Mass Airflow Meter

[944 man]

...for a 944? As Im sure that you realise, the 944 uses a very old-tech mechanical flap type airflow meter. I am trying to find out if the later hot wire (MAF) type of meter can be adapted to run on the cars? I am aware of at least one conversion, which uses a new Bosch MAF, but it costs in excess of £750! Im hoping to find a part that can be salvaged off a later VAG or maybe BMW (they used the same ECUs after all) and adapted to work on the ML1.2 / ML3.1. The nett result should be a cheap upgrade thatll result in better respone, smoother running and more power, whilst costing very little.....

 

[944 man]

Another option that I can see is to ditch the DME and replace it with a Megasquirt ECU. Thisll allow me to run without an airflow meter altogether, but it is far from turnkey (and mapping it could be fun or a right pain in the arse). Has anyone on the forum, or in the club, installed a Megasquirt system successfully?

 

[Peter Empson]

There are a few off the shelf MAF conversions, Vitesse and Scivision are probably the best known, I have the latter (which I've been very pleased with) but quite a few people here have the former and it's a rather more sophisticated solution (it's the one I'd buy now if I was doing it again), although neither are especially cheap. There have been a few diy threads on Rennlist and some people have definately had success, but I cannot find them at the moment (that's always the way).

 

[Peter Empson]

Not the threads I was thinking of, but loads of info here and here.
Btw, we dyno'd mine before and after and there was no HP gain but the massively improved throttle response was the reason I stayed with it, it was later on rolling road remapped and a small amount of extra HP was found.

 

[zcacogp]

Watching this one with interest ...


Oli.

 

[edh]

I'm assuming we're talking about 944 turbos here

Whatever you do, you're relying on someone being able to build a new motronic chip for you - and to support you. Get it wrong & it could be expensive....

Moving to MS is an option, but would probably take you a while to sort. I believe that there are some people on rennlist using MS who could help you get started - definitely worth a search if you fancy a DIY approach.

If you want a simple solution, Vitesse is plug & play. I think he's also released a MAP option. He doesn't support his MAF on standard injectors, so that's another cost to factor in.

Apart from the facts that John @ Vitesse has a very good reputation for support & a track record of delivering products that work, I think the main advantage of the Vitesse MAF is your ability to run different setups without having to change chips. When I get a DPW and MBC on the car, it should just work straight off at any (reasonable ) level of boost. At the moment I certaily get slightly faster spool, with boost coming in 2-300 rpm earlier, which may help for the occasional off-boost corner. This may be a function of better mapping rather than MAF vs AFM - the AMD chips I had went very rich as the boost kicked in.

Improved throttle response is possibly more noticeable on an n/a?

 

[Big Dave]

For those of you that are contemplating this upgrade.
I have a Scivision MAF kit that came off my S2 before i sold it.. It had been fitted + ran for about 5K miles. It improved the throttle response + the whole car generally felt livelier..
I bought this from Promax motorsport + it has performed faultlesly.[][][][]
Im sure itl fit to other N/A models..
So i guess what im saying is its for sale....£500...Complete kit with instructions.. Interested....
See link for current pricing...
http://www.deutschnine.com/mm5/merchant.mvc?Screen=PROD&Store_Code=porsche-transaxle&Product_Code=D9-944S944S2-MAF&Category_Code=porsche-transaxle-944-turbo-s2-tuning-handling

 

[944 man]

Thank you for your replies. I was aware of the Vitesse and Scivision products, but for me, they're both far too expensive, for the gains that they are able to offer. The car is an 8v Lux, currently running Bosch ML1.2. I was hoping for a cheap and simple MAF upgrade that could be sourced cheaply from another vehicle and adapted to work with a later ML3.1 ECU.

The more I look the more certain I am that a MegaSquirt system is the answer. Id considered the Vitesse products recently and youre looking at £1,100 (and that's just for the MAF and a piggy back ECU) excluding delivery, duty and VAT and even then you're not getting nearly as much in terms of features or (ECU) performance as MegaSquirt offers.

As I mentioned in my second post, virtually identical ECUs were used in same-period BMWs (as well as AUDIs and Volvos), so I was hopeful that there'd be a number of older BMWs that were now running a MegaSquirt ECU. It seems that all you need to add a MS system to an early ML installation, is an air temperature sensor and a new throttle position sensor. A number of sites suggested cannibalising the existing ECU for the plug, but a better solution appeared to be building the MS into the original ML ECU chassis. There's plenty of room inside to wire the connector and it'll be easier to mount and far more durable, so that would be ideal. After a little more digging I found a British firm who offer a MS already built into a Motronic control unit for £400. If youre happy to assemble your own kit then you could be ready to go for just over £100 plus the required sensors, which will cost very little from a dismantler. With a pin-out diagram and a Dremel it can be mounted in an old OEM chassis in next to no time.....

 

[944 man]

You'll probably need to budget to replace the injectors too, as they're maxed out 183bhp (late 229cc) to 189bhp (early 237cc): unless you turn the fuel pressure up...

 

[edh]

On an n/a the potential gains are more limited than a turbo & I wouldn't spend half the value of the car on an extra 5hp & some improved throttle response [] (unless you're racing & the regs allow it)

Ed

 

[944 man]

Im confident that theres about 20bhp to be had, along with a greatly improved throttle response. Im not racing the car, but it is broadly similar to a '944 Challenge' car (but without the moody seam welding)...

 

[944Turbo]

On a standardish car you will probably be fine without the piggyback on the vittesse MAF, However, it would be good to see a megasquirt car up and running in the UK. You will probably need to budget for a wideband(with data logging) or some hours on the dyno to get the mixture set right. With megasquirt other options would be available later, e.g. a supercharger or low pressure turbo []
Tony

 

[edh]

ORIGINAL: 944 man

Im confident that theres about 20bhp to be had, along with a greatly improved throttle response. Im not racing the car, but it is broadly similar to a '944 Challenge' car (but without the moody seam welding)...

I bet I'm nearer with 5! [] - happy to be proved wrong, but AFAIK you need some major work on the 2.5 8V to get 180-190 bhp. How much would EMC charge to build a 190 bhp motor?

 

[944 man]

I agree about the wideband lambda. Im trying to see how exactly the MS maps itself, as in theory it should be possible to get by without...

 

[944 man]

ORIGINAL: edh

ORIGINAL: 944 man

Im confident that theres about 20bhp to be had, along with a greatly improved throttle response. Im not racing the car, but it is broadly similar to a '944 Challenge' car (but without the moody seam welding)...

I bet I'm nearer with 5! [] - happy to be proved wrong, but AFAIK you need some major work on the 2.5 8V to get 180-190 bhp. How much would EMC charge to build a 190 bhp motor?

If you can get a straight answer out of Kevin then Id be interested to hear! More seriously though: theyre all running standard ECUs & meters and thats the limit.

 

[944 man]

ORIGINAL: edhI bet I'm nearer with 5! [] - happy to be proved wrong, but AFAIK you need some major work on the 2.5 8V to get 180-190 bhp. How much would EMC charge to build a 190 bhp motor?

I bet you arent, because I can get 5bhp by deleting the balance belt! []

 

[edh]

Good luck! - looking forward to the before & after dynos [] []

 

[Peter Empson]

We didn't get anything like 20hp on my S2 engine with the Maf, even when it spent most of a day on the RR being mapped the gains were under half that. I honestly can't see a 20hp gain on a Lux from a Maf alone, but I would love to be proved wrong.

 

[944 man]

Sorry: I wasnt particularly clear. With a MegaSquirt ECU replacing the OEM ML3.1, running without a an airflow meter and without any other restriction in the inlet tract (beyond the inlet manifold, which I believe is quite an obstruction ), without the balance belt and with a non restrictive exhaust then I would hope to see about 185bhp. I might not of course!

Im of the opinion that two principal things hold the 2500cc NA 8v back: the primitive ECU and barn door air meter and the inlet manifold. Bearing the latter in mind, I wouldnt be surprised to see more torque than bhp, but Id be happy with that.

 

[homesea]

Not to sound odd, but why do it? Is it just for fun? No point in trying to get 180bhp out of Lux why not just buy a S2 or turbo?