MAF/MAP - how about a reality check?
07-12-2003, 07:02 AM
#1
Burning Brakes
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MAF/MAP - how about a reality check?
I am probably going to purchase Gurus and MAF/MAP – (totally confused now after the thread on the subject) - from Danno.
However a quick discussion about convincing me totally?
I have super chips and I am boosting 14-15PSI as we speak.
What would MAF/MAP do realistically to improve my bhp and torque?
Isn’t 15PSI 15PSI – apart from better fuel mapping (lean-rich)?
How much of an increase – feeling-wise realistically (acceleration) would I gain? Would it be as much as going from stock to 15PSI with my current setup?
Fire away… <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />
However a quick discussion about convincing me totally?
I have super chips and I am boosting 14-15PSI as we speak.
What would MAF/MAP do realistically to improve my bhp and torque?
Isn’t 15PSI 15PSI – apart from better fuel mapping (lean-rich)?
How much of an increase – feeling-wise realistically (acceleration) would I gain? Would it be as much as going from stock to 15PSI with my current setup?
Fire away… <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />
07-12-2003, 08:55 AM
#3
Burning Brakes
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They removed plastic restrictor from the boost control valve - compressor line and fitted an aluminium restrictor into the compressor hose on the intercooler pipe - one of; 2,2, 2,3, 2,4 and 2,5 in size.
Also they re-wired boost control valve - as to being on - when the ignition is turned on.
Also they re-wired boost control valve - as to being on - when the ignition is turned on.
07-12-2003, 09:00 AM
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You will see an improvement just from replacing the VAF. With the MAF and the stock turbo, I now regularly see boost levels of 12psi in first gear. With the VAF, I was lucky to see 10psi. You would see the same improvement with a MAP setup, both remove the VAF restriction.
This all assumes you have a good functioning wastegate [shimmed stock (w/LBE or Reliaboost) or an aftermarket model].
This all assumes you have a good functioning wastegate [shimmed stock (w/LBE or Reliaboost) or an aftermarket model].
07-12-2003, 09:15 AM
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Burning Brakes
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ALSO the wg plays a big part,if you can't hold boost,map or maf is not going to help much.so in my opinion good wg frist,so you know you will be holding boost.i run at 15psi with 94 octane.
07-12-2003, 09:18 AM
#6
Burning Brakes
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Ok I have tested 60-100mph (3rd gear)just to get some performance figures so we can compare real world. I got the figure of 6.5 sec.
So where am I at comparing to you guys?
So where am I at comparing to you guys?
07-12-2003, 09:50 AM
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Keep in mind the AFM, MAF and MAP are just sensors. THE AFM is fairly restrictive, and will delay spool time. On large turbos much more pronounced than the stock turbo.
By going to MAF or MAB you will remove the restriction. Would it increase your peak HP/TQ numbers? Probably not by much, unless the chips you are getting with such system are much better than what you already have. If you increase boost with the new system (Same boost Level). However you area under the power curve will increase (your turbo spools up quicker and will make HP/TQ earlier in the RPM).
As of the 60-100mph? The MAF or MAP might do better but not by much. Again, if you replace the chips you have with chips that come with the new system, the results depends on the quality of tuning on the chips and how closely they match your car.
Whatever system you get. Make sure you can use it when you upgrade your turbo. Which, more than likely, you will
By going to MAF or MAB you will remove the restriction. Would it increase your peak HP/TQ numbers? Probably not by much, unless the chips you are getting with such system are much better than what you already have. If you increase boost with the new system (Same boost Level). However you area under the power curve will increase (your turbo spools up quicker and will make HP/TQ earlier in the RPM).
As of the 60-100mph? The MAF or MAP might do better but not by much. Again, if you replace the chips you have with chips that come with the new system, the results depends on the quality of tuning on the chips and how closely they match your car.
Whatever system you get. Make sure you can use it when you upgrade your turbo. Which, more than likely, you will
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07-12-2003, 01:34 PM
#8
Burning Brakes
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OK how fast am I?
Here are some figures;
20-40 (2nd) = 3,4 sec
30-50 (2nd) = 2,4 sec
40-60 (2nd) = 1,9 sec
50-70 (3rd) = 2,8 sec
60-80 (3rd) = 2,5 sec
70-90 (3rd) = 3,0 sec
80-100 (3rd) = 3,5 sec
90-110 (4th) = 3,9 sec
100-120 (4th) = 5,0 sec
110-130 (4th) = 6,6 sec
120-140 (5th) = 7,1 sec
130-150 (5th) = 12,6 sec - running out of steam!
Here are some figures;
20-40 (2nd) = 3,4 sec
30-50 (2nd) = 2,4 sec
40-60 (2nd) = 1,9 sec
50-70 (3rd) = 2,8 sec
60-80 (3rd) = 2,5 sec
70-90 (3rd) = 3,0 sec
80-100 (3rd) = 3,5 sec
90-110 (4th) = 3,9 sec
100-120 (4th) = 5,0 sec
110-130 (4th) = 6,6 sec
120-140 (5th) = 7,1 sec
130-150 (5th) = 12,6 sec - running out of steam!
07-12-2003, 01:34 PM
#9
Burning Brakes
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OK, What about this shims and waste-gate. Car is 951S, 1992 and it has 150K. What actually happens with this shims - All I know so far is they resist waste-gate opening time for longer before they open but can I use them with current set-up and will it make a difference?
07-12-2003, 01:39 PM
#10
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<a href="http://www.employees.org/~sbacchus/cars/dynoday/DYNO1.JPG" target="_blank">my car with just chips</a>
<a href="http://www.employees.org/~sbacchus/cars/dynoday/dyno3.jpg" target="_blank">my car with a maf (same K26-6 and same boost level)</a>
<a href="http://www.employees.org/~sbacchus/cars/dynoday/dyno3.jpg" target="_blank">my car with a maf (same K26-6 and same boost level)</a>
07-12-2003, 02:04 PM
#12
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"What actually happens with this shims - All I know so far is they resist waste-gate opening time for longer before they open but can I use them with current set-up and will it make a difference?"
The shims increase the spring-preload, thus the clamping pressure on the wastegate valve. This would tend to increase your max-boost level, so you need to re-adjust your boost-controller to provide the same boost as before. However, the benefit now is a decrease in the high-RPM boost-drop. Instead of going from 15psi max-boost around 4000rpm to 10psi at redline, it will only drop to 13psi. This alone is worth 30-40hp.
"Hm... do you think non S turbos achieve bigger hikes than S turbos when tuning proportion wise?"
It seems to be roughly the same gain. About +45-50hp with our chip-upgrade kit. Then another +35-40hp with the MAP kit on top of that.
The shims increase the spring-preload, thus the clamping pressure on the wastegate valve. This would tend to increase your max-boost level, so you need to re-adjust your boost-controller to provide the same boost as before. However, the benefit now is a decrease in the high-RPM boost-drop. Instead of going from 15psi max-boost around 4000rpm to 10psi at redline, it will only drop to 13psi. This alone is worth 30-40hp.
"Hm... do you think non S turbos achieve bigger hikes than S turbos when tuning proportion wise?"
It seems to be roughly the same gain. About +45-50hp with our chip-upgrade kit. Then another +35-40hp with the MAP kit on top of that.
07-12-2003, 02:18 PM
#14
Burning Brakes
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OK how fast am I?
Here are some figures;
20-40 (2nd) = 3,4 sec
30-50 (2nd) = 2,4 sec
40-60 (2nd) = 1,9 sec
50-70 (3rd) = 2,8 sec
60-80 (3rd) = 2,5 sec
70-90 (3rd) = 3,0 sec
80-100 (3rd) = 3,5 sec
90-110 (4th) = 3,9 sec
100-120 (4th) = 5,0 sec
110-130 (4th) = 6,6 sec
120-140 (5th) = 7,1 sec
130-150 (5th) = 12,6 sec - running out of steam!
Now for real - anyone did this test - how much beter will I be with an upgrade?
Here are some figures;
20-40 (2nd) = 3,4 sec
30-50 (2nd) = 2,4 sec
40-60 (2nd) = 1,9 sec
50-70 (3rd) = 2,8 sec
60-80 (3rd) = 2,5 sec
70-90 (3rd) = 3,0 sec
80-100 (3rd) = 3,5 sec
90-110 (4th) = 3,9 sec
100-120 (4th) = 5,0 sec
110-130 (4th) = 6,6 sec
120-140 (5th) = 7,1 sec
130-150 (5th) = 12,6 sec - running out of steam!
Now for real - anyone did this test - how much beter will I be with an upgrade?
07-12-2003, 02:44 PM
#15
Three Wheelin'
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john,
yup the chip only run was weltmeisters, the MAF run is with the APR chips that come with their MAF. since it's an APR MAF the only 'tuning' that i was able to do was the the adj fpr. you've seen my AF curve before, it is too rich in some points and could definitely use some cleaning up. simonk, i did my autothority MAF years ago, if i had to purchase a MAF today i'd definitely be picking the vitesse MAF. in fact if i can convice myself to lose all of the money i spent on the APR MAF i probably will get a vitesse MAF.
yup the chip only run was weltmeisters, the MAF run is with the APR chips that come with their MAF. since it's an APR MAF the only 'tuning' that i was able to do was the the adj fpr. you've seen my AF curve before, it is too rich in some points and could definitely use some cleaning up. simonk, i did my autothority MAF years ago, if i had to purchase a MAF today i'd definitely be picking the vitesse MAF. in fact if i can convice myself to lose all of the money i spent on the APR MAF i probably will get a vitesse MAF.