Dyno: cams, exhaust
April-22nd-2002, 06:30 PM
#1
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Dyno: cams, exhaust
Hey all, I'm heading to the dyno tomorrow. I've got some exhaust mods done that I've discussed here, and the FS-ZE intake cam. Will post the results tomorrow afternoon. I also just ordered the Sport 20 exhaust cam today. Should have it by Thursday and will install it over the weekend. Then I'm going to order the Mazdaspeed muffler. Once I have the muffler in hand, I'm going to put it in the trunk and go dyno the car again with the exhaust cam installed. Since I get three pulls with some minor tuning in between, I'm going to dyno it with the stock exhaust and then with the sport muffler.
So; results from my cat forward and intake cam tomorrow, and then will have seperate results for adding the exhaust cam, then another couple pulls with the sport muffler. Should give us a pretty good idea what these parts are worth power wise. If anyone feels that they'd like to contribute, I can give you an address to send a sport muffler to! I'll even pay for the dyno!
So; results from my cat forward and intake cam tomorrow, and then will have seperate results for adding the exhaust cam, then another couple pulls with the sport muffler. Should give us a pretty good idea what these parts are worth power wise. If anyone feels that they'd like to contribute, I can give you an address to send a sport muffler to! I'll even pay for the dyno!
April-22nd-2002, 11:03 PM
#4
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No prob. Only thing wrong that I can see with my approach for measuring power with the exhaust cam, then swapping the muffler on, is that the computer won't have a whole lot of time to 'relearn' and adjust. But I keep hearing that the 2.0 has a fixed calibration for WOT so it should still give us a good idea.
April-23rd-2002, 01:11 PM
#7
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And the results are in! Found out some really surprising things about the stock ECU calibration as a result also. Here's what I did.
We did one full pull with the car just the way I drove it in. Then we lifted the aircleaner lid off to get more air into the engine and did another pull. Then we unbolted the muffler and did another pull.
Lifting the air cleaner lid lets the engine run without the stock restrictive intake plumbing. Doesn't bypass the MAF or anything, just lets the engine breath. It's about the same as a really good flowing CAI like an Injen.
Taking the muffler off was really surprising. It's a whole lot quieter than you'd think. The 2 cats and the silencer must really be working. You could run a straight pipe from the last exhaust connection and be a whole lot quieter than just about all the rice rides you see running around.
Since I don't have a scanner, I'll go ahead and duplicate the 250 RPM increment printout. Keep in mind that the stock 2.0 puts around 96-98 HP to the wheels. I got that info from several places and they've all said the same thing.
Run #1 way I drove it in
RPM Power Torque A/F rat.
2250 45.7 106.7 14.9
2500 49.7 104.4 14.8
2750 54.0 103.1 14.9
3000 58.5 102.4 14.8
3250 65.0 105.1 14.8
3500 71.5 107.3 13.7
3750 77.5 108.6 11.7
4000 83.0 108.9 11.4
4250 87.1 107.6 11.2
4500 91.7 107.1 10.7
5000 96.8 101.7 10.7
5250 99.7 99.7 10.4
5500 101.5 97.0 10.2
5750 101.3 92.5 10.0
6000 100.9 88.4 10.0
Max power was 101.8 at 5400 RPM Max torque 109.2 at 4150 RPM
Run #2 Intake lid off
RPM Power Torque A/F rat.
2500 48.9 102.7 14.8
2750 54.2 103.5 14.8
3000 57.6 100.8 14.8
3250 64.7 104.5 14.8
3500 71.9 107.9 14.8
3750 77.6 108.6 12.4
4000 82.8 108.7 11.7
4250 88.2 109.0 11.4
4500 93.5 109.2 11.1
4750 98.3 108.7 11.1
5000 98.7 103.7 10.8
5250 103.1 103.2 10.8
5500 105.9 101.2 10.0
5750 103.7 94.7 10.2
6000 102.5 91.5 10.2
Max Power was 106.3 HP at 5600 RPM Max Torque was 110.4 at 4650 RPM
Run #3 Muffler removed
RPM Power Torque A/F rat.
2250 42.9 103.1 15.8
2500 50.7 106.4 14.9
2750 53.6 102.4 14.9
3000 60.0 105.0 14.9
3250 65.6 106.0 14.8
3500 72.8 109.2 14.9
3750 78.9 110.5 11.6
4000 84.5 110.9 11.4
4250 90.0 111.2 11.0
4500 95.9 112.0 10.6
4750 99.5 110.0 10.5
5000 100.9 106.0 10.6
5250 104.8 104.8 10.6
5500 106.8 102.0 10.4
5750 106.9 97.7 10.4
6000 107.3 93.9 10.0
6250 105.2 88.4 10.0
Max power was 108.1 at 5900 RPM Max Torque was 112.1 at 4450 RPM
Will analyze this next post
We did one full pull with the car just the way I drove it in. Then we lifted the aircleaner lid off to get more air into the engine and did another pull. Then we unbolted the muffler and did another pull.
Lifting the air cleaner lid lets the engine run without the stock restrictive intake plumbing. Doesn't bypass the MAF or anything, just lets the engine breath. It's about the same as a really good flowing CAI like an Injen.
Taking the muffler off was really surprising. It's a whole lot quieter than you'd think. The 2 cats and the silencer must really be working. You could run a straight pipe from the last exhaust connection and be a whole lot quieter than just about all the rice rides you see running around.
Since I don't have a scanner, I'll go ahead and duplicate the 250 RPM increment printout. Keep in mind that the stock 2.0 puts around 96-98 HP to the wheels. I got that info from several places and they've all said the same thing.
Run #1 way I drove it in
RPM Power Torque A/F rat.
2250 45.7 106.7 14.9
2500 49.7 104.4 14.8
2750 54.0 103.1 14.9
3000 58.5 102.4 14.8
3250 65.0 105.1 14.8
3500 71.5 107.3 13.7
3750 77.5 108.6 11.7
4000 83.0 108.9 11.4
4250 87.1 107.6 11.2
4500 91.7 107.1 10.7
5000 96.8 101.7 10.7
5250 99.7 99.7 10.4
5500 101.5 97.0 10.2
5750 101.3 92.5 10.0
6000 100.9 88.4 10.0
Max power was 101.8 at 5400 RPM Max torque 109.2 at 4150 RPM
Run #2 Intake lid off
RPM Power Torque A/F rat.
2500 48.9 102.7 14.8
2750 54.2 103.5 14.8
3000 57.6 100.8 14.8
3250 64.7 104.5 14.8
3500 71.9 107.9 14.8
3750 77.6 108.6 12.4
4000 82.8 108.7 11.7
4250 88.2 109.0 11.4
4500 93.5 109.2 11.1
4750 98.3 108.7 11.1
5000 98.7 103.7 10.8
5250 103.1 103.2 10.8
5500 105.9 101.2 10.0
5750 103.7 94.7 10.2
6000 102.5 91.5 10.2
Max Power was 106.3 HP at 5600 RPM Max Torque was 110.4 at 4650 RPM
Run #3 Muffler removed
RPM Power Torque A/F rat.
2250 42.9 103.1 15.8
2500 50.7 106.4 14.9
2750 53.6 102.4 14.9
3000 60.0 105.0 14.9
3250 65.6 106.0 14.8
3500 72.8 109.2 14.9
3750 78.9 110.5 11.6
4000 84.5 110.9 11.4
4250 90.0 111.2 11.0
4500 95.9 112.0 10.6
4750 99.5 110.0 10.5
5000 100.9 106.0 10.6
5250 104.8 104.8 10.6
5500 106.8 102.0 10.4
5750 106.9 97.7 10.4
6000 107.3 93.9 10.0
6250 105.2 88.4 10.0
Max power was 108.1 at 5900 RPM Max Torque was 112.1 at 4450 RPM
Will analyze this next post
April-23rd-2002, 01:35 PM
#8
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Here's what the techs thought after analyzing the data.
The ECU definately must have a set WOT calibration. It kicks in about 3500 RPM. You can shift this higher to 3700 RPM by changing to a better flowing air filter, but it's always there. They said a lot of factory cars go to a fairly rich WOT now, but ours is one of the worst they've seen. This is to keep pre-ignition from ever happening but it kills power. So, the idea that these engines not gettings enough fuel is a complete fallacy. They are getting too much fuel and not enough ignition advance
Next, The stock air box is a restrictive piece. Dropping in a K&N won't help much. I've got one and the box is just too damned restrictive to work. Getting air into the engine was worth 4.5 HP at the peak alone. It was worth between 3 and 6 all the way through the RPM range. That's my next mod. Average torque is also higher so this looks to be a really good mod.
Taking off the muffler netted another 1.8 HP at peak, but did it at the cost of several HP between 2250 and 3000. Also, it flattened out the torque curve and man, does this thing have a flat torque curve. The torque fell off a bit at higher RPM with the muffler off, but made more down low for longer. Their thoughts on this were that we should go to a higher flowing muffler, but not neccesarily a straight pipe since it seems to hurt HP down low. It did net a 1.8 HP increase in the average HP though. So, losing a bit down low is made up for through the rest of the RPM range. The Torque average stayed essentially the same as the #2 run due to the loss of torque in the upper RPM. More torque lower, less torque higher but only by a bit.
The intake seems like a no brainer with nothing to really lose and everything to gain. If I can make 106.3 with the stock muffler, then the cam and exhaust work must have done some good. Stock is approx 96 or so. I'm getting the Mazdaspeed exhaust cam this week and will try to dyno it again in a month or so. Will plan on getting an intake first if I can.
The good news about the ECU is that there may be a way to override it's WOT calibration. The place I had the car dynoed has a piggy-back computer that they use that should be able to remap the ignition and WOT fuel curves. It won't affect part throttle because the computer will attempt to adjust itself to whatever you program, but there should be some real gains in changing the fuel map. This thing is running way too rich at WOT. The dyno place will set it up and tune it for me if they can make it work on our system. It's supposed to be possible as they have a wiring diagram in their book for the 2.0 16V Mazda engine showing how to hook up the system. They have a call in to the factory to make sure it will work. It costs $595 for the piggy back comp, and about $120 for the dyno tuning session to adjust it and make sure it's right.
The ECU definately must have a set WOT calibration. It kicks in about 3500 RPM. You can shift this higher to 3700 RPM by changing to a better flowing air filter, but it's always there. They said a lot of factory cars go to a fairly rich WOT now, but ours is one of the worst they've seen. This is to keep pre-ignition from ever happening but it kills power. So, the idea that these engines not gettings enough fuel is a complete fallacy. They are getting too much fuel and not enough ignition advance
Next, The stock air box is a restrictive piece. Dropping in a K&N won't help much. I've got one and the box is just too damned restrictive to work. Getting air into the engine was worth 4.5 HP at the peak alone. It was worth between 3 and 6 all the way through the RPM range. That's my next mod. Average torque is also higher so this looks to be a really good mod.
Taking off the muffler netted another 1.8 HP at peak, but did it at the cost of several HP between 2250 and 3000. Also, it flattened out the torque curve and man, does this thing have a flat torque curve. The torque fell off a bit at higher RPM with the muffler off, but made more down low for longer. Their thoughts on this were that we should go to a higher flowing muffler, but not neccesarily a straight pipe since it seems to hurt HP down low. It did net a 1.8 HP increase in the average HP though. So, losing a bit down low is made up for through the rest of the RPM range. The Torque average stayed essentially the same as the #2 run due to the loss of torque in the upper RPM. More torque lower, less torque higher but only by a bit.
The intake seems like a no brainer with nothing to really lose and everything to gain. If I can make 106.3 with the stock muffler, then the cam and exhaust work must have done some good. Stock is approx 96 or so. I'm getting the Mazdaspeed exhaust cam this week and will try to dyno it again in a month or so. Will plan on getting an intake first if I can.
The good news about the ECU is that there may be a way to override it's WOT calibration. The place I had the car dynoed has a piggy-back computer that they use that should be able to remap the ignition and WOT fuel curves. It won't affect part throttle because the computer will attempt to adjust itself to whatever you program, but there should be some real gains in changing the fuel map. This thing is running way too rich at WOT. The dyno place will set it up and tune it for me if they can make it work on our system. It's supposed to be possible as they have a wiring diagram in their book for the 2.0 16V Mazda engine showing how to hook up the system. They have a call in to the factory to make sure it will work. It costs $595 for the piggy back comp, and about $120 for the dyno tuning session to adjust it and make sure it's right.
Last edited by Traveler; April-23rd-2002 at 01:49 PM.
April-23rd-2002, 01:59 PM
#9
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Join Date: Sep 2001
Location: Toronto
Posts: 401
Hey, looks like intake has cumulative effect when used with cam.
We cannot compare dynos and baseline it's unknown, but it's safe to assume that incremental hp are same.
So, removing airbox gave 4,5 hp on car with cam.
on my stock car dyno run with no airbox gave +1,5 hp.
I am surprised that removing muffler yields that little hp.
Again, its bad that baseline is unknown for this specific dyno. My stock number with no airbox were like 104 hp and 110 lb ft at the wheels(Dynojet)
Alex
We cannot compare dynos and baseline it's unknown, but it's safe to assume that incremental hp are same.
So, removing airbox gave 4,5 hp on car with cam.
on my stock car dyno run with no airbox gave +1,5 hp.
I am surprised that removing muffler yields that little hp.
Again, its bad that baseline is unknown for this specific dyno. My stock number with no airbox were like 104 hp and 110 lb ft at the wheels(Dynojet)
Alex
April-23rd-2002, 02:39 PM
#11
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Join Date: Oct 2001
Location: Central New York
Posts: 1,241
Originally posted by PseudoRealityX
Mazda's ECUs cannot be re-written. No piggy back can change those values set in the closed loop mode. And it WILL change the partial throttle controls, because what a piggy back does is lie to the computer about either volume or temperature, thereby making the computer think there is MORE air, and so it will lean out the system.
And all mazdas run VERY retarded ignition timing. This is why on the first gens that you can pickup some very nice gains from simply advancing it, but of course thats not possible with the 3rd gens and their indiviual coils.
Also, there was a P5 owner that dyno'd 110 at the wheels...anyone? anyone?
Mazda's ECUs cannot be re-written. No piggy back can change those values set in the closed loop mode. And it WILL change the partial throttle controls, because what a piggy back does is lie to the computer about either volume or temperature, thereby making the computer think there is MORE air, and so it will lean out the system.
And all mazdas run VERY retarded ignition timing. This is why on the first gens that you can pickup some very nice gains from simply advancing it, but of course thats not possible with the 3rd gens and their indiviual coils.
Also, there was a P5 owner that dyno'd 110 at the wheels...anyone? anyone?
April-23rd-2002, 10:46 PM
#13
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These numbers came from a dynojet. The techs know how to run it, and they also know how to tweak imports. The piggy back computer that they have (I can't remember the name) resets the WOT fuel mix as well as being able to adjust the timing map completely.
There is a wiring diagram from the company that makes the comp that shows what has to be done to hook it to the Mazda computer. There is also a footnote that says that it's one of the hardest computers to overwrite, but it can be done if done correctly and with technical assistance from the manufacturer. The unit is programmed by the techs with a computer that they have so it has to be done in a shop with a dyno and with the A/F meter hooked to it. If it doesn't work, they remove it and don't charge. Supposedly it specifically addresses overcoming the closed loop mode fuel curve. I'm waiting to hear back. The shop is talking with the manufacturer to see if they are sure it will work. The piggy back unit has different spark and fuel map positions much like some of the more expensive stand alones. You can change values all through the RPM range and throttle positions.
They did say that anything other than the full throttle adjustments are fairly useless on the new computers though. The ECU will attempt to adjust back to what it wants to see for values. Since WOT is closed loop, A/F can be adjusted by changing the values the computer sends to the injectors with this unit.
As to the fuel curve being rich and the timing being retarded, the first thing the techs said after running it was "50 HP NOS system". Run a dry type since we should have enough fuel to be right in the running for A/F being correct. They also said the retarded timing will be about perfect for NOS, turbo, or supercharging. It may be that a stock engine will take VERY well to 6-8 PSI from either a turbo or supercharger without even having to put on a 5th injector or an FMU. Maybe Mazda built it with a turbo in mind...
So, 50-60HP from NOS, turbo or supercharger should be fine with the stock fuel and timing maps. I wonder how much a rebuilt turbo would cost...then make a manifold...
There is a wiring diagram from the company that makes the comp that shows what has to be done to hook it to the Mazda computer. There is also a footnote that says that it's one of the hardest computers to overwrite, but it can be done if done correctly and with technical assistance from the manufacturer. The unit is programmed by the techs with a computer that they have so it has to be done in a shop with a dyno and with the A/F meter hooked to it. If it doesn't work, they remove it and don't charge. Supposedly it specifically addresses overcoming the closed loop mode fuel curve. I'm waiting to hear back. The shop is talking with the manufacturer to see if they are sure it will work. The piggy back unit has different spark and fuel map positions much like some of the more expensive stand alones. You can change values all through the RPM range and throttle positions.
They did say that anything other than the full throttle adjustments are fairly useless on the new computers though. The ECU will attempt to adjust back to what it wants to see for values. Since WOT is closed loop, A/F can be adjusted by changing the values the computer sends to the injectors with this unit.
As to the fuel curve being rich and the timing being retarded, the first thing the techs said after running it was "50 HP NOS system". Run a dry type since we should have enough fuel to be right in the running for A/F being correct. They also said the retarded timing will be about perfect for NOS, turbo, or supercharging. It may be that a stock engine will take VERY well to 6-8 PSI from either a turbo or supercharger without even having to put on a 5th injector or an FMU. Maybe Mazda built it with a turbo in mind...
So, 50-60HP from NOS, turbo or supercharger should be fine with the stock fuel and timing maps. I wonder how much a rebuilt turbo would cost...then make a manifold...
April-24th-2002, 09:20 AM
#14
The Primesuspect
Join Date: Oct 2001
Location: Australia
Posts: 256
not trying to discredit your dyno run traveler...but when i dynoed mine...i did three runs..however i did not remove or add anything to the car...the results were that second run was higher hp than first and third run was higher hp than second....however these runs were done back to back...i guess in your case there would have been some time in between runs which may have stabilised the results....in my opinion...if you really want to get the most out of your cams...your best bet is to go aftermarket computer.
