MAPping Land

[John Sims]

May I be the first to welcome Fen to MAPping Land. It is a strange place where driving is no longer a means of getting from A to B or a reason for having fun. Once in MAPing Land you spend all of your time in the car looking at gauges and pondering "what if....?", "why....?" and "what happens when....?"; most time out of the car is spent pondering the same things. It is a sad, geeky, world of matrices and tables, cells and numbers and has little joy but much frustration. It involves driving up and down the same piece of road time and time again, periodically stopping, and then driving off again. Or, sitting on your driveway moving very slowly with different amounts of brake applied. Then.....just when you think it works....the weather changes and it all goes to c**p again.[]

It is a land I know so well of late, and I only have to worry about fuel percentages and throttle enrichment. If one was to add to that injector cycles, acceleration decay, timing, knock control, idle speed control, air con enrichment, boost control, lambda control, hot and cold starting, crank enrichment and decay, etc, etc, etc, []I feel my head would probably explode.

I wish you all the very best as I fear it is a land you may be in for a very long time. I now travel everywhere with a clipboard and cell matrix in the car. How sad is that?

 

[Fen]

Thanks John - already way over my head and accepting I'll never get it right (or that if I do I'll never be sure that I have).

With that in mind funnily enough I just got off the phone with Mark Shead. He will be mapping my car on the morning of the 24th. Since he is the sole UK importer of my ECU and also has the distiction of tuning 5 of the 6 fastest Cossie's (using an earlier version of my ECU) in a magazine shootout I think he's the man for the job, knowing the software as he does.

All I need to do is cure a vacuum leak (where IS my "Laust Pedersen" vacuum manifold?) and satisfy myself that my boost control is working OK then present him with the car, filled with the poorest fuel I'll ever run it on (Esso SUL I expect; he says it's better than BP Ultimate; Optimax is both my tipple of choice and the best but not always available when you need it). He thinks 2-4 hours will see it done, a full day at worst.

So, do I book Silverstone for that evening or not? It will be getting mapped in Maidenhead which is almost on my way...

 

[John Sims]

ORIGINAL: Fen

where IS my "Laust Pedersen" vacuum manifold...

I've got mine, it's very nice. []

He thinks 2-4 hours will see it done, a full day at worst.

I seem to recall a certain LINK specialist telling me they could do my AFM in two hours, and we all know how that turned out. [:'(] I think I'm getting somewhere close now, within the constraints of the system.

I think you are wise going to a specialist. I have pretty much concluded that I will either have to go with a full EMS or go for the MAF conversion, that has be spoken about, and then have a bespoke chip produced. The 951 is a fairly unique car and I remain sceptical that any one supplier of EMS has had that much experience with them - in the UK particularly. I am pretty gutted that Alan wont pick up the mantle but can very much appreciate his commercial reasoning for leaving well alone.

Granted I know nothing about the system but I would have thought 4-8 hours may be a little optomistic for a first setup on an unknown car. Thor were looking towards three days for the first 951 with subsequent cars at 3 to 4 hours.

 

[Fen]

I was surprised at the estimate, but it's just a big air-pump connected to a computer he knows inside out and I don't think it matters if it's a 2CV or a W12 VAG engine in those terms, so long as the sensors are wired up correctly (they appear to be). All he's setting up is fuel and spark really, plus he is familiar with the WU settings and temperature compensating tables etc. so once he has a base map he can tweak them to suit.

So long as the car isn't going to grenade and makes something close to it's optimum performance then I'll be happy enough at that rate and it can always go back for some refinement in the future.

 

[eastendr]

Wise choice, Fen. I know Mark from way back in the old Cosworth days. When you see him, say hello from me (Rick with the Black RS500 @ the Middlesex) !

If you value your a??ehole, don't get in the passenger seat when he's driving ! Drive it like you stole it goes to a whole new level [] []

As an aside, I think the time scale is a bit optimistic ... all engines have their own quirks, and the 951 seems to have more than most. However, Mark is used to the T04e turbo. He is thorough and I'm sure you won't be disappointed with the end results.

I think that a whole day would be the least I'd set aside - particularly with a new built engine / car where things come to light that may have been overlooked.

I know I found at least one vacuum pipe that was snagged while I was at Weltmeister - took a while to isolate the problem, but the effect was like a very small venturi in line with the FPR, leading to very slowly compensating fuel pressure. The fault took a while to diagnose because the fuel rail gauge had gone faulty during mapping and showing a constant 47 psi ....

Ironically, I think the Link worked better with random fuel presure than with the correct delivery [] []

Best of luck and welcome back to turbot motoring.

Rick

 

[Fen]

Cheers Rick - I'll say hello for you.

Worst case we can spend the day on it and if it's looking even 80% there by 3:30 or so I can head to Silverstone. To be honest if it's two days it's still fair enough. Remember also that it has already mapped the fuel for itself on the low rpm and low load cells and I have logs of it so we won't be starting from nothing.

 

[eastendr]

ORIGINAL: Fen

Remember also that it has already mapped the fuel for itself on the low rpm and low load cells

Well, if you want to spend a track day at Silverstone at low rpm and low load cells .... [][][][][] you'll probably just pass beaky on the straights - i nearly did with 171 bhp in my S last time [][][][]

Que Beaky ....

Rick.

 

[John Sims]

ORIGINAL: eastendr

Well, if you want to spend a track day at Silverstone at low rpm and low load cells .... [][][][][] you'll probably just pass beaky on the straights - i nearly did with 171 bhp in my S last time [][][][]

Que Beaky ....

Rick.

It's no good you trying to goad me into comming Cannell. I can neither afford the time nor the money ......but Beaky is running better now, and despite being well down on power there was still little that past us last time, and if I were to lap you that would shut you up (unlikely, now that you can go around corners without shredding tyres), and I need to get another run at Weltmeister which I could do while I was there, and......

 

[Diver944]

At least you guys have cars to fiddle with []

Come back LIL , all is forgiven

 

[944Turbo]

I slipped it into another post but its more on topic here http://www.msefi.com/msinfo/PWC/ click on megasquirt,
Tony

 

[944Turbo]

With more stuff here http://www.darklightning.com/msns/
Tony

 

[John Sims]

I'm good for the case cutting and drilling. If someone else could do the other bits I think we could be there. []

Very interesting stuff. It was all looking spot on untill you get to the $500 to establish TDC.

What is also interesting is the consideration for using the stock wiring harness in comparison to a new bespoke harness. To some extent the original loom could be on the brink of failure any way so a new or improved loom could reap benefits. I guess that, by retaining the original loom and connectors, there is always the thought that the car could be returned to its original set up, but who is going to do that any way. A further arguement for retaining the original is that you might get away with it and save a $600 bill for a bespoke loom.

What we realy need is someone with all the computer gear, 944 and ECU tunning experience and sufficient interest to make some - Rick?

 

[Fen]

I don't know what the Megasquirt needs for triggering but you can make triggers for a lot less than $500. My cam trigger ("reference", so I guess TDC) is a bit of 1/2"x1.8" steel strip bolted to the cam pulley and "read" by a 964 crank sensor. For the speed sensor I have 2 1/4" square lugs welded to the back of the balance belt drive pulley and read by a hall sender that was something like £20 from RS Components. No trigger errors whatsoever up to 7,000 rpm. The Megasquirt sounds good but in all seriousness it's enough trouble getting a standalone EMS to work in a 944T and mapping it with the support and knowledge of the manufacturer without the added fun of doing it without a manufacturer at all. Possibly worth it in the end but a long slog and lot of effort to get there I bet.

 

[John Sims]

ORIGINAL: Fen

....... My cam trigger ("reference", so I guess TDC) is a bit of 1/2"x1.8" steel strip bolted to the cam pulley and "read" by a 964 crank sensor. ......

I guess that would make it a 2-1 reference cam then. A few teeth short of 40-1 of 60-2 perhaps []. How do you maintain balance on the cam pulley?

 

[Fen]

The cam pulley will be out of balance. It's a small diameter and only runs at half engine speed so I can live with it. Someone on Rennlist posted about the number of teeth and the more the better but TBH as with a lot on Rennlist I think it was someone sounding like they know what they are talking about more than actually being valuable info. The thrust (with calculations to back it up, mind) was that it would take the EMS x number of revolutions to notice the difference in engine speed when accelerating and x (which is a very low number, less than one with multiple teeth he suggested) increases inversely with number of teeth. Unfortunately the calculations were based on the engine being able to go from 1,000 rpm to 7,000 rpm more quickly than the ECU can see it which was about 1 second. If anyone has built a 944 engine that can get from 1,000rpm to 7,000rpm in under 1 second when the car is in gear so it is both safe and worthwhile to do such a thing then I'd like them to build me one, please. Secondly I think he also missed (no pun intended) that it is the missing tooth that the ECU counts, not the 31 or 61 teeth that are present. He was just a fan of the Ford EDIS system which is good and can look cool but where do you mount an EDIS wheel on a 944 engine?

 

[John Sims]

ORIGINAL: Fen

...where do you mount an EDIS wheel on a 944 engine?

Sounds like the distributer needs to go.

 

[Fen]

but the EDIS needs to run at crank speed, not cam speed. Ultimately the dizzy will go though, I just need to decide what to use instead. Mark Shead reckons wasted spark but Andy who built the car wants to fit CDI. I need to do research. I wasn't fussed but the MTTS seems prone to fouling a plug if it idles too long and a meatier spark might put an end to that.