70km/h on Wet asphalt (at +2 Celcius).

- After fitting the bracket I had traction problems at 70 km/h on Dry asphalt (at -4 Celcius).

Isn't that all you need to know ?!?


/Niclas

 

Dumb questions I am sure, but, where can I purchase one of these, Andy?
I'd like to get one!

Thanks!

 

This exact modification to the timing bracket was something I was contemplating back in the days of my LPG powered XJ40 3.2 mainly due to the higher octane rating and lower calorific value of the LPG compared to petrol. As usual I never quite got round to advancing the ignition in this way but its good to see that my theory was sound and would have worked.

I rebuilt the cylinder head and in anticipation of advancing the ignition I fitted an Aston Martin DB7 head gasket to increase the head gasket strength, assuming that greatly advanced ignition timing coupled with faster and hotter flame propogation would result in a possible compromised head gasket seal. Shame you weren't supplying them in 1998 to 2005!

I did, however, make some subtle porting modifications to the cylinder heads, inlet and exhaust manifolds, fitted a bell mouth inlet to the inlet manifold face (where the rubber bellows fit) and replaced the bellows with a straight 5" (IIRC) hose

 

Hi Dan,
You can email me direct andystodart@metronet.co.uk

 

Can anyone advise where I can find a constant speed fuel consumption graph - or the figures as used to be published in various tests.

 

The official figures for an XJR6 at 56mph and 75mph were 34.9mpg and 27.4mpg respectively. But don't expect to ever achieve these even if you try to cruise at these constant speeds. The test are peformed on rolling roads. You won't match them in real world driving.. If you are looking to measure the effect of fitting my bracket then I suggest you set the cruise control to a constant speed and drive many miles on a flat section of road. The engine and transmission will have to be fully up to temeprature first, say after 1hr of driving. The test will need to be done with AC off. The second test will have to be done under the same conditions including vehicle wieght (not forgetting the weight of fuel). The second test would also need to be done at a similar ambient temperature. Repeatable fuel consumption measurements are extremely difficult to achieve. Good luck.

 

Hi all,

my first post - this seemed like the best place for it. Sorry if I am asking a question already answered elsewhere, but I've had a good search around.
Yesterday i bought my first Jaguar - a 1995 X300 3.2 Daimler. It has been well-maintained and has 134000km on the clock. For a heavy car with only a 3.2 6cylinder I am amazed at it's performance. it isn't much slower than my 4litre 240bhp Ford Falcon, which weighs about 200kg less than the Jaguar.

I am already thinking of improvements - I know, should've bought an XJR, but that's next time. I have ordered one of Andy's 5' brackets, but I am wondering if there are other simple induction improvements that can be done.
For instance, is the airbox intake pipe on a 4 litre Jag bigger, and if so, is it worth swapping?
Also, is there any way of improving cold air induction simply? the pipe sits behind the front lights which doesn't seem the best set-up to me.
Is the throttle body on a 4 litre any bigger, is it worth upgrading if so, and will it help, or would it mess up the computer controls?

Also, is the factory fitted radio/cassette easily replaced by a car audio shop, or is that a problem given its rhomboidal shape?

Any advice appreciated, thanks


Best drive ever - SLS AMG at Mercedes World at Brooklands.

 

Hi AL NZ! I'll try to answer some of your questions Several people here replaced standard box with high flow air filter, including myself It was rather simple mod, I managed to modify the original airbox as well to fit it around the cone filter and I redrilled the hole just beneath it to stick a pipe giving it direct cold air feed from just behind the bumper (if my memory serves me well, then you should be able to find some pictures in the link in my signature).
And after-market units fit into the original slots without any problems, they don't look great (but they never look good in any car to be honest) but they are quite out of view from outside of vehicle and you gain extra space to put your house keys or mobile phone
All the best mate


Oh, nearly forgot! Go to the newbies section and introduce yourself, that'll keep everyone happy


New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum

https://www.jaguarforums.com/forum/n...gned-up-22253/

 

thanks FireCrow - been to new members section, introduced.

I have just doiscovered the cheapest go-faster mod of them all

I found the black cylindrical stopper under the accelerator and screwed it in a few turns. Kick down is better now (I have the 3.2 X300 with the 4HP-22 fully-mechanical auto 'box) and it holds longer in the gears. I will try twisting the stopper down a bit further and see what this brings

Meanwhile I am eagerly awaitng XJR-Andy's next batch of 5' advance brackets

Once I have tried the bracket with a tank of 95 then a tank of 98, I may fiddle with the air filter...

 

I have one original "leaded" bracket from a 3.6 litre. I used to work at Henlys of Chester back in 1989 and converted my uncle's car to unleaded and he told me I could keep the old bracket. I found it the other day when I was looking through my old tool box. It is in perfect condition as the car was very new when converted. If anyone is interested, I will accept the highest offer received by Feb 22nd.

The part number looks to be either CAC1253 or CBC1253. There is another marking of SG1.

I live in the USA now but if you need more info, please email me.

 

Many thanks - quite fascinating. Am curious as I thought that all these cars were for unleaded petrol - leaded fouls the lambda sensors. Am I wrong here and were some cars made for markets that had only leaded gas? Do you know what the difference is with a standard bracket?