Joined
·
3,948 Posts
Ok, what I'm going to do here is present the facts as determined by the HFXA (Houston FX Association) regarding the effectiveness of the Injen CAI on both a stcok RWD and AWD FX35 and give my own thoughts on the matter; others can feel free to chime in with their opinions.
A quick recap for those of you who've been off-world for the last couple of weeks: We met two weeks ago to install the Injen intake in DAVESNELLING's otherwise stock RWD FX35 (keeping in mind the intake was developed on an AWD and currently sold as an AWD only part). Upon installation, Dave's FX lost approx .2 sec in his 0-60 times (G-tech measured). Injentech said they never claimed the intake would reduce your 0-60 time and that the intake was geared toward top-end performance. FINE, however, based on the dynos they provided, we see no loss in the low end, so increased 0-60 times should not occur. At this point, the only logical conclusion was that there must be some difference between the RWD and AWD that is facilitating this condition. You can read more in any of the other related threads in this section.
Here's what we decided to do:
We (I) would make some G-tech runs in Dave's FX with the Injen, then immediately change it back to stock and make more runs. Then make runs in GeoFX's AWD in stock form, install the Injen and do runs again.
This is in no way a comprehensive test, looking at all aspects. Here's what we were looking for:
-increased performance off the line (0-60 times)
-difference in how the intake works on a RWD as opposed to an AWD
-bring up a couple of points regarding our results vs. Injen's Dynos
Conditions on the test day were:
85 deg, light breeze, sea level, low humidity, flat section of road. Keep in mind we do not intend these G-tech times to be compared to anything but themselves in regards to before and after performance with the Injen intake.
Here are the results (all runs in manual mode and all of this took place within 1.5 hours):
Dave's RWD w/ Injen:
1. 6.77
2. 6.88
3. 6.94
4. 6.81
ave 0-60 = 6.85
Dave's RWD back to stock:
1. 6.59
2. 6.61
3. 6.62
4. 6.63
ave 0-60 = 6.61
That's .24 sec faster 0-60 for the RWD stock than with the Injen. When switched back to stock, the car was quieter, the bottom end was back and it pulled smooth to redline, whereas with the Injen, the bottom end seemed to be lacking with a surge felt above 5k rpm. Now, lets try the AWD.
GeoFX's AWD stock:
1. 7.03
2. 7.10
3. 7.10
4. 7.11
ave 0-60 = 7.09
GeoFX's AWD w/ Injen (I did extra runs here):
1. 7.16
2. 7.33
3. 7.36
4. 7.44
5. 7.51 (shifted slightly early here)
6. 7.44
ave 0-60 (all runs) = 7.37
ave 0-60 (taking out the early shift run) = 7.35
ave 0-60 (dropping the fastest and slowest runs) = 7.39
ave of the above three = 7.37 sec 0-60
That's .28 sec 0-60 SLOWER for the AWD with the Injen than stock. Same feeling as in the RWD comparing stcok to the Injen.
Immediately, we can conclude without a shodow of a doubt that the Injen behaves exactly the same on an AWD as it does the RWD.
We can also conclude without a doubt that the Injen does not help and in fact is a detriment to your launch, the low end of the powerband and your 0-60 time. This DOES NOT necessarily mean the intake does nothing. Before showing the AWD Injen results to GeoFX, I had him go drive his car and come back with his impressions. He came back smiling, saying he felt that it helped, could really feel it in the top end (above 5k) and loved the sound. I then showed him the results and he was pretty amazed that the car was actually slower on take-off. He decided he'd rather go back to stock and the Injen is now a very shiny ornament in Dave's garage and he's SERIOUSLY considering ordering one of Mr. Stillen's meat grinders.
At this point, I'm not passing judgement on the Injen; you can draw your own conclusions. The intake DOES indeed feel as if it's helping in the top end, it DOES sound great and it MAY compliment other breathing mods nicely, HOWEVER, the fact remains that it makes your car slower where it counts for most of us; your launch. If you spend the majority of your time driving above 5k rpm, then it may very well be a great addition for you (even then, I'm not sure, b/c in doing 0-60 runs, you use ALL of the RPM band in the first two gears, so even if it does help more up top while losing a bit down low, you STILL are slower. Perhaps it would be more acurate to say that this part is not for the dragstrip, but may help in a roadcourse situation.), but be aware that you apparently lose some in the low end as a tradeoff.
This raises the question to Injentech: How can this be, based on the dyno results that show gains accross the RPM range?
The other point I want to mention is the ECU issue (b/c I know soebody'll bring it up). It is my firm beliefe that in the case of these mods, you will see the largest possible gains BEFORE it has a chance to adjust, not the other way around. I've covered this elsewhere, but the ECU tries to maintain the A/F ratios within a certain range, so when you add a part that changes those ratios, the ECU will adjust over time to bring them back into spec. Basically, what this means (especially for an intake that sits right in front of (or incorparates, in this case) the MAF sensor, is that the ECU will DETUNE your mod over time. Injen has even said that it's a good idea to reset your ECU every so often; this is why.
The interesting thing about this is that this makes sense when going from a more restrictive intake to an aftermarket one. You add more air, the ECU will adjust over time. I WAS slightly concerned that we may see worse results when switching Dave's back to stock, because we'd be replacing a free-er flowing intake with the more restrictive stock one when the ECU had already adjusted to the high-flow. I thought that in this case, the stock times might be worse until the ECU adjusted in the opposite direction, but this was not the case. So either:
- the stcok intake actually flows MORE than the injen (interesting note: the Injen's inside pipe diameter was measured at 2 13/16", while the stock tube has an inside diameter of 3 1/4"),
OR
- The ECU adjusts very quickly (notice how quick the first Injen run on the AWD was compared to the stock runs (yet still slower). The times then increased from the second run on).
OR
- The ECU doesn't adjust much at all.
Anyway, there it is and there are my thoughts. You can draw your own conclusions and I'm sure the other guys will chime in with there thoughts as well. I would just like to re-iterate that we are in no way "out to get" Injen or bash their product. We're just real guys looking for real world results and this is what we got.
A quick recap for those of you who've been off-world for the last couple of weeks: We met two weeks ago to install the Injen intake in DAVESNELLING's otherwise stock RWD FX35 (keeping in mind the intake was developed on an AWD and currently sold as an AWD only part). Upon installation, Dave's FX lost approx .2 sec in his 0-60 times (G-tech measured). Injentech said they never claimed the intake would reduce your 0-60 time and that the intake was geared toward top-end performance. FINE, however, based on the dynos they provided, we see no loss in the low end, so increased 0-60 times should not occur. At this point, the only logical conclusion was that there must be some difference between the RWD and AWD that is facilitating this condition. You can read more in any of the other related threads in this section.
Here's what we decided to do:
We (I) would make some G-tech runs in Dave's FX with the Injen, then immediately change it back to stock and make more runs. Then make runs in GeoFX's AWD in stock form, install the Injen and do runs again.
This is in no way a comprehensive test, looking at all aspects. Here's what we were looking for:
-increased performance off the line (0-60 times)
-difference in how the intake works on a RWD as opposed to an AWD
-bring up a couple of points regarding our results vs. Injen's Dynos
Conditions on the test day were:
85 deg, light breeze, sea level, low humidity, flat section of road. Keep in mind we do not intend these G-tech times to be compared to anything but themselves in regards to before and after performance with the Injen intake.
Here are the results (all runs in manual mode and all of this took place within 1.5 hours):
Dave's RWD w/ Injen:
1. 6.77
2. 6.88
3. 6.94
4. 6.81
ave 0-60 = 6.85
Dave's RWD back to stock:
1. 6.59
2. 6.61
3. 6.62
4. 6.63
ave 0-60 = 6.61
That's .24 sec faster 0-60 for the RWD stock than with the Injen. When switched back to stock, the car was quieter, the bottom end was back and it pulled smooth to redline, whereas with the Injen, the bottom end seemed to be lacking with a surge felt above 5k rpm. Now, lets try the AWD.
GeoFX's AWD stock:
1. 7.03
2. 7.10
3. 7.10
4. 7.11
ave 0-60 = 7.09
GeoFX's AWD w/ Injen (I did extra runs here):
1. 7.16
2. 7.33
3. 7.36
4. 7.44
5. 7.51 (shifted slightly early here)
6. 7.44
ave 0-60 (all runs) = 7.37
ave 0-60 (taking out the early shift run) = 7.35
ave 0-60 (dropping the fastest and slowest runs) = 7.39
ave of the above three = 7.37 sec 0-60
That's .28 sec 0-60 SLOWER for the AWD with the Injen than stock. Same feeling as in the RWD comparing stcok to the Injen.
Immediately, we can conclude without a shodow of a doubt that the Injen behaves exactly the same on an AWD as it does the RWD.
We can also conclude without a doubt that the Injen does not help and in fact is a detriment to your launch, the low end of the powerband and your 0-60 time. This DOES NOT necessarily mean the intake does nothing. Before showing the AWD Injen results to GeoFX, I had him go drive his car and come back with his impressions. He came back smiling, saying he felt that it helped, could really feel it in the top end (above 5k) and loved the sound. I then showed him the results and he was pretty amazed that the car was actually slower on take-off. He decided he'd rather go back to stock and the Injen is now a very shiny ornament in Dave's garage and he's SERIOUSLY considering ordering one of Mr. Stillen's meat grinders.
At this point, I'm not passing judgement on the Injen; you can draw your own conclusions. The intake DOES indeed feel as if it's helping in the top end, it DOES sound great and it MAY compliment other breathing mods nicely, HOWEVER, the fact remains that it makes your car slower where it counts for most of us; your launch. If you spend the majority of your time driving above 5k rpm, then it may very well be a great addition for you (even then, I'm not sure, b/c in doing 0-60 runs, you use ALL of the RPM band in the first two gears, so even if it does help more up top while losing a bit down low, you STILL are slower. Perhaps it would be more acurate to say that this part is not for the dragstrip, but may help in a roadcourse situation.), but be aware that you apparently lose some in the low end as a tradeoff.
This raises the question to Injentech: How can this be, based on the dyno results that show gains accross the RPM range?
The other point I want to mention is the ECU issue (b/c I know soebody'll bring it up). It is my firm beliefe that in the case of these mods, you will see the largest possible gains BEFORE it has a chance to adjust, not the other way around. I've covered this elsewhere, but the ECU tries to maintain the A/F ratios within a certain range, so when you add a part that changes those ratios, the ECU will adjust over time to bring them back into spec. Basically, what this means (especially for an intake that sits right in front of (or incorparates, in this case) the MAF sensor, is that the ECU will DETUNE your mod over time. Injen has even said that it's a good idea to reset your ECU every so often; this is why.
The interesting thing about this is that this makes sense when going from a more restrictive intake to an aftermarket one. You add more air, the ECU will adjust over time. I WAS slightly concerned that we may see worse results when switching Dave's back to stock, because we'd be replacing a free-er flowing intake with the more restrictive stock one when the ECU had already adjusted to the high-flow. I thought that in this case, the stock times might be worse until the ECU adjusted in the opposite direction, but this was not the case. So either:
- the stcok intake actually flows MORE than the injen (interesting note: the Injen's inside pipe diameter was measured at 2 13/16", while the stock tube has an inside diameter of 3 1/4"),
OR
- The ECU adjusts very quickly (notice how quick the first Injen run on the AWD was compared to the stock runs (yet still slower). The times then increased from the second run on).
OR
- The ECU doesn't adjust much at all.
Anyway, there it is and there are my thoughts. You can draw your own conclusions and I'm sure the other guys will chime in with there thoughts as well. I would just like to re-iterate that we are in no way "out to get" Injen or bash their product. We're just real guys looking for real world results and this is what we got.