Air Fuel Ratio under boost Question :
07-21-2002, 08:39 PM
#16
Drifting
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Rob,
No, darn it, I never got to dyno w/the k26 because of the mystery knocking that resulted in the teardown/rebuild. The car is up and running finally. Remapping was easy. Per rage's suggestion I just converted my fuel values across the board by the ratio of injector difference. It started right up and then I fine tuned the fuel values. I've only driven it twice and rather gingerly. You know, new rod bearings, turbo, lifters, etc. Having only gotten into about 20% throttle I can say that the spool-up is really quite good. Not at all the big lag I kind of expected.
The car's sitting right now because of a fuel leak. I ordered braided lines from Tim at SFR to replace the stock ones that have been folded to the side one time too many. 
No, darn it, I never got to dyno w/the k26 because of the mystery knocking that resulted in the teardown/rebuild. The car is up and running finally. Remapping was easy. Per rage's suggestion I just converted my fuel values across the board by the ratio of injector difference. It started right up and then I fine tuned the fuel values. I've only driven it twice and rather gingerly. You know, new rod bearings, turbo, lifters, etc. Having only gotten into about 20% throttle I can say that the spool-up is really quite good. Not at all the big lag I kind of expected.
The car's sitting right now because of a fuel leak. I ordered braided lines from Tim at SFR to replace the stock ones that have been folded to the side one time too many.
07-21-2002, 09:46 PM
#17
Race Director
"How do you measure the injector duty cycle? Is that something that the Link system can do?
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Lindsey racings Air/Fuel monitor does air/fuel ratios and percentage of injector usage"
Yup, that's the unit we have installed in Travis's car. It's a little chunky and large, so we might come up with our own that has a remote LED display. Perhaps a thin bar-graph type with both displays inline with each other that you can install at the very top of the dash under the overhanging lip.
"How much of those gains do you think you can attribute to a free-er flowing intake? And how much do you think you can attribute to the near-perfect a/f ratio?"
Hmmm, I would guess that the 25% increase across the board can be divided as follows: 10% from free-flow intake and 15% to precise air-fuel ratio. With a more efficient turbo, you will probably see a 40-50% increase in torque with about 30% from free-flowing intake and 20% from air-fuel control.
"Danno,
is there a stage made for upgraded turbos. or will we need to tune that in ourselves?"
Yes, we have a Stg.2 kit for people with upgraded turbos (or those planning ahead). This kit will include a 4" outlet K&N filter with a custom 4" conical J-pipe. A Purosil adapter at the very end will adapt the 3" outlet to fit any size turbo inlet. Most likely we'll be bundling our own custom chips, 3-bar FPR, and preset boost-controller @15psi to reduce the number of tuning-variables involved.
End-users can still customize the fuel-maps for their own configuration with the optional hand-held programmer (fits nicely in cassette arm-rest). This will allow for unlimited upgrade potential later on since there are no flow-limits or adjustment ranges on this unit.
------------------------------------------------------------------------
Lindsey racings Air/Fuel monitor does air/fuel ratios and percentage of injector usage"
Yup, that's the unit we have installed in Travis's car. It's a little chunky and large, so we might come up with our own that has a remote LED display. Perhaps a thin bar-graph type with both displays inline with each other that you can install at the very top of the dash under the overhanging lip.
"How much of those gains do you think you can attribute to a free-er flowing intake? And how much do you think you can attribute to the near-perfect a/f ratio?"
Hmmm, I would guess that the 25% increase across the board can be divided as follows: 10% from free-flow intake and 15% to precise air-fuel ratio. With a more efficient turbo, you will probably see a 40-50% increase in torque with about 30% from free-flowing intake and 20% from air-fuel control.
"Danno,
is there a stage made for upgraded turbos. or will we need to tune that in ourselves?"
Yes, we have a Stg.2 kit for people with upgraded turbos (or those planning ahead). This kit will include a 4" outlet K&N filter with a custom 4" conical J-pipe. A Purosil adapter at the very end will adapt the 3" outlet to fit any size turbo inlet. Most likely we'll be bundling our own custom chips, 3-bar FPR, and preset boost-controller @15psi to reduce the number of tuning-variables involved.
End-users can still customize the fuel-maps for their own configuration with the optional hand-held programmer (fits nicely in cassette arm-rest). This will allow for unlimited upgrade potential later on since there are no flow-limits or adjustment ranges on this unit.
07-22-2002, 04:14 AM
#19
Three Wheelin'
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[quote]Originally posted by Russ Murphy:
<strong>The car's sitting right now because of a fuel leak. I ordered braided lines from Tim at SFR to replace the stock ones that have been folded to the side one time too many. </strong><hr></blockquote>
Wow, EXACTLY what happened to me too! I had a fuel leak in the hoses right above the exhaust manifold. Luckily, I caught it before an engine fire. Which turbo did you end up with? Curious what kind of spool up you're seeing... I don't see big power until 4000rpm. You probably know that since I bitch about it every chance I get =).
<strong>The car's sitting right now because of a fuel leak. I ordered braided lines from Tim at SFR to replace the stock ones that have been folded to the side one time too many.
</strong><hr></blockquote>Wow, EXACTLY what happened to me too! I had a fuel leak in the hoses right above the exhaust manifold. Luckily, I caught it before an engine fire. Which turbo did you end up with? Curious what kind of spool up you're seeing... I don't see big power until 4000rpm. You probably know that since I bitch about it every chance I get =).
07-22-2002, 02:05 PM
#20
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rage,
It's a T04E with a 46 trim compressor wheel and a 3" inlet. The turbine side looks to be about the same size externally as my k26/6 but the outlet is 1 cm bigger and the impeller(?) is significantly larger. The specs are: 43lbs/minute @ 2.0 p.r. (559cfm). I asked for something that would support 440 hp.
Again, I haven't gotten on it really yet, but at approx. 20% throttle the boost builds quickly, well before 4000. I'll give you a more concise boost curve after the DE this weekend.
It's a T04E with a 46 trim compressor wheel and a 3" inlet. The turbine side looks to be about the same size externally as my k26/6 but the outlet is 1 cm bigger and the impeller(?) is significantly larger. The specs are: 43lbs/minute @ 2.0 p.r. (559cfm). I asked for something that would support 440 hp.
Again, I haven't gotten on it really yet, but at approx. 20% throttle the boost builds quickly, well before 4000. I'll give you a more concise boost curve after the DE this weekend.
07-25-2002, 09:35 PM
#21
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Rage,
First thing you gotta do is buy some Sunoco GT-Plus unleaded. In terms of Lmabda numbers, it is dependent on boost as well as RPM. The "richest" my motor runs, 20+lbs. boost @ 6900+ RPM is .83 Lambda. Between 5000 and 6000 RPM it is around .84 and .85 between 4000 and 5000 RPM. The timing is propietary, but is is fairly aggressive. Well over 20 degrees above TDC at high RPM. Running 20 lbs. of boost for a few seconds is one thing. Holding it deep into sixth gear, time after time, is more difficult. If you have not upgraded your intercooler you're loosing power and the ability to hold boost W/O knocking. Out of curiosity, what are your intake temps. at 20 lbs. boost in 5th gear at 6000 RPM?
First thing you gotta do is buy some Sunoco GT-Plus unleaded. In terms of Lmabda numbers, it is dependent on boost as well as RPM. The "richest" my motor runs, 20+lbs. boost @ 6900+ RPM is .83 Lambda. Between 5000 and 6000 RPM it is around .84 and .85 between 4000 and 5000 RPM. The timing is propietary, but is is fairly aggressive. Well over 20 degrees above TDC at high RPM. Running 20 lbs. of boost for a few seconds is one thing. Holding it deep into sixth gear, time after time, is more difficult. If you have not upgraded your intercooler you're loosing power and the ability to hold boost W/O knocking. Out of curiosity, what are your intake temps. at 20 lbs. boost in 5th gear at 6000 RPM?
07-26-2002, 12:23 PM
#22
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[quote]Originally posted by 86944turbo:
<strong>what are your intake temps. at 20 lbs. boost in 5th gear at 6000 RPM?</strong><hr></blockquote>
Next time I do 150mph on my way to work I'm going to have to take a look at that myself...
<img src="graemlins/oops.gif" border="0" alt="[oops]" />
<strong>what are your intake temps. at 20 lbs. boost in 5th gear at 6000 RPM?</strong><hr></blockquote>
Next time I do 150mph on my way to work I'm going to have to take a look at that myself...
<img src="graemlins/oops.gif" border="0" alt="[oops]" />
07-27-2002, 04:43 AM
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Paul,
I am hoping that IC stands for intercooler. The one in my car was made from 2 stock 944T units. Some minor, non-essential sheet metal was removed. Unless, I remove more, or chnage the nose, I cannot fit a larger unit. It is approx. 50% larger than stock. After 450 h/p, it's too small. That is why the spray bar was added. Not the ultimate solution, but in keeping the nose stock, the IC rests on the bottom of the nose panel and no room below.
I am hoping that IC stands for intercooler. The one in my car was made from 2 stock 944T units. Some minor, non-essential sheet metal was removed. Unless, I remove more, or chnage the nose, I cannot fit a larger unit. It is approx. 50% larger than stock. After 450 h/p, it's too small. That is why the spray bar was added. Not the ultimate solution, but in keeping the nose stock, the IC rests on the bottom of the nose panel and no room below.
07-28-2002, 07:38 AM
#26
Three Wheelin'
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[quote]Originally posted by Danno:
<strong>So I would recommend backing off the ignition a bit.</strong><hr></blockquote>
12.0:1 A/F ratio (just to be safe) dialed in. Car is a lot crisper now. Didn't gain any torque. Raced the SLK 32 again, no difference in results, but definately using a lot less fuel now. Should be able to run a bit higher boost with the ignition backed off a bit. More info coming soon.
<strong>So I would recommend backing off the ignition a bit.</strong><hr></blockquote>
12.0:1 A/F ratio (just to be safe) dialed in. Car is a lot crisper now. Didn't gain any torque. Raced the SLK 32 again, no difference in results, but definately using a lot less fuel now. Should be able to run a bit higher boost with the ignition backed off a bit. More info coming soon.
07-29-2002, 01:54 AM
#27
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Hey Rage why dont you upgrade your intercooler pipe from the turbo to the intercooler so it is free flowing and not stock in form, from the last pic i saw of your motor you were using the stock setup on the intercooler piping, the rubber boot that comes off the turbo is typically choking 30-40 percent of the turbos airflow, and then add in the 60 degree bend after that and also the smallish 2 in pipe and you got a major blockage of air and power, check this out, if you have done this mod forgive me, but how foolish to have what you got and not upgrade this section, again sorry if you already did this... good luck
07-29-2002, 06:28 AM
#28
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[quote]Originally posted by tecart:
<strong>Hey Rage why dont you upgrade your intercooler pipe from the turbo to the intercooler so it is free flowing and not stock in form, from the last pic i saw of your motor you were using the stock setup on the intercooler piping, the rubber boot that comes off the turbo is typically choking 30-40 percent of the turbos airflow, and then add in the 60 degree bend after that and also the smallish 2 in pipe and you got a major blockage of air and power, check this out, if you have done this mod forgive me, but how foolish to have what you got and not upgrade this section, again sorry if you already did this... good luck</strong><hr></blockquote>
It's on the way, as well as an intercooler upgrade and some exhaust mods.
Another update, after dialing the timing back significantly, I can now run 91 octane fuel at around 17psi without pinging (I could only run 12psi with my old agressive timing). Car's feeling awesome. 12.0:1 A/F all the way to redline. About 360rwhp at 17psi. No more black smoke from the exhaust, but there's still a lot of light blue smoke when going on boost. Doing a leakdown test next week to see if it's the bottom end, or if it's from the turbo. Burning 1 quart of oil every tank of gas if I got the foot planted.
<strong>Hey Rage why dont you upgrade your intercooler pipe from the turbo to the intercooler so it is free flowing and not stock in form, from the last pic i saw of your motor you were using the stock setup on the intercooler piping, the rubber boot that comes off the turbo is typically choking 30-40 percent of the turbos airflow, and then add in the 60 degree bend after that and also the smallish 2 in pipe and you got a major blockage of air and power, check this out, if you have done this mod forgive me, but how foolish to have what you got and not upgrade this section, again sorry if you already did this... good luck</strong><hr></blockquote>
It's on the way, as well as an intercooler upgrade and some exhaust mods.
Another update, after dialing the timing back significantly, I can now run 91 octane fuel at around 17psi without pinging (I could only run 12psi with my old agressive timing). Car's feeling awesome. 12.0:1 A/F all the way to redline. About 360rwhp at 17psi. No more black smoke from the exhaust, but there's still a lot of light blue smoke when going on boost. Doing a leakdown test next week to see if it's the bottom end, or if it's from the turbo. Burning 1 quart of oil every tank of gas if I got the foot planted.
07-29-2002, 08:56 PM
#29
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Oh rage.... I sure would like to see the new and improved fuel map. By the way, the new bearings and new turbo were awesome this weekend at the DE. The ambient temps on the track were over 100 degrees with high humidity and the water temp never budged above the normal position right above the first white line. There definitely is more lag than with the K26/6 but I've got 13 psi by 3200 rpm. I ran 16-17 psi all weekend. Exiting the hairpin turn 7 onto the banked oval in 2nd was pretty friggin' fun! I ran this boost with 93 octane on the first day with 19 degrees of total advance and 100 octane on the second day with 24 degrees of total advance. It seems like I could have run even more without problems.
By the way, the new bearings and new turbo were awesome this weekend at the DE. The ambient temps on the track were over 100 degrees with high humidity and the water temp never budged above the normal position right above the first white line. There definitely is more lag than with the K26/6 but I've got 13 psi by 3200 rpm. I ran 16-17 psi all weekend. Exiting the hairpin turn 7 onto the banked oval in 2nd was pretty friggin' fun! I ran this boost with 93 octane on the first day with 19 degrees of total advance and 100 octane on the second day with 24 degrees of total advance. It seems like I could have run even more without problems.
07-29-2002, 08:58 PM
#30
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Rage, what hp/tq wre you making before you got timing, a/f set and running 12psi?
I see you are at 360RWHP now with new adjustments. Just curous to know how much difference.
Also, anyone done dyno runs to see pros and cons of more boost with more retard timing? i.e. when does timing retard start to affect hp/tq gains regardless of increased boost (assuming a/f is set right) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
I see you are at 360RWHP now with new adjustments. Just curous to know how much difference.
Also, anyone done dyno runs to see pros and cons of more boost with more retard timing? i.e. when does timing retard start to affect hp/tq gains regardless of increased boost (assuming a/f is set right) <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />