Want to know power gains of various easy mods? Look/suggest here
08-19-2018, 09:48 PM
#16
Inventor
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Many dyno runs on all models of 928 show no benefit to K&N over the stock filter (note the Veyron uses two of these same filters).
The S3 airbox and tubes are restrictive vs. S4-up or earlier. S3 only have smaller intake tubes and the elbow to the filter is awful.
I did see a few HP on the dyno with an open airbox lid. On the street though, this can only be used in cool weather and/or the rear hood seal must be removed.
The S3 airbox and tubes are restrictive vs. S4-up or earlier. S3 only have smaller intake tubes and the elbow to the filter is awful.
I did see a few HP on the dyno with an open airbox lid. On the street though, this can only be used in cool weather and/or the rear hood seal must be removed.
08-21-2018, 02:24 PM
#18
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By the time you start spending billions to gain 3.6HP from the Porsche V8, you would be better served(in terms of HP/$) to rip and replace the engine with a crate Chebby LS type. 525HP for around $8000USD. Of course, you'll need to have the TC shaft fitted, but if you want HP, stop messing with the Porsche V8. Money better spent on crate engine.
11-16-2018, 10:27 PM
#19
Never saw any increase in HP from the K&N on the dyno's we've done up here in the PacNW, but did see gains at the drag strip. ..that said, Jalopnik just tested a dirty filter, clean filter, cheap filter replacement, and K&N filter... obviously not a 928 filter , but interesting results.. 
https://jalopnik.com/heres-the-diffe...EGoA0zPqTc6Dy4
https://jalopnik.com/heres-the-diffe...EGoA0zPqTc6Dy4
Many dyno runs on all models of 928 show no benefit to K&N over the stock filter (note the Veyron uses two of these same filters).
The S3 airbox and tubes are restrictive vs. S4-up or earlier. S3 only have smaller intake tubes and the elbow to the filter is awful.
I did see a few HP on the dyno with an open airbox lid. On the street though, this can only be used in cool weather and/or the rear hood seal must be removed.
The S3 airbox and tubes are restrictive vs. S4-up or earlier. S3 only have smaller intake tubes and the elbow to the filter is awful.
I did see a few HP on the dyno with an open airbox lid. On the street though, this can only be used in cool weather and/or the rear hood seal must be removed.
11-19-2018, 06:18 PM
#21
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What do you mean “stepped”? Is that the thing f1 cars do where they have a step/bulge in each cylinders exhaust pipe? Or do you mean stepped as in different stages of exhaust mods (1-pumpkin delete,2-x pipe, 3-headers, etc)?
11-20-2018, 12:19 AM
#22
Louie Ott showed HP gains by using the S3 airbox bottom, and spacing the filter up 3/4 to 1 inch. He had many dyno runs to refine this.
11-20-2018, 12:36 AM
#24
True, but he did all of the development of the current x pipe, and also did the airbox mods every little bit adds up. His numbers were better than your quotes...
11-25-2018, 02:39 PM
#25
Rennlist Member
Delete muffler
Add X/Y pipe
Add 85/86 manifolds
Add headers
To see which parts add what improvement. For example, you will see "headers add 50hp" and that seems to be like "once you do headers, you also upgraded y-pipe, deleted cat, installed 3" pipe, etc maxed out exhaust improvements". If you install a wideband at the start and video each run will also help (of dash and wideband) since we lack the ability to log sensor data through OBD2 or stand alone.
11-25-2018, 08:06 PM
#26
There are stepped headers. Mine start out with 1 3/4 primaries, stepped to 1 7/8 secondaries before going into the collectors.
https://www.hotrod.com/articles/step...es-area-curve/
https://www.hotrod.com/articles/step...es-area-curve/
11-26-2018, 01:00 AM
#27
11-26-2018, 11:38 AM
#28
Nordschleife Master
Mine has the (very beat up) original.
There is a reproduction available.
It's a fairly important piece. It keeps water out of the wiper motor and the HVAC stuff.
Price out a new wiper motor and see why that's important.
There is a reproduction available.
It's a fairly important piece. It keeps water out of the wiper motor and the HVAC stuff.
Price out a new wiper motor and see why that's important.
11-27-2018, 11:47 PM
#29
James