944 DME Project

[barks944]

Should be easy enough to implement . I've been out doing a load of on the road mapping today to get things in order for the rolling road. The misses did a really good job of mapping the car and its running really well know. Must have covered about 100 miles so far. Not really got stuck into the ignition mapping yet though...

 

[Eldavo]

Get stuck in then I can buy one!

 

[barks944]

Seem to be getting close to maxing out the standard injectors now. Seeing really large drops in manifold pressure at high rpm's from ~0.9BAR at WOT below 5K to about 0.7BAR at >5K. Suspect standard air filter or perhaps the throttle body is the cause. Wonder if I can run without the intake .

Edit: Too much alcohol, seem to be repeating myself .

 

[George Elliott]

Just use Birdlip hill, 3rd gear, 2am, and you wont need a rolling road...

(remember the roundabout at the top)

 

[barks944]

ORIGINAL: George Elliott

Just use Birdlip hill, 3rd gear, 2am, and you wont need a rolling road...

(remember the roundabout at the top)

Funny you should say that, I was up there the other night using it as a rolling road! Was using the M5 last night too .

 

[barks944]

Anyone know of a larger throttle body that will fit on the 944, 928 perhaps?

 

[944 man]

Perhaps, but Id be looking at similar period large capacity BMWs and Mercedes, which ran Bosch DME too.

 

[edh]

ORIGINAL: barks944

Seem to be getting close to maxing out the standard injectors now. Seeing really large drops in manifold pressure at high rpm's from ~0.9BAR at WOT below 5K to about 0.7BAR at >5K. Suspect standard air filter or perhaps the throttle body is the cause. Wonder if I can run without the intake .

Edit: Too much alcohol, seem to be repeating myself .

The smallest / most restrictive opening is in the airbox isn't it? Maybe you can try a quick run without the std airbox before you try & source a new TB ?

(What size is the TB? - I'm sure there will be a reference site somewhere that shows you how big a TB you need to flow enough air for your power requirements)

 

[barks944]

ORIGINAL: edh

ORIGINAL: barks944

Seem to be getting close to maxing out the standard injectors now. Seeing really large drops in manifold pressure at high rpm's from ~0.9BAR at WOT below 5K to about 0.7BAR at >5K. Suspect standard air filter or perhaps the throttle body is the cause. Wonder if I can run without the intake .

Edit: Too much alcohol, seem to be repeating myself .

The smallest / most restrictive opening is in the airbox isn't it? Maybe you can try a quick run without the std airbox before you try & source a new TB ?

(What size is the TB? - I'm sure there will be a reference site somewhere that shows you how big a TB you need to flow enough air for your power requirements)

The hole in the airbox is probably pretty comparable with the throttle body. But I certainly will try this first, I've got a K&N at home I will try later this week.

 

[TTM]

When I looked into using another throttle body, I noticed that the old unit as used on the 335/535i engine could be adapted without too much work.
However I dropped the idea for the simple reason the standard one can arguably handle already a lot more power than it was supposed to.

 

[edh]

ORIGINAL: barks944

ORIGINAL: edh

ORIGINAL: barks944

Seem to be getting close to maxing out the standard injectors now. Seeing really large drops in manifold pressure at high rpm's from ~0.9BAR at WOT below 5K to about 0.7BAR at >5K. Suspect standard air filter or perhaps the throttle body is the cause. Wonder if I can run without the intake .

Edit: Too much alcohol, seem to be repeating myself .

The smallest / most restrictive opening is in the airbox isn't it? Maybe you can try a quick run without the std airbox before you try & source a new TB ?

(What size is the TB? - I'm sure there will be a reference site somewhere that shows you how big a TB you need to flow enough air for your power requirements)

The hole in the airbox is probably pretty comparable with the throttle body. But I certainly will try this first, I've got a K&N at home I will try later this week.

I was thinking of the inlet to the inbox, no the outlet, which I think is bigger (mind you it's a long time since I looked at an n/a 944...)

 

[JamesO]

The outlet of the airbox is smaller (and square) than the throttle body, I modded mine as below. Its a bit rough and ready but you're welcome to it if you want it.

 

[os951]

Anyone know of a larger throttle body that will fit on the 944, 928 perhaps?

At least BMW E34 535I unit is easy to bolt on. Needs only minor modification

 

[George Elliott]

I think the std TB is OK for a 2.5L capacity, but I have done a knife edge mod to the butterfly, and "waisted spindle". This was a WUF mod if I recall correctly. If I could post images I would because its not fitted yet. Just replaced the Silkolene Pro-R 5w 50 []

Still need to find a snorkel flow increase, it seems very restrictive.

Barks, you want a bigger TB for a 2.5?

George
944t

 

[os951]

Bigger TB can cause problems on lower rpm's since flap opens just as much as original lap does. A very well known Audi engine builder here in Finland uses special flap which does not flow more than original one on part throttle. but with WOT it gives full advantage of the bigger TB.

 

[George Elliott]

No doubt some exquisite work of 951 art from Polar Bear land will follow....[]

The old VAG group TB with double butterflies and sequential opening mechanism were nice, but probably too expensive for Herr Piech in 2011

George
944t

 

[barks944]

This sorted out the problem. Improved the manifold pressure across the RPM range. The car is going really well now, I realised this when I got in my 3.0 Mercedes 190 and thought it seemed slow [8|].

 

[George Elliott]

another inlet manifold pressure solution is available from KKK or Garrett []

3.0 190.........[8|]....mini E500

 

[barks944]

Started bolting the turbo back onto my turbo's engine last weekend, need to get a few more gaskets and seals for the turbo oil and water feed and I can start re-fitting the engine.

 

[TTM]

Any news?