off the topic, but I like your user name, Scaldedcat. the scalded cats were a pair of prototype straight-8 Bentleys in the 50s which went like the clappers and were sadly never put into production. is that the origin of your name? Or more likely, the Jag - cat reference?

 

Hi AL NZ,
I'm relatively new to posting on this forum and I have found it to be a fantastic vault of knowledge. That's interesting about the 1950's Bentleys. You are right on the money re reference to the Jaguar. My current beauty is my seventh and my XJR certainly goes like a scalded cat.
Cheers

 

Hi Scaldecat,
I'm afraid that I don't know anything about the internal wiring of the GM Hydramatic 4L80E gearbox. However, I think it is highly unlikely that this wiring will be Jaguar specific.

 

I think ( not 100% sure) that the external wiring harness plug is different, so there will be some slight internal differences. I agree, the the wiring to the solenoids etc is probably the same.

 

Hi XJRengineer and Jagboi64,
Thank you for your information and I'll keep you posted on my progress with my transmission challenge.

 

For the record, this is far and away the most cost-effective modification that I have ever done to a car. And I have owned and modified more than a few. I highly recommend this based on my experience with both XJ6 and XJR.

 

Thanks for the really positive feedback. It is much appreciated. For anyone else reading this post, these revised crank sensor brackets are still available.

 

Hi XJRengineer,
thanks for the fast shipping of the bracket to Germany.

I haven't installed the bracket yet.
I have a few question regarding the AJ6 version.

Is there any way to detect a knocking engine in the XJ40?
I think there won't be any check engine light or VCM Message right?

And how long does it take for the engine to reach stable temperatures?
Should i use 98 or 100+ RON fuel if i'm driving 10 or 20 minutes at a constant speed of 200 km/h (120mph)?

 

Hello Browny2,

Welcome to the Jaguar Forums! It's great to have you with us.

You will really enjoy the improved performance and fuel economy after you install Andy's revised CPS bracket. I really liked the results on our '93 XJ40.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

@XJRengineer What spark plug gap do you recommend for use with the bracket?

 

Hello Bogdan Blazeski,

Welcome to the Jaguar Forums. It's great to have you with us.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Hi 5tevie,

I installed Andy's bracket on our '93 XJ40 with 4.0L AJ6 engine and the difference in performance was instantly apparent, with more immediate engine response from around 2,000 rpm upward. In the 0-60 tests I ran, I could not measure an improvement, but I did all my tests starting from idle. I think if I had revved the engine with the brake depressed before starting each run like any self-respecting street racer, I would have found a measurable difference in 0-60 times with Andy's bracket. There is no question that your "butt dyno" will feel the difference.

One of my friends installed Andy's bracket in his '96 XJ6L with AJ16 and agrees that the difference in performance is not insignificant.

One thing I was able to demonstrate somewhat scientifically is that Andy's bracket improves fuel economy. Here's how I did it: I mapped out a route 60.0 miles long beginning and ending at a Shell gas station. The route, which I measured by Garmin GPS, had only 6 stop signs or lights to minimize time at idle. The elevation change was just over 400 feet (also measured with the Garmin), which is more than I would have liked, but unavoidable in our area. Before installing Andy's bracket, I drove this route four times on different days as opportunities arose. About half of the route was on the Natchez Trace Parkway, a limited-access road with a maximum speed limit of 50 mph. I used cruise control on this stretch to help minimize my own variations in throttle application. At the beginning of each loop, I filled the fuel tank as full as possible at the Shell station, and reset the trip computer fuel economy measurements. At the end of each trip, I again filled the tank, then calculated the fuel economy by measuring how much fuel was used and compared this to the vehicle trip computer (which consistently gave fuel economy averages that were 1 - 2 mpg too low). I averaged the numbers from the four trips. I then installed Andy's bracket and drove the route another four times on different days. This is how I proved to my own satisfaction that Andy's bracket was responsible for improving our fuel economy by nearly 2 mpg (1.9 mpg if I recall correctly).

Assuming your car is in reasonably good tune, you will love the difference with Andy's bracket. One other easy modification that works well with Andy's bracket is to remove the conical snorkel from your air filter housing and replace it with a large straight rubber hose, which will approximately double the cross-sectional area of your intake and further improve engine response at mid- to higher revs, at the expense of a mild increase in induction noise.

EDIT: Well, I just realized that when I clicked on this thread in my Subscribed Threads it took me to Page 1 instead of the most recent page, so I have responded to 5tevie's post from 2012. But I'll leave my post to hopefully persuade others to give Andy's bracket a try. Trust me, you'll love it!

Cheers,

Don

 

Very interesting stuff. Thanks to this thread I have full trust in the knock control system and run nothing but 87 for the past 20k miles.

 

Maybe Andy can tell us for certain, but my understanding is that if you run 87 octane fuel the ECM may retard ignition timing to avoid detonation or pre-ignition, which will have the undesirable consequence of reducing both engine performance and fuel economy, which are the exact opposites of the benefits of using Andy's bracket.

Can you enlighten us, Andy?

 

Dear Andy,

years ago I ordered one of your brackets to be installed on my much beloved X306 XJR.
I loved the enhanced performance.

Due to being pensioned of I sold my swift mover, but no stress, bought a very early ‘87 3.6 Sovereign. In good shape, under 200K km’s.
So I’m in dire need of a new bracket.
How do I go about ordening one, it,s been years?

Best regards from Bertus from the Netherlands.

 

After Some quiet contemplation: my early XJ40 has a distributor cap (correct word?) so I think the bracket won’t be of use?

 

Can’t you just move the distributor to give you a bit of extra advance?

 

That’s an idea. But I don’t think I have an anti knock-out sensor, how would that work?

 

Back in the day before knock sensors you drove by ear lol
Add a bit of advance (I am guessing there are timing marks) then go for a drive. If it’s not pinking/knocking on your favourite hill, then add a bit more till it does, then take it back a bit

 

Use high octane gasoline