Hi All,

I have been in touch with AJ6 Engineering in the UK.

I am changing to a 3.54 diff as the long legs of the 2.88 are at the wrong end of where I enjoy my power. (I often run on the open road (110km/h) in second gear and fuel economy is not an issue for me)

I am about to push the go button on the SE ECU Large Throttle Kit, but have seen a couple of conflicting reviews that I would like to clear up.

My guess is that these reviews are few and far between and everything will probably be fine, but wanted to see how many of you are doing a similar thing with Rogers products.

He appears to know his stuff and seems to have been in this business for a long time.

Has anyone had experiences (good or bad)? I would love you to elaborate on any knowledge you may have.

Thanks all.

Craig

 

I've used two of his Superenhanced ECUs for the V12s and, plainly, they worked as advertised

Cheers
DD

 

Open up your exhaust and intake or these mods won't really get fully realized. The CATs and center mufflers are awful, the intake trumpets to coffee strainer airfilter might aswell be a noose.

AJ6 is one of the only reputable sources for actual enhanced parts.

 

Thanks Vancouver...

Exhaust is already opened up. 2.1/4 inch pipes all the way back via straight-through mufflers.

Never had cats installed. so all good.

Cheers!

 

Thanks Doug, I feel better now!

 

The AJ6 stuff with transform the car. You need the ECU and the larger throttle bodies. I have had it for 18 years now and it is just terrific. Bywater is the most knowledgeable person on the planet about the V12, you will not be disappointed.

 

He's getting on in years so if you want his expertise and modifications, sooner might be better than later.

Cheers

 

Good your all set for maximum performance!

 

Ummm...

Where do actually find this ECU on a 1984 coupe?

 

It is in the trunk on the right side behind the carpeted panel by the battery. Kind of tucked away in the "flying buttress". I believe it is attached with 3 small nuts, the large connector, and a vacuum hose. Once the carpet panel is removed you'll be able to see it if you stick your head into the right side of the trunk and look up. Just another instance where this car demands you be a contortionist!

Thanks for this post. I've been considering this kit for a long time and I'm going to pull the trigger asap since it sounds like it's not going to be available forever.

 

Thanks ECB

 

Norman Lutz is building my engine and I asked him about the large TB's, his response was don't waste your money the stock ones are good for 500hp EACH and are NOT a restriction, larger plenums would be a better option. Then optimise ignition timing for 95 or 98RON fuel, the stock V12 (Lucas ignition) here in Aus is tuned for 91RON.

 

Finally the AJ6 large throttle kit is installed and in...

Wow... well worth the money!

The engine now starts with just the key when hot which is remarkable
Heaps better throttle response
Much smoother engine feel
The engine has completely woken up
Seems like its added 50hp but probably not unless my ECU was tuned rubbish from factory.

It is clear that Roger is very knowledgeable and knows his stuff, albeit a little slow!

It did take four months!

 

Hi Craig,

Thanks for posting this.

Do you still have the 2.88 in place? I was wondering if you did both the diff swap and AJ6 stuff at the same time.

I have an '88 XJS I want to make accelerate faster too. I have the 3.54 diff, and have no-cat down pipes, and plan the center muffler delete.

Maybe I'll buy the throttles and ECU as well. I don't think I need the intake boxes, as I've made some with big snouts, and don't mind if there's intake roar. Plus, shipping those big items so far is a cost concern.

I see AJ6 wants to exchange your throttles and ECU. Did you send yours? Did you have no car for 4 months?

One more thing I may try is the B&M adjustable trans modulator.

I'll be following your work,
Thanks
Rob

 

Hi Rob,

Unfortunately yes I had to send my bits t him and yes I had no car... But it is actually worth it!

Yes I had installed the 3.54 which gave a bit more pep, but I struggled a bit with the higher revs at top end. (Not super bad, but just a little bit annoying for me - 2900 rpm at 70mph was a touch too much)

A 3.31 would be better if you were happy to change speedo gears.

So last weekend I switched back to a 3.058 from a SIII XJ sedan and along with my 235-70 rear tyres, which is almost a perfect match back to the original 2.88 ratio. (2% out on speedo - or 2 miles out per 100 miles driving)

I am happy again now and I will use my 3.54 locker on the LSA project, seeings as the 6 speed auto has 2 x overdrive gears.

To be honest, the AJ6 kit changes it enough to not worry so much about the diff swap, but that's only my opinion i guess!

Cheers
Craig