Airflow/Horsepower limit for stock 2.0L intake system? |
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Airflow/Horsepower limit for stock 2.0L intake system? |
greggearhead |
Dec 12 2019, 11:32 AM
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#1
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Newbie Group: Members Posts: 35 Joined: 19-March 11 From: Colorado Springs, CO Member No.: 12,836 Region Association: None |
OK, I did search, and couldn't really find anything.
My basic question - when does the 914 2.0L intake become a restriction to power? I have a built VW 412 - 2056 cc Type 4 * 9550 RAT cam * LE-180 heads (914 2L combustion chamber, 42mm intake, 36mm exhaust) * Mallory Unilite vacuum advance distributor, Mallory Promaster coil, Mallory Hyfire CDI * Stock 412 heater boxes & Thunderbird exhaust * 2L Bus plenum and throttle body * 2L 914 runners * Ford "Design II" F1TE-D9A (Bosch 0280150947) 24# injectors (modified) * SDS programmable EFI * Oil bath air cleaner housing modified to use large circular filter element I have a pair of IDF manifolds, and some VFR throttle bodies. Roughly equivalent to Weber 40IDFs (maybe a bit better in terms of flow). Engine made 115hp at the wheels. I'm just wondering if the (improved) stock intake is a cork or not? (IMG:http://www.914world.com/bbs2/uploads_offsite/i61.photobucket.com-12836-1576171976.1.jpg) |
greggearhead |
Dec 13 2019, 10:12 AM
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#2
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Newbie Group: Members Posts: 35 Joined: 19-March 11 From: Colorado Springs, CO Member No.: 12,836 Region Association: None |
OMG - are you guys even reading my post?
I already have the largest throttle body, largest plenum and largest runners. I asked about if anyone knew the limit of the factory components because I am switching to ITBs. I'm not asking about making an intake manifold, or adapting varioram, or changing the plenum, etc. I've used ITBs on lots and lots of different engines over the years, and throttle response, when tuned correctly, is usually noticeably much better. I'm not asking about those things. |
JamesM |
Dec 15 2019, 04:41 PM
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#3
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Senior Member Group: Members Posts: 1,900 Joined: 6-April 06 From: Kearns, UT Member No.: 5,834 Region Association: Intermountain Region |
OMG - are you guys even reading my post? I already have the largest throttle body, largest plenum and largest runners. I asked about if anyone knew the limit of the factory components because I am switching to ITBs. I'm not asking about making an intake manifold, or adapting varioram, or changing the plenum, etc. I've used ITBs on lots and lots of different engines over the years, and throttle response, when tuned correctly, is usually noticeably much better. I'm not asking about those things. I am reading your post, and you dont have the largest throttle body (IMG:style_emoticons/default/tongue.gif) The late vanagon 2.1 throttle body is larger ~50mm back to your question though, I dont have the sources in front of me but I remember reading at one point that the 1.8 intake flows enough for ~140+ HP. With the bus 2.0 intake being of similar design I would imagine it would be similar flow as long as you have swapped for the larger 914 intake runners. Personally I prefer the 1.8 intake + 50mm Vanagon TB to the bus 2.0+runner swap, basically trade some plenum volume for cleaner intake runner path. Not sure it makes much difference, its just an easier install and I like how it looks. With a 2056 and 9550 cam I doubt you are giving up anything power wise with that intake setup You would need more exhaust and cam before the intake becomes the limiting factor. Throttle response is another story, ITBs may help there though I found with a LOT of work on the tune my throttle response is pretty damn good. You may loose some low/mid torque along with precision in your throttle control with the ITBs swap so that is something to think about. With 40mm ITBs you will maybe get about 20-25% of your throttle motion in the lower RPM ranges before you are basically WOT. For autocross I prefer having more precise throttle control, but that is just personal preference. |
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