Porsche-O-Phile

Okay, which one and why?

A week ago I was sold on the Vitesse MAF kit, now I'm not so sure and am leaning towards a MAP setup. Whaddya' all think?

jimbo1111

When you say map. Do you mean piggyback or standalone?

aeronautica86

apparently MAP doesn't work too well with the stock motronic. if you are going with a standalone engine management, go MAP, if you are staying with the stock motronic with an added piggyback, stick with the MAF

User 41221

Only use MAP if you replace the ECU as well. MAP is not "best suited" for use with our Motronic's boxes and in my opinion, has some inherent liabilities that you will have to "tune out" of the car. Do a search, some folks have been happy with the results, but a LOT of folks haven't been. THere are part throttle issues, stumble and hesitation on acceleration, and the LinkAFM boxes and the handheld tuners for them have been less than reliable and have had to be sent in repeatedly for repair by some folks.

MAF, on the other hand, has a very good track record with our cars. I've had both Lindsey Stage II and a Vitesse tuned MAF (as well as a Guru Stage II MAP, so I think I can speak with some authority on this subject) and either will work well and are quite trouble free. My preference is Vitesse, as Johns service can't be beat, but there's nothing wrong with Lindsey.

HP gains between a well tuned MAP and a well tuned MAF will show a minimal difference. I am estimating you will see ~20rwhp tops, but it gives you good potential for future upgrades. Warning tho, John matches his MAFs to the turbo you are running, so if you want to get the best bang for your buck with Vitesse, you should think of the MAF and turbo as a system, instead of something where you buy one pice at a time.

Regards,

Porsche-O-Phile

I was looking at standalone. . .

Interesting observation - any idea why there are problems with linking up to a Motronic computer? It's just an input signal value after all - why would it make that much difference?

hosrom_951

Search the archives, there is lot of info there.

Mike S

I just converted from the AFMLink Map (Guru) piggy back to the Vitesse MAF (SMT6 piggyback) and although I will have a full comparison in a month or so when I get some dyno results...i can tell you that throttle response is much improved with the MAF. Power wise...they really feel about the same. It seems like most of the throttle response issues with MAP are due to the slow Motronic response. Standalones shouldn't have that problem.

TurboCab

Jeff:
The main difference between the MAF and the MAP is that the Mass Air Flow Meter as the name implies will measure mass of air entering the engine. Since mass is temperature dependent, the MAF will give a correct reading regardless air temperature. With vane type meters and MAP (Manifold Absolute Pressure) you will need an ambient air temperature sensor to compensate for changes in air temperatures. I have a stand alone system with a MAP sensor a don’t have any problems, but I live in the Tropic when the temperatures are basically the same all years. The MAP sensor will not measure quantity of air, but instead will provide the ECU with an Engine "LOAD" related signal for A/F ratio and acceleration enrichments. This is not really the best way to reference for A/F ratio adjustment, but if properly tuned will work OK. It has the advantage that "False air" will not be a problem. The issues mentioned above are related to the adaptation of the MAP sensor to the Motronic ECU, not of the MAP sensor itself. Hope this help.

DDP

I agree. Ton of good info to be read.

eastendr

I'm another one who's thrown away the link AFM in favour of a standalone MAP setup - Wolf-3D.

The car now tunes properly.

HTH

Rick.

pk951

Rick

On the linsdey site they say the system is plug and play?

Did you get any start up maps with the Wolf system?

How much tuning have you done to get the tinning and fuel maps right?

Laust Pedersen

Although most auto manufacturers now use MAF systems, I still prefer a MAP system for a couple of reasons.
The MAP sensor is relatively small and does not have to be in the intake air stream, giving more freedom to optimize the intake air path. A MAP (+ MAT) sensor also is less costly than a MAF sensor and lastly in setting up the fuel and ignition maps, I find it easier (more intuitive) to have rpm and load as independent variables.

A tricky part of a MAP system is making sure that pressure signal is a good measure of the load. Fortunately our intake manifold has a good pick-up for that and our cams also provide good vacuum at idle.
I have had good experience with Electromotive’s TEC-1 and TEC-3 on my other cars.

Laust

Tomas L

I don't understand why a MAP system should be easier to set up or more intuitive than a MAF system. First of all, a MAF system like the Motronic, has load and rpm as independant variables (at least from a setup point of view). A MAP system doesn't even have load (amount of air in the cylinders, or nearly cylinder absolute pressure), it has MAP which really is a lesser relative.
But from a user setup angle I really don't see the difference in that respect.
The big difference setup wise is the fact that a MAF measures mass air flow which is exactly want you need to know to determine how much fuel that should be injected. This means that if you have a correctly built MAF system you can set it up very close to target without even trying it on the car.

Porsche-O-Phile

I'm virtually sold on the MAP system and am leaning heavily towards a standalone engine management setup. This is something that as recently as two weeks ago I'd have not considered just because I didn't feel like dealing with all the electronics stuff, but the more I research it, the less daunting it seems. . .

Besides, in terms of h.p. gains per dollar, this seems way more cost-effective than many of the alternatives. . . The potential is WAY higher and you're not paying a premium on stuff that's at the peak of its cost/life-cycle curve as is the case with some of the other choices. AND it offers more tunability in the long-term.

And yes, there is some pretty good information on this subject in the archives - thanks for the tip.

Tomas L

I agree that an aftermarket standalone has advantages but it can end up much more expensive than you think. First you should check if you need to buy new sensors and other things like a new ISV or trigger wheel. Then there is installation that some can do themself and others can't. Finally the fuel and ignition should be mapped up, this can be very expensive, I've heard about people paying more than $5k for this. Even if you do it yourself, there is a lot of work before you have everything sorted out, for instance cold start enrichment, idle control and so on.