Gains with just MAP
06-26-2003, 01:15 AM
#17
Three Wheelin'
Join Date: Oct 2001
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Lorenfb:
<strong>With a MAP you get "tons" of fuel at start-up.
It's very difficult to get a good air/fuel ratio
with it. I guess those turbos love "tons" of
fuel. Check out this website, Systemsc.com. It
may have some helpful info about fuel injection.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">This *could* be a problem if the system wasn't smart enough to determine fueling from not just the map sensor, but also based on the engine speed, throttle position sensor, and various other correction sensors, not to mention understanding that it is performing a cold start. This stuff has come a long way from the MAP system used in D and L jetronic efi as mentioned on that website.
Are you certain that Porsche was using a mass air measuring strategy on their recent (90's) prototype turbocharged racecars. I've read some unconfirmed information that suggested that the Bosch racing fuel injection systems they used utilized a speed density strategy.
<strong>With a MAP you get "tons" of fuel at start-up.
It's very difficult to get a good air/fuel ratio
with it. I guess those turbos love "tons" of
fuel. Check out this website, Systemsc.com. It
may have some helpful info about fuel injection.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">This *could* be a problem if the system wasn't smart enough to determine fueling from not just the map sensor, but also based on the engine speed, throttle position sensor, and various other correction sensors, not to mention understanding that it is performing a cold start. This stuff has come a long way from the MAP system used in D and L jetronic efi as mentioned on that website.
Are you certain that Porsche was using a mass air measuring strategy on their recent (90's) prototype turbocharged racecars. I've read some unconfirmed information that suggested that the Bosch racing fuel injection systems they used utilized a speed density strategy.
06-26-2003, 01:18 AM
#18
While Danno's Map system is EXACTLY what the 951s needed, a MAP system combined with any aftermarket system will use Barometric, MAP, Throttle position sensor, and sometimes coolant temp ALL to figure out acceleration mapping for fuel and spark, as well as part throttle.
The idea is to get the restriction OUT of the intake path. The map system usually does this.
The idea is to get the restriction OUT of the intake path. The map system usually does this.
06-26-2003, 01:36 AM
#19
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It's all in the mapping. I would like to see a system that utilizes both. Both have their strong and weak points. It's all about what you choose to sacrifice. Judging from the board, it seem that Danno has a good grasp on what the needs of the 951 are. Less restriction matched with good mapping and the MAP seems to be the way to go. Atleast for now, I'm sure someone will come up with something else that will be the shiznik after a while. And then that will be old news when something else becomes the next best and so on and so on. Even if it is the worst thing to do, it still shows the best results so far.
06-26-2003, 01:51 AM
#20
Nordschleife Master
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by Lorenfb:
<strong>Whatever makes you guys happy is all that
matters, right? If your mods make your car feel
faster, then do it!
Have Fun
Loren
'88 3.2</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">You mean what makes the car actually faster? As proven on a dyno?
MAF vs. MAP, I dont think there's much of a difference, but there's nothing wrong with a MAP kit when done right.
<strong>Whatever makes you guys happy is all that
matters, right? If your mods make your car feel
faster, then do it!
Have Fun
Loren
'88 3.2</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">You mean what makes the car actually faster? As proven on a dyno?
MAF vs. MAP, I dont think there's much of a difference, but there's nothing wrong with a MAP kit when done right.
06-26-2003, 05:16 AM
#21
Race Director
"While Danno's Map system is EXACTLY what the 951s needed, a MAP system combined with any aftermarket system will use Barometric, MAP, Throttle position sensor, and sometimes coolant temp ALL to figure out acceleration mapping for fuel and spark, as well as part throttle. "
Yes! Hi Brendan <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" /> ! The more I work with the Motronic v3 DME in our cars, the more I'm impressed with it; not bad for mid-70's technology. As Brendan mentioned, getting the restrictive AFM-air flow meter out of the way really frees up the intake (gives you 1.5-2 psi more boost automatically). I've tried configurations with just a K&N filter clamped to the turbo-inlet, doesn't get any more free-flowing than that.
Remember that the GURU MAP kit simply replaces the AFM with a simulated AFM signal, the Motronic is still managing the engine. In that respect, all the various sensors that give the DME critical information about the operating conditions, such as engine-temp, ambient air-temp, TPS-position, TPS-velocity, are all still retained. Thus we can continue to re-use all of Porsche's R&D.
Yes! Hi Brendan <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" /> ! The more I work with the Motronic v3 DME in our cars, the more I'm impressed with it; not bad for mid-70's technology. As Brendan mentioned, getting the restrictive AFM-air flow meter out of the way really frees up the intake (gives you 1.5-2 psi more boost automatically). I've tried configurations with just a K&N filter clamped to the turbo-inlet, doesn't get any more free-flowing than that.
Remember that the GURU MAP kit simply replaces the AFM with a simulated AFM signal, the Motronic is still managing the engine. In that respect, all the various sensors that give the DME critical information about the operating conditions, such as engine-temp, ambient air-temp, TPS-position, TPS-velocity, are all still retained. Thus we can continue to re-use all of Porsche's R&D.
06-26-2003, 06:48 AM
#22
Nordschleife Master
Jason + everyone else, I wouldn't put 100% trust on the Dyno sheets solely because not two days after getting the chips my clutch started to die, and my wastegate was not shimmed, and I had a pretty bad exhaust leak.
If I dynoed the car now, it would definately do 230-235 or more, I can feel a serious difference with the new clutch, cat/exhaust and shimmed wastegate.
Next I'll learn to race the car properly, then maybe I'll get the 363kit.
If I dynoed the car now, it would definately do 230-235 or more, I can feel a serious difference with the new clutch, cat/exhaust and shimmed wastegate.
Next I'll learn to race the car properly, then maybe I'll get the 363kit.
