Anyone with 3.2 running 964 40/40 grind cams, SSIs, Dansk 2-in-1-out muf?

[Discseven]

If you're running this 3.2 config, what's your city mpg?
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[Cairo94507]

I ran a 3.2 with Motronic injection, 964 cams, Steve Wong custom chip large tube (Ben's) SS heat exchangers and a Dansk 2-in 1-out muffler and routinely got about 23 MPG. I recently swapped in a '95 3.6, stock with the exception of a Steve Wong chip and the same heat exchangers with a Sport Dansk muffler and now get about 27 MPG. Runs great with plenty of power.

[Discseven]

Originally Posted by Cairo94507

I ran a 3.2 with Motronic injection, 964 cams, Steve Wong custom chip large tube (Ben's) SS heat exchangers and a Dansk 2-in 1-out muffler and routinely got about 23 MPG. I recently swapped in a '95 3.6, stock with the exception of a Steve Wong chip and the same heat exchangers with a Sport Dansk muffler and now get about 27 MPG. Runs great with plenty of power.

Cairo...27...is that your city mpg?
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[Schulisco]

See my car and it's specs in my signature. I can confirm a mileage between 19-24mpg. Mixed conditions, so a bit autobahn, country roads and a bit more(but not only) city driving with almost no traffic jams. Lambda-CIS works, I use a heated oxygen sensor from the 3.2 Carreras.

Thomas

[Cairo94507]

27 MPG was with city and freeway combined over about 225 miles if I recall correctly. I typically check my mileage every time I gas up.

[Discseven]

Thank you guys. You both are seeing good numbers as far as I'm concerned. I have a mystery in hand... 10-12 city and 27 highway on a fresh 3.2 engine with the noted mods. I failed to mention pushing overlap to 1.45.

[Schulisco]

Do you run the engine with CIS or Motronic? Which one exactly? US or ROW version? Oxygensensor? Did you already checked the mixture?

[dkirk]

Karl, I'm running the exact setup you mention on my 3.2 liter, '88 Coupe with Motronic FI. I don't do much city driving, car is mostly driven on back country roads. My 964 cams are timed per the 964 engine spec. I'm running a custom Steve Wong chip. I always log my mileage when refueling and it averages out to 25 mpg. Highest I've ever recorded was 26.5.

[Discseven]

Originally Posted by Schulisco

Do you run the engine with CIS or Motronic? Which one exactly? US or ROW version? Oxygensensor? Did you already checked the mixture?

Schilisco... Motronic. USA. DME has been tested... no faults. Have dual 4.9 Innovate wideband, LC-2 units. LogWorks is my "gauge." Pulls hard & clean to redline. Zero hesitation through all rpm. Clean idle. Great performance and city mpg sux. I've been through everything I can imagine. Did find parking brakes were dragging. Rebuilt those and city went from 10 to 12 mpg. Recent logs below are Lambda...

Green = 1-2-3
Blue = 4-5-6
Red dot-dash = 1.0 Lambda / Stoich
WOT Blue dot-dash = 0.89 Lambda

WOT:




Steady 3000 rpm in 4th gear:




Warm idle, 850 rpm, mixture screw 4 and not quite 1/4 turns out. Blue dot-dash = 0.96 as target Lambda for 1-2-3 side:



Credit for suggesting these tests and defining targets for WOT (0.89) and warm idle (1-2-3 = 0.96): Sal / "scarceller" ---- much appreciated Sal.


Engine's on target AFR-wise. So, were is the city-driven fuel going? There's also the oddity of 10-12 city and 27 highway mpg. One would think if the city mpg was low, the highway would follow suit.

I've been through fuel & engine components to the extent that I can help but return to the 964 (40/40) cams with 1.45 overlap, SSI, Dansk muffler combo as these are what have obviously changed since the engine was doing 18 city (and I don't recall what highway was but it was good.)

Originally Posted by dkirk

Karl, I'm running the exact setup you mention on my 3.2 liter, '88 Coupe with Motronic FI. I don't do much city driving, car is mostly driven on back country roads. My 964 cams are timed per the 964 engine spec. I'm running a custom Steve Wong chip. I always log my mileage when refueling and it averages out to 25 mpg. Highest I've ever recorded was 26.5.

Thanks Dave. I drive mostly city so 10-12 mpg is an attention getter on my end. I know my ECU has a current stock chip. 10-12 is city only mpg. 27 is highway only mpg. I've driven these tests separately and a number of times to be sure of the numbers.
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