Protomotive MAP ECU (long)

[WydRyd]

This past Sunday I spent most of the day performing brain surgery on my car by ripping out the old DME and installing a new Protomotive modified Motronic DME. This post would probably be more useful for those aftermarket Carrera turbo junkies who are considering a MAP based ECU solution to totally eliminate the BOSCH AFM sensor.

Overall, the installation is fairly basic and went quite smoothly. It consisted of:

- running a 1/8" vacuum line from the rear of the throttle body to the DME

- drilling & tapping the throttle body for a new BOSCH NTC IAT sensor. Since the AFM flapper box is removed, so is the OEM IAT sensor, which is integrated into the AFM housing.

- removing the OEM dual-pole TPS switch from the throttle body and installing a new variable TPS sensor.

- re-wiring the signals which use to terminate in the AFM and soldering the appropriate IAT and TPS signals onto the OEM loom.

- fitment of a hard 90 degree elbow from i/cooler to throttle body and re-routing the ICV/ISV vacuum hose to the neck of the air filter.

Once everything was completed, she fired right up and settled to a steady smooth idle (albeit slightly higher than usual). There's quite a bit of intake/suction noise after this mod, possibly due to the free'er flowing intake to the throttle body

Anyway, I took her around some of the back streets and immediately noticed a significant improvement in throttle response. Certainly much crisper throttle compared to the AFM barn-door style intake (which often felt quite lethargic). Again, the beauty of having no restrictions in the intake

The acceleration and crispness of the throttle totally transforms the feel of the car. It literally feels like a larger displacement motor has been installed Due to the more accurate fuel/ignition mapping under various loads, the response from the GT35R feels pretty much instant. Barely no lag and the torque and acceleration feels much nicer with the speed density based ECU.

For you blown Carrera converts who are considering an aftermarket ECU, I highly recommend the Protomotive solution. The ECU even comes calibrated with a fairly accurate tune for whatever platform you're running as Todd has a number of engine dyno'd calibrations for the various stages of his Carrera turbo systems. No doubt some fine tuning may be required, but to get you up and running fast with a pretty accurate tune, the Protomotive ECU is a very cost effective, drop-in product

Very soon I'll be hooking up the second plugs on my motor and will get this baby on the dyno to verify numbers

[jbrinkley]

congrats, in time I'm sure something like that will be in my car.
maybe after the divorce dust settles.

I always like hearing about your car Merv

[WydRyd]

Thanks, Jerry. It's worth considering the Protomotive system. It's a true drop-in upgrade and a VERY nice upgrade at that

[930gt-40r]

Yes Merv..... No "barn door meter" = serious wood

[WydRyd]

I'd say it's at half wood right now

Next week Todd is sending me an enlarged/bored throttle body to compliment the new ECU... now THAT is what I call WOOD

Who needs Viagra when you drive a 911 turbo

[930gt-40r]

No, big bore throttle body = petrified wood

[kellcats521]

How is this unit programmed? New Chip? Will you get a new chip/reprogram with the bigger TB? How much to reburn/reprogram?

The beauty of MAF is that reprogramming is generally not needed when you go to bigger cams, turbo, TB, intake, ect. since the MAF can 'measure' the mass of air entering the motor and calculate the correct pulsewidth based on the desired AF ratio and the injector size. The downsides include intake resistance (especially with a flapper AFM, but hot wire AFM's also impede flow slightly), and difficulty in dealing with poor AFM signals (big cams cause reversion at idle which really messes with AFMs).

With MAP, the ECU infers the air mass based on the temp, pressure, and throttle position with the proper programmed information (volume of the intake system with any cam related adjustments), and uses this air mass 'calculation' to set the pulsewidth. If all of the parameters are accurate, MAP can work better than MAF because you can 'tune out' some of the MAF related issues, and the intake will flow better. The downside is that phased-based upgrades (like discussed above - now adding a bigger TB) MAKE you either need to know how to tune your MAP program, or force you to PAY for a reburn/new chip. You are basically chained to your tuner if you plan future upgrades - with MAP, your best bet is to save all of your $$ and do one big upgrade to include the new programming.

I have been doing aftermarket Bosch EFI programming for over 10 years (mainly SEFI MAF w/hot wire MAF, but also a lot of MAP work), and the genral advice I give is to stick with a MAF unless you are SURE the horsepower bug is not still biting you....

Pat K
87 930

[WydRyd]

Hi Pat... thanks for the input and feedback. In short, yes, the bigger TB will come with a re-cal CHIP. I'd just have to send the original chip back. The re-cal fee costs ~$100. All I can really say is that the MAP ECU is a significant improvement over the AFM setup. Much better throttle response and torque down low. The bigger TB will improve upon that too

I think this is where I'll end it though. The car is plenty fast enough as it is and I'm quite content with the power it puts out. Sure, I can fit a bigger GT40R turbo for even more top end power, but that will sacrifice streetability, which is important to me as my car is my daily streeter

[930gt-40r]

Merv, I can only imagine how nice your car runs with speed density. I only have a few more hours worth of work to do to my car before I start it with pressure sensing and cant wait. One instance that I can relate to you is when I had my Galant VR-4 mitsubishi; I bought an HKS VPC (Vein Pressure Converter) and exchanged it for the Karman vortec mass air meter. Before I turned to pressure sensing, the car would break up and sputter at 16 psi due to improper tuning (I was too cheap to get dyno time for my beater car). After I put the VPC in, I tuned the very user friendly analog nobs and went to town. Before I knew it, I was running 25 Psi and the car was as smooth as it was stock. It just seemed that speed density is much more friendly with boost than a mass-air metering system is.

[WydRyd]

Well, from what I've seen, all high powered turbo motors run aftermarket speed density ECU's.

Main advantages of MAP sensing is lowest restriction due to lack of air flow measuring device and there's a single large table of pressure vs. rpm enabling a wide variety of conditions to be considered.

The only thing I really need to do to complete my motor off is to fit the larger TB and also hook up my twin plugged heads. These mods should provide even nicer drivability

The issue with MAF is the air-flow measurement in both directions would create problems on turbocharged engines due to large volume of air returning on throttle closure.

[Fast951]

Not all MAF sensors are the same. The MAF sensor we use handles the reversion problem. Not an issue.

For fine tuning, why not invest in a PiggyBack? I'm yet to see 2 engines that are 100% identical. With a PB you can hone it to match your engine 100%. You can even alter timing with some PBs.

Pat K, what sort of MAF programming do you do. Do you actually change the transfer function in the code itself?

[WydRyd]

Originally posted by Fast951
For fine tuning, why not invest in a PiggyBack? I'm yet to see 2 engines that are 100% identical. With a PB you can hone it to match your engine 100%. You can even alter timing with some PBs.

Yeh I looked at the MAP-ECU2 piggy back computer, which does fuel & ignition mapping and reads input via MAP sensor, RPM, IAT etc, but I prefer a standalone solution and the Protomotive product was the most convenient. Purely a drop in replacement for the OEM Motronics. They actually modify the circuit for the MAP sensor and re-write the tables/code for the speed density setup.

I didn't really want a 2nd ECU to "fool" the factory ECU, which is pretty much what a piggy back does. It alters the signals to and from the factory ECU. Not something I was comfortable with.

I intend to invest in a LM-1 with AuxBox wideband controller and I'll use the LogWorks software to plot the AFR, RPM, Boost & TPS and provide these maps to Protomotive so they can more accurately calibrate my ECU for my engine. For now though, their base Stage3 map performs great

[930gt-40r]

Originally posted by WydRyd
I'll use the LogWorks software...

The name sounds like it was thought up in the bathroom

Just playin' Merv

[WydRyd]

LOL! Very good

[kellcats521]

Originally posted by Fast951
Not all MAF sensors are the same. The MAF sensor we use handles the reversion problem. Not an issue.

For fine tuning, why not invest in a PiggyBack? I'm yet to see 2 engines that are 100% identical. With a PB you can hone it to match your engine 100%. You can even alter timing with some PBs.

Pat K, what sort of MAF programming do you do. Do you actually change the transfer function in the code itself?

Yes - we are altering the response curve of the meter by changing the code. Here is a typical mass air transfer function for a hot wire MAF


MAF_FUNCTION # Mass Air Transfer Function (Volts, Kg/Hr)
( 15.9998, 1222.07 ) ( 5, 1222.07 ) ( 4.69995, 1008.517 )
( 4.30005, 798.170 ) ( 3.98999, 656.017 ) ( 3.69995, 528.912 )
( 3.3999, 417.494 ) ( 3.19995, 355.703 ) ( 3, 299.354 )
( 2.80005, 251.649 ) ( 2.6001, 205.866 ) ( 2.3999, 170.327 )
( 2.19995, 138.311 ) ( 2, 109.496 ) ( 1.8999, 96.369 )
( 1.80005, 85.1637 ) ( 1.69995, 67.5547 ) ( 1.6001, 56.9892 )
( 1.5, 47.7045 ) ( 1.3999, 41.6214 ) ( 1.30005, 33.9374 )
( 1.1001, 22.1874 ) ( 1, 18.7296 ) ( 0.899902, 15.2718 )
( 0.800049, 12.6786 ) ( 0.699951, 10.0852 ) ( 0.600098, 8.56460 )
( 0.5, 8.02427 ) ( 0, 0 ) ( 0, 0 )

Also, I'm not averse to using a piggy-back circuit to load a revised engine management program. We've done it for 10 years with no issue. Wheter you actually burn your revised code into a chip, or use a piggy-back circuit to 'load' a revised code over the stock code isn't really an issue - what is the issue is that the code that is being used was developed by folks who know what they're doing.
It's very easy to modify a few lines of code to adapt a program developed for a somewhat similar motor to 'fit' something different. Some folks I worked with were really doing some neat stuff - very little of the OE code was unchanged in some of the stuff they developed.

Pat K

[WydRyd]

Originally posted by kellcats521
It's very easy to modify a few lines of code to adapt a program developed for a somewhat similar motor to 'fit' something different. Some folks I worked with were really doing some neat stuff - very little of the OE code was unchanged in some of the stuff they developed.

Pat K

I think this is a prime reason why Protomotive choose to stick with the OEM Motronic ECU's. They don't have to reprogram the ECU from ground up and worry about getting the cold/hot start maps set correctly, or the idle quality etc.. The factory has already done all the R&D in that area, so all the tuner has to do is alter a few lines of code here and there to adapt the ECU to slightly different engine configurations

[kellcats521]

Originally posted by WydRyd
I think this is a prime reason why Protomotive choose to stick with the OEM Motronic ECU's. They don't have to reprogram the ECU from ground up and worry about getting the cold/hot start maps set correctly, or the idle quality etc.. The factory has already done all the R&D in that area, so all the tuner has to do is alter a few lines of code here and there to adapt the ECU to slightly different engine configurations

This is really not accurate - a turbo 3.2 has a totally different program, if you do it right. Many, many parts of the code should be modified. You could get by with some basic changes, but a force-fed motor has little in common with an N/A sibling. On the Bosch SEFI programs developed by Ford for N/A motors, we would alter code that effected EVERY aspect of the engine operation when we added forced induction (turbo or supercharger) - the startup algorithms were changed due to the larger injectors, the base fuel tables were heavily modified, the cold-start tables were again changed due to bigger injectors (simply changing the injector size in the code isn't enough to produce great running motors at low/part throttle because the big injectors really behave poorly at short pulsewidth), the 3-4 timing maps were changed, the WOT voltages were altered, etc........

Don't believe all you're told or read - if it's really done right, it takes a LOT of time and real datalogging of many parameters, not simply putting a few cars on a dyno with O2 sensors...... My SCCA IT-E car would datalog 20 parameters - everything from battery voltage (which has a REAL effect on a lot of injector-related activity) to MPH, RPM, Lamba, O2 voltage, Load, pulsewidth, ECT, ACT, MAP, ........ We would make subtle changes based on performance within specific load/RPM ranges and spend lots of time dissecting datalog files. And, this was for a track car that didn't need to be near as drivable as a road car.

[WydRyd]

Well, I'm not saying Protomotive just alter little bits here and there to get it working for forced induction. I don't know how to read Motronic code and I'm sure a LOT of R&D has gone into their Motronic turbo calibrations. I guess I speak out of ignorance and lack of true appreciation for what really goes into tuning and modifying these ECU's for aftermarket forced induction. I'm just the end user.. what do I know?

All I know is that their MAP ECU is a significant improvement over the AFM setup

[polizei]

Is anyone else running this MAP ECU kit? Anyone know the cost off hand? I can contact Todd just as well, but I'm curious.

[jbrinkley]

it's like 2k something.