The test car is my personal 16 A6 and it is bone STOCK aside from the Tune.
I ran the car back to back to back on the dyno before the IM swap to validate the before power numbers. Numbers were a little higher than previously tested but I have changed the wheels/tires and they are 16+lbs lighter each and 1/2" smaller in diameter. Stock GT IM dyno runs were within 1HP at 390-391. All testing done on CA 91 octane from Unical 76. I saw no knock issues and I did not add any timing when tuning the GT350 Setup. Timing peaked at 28 degrees at 7500 with the knock sensors adding everything allowed.
Pic with the new wheels/tires before lowering:
The dyno overlay below illustrates the gains and losses across the RPM band. I believe this data pretty well mirrors JDM's results and is indicative of what I've seen from the Boss IM on the 11-14's when adding a CAI along with the Manifold.
Again these runs were done on the SAME DAY. I did the install while the car was still strapped to the chassis dyno.
Torque loss was at 4250RPM was 24ft/lbs.
HP difference at given RPM's below (GT IM vs GT350)
6500RPM 389 vs 403
7000RPM 362 vs 411
7500RPM 347 vs 401
7600RPM 341 vs 398
7700RPM 334 vs 390
Keep in mind this car did NOT have a CAI before testing, and the GT350 factory CAI flows significantly more than the GT Unit, so this is NOT an apples to apples Manifold ONLY comparison. Same goes for the TB, I used the GT350 TB which flows more than the GT.
The GT350 IM seems to be out of breath above 7200 vs the stock GT IM running out above 6500, so a net gain of roughly 700 usable RPM. Like the GT IM you can watch the vacuum increase as power drops off at RPM.
Given this is an auto car and has a very wide gear split (2 to 3 gear shift recovery is 2100RPM) I believe there WILL be *some* gains in ET/MPH at the track, assuming the torque loss does not affect the 60ft much (converter recommended). For an M6 car with tighter gearing the GT350 IM likely would not see the same ET/MPH gains.
I do not plan on testing this IM at the drag strip, so this is all conjecture based on experience with these engines and modifying their power bands.
Basically the manifold showed solid gains above 5500RPM, so that is where you will want to keep the RPM's above when racing.
Oh, and the tuning R&D has been completed for both the M6 and A6 2015+ cars. We are not seeing any throttle surge on heavy tip-in for those that are interested. The throttle does jump around at idle and low speeds, but that is due to the scalloped TB design unlike the GT TB. Until the blade moves past a certain point the TB does not flow much air and is programmed to move significantly more to control idle/low speed. (They idle at more than double the throttle angle of a stock GT TB)
I do not recommend porting these 87MM GT350 Throttle bodies.
I ran the car back to back to back on the dyno before the IM swap to validate the before power numbers. Numbers were a little higher than previously tested but I have changed the wheels/tires and they are 16+lbs lighter each and 1/2" smaller in diameter. Stock GT IM dyno runs were within 1HP at 390-391. All testing done on CA 91 octane from Unical 76. I saw no knock issues and I did not add any timing when tuning the GT350 Setup. Timing peaked at 28 degrees at 7500 with the knock sensors adding everything allowed.
Pic with the new wheels/tires before lowering:
The dyno overlay below illustrates the gains and losses across the RPM band. I believe this data pretty well mirrors JDM's results and is indicative of what I've seen from the Boss IM on the 11-14's when adding a CAI along with the Manifold.
Again these runs were done on the SAME DAY. I did the install while the car was still strapped to the chassis dyno.
Torque loss was at 4250RPM was 24ft/lbs.
HP difference at given RPM's below (GT IM vs GT350)
6500RPM 389 vs 403
7000RPM 362 vs 411
7500RPM 347 vs 401
7600RPM 341 vs 398
7700RPM 334 vs 390
Keep in mind this car did NOT have a CAI before testing, and the GT350 factory CAI flows significantly more than the GT Unit, so this is NOT an apples to apples Manifold ONLY comparison. Same goes for the TB, I used the GT350 TB which flows more than the GT.
The GT350 IM seems to be out of breath above 7200 vs the stock GT IM running out above 6500, so a net gain of roughly 700 usable RPM. Like the GT IM you can watch the vacuum increase as power drops off at RPM.
Given this is an auto car and has a very wide gear split (2 to 3 gear shift recovery is 2100RPM) I believe there WILL be *some* gains in ET/MPH at the track, assuming the torque loss does not affect the 60ft much (converter recommended). For an M6 car with tighter gearing the GT350 IM likely would not see the same ET/MPH gains.
I do not plan on testing this IM at the drag strip, so this is all conjecture based on experience with these engines and modifying their power bands.
Basically the manifold showed solid gains above 5500RPM, so that is where you will want to keep the RPM's above when racing.
Oh, and the tuning R&D has been completed for both the M6 and A6 2015+ cars. We are not seeing any throttle surge on heavy tip-in for those that are interested. The throttle does jump around at idle and low speeds, but that is due to the scalloped TB design unlike the GT TB. Until the blade moves past a certain point the TB does not flow much air and is programmed to move significantly more to control idle/low speed. (They idle at more than double the throttle angle of a stock GT TB)
I do not recommend porting these 87MM GT350 Throttle bodies.
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