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oil pan 4
I'd like to put a larger diameter intake on it, you've done well to go from 3" to 4", in terms of cross sectional area that is nearly double, mine is just under 3" at filter box, tapering down to about 2" at turbo inlet, the problem is all the attachments, pcv, resonator and in particular MAF are all on this section, to go to a larger section will likely play havoc with MAF, so I'm looking to what I can add to the periphery and before filter and have a few more ideas yet.
Getting positive pressure to airbox from front of vehicle using the ram setup netted around 0.5l/100km around 5% improvement for me, more power and better driveability.
Did a small round of tests and added a small air bleed in, post MAF (around 4% more air)to run a bit leaner, the test results were good and bad.
I decided to do simple acceleration test full throttle 4th gear from 60km(40mi) to 90km/hr(55mi/hr), didn't want to mash through gears at full throttle and staying below boost limmiter rpm.
The total results were very similar for with and without mod, if anything without was marginally faster, that was the bad.
The good was that the vehicle with mod in was faster in the first half (60-75km/hr) of the acceleration test, but lost ground in the second half (75-90km/hr), whereas without mod it lagged in first half, but kicked in in second half of test, so "seat of the pant's" dyno wasn't wrong.
The mod gave more power lower down but less power at the upper end, acceleration was quite smooth right through and spool up seemed to be a bit quicker.
Averaged numbers were
with mod , total 10.05 sec, 1st half 5.00, 2nd half 4.95
without mod, total 9.80, 1st half 5.35, 2nd half 4.45
I'm due for a tank re fill so will try to stop playing and run out a full tank with current setup and see if economy improves.
I suspect the loss in the top end is due to lower fueling by MAF because of unmetered air.
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