NineMeister

Fairly recently Motec introduced a new M84 ecu (essentially a software-limited M600 that has datalogging & single lambda enabled as standard) to fulfil the requirements for a high quality "entry-level" ecu within their range. At this specification level because it works out slightly cheaper than the M48 (£1475 against £1573) it will hence become the preferred choice for all future 9m Motec 964 & 993 conversions that would have previously been based on the M48. After we received the first order for a 9m Motec conversion package to suit a 964 fitted with a 993 non-Varioram engine we revised the 9m adapter harness and had the kit ready to go in next to no time.

We hit a snag in that the Motec M84 has its own unique programme and does not run M800 software, hence at this time there are no applications to convert M48 or M600 files to the M84, so the run file had to be written from scratch. Since this was our first M84 based conversion and was to be supplied in kit form, rather than copy files and hope the engine would run (!?!) we made the decision to help the customer out by installing his kit onto 993 engine and compile the new start file by live mapping the engine on our dyno. The next problem was that we needed a suitable car to play with and this came in the form of a G50 3.2 Carrera that 9m had upgraded with a 993nVr engine around 10 years ago which I just happened to have bought from its previous owner when he decided to part with it. The engine is nothing special, just a stock motor that has done around 100,000 miles and is probably due for a freshen up. Aside from the usual oil leaks, it is blessed with 964 heat exchangers and a modified 3.2 side silencer & stock 3.2 Carrera rear silencer. It's a quiet system, measuring only 97dBa at 0.5m when noise tested at an Oulton Park track day recently.

To install the kit I could not use the customers new 9m 964 wiring box so I adapted an old M600 version that I had used in my 993RS, otherwise everything was pretty much as it would be in a M48 package. The kit consisted of:
M84 ecu
9m M84-993 wiring box & additional sensor loom
9m/Bosch injectors x 6
9m air intake & K&N filter
MAP, AT, OT sensors
Wide band lambda sensor

Because the kit is destined for Bahrain the engine was mapped on regular 95ron unleaded rather than the usual Shell V-Power, resulting in a smaller gain than usually experienced at 306bhp & 395Nm in comparison to the start point of 275hp & 350Nm. As can be seen from the graph, peak numbers though are not the only part of the story as the engine makes a lot more power everywhere on the curve in comparison to the standard ecu. The increase in performance is immediately noticeable on the road and after driving it to fine tune the maps all I can say is that the car feels easily as fast as any (stock) 3.3 turbo and now shows up the limitations in the 3.2 braking system! With a lightweight flywheel & properly calibrated idle valve & MAP corrected fuelling, the idle is now also very strong and the car will pull 4th gear, uphill from 700rpm with zero throttle.

Job done.

Bill Verburg

I love these threads

NineMeister

There's no popcorn in your reply Bill so should I be happy to assume you are genuinely enjoying the thread and not simply waiting to enjoy the ensuing "discussion"?

Bill Verburg

Genuinely enjoying. One of these days I'll get Geoffrey to do one for me.

NineMeister

Cool. You will not regret that decision.

SwissSC

Hi NineMeister

how much does an 9m Motec M84 upgrade on Varioram cost? I have a 1996 none sr (1332kg full) 993 fully prepped by FVD in Germany with 3.8 (p&c from Wössner), sport cams by Schrick, solid lifters, enlarged throttle body, lwt single mass clutch, uprated FVD ecu 98 Ron, titan spring caps, x-cross 100 cell GT-cats, etc. Car makes "only" 305hp/7055 and 355nm/5500. Seeing your results I get jealous and think my car could/should make at least 350hp/400nm

Thanks

RDS928S

Hi Colin,

what could USA customers expect with endless supply of 93 octane on a 1995 Non VR motor?
Also could you quote/convert to US $ & how long to install in labor hrs?

Regards Rich

camlob

Excellent results on just installing the motec!

NineMeister

I agree, I would fully expect your car to pull around 350-360hp on our dyno with Motec because similar engines that we have built easily make this kind of power. That said, please don't get carried away with looking just at the numbers because there are too many variations between dynos to make meaningful comparisons of results on different equipment.

The cost of the installed and mapped 9m Motec M84 conversion on a 993 with all sensors is £4450+VAT.

Macca

Hi Colin,

Great work. Im glad Motec have finally filled that gap in the market. It was being filled by other tuners using LINK/Vipec and Autronic Down Under at far lower cost with at least as much versatility. Motec's a good product even if it was developed by Australians ;-P

I'm curious. In your comment below you allude to making adjustments to the ISV. Is this via the Motec software (air on idle) or manually via adjusting the ISV?

"With a lightweight flywheel & properly calibrated idle valve & MAP corrected fuelling, the idle is now also very strong and the car will pull 4th gear, uphill from 700rpm with zero throttle...."

I ask as I am fine tuning cold idle with a slightly lumpy cam and finding head temps can lead to erratic cold start idle behaviors (especially under load - headlights, air con etc). Obviously Im concious of potential stalling also with LWFC and RS hub and lighter dual crank pulley. Oil temp seems a red herring as it takes too long to give meaningful readings from dead cold...

Would appreciate your thoughts?

Cheers

NineMeister

US fuel is measures as (RON+MON)/2 whereas UK is straight RON which is a higher number.

I would expect the conversion and mapping to take around 10 hours from scratch, but then you have to allow for dialling in the cold start & road tuning so we would expect to have your car in the shop for a week.

Including all hardware & 9m intake pipe we charge £4350 for the system installed on a non-Varioram or 964 out of which £800 is installation cost. You need a US tuner to do the conversion, so Geoffrey is your man there, no doubt he can give you the price in $ which will take into account the difference in Motec USA pricing.

NineMeister

The idle valve of choice is a 964 two wire unit simply because it only requires one high current output from the M84, the 993 three wire valve will work just as well but this is a push-pull device which would tie up both the high current outputs, hence the choice is based on electrical limitations. I also programme all our Motec systems to use cylinder head temperature as the primary engine temperature measurement because as you say, using oil temperature leads to erratic behaviour with cold start.

We do make significant adjustments to the ISV within the Motec software. The ISV is a PWM (pulse width modulated) device for which Motec uses PID (Proportional, Integral, Derivative) control, so as well as the frequency of the valve we can play with opening duty cycles at various temperatures and the response speed/damping of the valve by manipulating the PID parameters. It's more than 10 minutes work, but once the valve is dialled in my engine would start and idle at 1100rpm from cold and ramp down to 920rpm when hot.

The second aspect to successful idle strategy is fuel correction. We're using Alpha-N for the main tables so at idle there is only one fuel number in the table and if left to its own devices the engine would hunt badly due to fuel mixture variation as the ISV opened and closed to maintain speed. To counteract this we add manifold pressure (MAP) correction to the fuel table which then maintains the desired mixture strength nomatter where the ISV is open to. With the correct mixture & ISV working properly the idle is rock solid and the engine will make good torque, hence why it will pull 4th gear at zero throttle.

An engine with a LWF & lumpy cams it may not pull 4th but would still be stable if the ISV is programmed correctly. That said, my 3.82 litre 9m race engine on 320 degree high lift cams would pull 2nd gear at idle around the paddock and it was on throttle bodies with no ISV, so if you have a problem it is probably just down to the quality of the installation and programming.

Macca

Thanks Colin. Really appreciate the input. That heads me in the right direction.

My programming seems to be in line with what you have suggested (alpha N base tables etc). I idle warm at 1100. Idle is stable but first gear clutch balance at this idle isn't as easy as a lower idle speed. I have adjusted this down to 1000 rpm but have found that below this with electrical loads/air con clutch on that the engine may stall in certain situations.

Im pretty sure the cam may have something to do with this. That in conjunction with the LWFC etc. Since the cam (993SS) install the first 10-20 seconds cold idle produced wild hunting (600-1300 rpm) before it settles down (as soon as it can latch onto a head temp reading). I think this may be partly mechanically induced and possibly difficult to eliminate (it did this on Motronic as well as aftermarket ECU).

I will check with the tuner re the ISV based on your comments.

Looking at my programming console I have ISC set "open loop sol/stepper". Type = Unipolar (6 terminal) then a "max clamp" set at 70% and a "min clamp" at 5%. These mean nothing unless reverting to the base fueling alpha N tables and "idle base position table", but on the idle base position table I use the solenoid (%/DC) field to tune the idle for varying cylinder head temps by varying the % for each temp mark.

The tuner has installed 100s of these ECUs but I must confess mostly to race cars and almost never to 911s. Obviously there are some peculiarities to setting up a 911/993 on LINK ECU which they have no anecdotal experience in (although they did get LINK HQ in Christchurch to check their theory). I could find no other 993s running aftermarket ECU in a street application (drive ablility, electrical and air con loads etc being primary concerns).

I should think we almost have it as good as we can make it but will investigate the PWM vs PID angle and associated programming....

Shame you couldnt make it down for the Rugby World Cup. I could have shouted you a quarter final ticket for a few hours of your time on the dyno :-)

Cheers

Jean

Hi SwissSC

Don't hold your breath...and be happy with your engine.

Naturally aspirated engines have characteristics that makes them breathe (pun intended) a maximum certain amount of air that burns with fuel and produce a certain amount of torque. The maximum amount of torque by cubic centimeter of engine displacement (efficiency if you want) is extremely difficult to improve on a production based engine without doing dramatic changes to the engine design itself, I am not talking about exhaust modifications, or air fuel ratios or timing, not even improvements in head flow, I am talking about millions of dollars in R&D of inherent design changes of the engine and its electronic management.

To put things into perspective, it took Porsche 10-12 years of development (from the 993 to the 997) to see this efficiency increase by a mere 15%.. Meaning maximum torque produced by their engines per cubic centimeter increased by 15% only. Add to this, that most of this increase was achieved through an increase in compression on the engine, going to 4 valves and watercooled, and the rest from drastic improvements in engine electronic management.

Your car with specific cams and all those changes had its efficiency increase by 6% based on your max torque reading, and once you adjust for your displacement increase to 3.8, your maximum efficiency increase by 1% only, which is reasonable, maybe very slightly low. The Porsche varioram introduction on the 993 engine which was a great innovation and cost $$$ in R&D had almost similar results.

This engine achieved the efficiency that Porsche achieved with all the above modifications across 3 generations and millions spent in 10-12 years just by slapping a Motec on it

Motec is great, and I would install it on an old generation engine needing help, but dyno numbers like these are totally worthless from a buying decision perspective.

evoderby

Interesting input Colin!

On your non-ISV race car do you run some sort of ignition timing idle control? I use this on my Cooper S with pretty nice results: programmed the DTA (Alpha-N) ignition map for the desired idle RPM as well as a 200RPM window around this increasing advance when the engine undershoots the desired RPM and vice versa.

Works rather well, especially considering it runs quite a lumpy cam (286 scatter) and the time honoured weber 45 to take care of fueling (injection is next to useless on siamese intake ports). In fact my 964 with modified ISV to prevent stalling doesn't do a much better job (70-100rpm hunting).

Then again didn't Porsche who had a big hand in designing the Harley V-Rod watercooled engine specifically (counter)map the engine to give the characteristic lumpy Harley idle? ;-)