AJP V8 Spark & AFR Tables

[CerbWill]

Afternoon all. Does anyone have a copy of or any info on the spark timing & fuel tables for an AJP V8? My engine is slowly on its way back together and I'm considering management options. I was thinking of keeping the standard 941, however mapping is expensive (but still good value I accept) and a few stories recently about the lack of ability to repair 941's, and the scarcity/cost of replacements has got me wondering if an alternative would be better. The obvious candidate is Emerald, however the ability to run only a single lambda doesn't strike me as ideal, plenty of people run it though so maybe I'm overthinking the limitation.

If I'm going to use any other ECU, (CANEMS sequential maybe?) the spark & fuel tables for an AJP would be of great interest so I can see roughly what the engine likes so I can get it running safely to get it to a mapper. So, has anyone get any from a 941 or an Emerald they wouldn't mind sharing?

[Jhonno]

I thought they had introduced dual lambda control for Emerald now?

[CerbWill]

There's nothing on their website and I emailed them back in April. The owner didn't seem too bothered about introducing it and just pointed out how much work it would be.

[ukkid35]

I had assumed that if anything went wrong I could just send the MBE to Ian

http://www.oddified.com/mbe912.php

I have been in contact with him in the past and he was very generous with his time and advice

[Jhonno]

CerbWill said:

There's nothing on their website and I emailed them back in April. The owner didn't seem too bothered about introducing it and just pointed out how much work it would be.

Hmm.. I thought they had earlier this year..

Considering I know quite a few people who would have bought Emerald if it did dual lambda they are missing out if that is their attitude.

[CerbWill]

Jhonno said:

Hmm.. I thought they had earlier this year..

Considering I know quite a few people who would have bought Emerald if it did dual lambda they are missing out if that is their attitude.

I'd be happy if they did. I'd be off to Jools for an Emerald. But no dual lambda means I'm not buying it. Dual wideband would be even nicer but dual narrowband is, IMHO, necessary to protect the engine by alerting me to any dangerously rich/lean conditions if a fault develops.

In the meantime, anyone with an Emerald got a map they could send me?

Edited by CerbWill on Thursday 1st November 15:07

[itsallyellow]

Run a Syvecs system. Top notch quality and they have the AJP base maps already as they have done all my AJP race cars. Also noticed they have just converted a road Cerbera as well. We made big torque gains on the Cerbera.

Mike

[CerbWill]

Looks like I'd need a minimum of an S6 Plus which seems to be around £2500 for the ECU. What setup are you using and how much did it cost? Feel free to PM the cost if you'd prefer. I'll have a look at Syvecs software later. Would you mind sending me a map? My engine should be coming back as a 4.7 with heads skimmed to make the compression ratio 12.5:1 and bigger fuel injectors (Bosch 36lb/hr, don't have the part number to hand at the moment).

[spitfire4v8]

Jody at python racing can fix many electical boxes .. many in the trade like me use his services, he's very good. I think he said the 941 and poss 970 ign and inj drivers are obsolete and he was trying to source an alternative though .. but realistically how many ecu failures do we see? There's an issue with the SP6 versions clipping the outputs at high revs on a few cars, but I really cannot think of the last time I saw a V8 ECU failure..

with those injectors you're good for 500hp at 3.5bar at 80percent duty .. with most 4.7s struggling to make 400 these days you're not exactly going to be pushing the injector drivers to their limit ..

[gruffalo]

Does the Syvecs use wide or narrow band lambda's?

[CerbWill]

spitfire4v8 said:

Jody at python racing can fix many electical boxes .. many in the trade like me use his services, he's very good. I think he said the 941 and poss 970 ign and inj drivers are obsolete and he was trying to source an alternative though .. but realistically how many ecu failures do we see? There's an issue with the SP6 versions clipping the outputs at high revs on a few cars, but I really cannot think of the last time I saw a V8 ECU failure..

with those injectors you're good for 500hp at 3.5bar at 80percent duty .. with most 4.7s struggling to make 400 these days you're not exactly going to be pushing the injector drivers to their limit ..

Hi Jools, I'm the Will whose been emailing you on and off about options with the MBE as progress is made on my rebuild in fits and starts. I think I'm over thinking all of this because time is dragging on and is permitting me to do so. I also like messing with stuff as a technical exercise but I need to balance that with value for money and anything I attempt myself is unlikely to result in maximum power/driveability per £ spent.

Interesting that 400bhp seems to be the limit when some 4.5s make nearly or over 400bhp, see ukkid's engine for example. I'd have been hoping for more from a 4.7 with (lightly) ported heads and 12.5:1 compression ratio.

[spitfire4v8]

Yes, the 4.7s make more midrange as you'd expect, but for some reason cap out at 400 whilst we know a good 4.5 on whirlwind makes 400 plus.
When I questioned one of the engine builders he swore that the only change between the earlier 4.7s and the later ones was a change of gudgeon pin position to quieten them down, to which my reply is put it back where it was, because the recent 4.7s make less than a 4.5 top end.

I was going to be doing a bit of research on a 4.7 that made under 400hp but it never happened sadly

the last few large capacity ajps I've seen have made these hp/torque numbers
399 / 375 - 4.7
387 / 380 - 4.8
393 / 390 (but very very peaky) - 4.7

I had a 4.7 make 409hp a while ago, but its midrange was poor at only 360lb.ft peak

fingers crossed for your version.

Ps I no longer have a copy of mike saunders' 477bhp graph as it was on my previous dyno but if you PM him he might have a copy somewhere .. that engine (an APM build I think ?) really was great .. but sadly nothing has come close since.

Edited by spitfire4v8 on Friday 2nd November 12:26

[itsallyellow]

It’s interesting what you have been seeing with the new 4.7’s Joo.

All 4 of mine are now “New spec” and all make similar power to the first one. In fact apart from the escort having rubbish induction they all seem pretty much the same.

Have you ever seen one with different manifolds? I wonder if the big difference I’m seeing is due to the exhaust systems we have made? It’s the only difference.

Mike

[itsallyellow]

gruffalo said:

Does the Syvecs use wide or narrow band lambda's?

Wide I believe

[CerbWill]

itsallyellow said:

Have you ever seen one with different manifolds? I wonder if the big difference I’m seeing is due to the exhaust systems we have made? It’s the only difference.

Mike

I'm all ears . What's the difference? Doubt I'll be able to follow up on it. The engine and mapping is just about in budget at the moment, never mind custom exhaust manifolds.

[gruffalo]

itsallyellow said:

gruffalo said:

Does the Syvecs use wide or narrow band lambda's?

Wide I believe

Thanks Mike.