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Which ECU should I use on a Jaguar AJ30?
mgb281 - 23/11/20 at 09:03 PM

I am building a MGB GT with an AJ30 engine, RX8 gearbox, ST200 inlet manifold and 65mm throttle body and although I will not need it until next summer at the earliest I would like advice as to which ECU to use. I am attracted to the ME442 despite their falling out with Rocketeer, partly because they have had good results with MX5's partly because they are just up the road from me and partly because I have a Rocketeer loom (a £10 purchase). The loom is quite basic considering what the ME442 is capable of, ie no VVT, wideband sensor or knock sensing, it seems the bare minimum to get an engine running. The extra sensors could easily be added but should I be looking elsewhere.
Basset Down will sell me a MBE with loom for just over £1600 but that's too rich for me. Then there's the Emerald and Megasquirt. On top of that there are a whole host of others; Omex, ECU Masters, Halltech etc From what I can see when they are all brought up to a similar spec there is little price difference between them, and a local tuner tells me that the performance will be the same from any of them if tuned properly.
So where do I spend my hard earned money when the time comes?


cliftyhanger - 23/11/20 at 10:48 PM

I have a rocketeer me442 ecu and loom, all unused. I really ought to be selling as my trusty Triumph won't be getting an AJ30 anytime soon.
Let me know if interested.


40inches - 23/11/20 at 10:55 PM

I used a MS2 extra, it worked very well Standard AJ30 with ST200 inlet and 65mm TB.
After VVT adjustment
After VVT adjustment


[Edited on 23-11-20 by 40inches]


sdh2903 - 23/11/20 at 11:00 PM

Having heard a couple of tales of woe with the Me ecu on this particular engine,I wouldn't touch one.

I went with the emerald k6 for my build running the exact setup as you. Out of the box it does the 6 cyl, vvt control, wideband (sensor extra obvs) and important to me it does can bus so can display all the info on my Aim dash. it can also do coil on plug or coil pack wasted spark depending on what you choose.

I bought direct from emerald and also bought their harness which was an ecu plug and all the flying leads for you to route and terminate. Was a doddle to wire up. I was about 800 all in. Their aftersales care is also top notch even remotely wirelessly connecting into my ecu when I'd made a schoolboy error.

To get a similar spec omex or me ecu I was quoted 1200+

Mine runs like a charm and makes great power.

One major consideration is who's mapping it, if your local tuner of choice won't/can't map your ecu of choice it makes a difference.


magpies - 5/1/21 at 06:36 PM

I'm also running an Emerald K6+ bon my AJ30 engined TVR. I purchased the ecu and harness from Emerald and as said easy to install and wire. I run the standard Jag coil on plugs, the VVT is not wired as yet. Have a narrow band lambda but will change to a pair of wide band at some time probably at the same time as including the VVT. Set up on Kits and Classics rolling road and gives 265bhp. I junked the Jag 'Alien' inlet and fitted an Alfa one with a 70mm fly by wire TB which Emerald set up with the Jag electric throttle pedal.


CosKev3 - 5/1/21 at 07:31 PM

As above,use whichever ECU your preferred tuner recommends


mgb281 - 12/1/21 at 09:22 PM

I have decided to go with the ME442, since I already had the loom and a totally intact AJ30 loom I have decided to combine the two to hopefully get what I want. I have mulled this over and spoken to a few tuners and the very last one gave me a tiny piece of info which helped me to decide. He said that although he had never tuned a Rocketeer (although lots of MX5's) he had seen one and he thought the manifold design was wrong. I then spoke to the guy that I bought the loom from and he was very happy with the MBE but only after they had it for a few weeks to get it running right. I then mentioned about the tuners thoughts on the manifold and he said that MBE (Basset Down?) had modified it. They also added the VVT and a wideband sensor. A good few months ago I spoke to ME about the problem with this engine and asked them why the VVT was not connected to the ME442 on the Rocketeers and it was because Rocketeer did not want it, or the wideband either. Although this is partly circumstantial it does seem to suggest that the combination of the ST200upper manifold to the ST220/AJ30 lower manifold is as good as the fancy carbon fibre one. Since all the results that I have seen seem to plateau at around 270/280 bhp is the restriction the injector flow rate or is that the maximum without other head work?
One other factor that has helped is that ME are selling a 442 without DBW for £895 which is not much more than an Emerald or Megasquirt after you add a wideband controller.
This brings me to a final question, are all Bosch LSU 4.9 wideband sensors the same? I do not mean copies but genuine Bosch ones. I can buy a genuine Vauxhall one for £52 or an Innovate one for £78. I am assuming that they are all calibrated the same just like their other sensors.


sdh2903 - 13/1/21 at 03:35 PM

What you have to remember is that the rocketeer inlet design always had to sit under a standard mx5 bonnet so is always going to be compromised in some way, pretty much like it is in a 7/locost etc. In fact I have considerably more height under my Westfield v8 bonnet than in an mx5.

You're right that there have been 2 iterations of the rocketeer inlet, the second is more compact and designed to work with the new throttle bodies. Am pretty sure that this change came about before Basset down got involved. If you look at the rocketeer website there's a good chunk of info on the development and the cfd analysis.

With regards to the vvt I could be wrong but am pretty sure the 442 didn't have the vvt capability a few years ago, as when I enquired with them I would have needed to go up to the next ecu in the range which was near double the cost, looking at the 442 now it has far more features than a couple of years ago. Am sure if you get a tuner who knows it will get decent results.

Your right on injectors, the stock 260cc injectors are right on the limit. My last dyno run saw them starting to max out. I'm currently copying CosKev in fitting some bigger ones as I'm currently cobbling together a budget throttle body install to run back to back on the same dyno in the spring to see if they are worthwhile vs the st200 inlet.


mgb281 - 13/1/21 at 07:41 PM

I have a little more info regarding the Rocketeer version of the ME442, they are one and the same. I thought the simplest way to reach a conclusion was to phone ME and ask them. However there are differences between the early and later versions, the early versions do not control Continuously Variable Valve Timing but they do control On/Off Variable Valve Timing as found on the S Type until 2002.5. So it seems that at some point the software was altered to facilitate full VVT. Again they were very helpful and said that they will guide anyone installing this system.
Reading between the lines I do believe they were a little naive in just producing what Rocketeer asked for rather than telling them what the spec should have been. On the other hand they should have been able to sort out customers cars without telling them that they are all like this. Whether that was cost cutting by either side we will never know.
As for the manifold design I only know what I was told by the previous owner of the loom, (if you search MX5 build threads he has 45 pages to go through) he had a lot of problems getting his car to idle and poor cold starts etc. In the end a new MBE ECU and loom was fitted and it had VVT enabled but it still was not right. As I understand it took a number of weeks to get it to run correctly, he has told me that some modifications were made to his manifolds relating to the sizes of the connecting pipework Now contrast that with a couple of cars on this forum, same engine same Mondeo inlet manifold and making more power than the carbon fibre manifolds do with either ME or MBE ECU's, this suggests to me the problem is partly or even fully connected to the manifold. If you remember Coskev got circa 280 bhp on just one visit to Bailey Performance why did it take two companies weeks to get one to run well.


sdh2903 - 13/1/21 at 08:10 PM

Yes I've read his build diary. It sounds to me as though they've tweaked the idle valve and possible connecting pipework to get a better idle/cold running I don't see how you can 'alter' a moulded carbon manifold to achieve that. I've tried 3 differing idle valves on mine with 2 different plumbing setups and I've not been able to get it to work. However I've been able to get a decent cold start and idle without one. The twin throttle arrangement is always going to add another layer of complication aswell.

Also dyno figures are irrelevant in isolation. Ask kev himself, he's been on a few different dynos with massive differences in results. Only runs on the exact same dyno can be compared.


mgb281 - 13/1/21 at 08:30 PM

I totally accept all of your points, although the number of cars in this sample are too small to be with 100% confidence it has to be accepted that if you try a number different cars on different rolling roads and there is a degree of consistency in the results it may safely be interpreted as correct. It does appear that the Mondeo combo does outperform the carbon fibre ones.
It is an interesting thread and he clearly states that he is no expert, what he told me was that the hose sizes had been changed but not the manifolds themselves. Did they change the manifolds when the IAT sensors were moved due to heat soak?


sdh2903 - 13/1/21 at 08:56 PM

Not really. I know of one guy with a rocketeer who has a dyno print of 290 on the mbe ecu. Some are 260 270.

Kev can probably give a more accurate answer but am sure his 3 dyno runs have had a 40+bhp swing, same car different dynos. Dyno figures are only good for back to back runs to make upgrades and comparisons.

Although yes I do agree the st200 Inlet seems to be a sweet spot. The huge runner length is obviously a good match. Even the 2.5k jenvey kits only give moderate gains on the couple of figures I've seen.


CosKev3 - 14/1/21 at 10:42 AM

'If you remember Coskev got circa 280 bhp on just one visit to Bailey Performance why did it take two companies weeks to get one to run well'

I would put it down to me using a tuner that knows what hes doing,and I used the ECU he specializes in!

When you book a full day mapping with Dale that's what you get, from the time you get there until hes happy he works on your car non stop.

My engine is set up very simply, I run a wasted spark coilpack from a Mondeo,so no cam sensors,injection is batch fire.
So I run TPS,CPS,AIT,Coolant Temp and the on/off early VVT.

Starts off the key every time running no idle control valve,runs like a dream


CosKev3 - 14/1/21 at 10:47 AM

Yeah ref RR's the way different people operate them and work out the figures from wheel to crank etc varies massively!

Every RR you go to swear their RR is bang on and more accurate than any other.......

Mines varied by 40bhp as Steve says,the lowest being calculated at 230bhp on a RR where the operator ran it in some sort of strange stepped set up,on another more modern one it did 240bhp.


40inches - 14/1/21 at 12:50 PM

quote:
Originally posted by CosKev3
Yeah ref RR's the way different people operate them and work out the figures from wheel to crank etc varies massively!

Every RR you go to swear their RR is bang on and more accurate than any other.......

Mines varied by 40bhp as Steve says,the lowest being calculated at 230bhp on a RR where the operator ran it in some sort of strange stepped set up,on another more modern one it did 240bhp.

It would be interesting to see the results from a power run on Dales RR?
You didn't accidentally fit a 2.5 replacement did you????


CosKev3 - 15/1/21 at 05:06 PM

quote:
Originally posted by 40inches
quote:
Originally posted by CosKev3
Yeah ref RR's the way different people operate them and work out the figures from wheel to crank etc varies massively!

Every RR you go to swear their RR is bang on and more accurate than any other.......

Mines varied by 40bhp as Steve says,the lowest being calculated at 230bhp on a RR where the operator ran it in some sort of strange stepped set up,on another more modern one it did 240bhp.

It would be interesting to see the results from a power run on Dales RR?
You didn't accidentally fit a 2.5 replacement did you????


Ha ha!

When I took it back after swapping the engine we couldn't run it all the way to the rev limiter because my lowered floor pan was touching the rollers,and I had had the car corner weighted so didn't want to lift the rear coilovers!