Installing a ProMax MAF & chip
 

I have had a few pm's about my impression of the ProMax MAF as well as it's installation.

While my alternator troubles prevented me getting to the dyno as planned, I thought I'd post my installation and impressions of the ProMax unit - hopefully I can add a dyno plot soon.

Marc

Disclaimer
 

I have no personal or financial affiliation with either ProMax or Andew (who sells the ProMax things here on Rennlist). While ProMax are a Rennlist sponsor and I respect that, I hope that they appreciate my being as honest and objective as possible. I was blessed with the assistance and experience of Geoff (Red rooster) for this installation. Geoff apparently knows Andrew in a professional capacity but also has no personal or financial affiliation with either ProMax or Andrew. In addition, I make no claim that this is either the best way or the even the only way to install this kit. Neither I nor Geoff (nor Rennlist) will be liable if you install your chip incorrectly, start an electrical fire, or fry your ECU - this just recounts my experience.

First Impressions
 

Okay, open the box and this is a cool-looking kit. It arrived well packaged from the UK to Canada about 3 weeks after being ordered - it did get held up for a few days at Canadian Customs (why, I'll never know). Andrew was very good to extend the 30 day money back guarantee from the date of installation as he was well aware my car was in pieces and there was 4 feet of snow on the ground when the kit arrived.

It includes:
a Bosch 80 mm hot-film air-flow meter
a machined aluminum adapter bracket
a short (about 4 cm) segment of 80 mm hose
2 large hose clamps
4 non-locking nuts
a wiring loom with male/female plugs, power supply wire, and a signal converter box
the ProMax ECU chip in an anti-static box
half a dozen zip ties
instructions for installation in a 944....

Okay, as a plug-and-play kit, I would knock a couple of points off for the 944 instructions (the 964 ones were not written when I got the kit, they may be written by now). On my own, this would have delayed me trying to determine what to do and where things go, however, with Geoff's assistance, it was a piece of cake.

First impressions: A-

Edit: Andrew informs me that 964 specific instructions are now included (mine was a very early kit).

Installation
 

Well, if we had put our minds to it and got on with the job, this would have been a job completed in an hour or so. As it was (with a few cups of coffee and lots of car-related chatting), it took us just under 6 hours. This time also includes a few runs up and down the highway looking at the air-intake temperatures on the Hammer and getting some butt dyno readings. We debated hooking up Geoff's LM-1 for air/fuel readings but it was getting late in the day so decided against. The lambda readings from the Hammer looked okay so there were no concerns about the air/fuel mixture in that regard.

Okay, how to install this unit:
1. remove air box cover & air filter
2. remove rear fuse cover
3. remove rear heater tube & blower *
4. unplug the ISV **

* removing these bits permits easier access for cable routing later on.

** this is not really necessary but it gets the plug and wires out of the way

5. remove stock airbox & old AFM
5a. undo 1 nut in front of the airbox
5b. undo 1 nut inside the airbox at rear, lower edge
5c. undo 1 bolt on top of the old AFM on a clamp holding the wiring loom
5d. loosen the hose clamp by the ISV around the old AFM
5e. wiggle the old AFM off and the airbox to the right
5f. unplug the wiring harness off the old MAF
5g. undo 1 screw holding the vacumn canister on the back of the airbox
5h. pop the vacumn canister off the bracket on the back of the airbox
5i. wiggle the old AFM and airbox out completely

6.remove the old AFM from the airbox
6a. pop the inner air horn off the inside of the airbox
6b. undo the 4 nuts holding the old AFM onto the airbox and separate the old AFM and the airbox

7. install new MAF onto the airbox
7a. the airbox inlet has a ridge on the back that must be trimmed so the machined aluminum adapter bracket fits *
7aa. hold the adapter bracket on the back and mark the corners of the ridge
7ab. trim and smooth the corners using a knife, hacksaw, or Dremel
7b. bolt the adapter bracket to the airbox using the bolts and locking nuts (not supplied) **
7c. slip the 80 mm hose onto the adapter bracket
7d. slip a hose clamp around the hose at the adapter bracket and secure
7e. slip the second hose clamp around the hose
7f. slip the end of the new MAF with the plastic screen into the end of the hose ***
7g. secure the second hose clamp around the hose and new MAF ****


* the back of the air intake on the airbox has a ridge that impedes the adapter bracket from sitting flush. The very corners of this ridge (3 - 4 mm) must be trimmed down so the bracket sits flat. This is not a big deal and would not be a problem if the old MAF was ever re-installed.

** as only nuts were supplied, you'd have to remove the studs from the old MAF and re-use them. Instead, we used new bolts. In addition, the nuts supplied are not the locking type so we used Nylock locking nuts on the bolts so the obvious concern about sucking a loose nut into the air intake would not become a reality.

*** the new MAF is direction specific so you must orient it the right way around. The intake side of the new MAF is covered with a coarse plastic screen while the outlet side is not. There is also an arrow on the side of the new MAF to ensure you get it the right way around (get it wrong, and I'm told the car will barely run, if at all).

**** finally, don't forget to rotate the new MAF so you can reach the wiring harness plug. Ideally it should be as close to vertical as possible to keep water out of the plug. If it is perfectly vertical, you can't reach it so we aimed it backwards (to the rear of the car) by about 30 degrees.

8. install the new MAF and airbox (the reverse of the removal)
8a. wiggle it in to place
8b. snap the vacumn canister on the back and secure it with the screw
8c. slip the end of the new MAF into the inlet hose on the car and secure the hose clamp
8d. secure the airbox with the two nuts (one on the front edge and one inside) *

* the new MAF has no provision for the bolt and hose clamp that secured the wiring loom. We just removed the hose clamp so it would not fall off. Not securing the wiring loom did not appear to be a problem as it can't move anywhere anyway.

9. install the new wiring harness and signal converter box
9a. plug the male of the new harness into the new MAF
9b. plug the female of the new harness into the car's MAF plug
9c. secure the signal converter box somewhere in the engine bay away from heat and moisture *
9d. route the separate 12v power supply wire from the new wiring harness between the a/c lines
9e. thread the wire up into the rear fusebox through the grommet at the bottom rear
9f. unplug the rear-most of the two large power plugs in the fuse box
9g. find the red wire coming off pin 8 (a 12v ignition line that powers the DME) **
9h. strip some insulation off the wire and solder the power line from the new wiring harness to this wire
9i. insulate the new connection with tape and re-insert the large plug back in
9j. secure the power line in place in the left side of the engine pay so it won't move, bind, or chaffe
9k. secure the new wiring harness in place using a couple of zip ties

* I elected to secure it to the bracket above the right shock tower that hold the oil lines up. In this location, it will remain dry and also be away from the engine heat. Be sure it will not vibrate or rub on anything. The signal converter box is also very smooth and has no tabs or anything so we had to use a hose clamp as the zip ties would not hold it securely.

** be VERY SURE you have the right 12v wire. I will not be held responsible if you tap into the wrong wire and cause an electrical fire in your fuse box or engine bay!!!! It is also not my fault if you tap into the wrong wire and fry the signal converter box or your new MAF!!!!

10. re-install the air filter and airbox cover
11. re-install the fuse box cover
12. re-install the rear blower blower and heater tube
13. plug the ISV back in
14. change the chip in the ECU
15. make sure everything in the engine bay is secured (no loose wires or stray tools)
16. fire up the engine and make sure it runs
17. if you have a Hammer, do an "idle stabilization" to force a DME adaptation and check for any errors - if you don't have a Hammer, just let the car idle for a few mitnues and go for a "spirited" drive to re-map the DME.
18. go for a drive and check it out

Okay, while the installation is not exactly plug and play, ProMax have obviously made a concerted effort to make it as simple as possible. The lack of instructions (in my early kit) and the need to tap into a 12v ignition power supply line might be a bit daunting for some.

I would also suggest supplying bolts (so the old MAF studs do not have to be re-used) and locking nuts so they can't vibrate loose and get sucked into the air intake. Nit-picking perhaps but the hose clamps were larger than necessary (so the tails were quite long once snugged down), and the connectors on the plug by the new MAF were bright blue - not the best if a stealth installation is required. It would also be nice if the signal converter box had tabs or loops on it to make it easier to secure in the engine bay. Finally, the need to trim that ridge on the back of the airbox is not a big deal but, if the opening for the adapter bracket was a couple of mm larger, it would not be an issue.

Installation: B+

Driving Impressions (the butt dyno)
 

After we got it all buttoned up again, we headed out on the highway with the Hammer showing lamda values and air intake temperatures (if you have a chance to buy a Hammer - do it!!! It is a wonderful tool). Now driving impressions are very subjective of course and initially I was hampered by the weight of my luggage, a passenger (although Geoff is not a large man by any means!), and unfamiliar roads. Even so, I was impressed as I could notice a difference already. The throttle was more responsive, the power delivery was very smooth, and there were no flat-spots in the curve. There was no hesitation and no nastiness like back-firing.

With the engine heated up, we pulled up an off-ramp and, once idling, put the a/c on full bore.....no stalling issues and the Hammer showed the idle stayed solid at around 880 (840 - 920, same as with the a/c off).

So far, I am pleased with the positive changes this seems to have made in the driveability of the car with no unpleasant surprises or trade-offs.

Finally, at a recent DE held at Tremblant, my instructor (who drives a 964-C2) commented on a subjective feeling of improved responsiveness and a stronger pull in the mid-range rpm after driving my car. This was unprompted and before we discussed any engine modifications.

Driving impressions: A+

Hopefully I can add a dyno plot or two once I get a chance to get to a AWD dyno. :)

Marc

Marc... You need to make sure this goes into the DIY section! Excellent write-up!