Over the last week or so I've been trying different combinations of tubing from the MAF to filter in the fender well. During testing I've used my techtom to get peak MAF voltage/coolant temp readings, and
road dyno for comparing torque/hp curves. For the dyno tests I did 3 pulls 2 in 2nd gear and 1 in 3rd gear since the speed limit is 65mph and I don't need tickets
. All of the road dyno runs are SAE corrected for weather conditions, otherwise the results could skewed. Unfortuatley I didn't get pics of all the setups I tried, however the setups I tested were a 2.5in, 3in, 2.5in-3in hybrid piping also I'm still using the OEM tubing from the MAF to TB. As of now all of my power mods are PS header, 2.25in cat/B-pipe, JWT s3's/ECU (cam program), outlaw phenos, UR udp. Here is the test results in excel format
3rd gear CAI test,
2nd gear test.
I'll start with the 2.5in CAI, out of all the setups this one sounded the best to me. It gave the engine a very nice throaty sound from 5000-6000rpm and 7000-7500rpm. The throttle response seemed slightly quicker than before but it could've been from a miscalibrated butt dyno. After a few WOT runs I felt the engine seem to labor more after 6600rpm than before. No matter what gear was used the MAF only registered 4.55-4.57v @ 7500rpm. The engine seemed to pull smoothly from 4000-6000rpm, however once I used road dyno there was a loss in torque from 3500-4500rpm of an average 2.6wtq/2.1whp with a max of 4tq/3hp around 3800-4000rpm. This setup also hit power peak about 200rpm earlier than the other setups and seemed to offer less power from 6500-7000rpm. Overall this style didn't make much power and it actually lost some in spots but it
did sound the best if that matters.
The next setup was a full 3in piping from MAF to filter, since funds were limited I used dryer tubing
. The first thing I noticed was the engine sounded different, the throaty roar of the 2.5in was gone as if the engine changed to a higher pitch. Throttle response may have been better than with the 2.5in CAI but I can't confirm it lol butt dyno = broken. According the MAF however it wasn't flowing any more air than the 2.5in piping did. I only got 4.55-4.57v @ 7500rpm again as I did with the 2.5in. It seems that there is a difference in power delivery between 2nd and 3rd gear. During the 3rd gear pull the engine didn't seem like it wanted to pull up top. So there was a noticable fall off up top the dyno run confirmed it, there was an average 5hp loss from 6900-7500rpm. 2nd gear had a different result 3in had 1-2hp average gain over the others at the same rpm
. Overall I like this setup better than 2.5in.
My baseline before going with 2.5in and 3in was with my hybrid (ghetto) setup which is below.
.
What it's is a 2.5in piping (tailpipe repair flex tubing lol cheap and used in 2.5in test) that grows into 3in where it meets the couplers. Actually the ID of the couplers is like 3.25in so I cut the lip where the clamp goes off one elbow and put it around the 2.5in pipe so the OD would match the ID of the coupler and it work perfectly as seen with extra tape. The sound didn't change much if at all from the 3in and throttle response at first didn't seem as quick. But this setup does pull better up top, actually alot better. I registered
4.65-4.68v from the MAF and it pulled hard all the way to my shift light (7400rpm). On the dyno it made more power than the 3in over 6900rpm and almost matched it everywhere else in 3rd gear. For 2nd gear the 3in had 1hp average advantage from 4600-7300rpm but the hybrid had the best average midrange (4000-6000rpm). Basically hybrid is better in 3rd gear, 3in is better in 2nd gear and since a the last 1/8 mile of a 1/4 mile race is all 3rd gear (for me at least) hybrid is better setup. Not to mention is topend pull is better, the engine revs so much quicker up top. Overall I like this hybrid the best, I wanted to try a 4in piping but my battery is too wide to allow it later on I plan on getting that genesis 11lb battery and then i could give the 4in a try.
