HKS Hi Power Review * Dyno, install, Dyno *will post results later
01-25-07, 10:10 AM
#31
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rolling stock
Damn, an 11 rear wheel hp gain??? That's REALLY good. Almost too good to believe for an exhaust that leaves all the cats in place.
Are you running stock other than the exhaust?
If Gernby's results are similar, I might just be sold on this exhaust.
EDIT: But I gotta say, I'm a little discouraged by the way you described the size of the tips... I mean, I don't want it to look ricey, like there's a couple of fart cans in the back.
Are you running stock other than the exhaust?
If Gernby's results are similar, I might just be sold on this exhaust.
EDIT: But I gotta say, I'm a little discouraged by the way you described the size of the tips... I mean, I don't want it to look ricey, like there's a couple of fart cans in the back.
my car is completely stock with respect to performance aside from the exhaust
01-25-07, 10:15 AM
#32
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Something else to keep in mind about the peak gains is that it doesn't sound like the car was driven at all after installing the exhaust. The long and short term fuel trims would not have had any time to adjust for the slightly leaner AFRs. This could have caused a temporary gain in power that will quickly be reduced as the ECU compensates with more fuel. Did the shop record AFRs for all of the dyno runs?
As for the AFRs, I will not know until I pick up my old exhaust and pick up the files.
Hopefully we can see other before and after dyno results from other cars and see if there are similar results.
01-25-07, 10:23 AM
#33
that is not true, the car was driven after the install. The install and dyno was not done at the same place. They had to move the car after the dyno, to do the install.
As for the AFRs, I will not know until I pick up my old exhaust and pick up the files.
Hopefully we can see other before and after dyno results from other cars and see if there are similar results.
As for the AFRs, I will not know until I pick up my old exhaust and pick up the files.
Hopefully we can see other before and after dyno results from other cars and see if there are similar results.
I plan to dyno mine early next week, but the results won't be comparable to yours since I removed my secondary cats as well. I'm installing my HKS exhaust today so it will have plenty of driving on it before the dyno test.
01-25-07, 11:41 AM
#34
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How far would you guess the car was driven before the 2nd dyno test? It would probably take several driving cycles over maybe 100 miles for the long term fuel trim to adjust (important for wide open throttle).
I plan to dyno mine early next week, but the results won't be comparable to yours since I removed my secondary cats as well. I'm installing my HKS exhaust today so it will have plenty of driving on it before the dyno test.
I plan to dyno mine early next week, but the results won't be comparable to yours since I removed my secondary cats as well. I'm installing my HKS exhaust today so it will have plenty of driving on it before the dyno test.
01-25-07, 12:00 PM
#36
Generally speaking it is true that the car needs to learn the mod after installing it for the most accurate results.
ECU Reset Dyno Method:
1. Start with a tank of gas that you know will last you 200+ miles. This will ensure the same fuel is in the tank for both dyno sessions.
2. Reset ECU (Remove negative battery terminal for a minimum 30 minutes)
3. Drive a minimum of 100 miles
4. Check tire pressures cold and ensure they are the same before each dyno session.
5. Dyno the car at shop A in 4th gear starting around 3000rpm. (ECT Snow mode on)
6. Install modification
7. Reset ECU (Remove negative battery terminal for a minimum 30 minutes)
8. Drive a minimum of another 100 miles
9. Return to shop A and dyno on the same roller as previous session facing in the same direction as well.
10. Dyno the car once again in 4th gear and overlay the results using SAE Correction and a smoothing factor of 5.
11. Post the results!
NO ECU Reset Dyno Method
1. Start with a tank of gas that you know will last you 200+ miles. This will ensure the same fuel is in the tank for both dyno sessions.
2. Check tire pressures cold and ensure they are the same before each dyno session.
3. Dyno the car at shop A in 4th gear starting around 3000rpm. (ECT Snow mode on)
4. Install modification
5. Drive a minimum of 200 miles
6. Return to shop A and dyno on the same roller as previous session facing in the same direction as well.
7. Dyno the car once again in 4th gear and overlay the results using SAE Correction and a smoothing factor of 5.
8. Post the results!
BTW.. Fan placement is also very important. Make sure the same fan(s) are used and placed in the same location for each dyno session.
There are other variables involved of course, but by following these steps this will minimize error. Also having AFR, Fuel trims, etc check along with the dyno's couldn't hurt.
ECU Reset Dyno Method:
1. Start with a tank of gas that you know will last you 200+ miles. This will ensure the same fuel is in the tank for both dyno sessions.
2. Reset ECU (Remove negative battery terminal for a minimum 30 minutes)
3. Drive a minimum of 100 miles
4. Check tire pressures cold and ensure they are the same before each dyno session.
5. Dyno the car at shop A in 4th gear starting around 3000rpm. (ECT Snow mode on)
6. Install modification
7. Reset ECU (Remove negative battery terminal for a minimum 30 minutes)
8. Drive a minimum of another 100 miles
9. Return to shop A and dyno on the same roller as previous session facing in the same direction as well.
10. Dyno the car once again in 4th gear and overlay the results using SAE Correction and a smoothing factor of 5.
11. Post the results!
NO ECU Reset Dyno Method
1. Start with a tank of gas that you know will last you 200+ miles. This will ensure the same fuel is in the tank for both dyno sessions.
2. Check tire pressures cold and ensure they are the same before each dyno session.
3. Dyno the car at shop A in 4th gear starting around 3000rpm. (ECT Snow mode on)
4. Install modification
5. Drive a minimum of 200 miles
6. Return to shop A and dyno on the same roller as previous session facing in the same direction as well.
7. Dyno the car once again in 4th gear and overlay the results using SAE Correction and a smoothing factor of 5.
8. Post the results!
BTW.. Fan placement is also very important. Make sure the same fan(s) are used and placed in the same location for each dyno session.
There are other variables involved of course, but by following these steps this will minimize error. Also having AFR, Fuel trims, etc check along with the dyno's couldn't hurt.
Last edited by caymandive; 01-25-07 at 01:06 PM.
01-25-07, 12:45 PM
#38
I disagree with #5 unless you are going to do #5 and #6 before the first dyno session as well. The ECU reset alone could generate "gains" on the dyno due to fresh ignition timing. I think the best thing is to NOT reset the ECU, but drive it for a couple days normally before the next session.
SAE corrections and smoothing are really part of #9, since the SAE corrections are done after the fact via the WinPEP software.
SAE corrections and smoothing are really part of #9, since the SAE corrections are done after the fact via the WinPEP software.
01-25-07, 01:01 PM
#39
I disagree with #5 unless you are going to do #5 and #6 before the first dyno session as well. The ECU reset alone could generate "gains" on the dyno due to fresh ignition timing. I think the best thing is to NOT reset the ECU, but drive it for a couple days normally before the next session.
SAE corrections and smoothing are really part of #9, since the SAE corrections are done after the fact via the WinPEP software.
SAE corrections and smoothing are really part of #9, since the SAE corrections are done after the fact via the WinPEP software.
Anyone have more suggestions?
Last edited by caymandive; 01-25-07 at 01:07 PM.
01-25-07, 01:02 PM
#40
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Gernby.... You got yours? How do you like the look of it so far? Bigger in person? So you say your getting it installed today? Man I hope you can post some clips, I really want to hear this before purchasing. 
01-25-07, 01:13 PM
#41
I just received it, and weighed it. It weighs 32.5 lbs (stock is 39.5 lbs). The tips are WAY bigger than I expected. I will install it after I'm done with this conference call. I've already removed my stock exhaust, so it shouldn't take more than 15 minutes. I'll post some video / pics when this evening.
01-25-07, 01:17 PM
#42
I just received it, and weighed it. It weighs 32.5 lbs (stock is 39.5 lbs). The tips are WAY bigger than I expected. I will install it after I'm done with this conference call. I've already removed my stock exhaust, so it shouldn't take more than 15 minutes. I'll post some video / pics when this evening.
