wideband o2
11-29-2002, 09:21 AM
#18
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With the 'out board' card the lambdaboy can be made to emulate the voltage range a 'normal‘ O2 sensor puts out. The wide band actually has a voltage slope that is opposite a typical O2 sensor and it has a positive voltage offset. These can be fixed by the outboard card that lambdaboy offers but it will still act differently than a standard O2 sensor. In theory you could get it to run with an Arc2 or some device that lets you play around with the voltage output. If you have a standalone system then you are in good shape.
As for the exhaust temps – the thermocouple is about 1 ½” from the head…coatings won’t really make any difference. I have not had a problem with under hood temps at the track – I guess that the speed at the end of the straights helps keep the air circulating in the engine compartment (155 at VIR and 150 at Watkins Glen). The coolant temps never get much above the first white mark and I have verified them with my infrared pyrometer. The engine block/coolant temps are the same as normal street driving!
Chris White
As for the exhaust temps – the thermocouple is about 1 ½” from the head…coatings won’t really make any difference. I have not had a problem with under hood temps at the track – I guess that the speed at the end of the straights helps keep the air circulating in the engine compartment (155 at VIR and 150 at Watkins Glen). The coolant temps never get much above the first white mark and I have verified them with my infrared pyrometer. The engine block/coolant temps are the same as normal street driving!
Chris White
11-29-2002, 04:01 PM
#19
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posted by rage2
[quote]Some of the tuners' MAF kits comes with fuel correction devices such as the ARC 2. You can adjust fuel on a low/mid/high rpm range... not very accurate, but you can use a wideband o2 sensor to ensure you're not going any leaner than 12.5 A/F ratio.
<hr></blockquote>
Thanks rage for the info. A cheap wideband starts at about $500 one hour on the dyno with a/f is about $200 and may need more time as well.What i an trying to say is that if a wideband 02 is accurette enough why even go to a dyno unless you looking for hp numbers. Now if i go to a dyno and setup the car for 18 psi with proper a/f for max output on pumpgas when you go back to street driving and turn down the boost say to 14psi. The car will than be running a rich condition. at least thats what i think. if this is not true please correct me. That is why i am thinking of buying a wideband 02.I also know that map and stand alone are much better as far as tuning but i have also heared from many tuners that you can setup high hp cars with maf as well. Map or stand alone is in the future for me but in the meantime i am useing maf and would like to max out this tecnology before i move on.
[quote]Some of the tuners' MAF kits comes with fuel correction devices such as the ARC 2. You can adjust fuel on a low/mid/high rpm range... not very accurate, but you can use a wideband o2 sensor to ensure you're not going any leaner than 12.5 A/F ratio.
<hr></blockquote>
Thanks rage for the info. A cheap wideband starts at about $500 one hour on the dyno with a/f is about $200 and may need more time as well.What i an trying to say is that if a wideband 02 is accurette enough why even go to a dyno unless you looking for hp numbers. Now if i go to a dyno and setup the car for 18 psi with proper a/f for max output on pumpgas when you go back to street driving and turn down the boost say to 14psi. The car will than be running a rich condition. at least thats what i think. if this is not true please correct me. That is why i am thinking of buying a wideband 02.I also know that map and stand alone are much better as far as tuning but i have also heared from many tuners that you can setup high hp cars with maf as well. Map or stand alone is in the future for me but in the meantime i am useing maf and would like to max out this tecnology before i move on.
11-29-2002, 06:21 PM
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[quote]Originally posted by jimbo1111:
<strong>Now if i go to a dyno and setup the car for 18 psi with proper a/f for max output on pumpgas when you go back to street driving and turn down the boost say to 14psi. The car will than be running a rich condition. at least thats what i think. if this is not true please correct me.</strong><hr></blockquote>
OK I'm here to correct you .
It depends on the chip/MAF size, and a bunch of other factors. Generally speaking, with the stock ECU, at WOT you're running a fixed map, so yes you will run rich when lowering boost to 14psi. On the guru MAP kit and standalones, you have a fuel setting for 14psi point, 15psi point, 16psi point... etc. On my car, the boostfuel curve is set perfectly, so I get 12.5 A/F regardless of what boost I decide to run. For MAF kits you'll have to fiddle with the ARC2 when you change boost.
<strong>Now if i go to a dyno and setup the car for 18 psi with proper a/f for max output on pumpgas when you go back to street driving and turn down the boost say to 14psi. The car will than be running a rich condition. at least thats what i think. if this is not true please correct me.</strong><hr></blockquote>
OK I'm here to correct you
.It depends on the chip/MAF size, and a bunch of other factors. Generally speaking, with the stock ECU, at WOT you're running a fixed map, so yes you will run rich when lowering boost to 14psi. On the guru MAP kit and standalones, you have a fuel setting for 14psi point, 15psi point, 16psi point... etc. On my car, the boostfuel curve is set perfectly, so I get 12.5 A/F regardless of what boost I decide to run. For MAF kits you'll have to fiddle with the ARC2 when you change boost.
11-29-2002, 07:32 PM
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One thing to keep in mind is that when you raise and lower your boost you do affect your fuel flow a little. With the higher boost you will have a higher fuel pressure since our FPR is a rising rate unit. I have not had a chance to see how much of a difference it makes from one boost setting to another.
11-29-2002, 10:23 PM
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ok now that i have your attention i would like to pick your brains alittle lol. i have heared from many that 12.5 is to agressive for a/f most racers are running 12.1 anyway i think that 12.1 gives you a bit of leway just incase you get boost spikes.also dose anybody know how rich can i possibley get away with, with out washing away oil from the cylinders and distroying the motor?
If i am tuning my maf in fourth gear for max psi once it is dialed in will it through off the other gears 1,2,3,5 out of wack like to rich because of less boost. that is why am asking about oil wash. i think when off boost low rpm or idle to rich is not that important but would like your input on that as well. i already know that with a richer a/f i'm going to loose power someware.
If i am tuning my maf in fourth gear for max psi once it is dialed in will it through off the other gears 1,2,3,5 out of wack like to rich because of less boost. that is why am asking about oil wash. i think when off boost low rpm or idle to rich is not that important but would like your input on that as well. i already know that with a richer a/f i'm going to loose power someware.
11-29-2002, 10:31 PM
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[quote]Originally posted by tazman:
<strong>One thing to keep in mind is that when you raise and lower your boost you do affect your fuel flow a little. With the higher boost you will have a higher fuel pressure since our FPR is a rising rate unit. I have not had a chance to see how much of a difference it makes from one boost setting to another.</strong><hr></blockquote>
Oops, forgot about that. I use a 3bar fixed rate FPR .
<strong>One thing to keep in mind is that when you raise and lower your boost you do affect your fuel flow a little. With the higher boost you will have a higher fuel pressure since our FPR is a rising rate unit. I have not had a chance to see how much of a difference it makes from one boost setting to another.</strong><hr></blockquote>
Oops, forgot about that. I use a 3bar fixed rate FPR
.
11-29-2002, 11:17 PM
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[quote]Originally posted by rage2:
<strong>
Oops, forgot about that. I use a 3bar fixed rate FPR .</strong><hr></blockquote>
Really you don't have a vacum line connected to your FPR at all? This is the first I have heard of running with a fixed rate FPR on these cars.
Jimbo I would listen to Chris on the fuel settings it seems he has alot of experience with these cars. As for the different gears remember that with the higher boost you get more fuel even though the injectors will be open for the same amount of time, because it will be at a higher pressure. So when your boost is lower you will get less fuel because the fuel pressure is lower.
<strong>
Oops, forgot about that. I use a 3bar fixed rate FPR
.</strong><hr></blockquote>Really you don't have a vacum line connected to your FPR at all? This is the first I have heard of running with a fixed rate FPR on these cars.
Jimbo I would listen to Chris on the fuel settings it seems he has alot of experience with these cars. As for the different gears remember that with the higher boost you get more fuel even though the injectors will be open for the same amount of time, because it will be at a higher pressure. So when your boost is lower you will get less fuel because the fuel pressure is lower.
12-03-2002, 01:42 PM
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Just thought I would post an update; The BOSCH premium oxygen sensor, #13246, is an NTK L1H1 sensor, which will work with the Tech Edge controller and display kit. Mine just came in and it is stamped NTK L1H1, with the correct Sumitomo connector on it.
The Napa part OS791 is still on big time back order. I got the Bosch through Parts America @ $189.00; for those that want a stand alone WBO2.
Install is next week when I get home,,I'll take some shots of it.
The Napa part OS791 is still on big time back order. I got the Bosch through Parts America @ $189.00; for those that want a stand alone WBO2.
Install is next week when I get home,,I'll take some shots of it.
12-03-2002, 06:30 PM
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[quote]Originally posted by tazman:
<strong>Really you don't have a vacum line connected to your FPR at all? This is the first I have heard of running with a fixed rate FPR on these cars.</strong><hr></blockquote>
Nope .
A bit easier to tune a fixed FPR on standalone EFI systems IMO.
<strong>Really you don't have a vacum line connected to your FPR at all? This is the first I have heard of running with a fixed rate FPR on these cars.</strong><hr></blockquote>
Nope
.A bit easier to tune a fixed FPR on standalone EFI systems IMO.
12-05-2002, 11:24 AM
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Holy Crap! 
No wonder when I tried to emulate your fuel curve it was too fat up top for me. <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
It makes sense to go this way for me too. When I'm driving down the highway and I see injector duty cycles of 2-3%, I hardly need more fuel flowing capacity, even under boost.
Rage,
are you running the SDS closed-loop with the wideband sensor or the stock Bosch three-wire?
No wonder when I tried to emulate your fuel curve it was too fat up top for me. <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />
It makes sense to go this way for me too. When I'm driving down the highway and I see injector duty cycles of 2-3%, I hardly need more fuel flowing capacity, even under boost.
Rage,
are you running the SDS closed-loop with the wideband sensor or the stock Bosch three-wire?
12-05-2002, 11:46 AM
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Just remember what you are doing here – the purpose of the changing rate FPR (stock type) is to compensate for the manifold pressure.
The basic theory is that to remain linear the injector needs to see the same pressure drop at the tip of the injector. So if you want the injector to see 40 psi of pressure differential (that’s what dictates the fuel flow) you need to raise the input fuel pressure by the same amount as the boost pressure. So if the manifold pressure is 15 psi under boost you need 55 psi of fuel pressure to keep the fuel delivery linear. (ie – 40 psi of pressure differential).
If you don’t do this you will have to make a bunch of adjustments to the fuel curve to compensate.
My Tec3 street car has less than 5% adjustment to the VE tables across the boost / rpm band because the pressure differential is kept linear.
That being said – there are raising rate FPRs that are designed to increase the fuel pressure in a non linear fashion – these are for the folks that want to ‘fool’ a stock based system, no use for stand alone installations….
Chris White <a href="http://www.944enhancement.com" target="_blank">www.944enhancement.com</a>
The basic theory is that to remain linear the injector needs to see the same pressure drop at the tip of the injector. So if you want the injector to see 40 psi of pressure differential (that’s what dictates the fuel flow) you need to raise the input fuel pressure by the same amount as the boost pressure. So if the manifold pressure is 15 psi under boost you need 55 psi of fuel pressure to keep the fuel delivery linear. (ie – 40 psi of pressure differential).
If you don’t do this you will have to make a bunch of adjustments to the fuel curve to compensate.
My Tec3 street car has less than 5% adjustment to the VE tables across the boost / rpm band because the pressure differential is kept linear.
That being said – there are raising rate FPRs that are designed to increase the fuel pressure in a non linear fashion – these are for the folks that want to ‘fool’ a stock based system, no use for stand alone installations….
Chris White <a href="http://www.944enhancement.com" target="_blank">www.944enhancement.com</a>
