Why were some characters banned? Because more fuel = more power.
09-14-2011, 06:14 AM
#42
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If I remember that conversation correctly, he was saying that 14.7 at WOT on an N/A car was safe. I also remember somebody posting their AFR target table and I believe that it showed 14.7 through the entire range up to redline. (N/A)
I don't know about you but that scares me a little.
Take some readings off of any car from the factory and I am willing to bet that none of them will read 14.7:1 at WOT.
I'm pretty sure that was someone else...
I don't know about you but that scares me a little.
Take some readings off of any car from the factory and I am willing to bet that none of them will read 14.7:1 at WOT.
I'm pretty sure that was someone else...
I didn't think he said anything about 14.7 is safe at wot
Here we go
http://forum.miata.net/vb/showpost.p...&postcount=108
he says transitioning into boost at 100kpa is 14.7 but notes only that, does not note if it is the same thoughout the rpm range.
100kPa is 100kPa, regardless of whether the car is N/A or turbocharged, so one should aim for the good old 12.5:1 between 90 and 100kPa.
at low rpms no
Last edited by Techsalvager; 09-14-2011 at 07:02 AM.
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09-14-2011, 09:23 AM
#43
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A lot of turbo cars stay at 14.7:1 in boost below peak torque...Think of the MSM or MS3 stock AFTR curves.
The N/A motor from that factory stays stoich below ~5.5K.
But if you are taking it to redline, you are crazy.
The N/A motor from that factory stays stoich below ~5.5K.
But if you are taking it to redline, you are crazy.
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09-14-2011, 09:35 AM
#44
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around 4k rpm 100kpa I start adding more fuel.
its been a while but I iirc even at wot the factory computer in the 1.6 N\A wouldn't go open loop till after 4k rpms, but its been a while
its been a while but I iirc even at wot the factory computer in the 1.6 N\A wouldn't go open loop till after 4k rpms, but its been a while
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09-14-2011, 06:14 PM
#49
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N/A cars get tuned to ~12.5-12.8:1, which is where turbo cars should get tuned to at low boost. And by low boost I mean like 2psi. At 4psi it should be 11.6:1 because that's where it makes the most power.
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09-14-2011, 06:25 PM
#51
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I agree with him there as long it under certain rpm, my turbo likes to easily bring up to 100kpa under low rpm
shift, open throttle, to start going again and its back up to 100kpa easily
before tuning that area it would go to 13.x, why waste fuel, I haven't heard any det or noticed anything wrong yet, liked to see what EGT would show.
shift, open throttle, to start going again and its back up to 100kpa easily
before tuning that area it would go to 13.x, why waste fuel, I haven't heard any det or noticed anything wrong yet, liked to see what EGT would show.
The load on the motor itself is still fairly high, since it's ingesting all the air it wants to, but the EGTs probably aren't high enough to worry about at such low RPM/low exhaust restriction.
Fuel is cheaper than engines, so I tune conservatively.
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09-14-2011, 06:37 PM
#52
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All of these cars can make a lot more power when properly tuned. My suspicion is that the factory tune is set up based on EPA and fleet MPG targets.
Want to be jealous? Look what Vishnu does with a stock 335i with tuning tweaks (a lot of which is just adding fuel)...
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09-15-2011, 01:37 PM
#56
[QUOTE=Ben;771351]Yeah or the BMW 335 twin turbo.
All of these cars can make a lot more power when properly tuned. My suspicion is that the factory tune is set up based on EPA and fleet MPG targets.
Want to be jealous? Look what Vishnu does with a stock 335i with tuning tweaks (a lot of which is just adding fuel)...
that is crazy ^^^^ you sure that's stock filter/exhaust? amazing if so.
All of these cars can make a lot more power when properly tuned. My suspicion is that the factory tune is set up based on EPA and fleet MPG targets.
Want to be jealous? Look what Vishnu does with a stock 335i with tuning tweaks (a lot of which is just adding fuel)...
that is crazy ^^^^ you sure that's stock filter/exhaust? amazing if so.
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09-15-2011, 09:07 PM
#59
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Too lean. If you are in boost, it means that you're making as much/more torque than the car did naturally aspirated, which means that internal pressures/temperatures are just as high/higher than they were naturally aspirated.
N/A cars get tuned to ~12.5-12.8:1, which is where turbo cars should get tuned to at low boost. And by low boost I mean like 2psi. At 4psi it should be 11.6:1 because that's where it makes the most power.
N/A cars get tuned to ~12.5-12.8:1, which is where turbo cars should get tuned to at low boost. And by low boost I mean like 2psi. At 4psi it should be 11.6:1 because that's where it makes the most power.
Also, I thought the most power was at 12-12.5:1 (when timing isn't not knock limited). I was a bit surprised while playing with mixtures at idle, the engine started dropping in revs below 12 or 12.5:1.
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09-16-2011, 03:54 AM
#60
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Dyno testing shows that 11.6:1 makes more power than 12.0:1, even way down at 6psi. I was surprised too, I did not expect to pick up 5whp by going from 12.0:1 to 11.6:1 at ~6psi, but the dyno doesn't lie.
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