944S (16valve) NA-Tune, dyno results!
#16
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Location: Elkins Park Pa.
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Agreed, mine is a totally different animal at part throttle and full throttle,
it picks right up when you hit WOT.
By chance do you have the air/fuels between stock and your setup? Mine is
pig rich stock..
Also how is the throttle response and overall drivability compared to stock?
Steve
it picks right up when you hit WOT.
By chance do you have the air/fuels between stock and your setup? Mine is
pig rich stock..
Also how is the throttle response and overall drivability compared to stock?
Steve
#17
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Back on topic, this is EXCITING!!! Any comments on the drivability and feel of the car? One thing I've always hated about my car is how much of a difference there is between WOT and not WOT (gets a bit raspy up top until you hit WOT). Always wished it was slightly more seamless.
It is very aggressive about keeping the car in closed-loop operation. This means the car stays around 14.7:1 AFR (stoichiometric) for the majority of loads. However, running stoich does not make as much power as a richer mixture. This has a dampening affect on power, making the car feel less crisp when in part-throttle...
A big part of the 944S NA-Tune development was to rewrite parts of the closed-loop operation, to make it a more performance-oriented function. This combined with removing the AFM restriction, the part-throttle power/torque is significantly better! The dyno plot doesn't really do part-throttle operation justice, but it is very noticeable when driving the car.
Here is the plots w/ AFR:
#18
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The O2 is about 5 months old, and the wideband is fairly new as well. The
problem isn't part throttle, it's stays in closed loop just fine, too fine...
At WOT and higher rpm's it pegs the gauge at 9 to 1, if I drop fuel
pressure down to 47ish from 55 it "only" hits 9.3 to 1.. Also cold start
is super rich till the narrow band heats up.
4-5000 is 11.5 to 1, 5-6 falls into the 10's and 6 to 7 goes into the 9's.
Not sure if mine has been chipped, I can't seem to be able to separate the
2 boards to get to the chip.
problem isn't part throttle, it's stays in closed loop just fine, too fine...
At WOT and higher rpm's it pegs the gauge at 9 to 1, if I drop fuel
pressure down to 47ish from 55 it "only" hits 9.3 to 1.. Also cold start
is super rich till the narrow band heats up.
4-5000 is 11.5 to 1, 5-6 falls into the 10's and 6 to 7 goes into the 9's.
Not sure if mine has been chipped, I can't seem to be able to separate the
2 boards to get to the chip.
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The O2 is about 5 months old, and the wideband is fairly new as well. The
problem isn't part throttle, it's stays in closed loop just fine, too fine...
At WOT and higher rpm's it pegs the gauge at 9 to 1, if I drop fuel
pressure down to 47ish from 55 it "only" hits 9.3 to 1.. Also cold start
is super rich till the narrow band heats up.
4-5000 is 11.5 to 1, 5-6 falls into the 10's and 6 to 7 goes into the 9's.
Not sure if mine has been chipped, I can't seem to be able to separate the
2 boards to get to the chip.
problem isn't part throttle, it's stays in closed loop just fine, too fine...
At WOT and higher rpm's it pegs the gauge at 9 to 1, if I drop fuel
pressure down to 47ish from 55 it "only" hits 9.3 to 1.. Also cold start
is super rich till the narrow band heats up.
4-5000 is 11.5 to 1, 5-6 falls into the 10's and 6 to 7 goes into the 9's.
Not sure if mine has been chipped, I can't seem to be able to separate the
2 boards to get to the chip.
Check out this page for how to separate the boards:
http://www.911chips.com/Chip%20InstallC2.htm
#20
Interesting. I don't really know what changes would need to be made to the design with .5 more liters and bigger valves. I believe the inner diameter of the runners is the same, but the design is just open inside, which makes me think that the (sort of) spiral design from the S was traded for more flow in the S2. I'll be curious to see what happens when you get an S2 to work on. Though it would be a lot of work for not much info, it'd be cool to see some flow bench numbers on both systems. S2 mani works good with the stock system, but I can't imagine things not getting FUBAR'd with the new tech. We shall see...
#21
https://rennlist.com/forums/924-931-...hawk-chip.html
and a few more. Might help you figure out the peaks.
http://www.weissach.net/DynoResults-944S2.html
#22
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This may be of interest to you Josh, an S2 dyno plot w/afr on a car running the "firehawk" chip
https://rennlist.com/forums/924-931-...hawk-chip.html
and a few more. Might help you figure out the peaks.
http://www.weissach.net/DynoResults-944S2.html
https://rennlist.com/forums/924-931-...hawk-chip.html
and a few more. Might help you figure out the peaks.
http://www.weissach.net/DynoResults-944S2.html
It looks like the S2 intake manifold tuning is very similar to the S...
#23
The biggest thing I can see between them is that the internal volume of the intakes increased as 16v development continued. The 968 intake should be the one to show different resonance peaks as it was designed for more low end torque.
https://rennlist.com/forums/5480838-post28.html
Heres a 968 dyno for comparison
https://rennlist.com/forums/9515570-post10.html
https://rennlist.com/forums/5480838-post28.html
Heres a 968 dyno for comparison
https://rennlist.com/forums/9515570-post10.html
#26
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Josh- I can vouch for the validity of the firehawk dyno. my car put down almost an identical dyno plot a few years back.
My only complaint is the firehawk tune runs super rich. The dyno plot of the other car must have had either a different tune or a very good cat. With my test pipe you can really tell its rich.
My only complaint is the firehawk tune runs super rich. The dyno plot of the other car must have had either a different tune or a very good cat. With my test pipe you can really tell its rich.
#28
I need a tune for my S. I am also planning on doing the intake manifold swap which I have in the garage. I am just trying to decide if the stock S throttle body is sufficient and if Megasquirt might be a better option.
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If you are the type who wants to completely develop the tune (many times from nearly scratch) for your car, and deal with any issues - then Megasquirt is a great learning tool.
OTOH, if you simply want the ease of plug-n-play and factory reliability, then the NA-Tune is a better option.
#30
I've got more aggressive cams, headers, full exhaust 2.5 and some 3. No cat. Custom cone intake setup. Competition valve job bigger exhaust valves etc. Quite a bit of headwork!
This winter I'll be bolting up an S2 intake. I have a chip, but its off, mainly because of the different mods I have and having to send the chip out for guestimates.
Would this system get me more power and a more accurate tune even with my mods?
This winter I'll be bolting up an S2 intake. I have a chip, but its off, mainly because of the different mods I have and having to send the chip out for guestimates.
Would this system get me more power and a more accurate tune even with my mods?