Expert Advice Needed: Fuel Tuning a Turbo'd S2K
11-19-2002, 12:53 PM
#22
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Originally posted by RT
We probably shouldn't be hijacking Chris's thread like this....... PM you're V-AFC settings and relevant mod list.
We probably shouldn't be hijacking Chris's thread like this....... PM you're V-AFC settings and relevant mod list.
11-20-2002, 01:31 PM
#24
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Oops, I forgot to log off evo S2000 account, this is Hybrid by the way.
I been reading the thread a few times and I still have a question.
What are you guys going to do about the boost??
N/A car involves injector duty cycle, throttle position, Manifold absolute pressure.
Forced induced car involves, injector duty cycle, Vaccuam transition, boost transition, and rising fuel pressure via FMU.
No matter how you trick the V-AFC and interplot them, the third variable boost is added to the once N/A configuration. Boost seriousy affects instant acceleration and rapid gear changing.
Example:
1. You are cruising at 40mph with 3500 rpm, . Stomp on gas to accelerate. On pressure state, you were once let's say -14.7 psi and suddenly jumps to 0 vaccuam or into the boost section. How will your ECU or V-AFC get notified with the mass increased air pushed into the motor? Your fuel setting is programmed for current N/A state via TPS as load and have no idea of what boost is. So, your motor suddenly goes lean and then richen up by O2 sensor. By the time O2 sensor richen it up, you motor hiccup alittle and then goes normal. Is that what some of your turbo s2k doing? This also happens when you are at a turn and exiting which you stump on gas and car bucks a bit. I don't think there is anyway of fixing this problem unless you have some sort of device to detect boost for the ecu. Standalone can adjust Accel/decel to your desire and uses MAP sensor only to detect load.
2. Like I stated earlier, once you are in the max load on the preprogrammed open loop map from the ECU which is 0 vaccuam, what are you going to do correctly anticipate increased boost? By Vortech FMU? with increasing 10 psi of fuel pressure to 1 psi of boost, I think that a bandage for fuel tuning. V-AFC control fuel enrichment using rpm as factors and FMU enrich by climbing boost pressure via increase fuel pressure. Increasing fuel pressure above 100psi is everyway a bandage.
I honestly think standalone is very good investment for turbo vehicle. I am not stating that V-AFC will not work. I can certain that V-AFC will perform okay but will not resolve the issue of some drivibility problems.
BTW, I have not tested the open loop closed loop via with what factors and what rpm. I don't think it's relevant to anyone anyway so I stand down on that statement and say you are probably correct on S2000 but not other vehicles.
I been reading the thread a few times and I still have a question.
What are you guys going to do about the boost??
N/A car involves injector duty cycle, throttle position, Manifold absolute pressure.
Forced induced car involves, injector duty cycle, Vaccuam transition, boost transition, and rising fuel pressure via FMU.
No matter how you trick the V-AFC and interplot them, the third variable boost is added to the once N/A configuration. Boost seriousy affects instant acceleration and rapid gear changing.
Example:
1. You are cruising at 40mph with 3500 rpm, . Stomp on gas to accelerate. On pressure state, you were once let's say -14.7 psi and suddenly jumps to 0 vaccuam or into the boost section. How will your ECU or V-AFC get notified with the mass increased air pushed into the motor? Your fuel setting is programmed for current N/A state via TPS as load and have no idea of what boost is. So, your motor suddenly goes lean and then richen up by O2 sensor. By the time O2 sensor richen it up, you motor hiccup alittle and then goes normal. Is that what some of your turbo s2k doing? This also happens when you are at a turn and exiting which you stump on gas and car bucks a bit. I don't think there is anyway of fixing this problem unless you have some sort of device to detect boost for the ecu. Standalone can adjust Accel/decel to your desire and uses MAP sensor only to detect load.
2. Like I stated earlier, once you are in the max load on the preprogrammed open loop map from the ECU which is 0 vaccuam, what are you going to do correctly anticipate increased boost? By Vortech FMU? with increasing 10 psi of fuel pressure to 1 psi of boost, I think that a bandage for fuel tuning. V-AFC control fuel enrichment using rpm as factors and FMU enrich by climbing boost pressure via increase fuel pressure. Increasing fuel pressure above 100psi is everyway a bandage.
I honestly think standalone is very good investment for turbo vehicle. I am not stating that V-AFC will not work. I can certain that V-AFC will perform okay but will not resolve the issue of some drivibility problems.
BTW, I have not tested the open loop closed loop via with what factors and what rpm. I don't think it's relevant to anyone anyway so I stand down on that statement and say you are probably correct on S2000 but not other vehicles.
11-22-2002, 02:51 AM
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Thanks, again. There's a goldmine's worth of information already posted here. Truly, I'm grateful. 
The car's in the shop for another week or so. I was growing fond of the pelt of embedded brown hair in the nosecone (courtesy of a deer which jumped the tire wall at Turn 9 at Summit Point), but it added too much drag on the backstraight.
After Thanksgiving, when I pick the car up, I'll start working on the fuel tuning. Schwett, I'd love to borrow your OBDII datalogger and cable, but only if you'll find an excuse to swing through northern Virginia next spring for an afternoon's drive through the twisties. I'll PM you an address.
Ultimate Lurker, would you zero out the High VTEC narrow throttle settings, as well as the Low VTEC ones? Thanks for posting to this thread. "You de man."
A very good Thanksgiving holiday to you all.
CBender
The car's in the shop for another week or so. I was growing fond of the pelt of embedded brown hair in the nosecone (courtesy of a deer which jumped the tire wall at Turn 9 at Summit Point), but it added too much drag on the backstraight.
After Thanksgiving, when I pick the car up, I'll start working on the fuel tuning. Schwett, I'd love to borrow your OBDII datalogger and cable, but only if you'll find an excuse to swing through northern Virginia next spring for an afternoon's drive through the twisties. I'll PM you an address.
Ultimate Lurker, would you zero out the High VTEC narrow throttle settings, as well as the Low VTEC ones? Thanks for posting to this thread. "You de man."
A very good Thanksgiving holiday to you all.
CBender
11-25-2002, 10:41 AM
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UL and Schwett, as always, thanks for your help.
GilbertG's just sent me his VAFC settings, which DO include fuel trim settings under narrow throttle conditions. If changing the narrow throttle settings helps with partial throttle tuning, then perhaps the solution is to prevent the ECU from learning around them? What do you think about the idea of pulling the backup fuse on the ECU?
Just a thought, but I'd be interested in your thoughts. I've been reluctant to try this in the past, as presumably the "learning" done by the ECU serves some purpose beyond the maximization of fuel economy. But perhaps not.
Wes, when do you think you'll have an update on your car (and the GReddy eManage system)? It's the leading contender (at this point), if I can't get things to work with the VAFC.
Thanks -- and Happy Thanksgiving to all of you.
CBender
GilbertG's just sent me his VAFC settings, which DO include fuel trim settings under narrow throttle conditions. If changing the narrow throttle settings helps with partial throttle tuning, then perhaps the solution is to prevent the ECU from learning around them? What do you think about the idea of pulling the backup fuse on the ECU?
Just a thought, but I'd be interested in your thoughts. I've been reluctant to try this in the past, as presumably the "learning" done by the ECU serves some purpose beyond the maximization of fuel economy. But perhaps not.
Wes, when do you think you'll have an update on your car (and the GReddy eManage system)? It's the leading contender (at this point), if I can't get things to work with the VAFC.
Thanks -- and Happy Thanksgiving to all of you.
CBender
11-26-2002, 01:47 PM
#28
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Addendum (for Schwett) -- Yellow Streak's offered up the loan of his OBD-II datalogger cable and software. Given that he's local to me, it'll save you a trip the Post Office. Thanks, though, for the offer, and know you've got a chit for an afternoon's drive in the twisties in my car, should you make it to DC.
In another week or so, I'll let you all know how Gile's VAFC settings work out for me. Rieger328 PM'd me to say that his MAP sensor was the reason behind his engine's hesitation. Makes me wonder if that's contributing in some part to the problems I'm having. Will let you know once I check it out.
CBender
In another week or so, I'll let you all know how Gile's VAFC settings work out for me. Rieger328 PM'd me to say that his MAP sensor was the reason behind his engine's hesitation. Makes me wonder if that's contributing in some part to the problems I'm having. Will let you know once I check it out.
CBender
11-26-2002, 03:08 PM
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Originally posted by RT
...what are you using to block the boost from the MAP? (did I already ask you that?)
...what are you using to block the boost from the MAP? (did I already ask you that?)
He's using the same checkvalve that I'm using, supplied by Speedcraft.