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YOUR RESEARCH3.4 SAI delete - changing vacuum lines?
Leading reported evidence
Check ohms
Performed · outcome unconfirmed
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Read evidence and context
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Performed · outcome unconfirmed
I checked ohms on the solenoid and got 22.5 so thats good.
Leading evidence: 'Check ohms' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check flap out of the car' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
You also need to make sure the black/white one way valve is installed correctly.
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I tested the flap via durametric but I don't hear any actuation.
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I used essentially just used positive negative pressure on the flap.
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I used essentially just used positive negative pressure on the flap.
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Suggestion
I'm also considering pulling the resonance flap tube and setting the flap open manually, disconnecting the arm and driving the car to see if anything is different.
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Suggestion · Original poster
Allcool said it best but he left out that the ROW tuning also makes the DME ignore the post-cat o2, so one could run high flow cats/catless with no ill affect ( to the government agent watching this thread, I would only do this to an offroad vehicle - in fact this is all speculation)
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Suggestion
I'm also considering pulling the resonance flap tube and setting the flap open manually, disconnecting the arm and driving the car to see if anything is different.
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In the process of removing the SAI on my 99 c2 utilizing the ROW software. For those who have done this, did you keep the vacuum reservoir, or remove it and run the vacuum directly to the flap solenoid?
nothing uses it except SAI and the tuning flap solenoid. If I remove it, the tuning flap can get direct vacuum however I�m not sure if that�s the correct approach
Needed because at WOT there is no vacuum in the intake. The resonance flap can't work properly with no vacuum. That is why there's a vacuum check valve & the resi - to hold a supply of vacuum to work the resonance flap at WOT.
Unless you don't plan to use full throttle..
Update - there is a factory bracket for the reservoir to be mounted without SAI (readily available in the US) when i have a chance ill make an actual write up for everything
The ROW tune deletes the stringent emission controls USA cars needed to pass emission requirements. As European cars didn't require those stringent emission.controls.
ROW tune allows the USA cars to delete the SAI pump and block off the SAI port with no cel on the dash.
IMHO, the emission requirements that came into effect at those time periods was impossible to meet for most manufactures making powerful engines that drove nicely at cold starts. So they found a workaround. The SAI pump blows a ton load of extra air into the exhaust at cold start enriched conditions. This effectively
dilutes the emissions
coming out the exhaust pipe fooling emission testing into compliance...
SAI
jmo
Allcool said it best but he left out that the ROW tuning also makes the DME ignore the post-cat o2, so one could run high flow cats/catless with no ill affect ( to the government agent watching this thread, I would only do this to an offroad vehicle - in fact this is all speculation)
All in all, I work at a dealer and thus the tuning is free for me.
I had the RoW tuning done in my "off-road only" 996 but left the SAI bits intact case I sell the car to someone that intends to register the car in a state that requires it (like CA).
I have original Finland delivery (EU) MY 2001 996. This car has always had pre- and post cat (4ea total) O2 sensors and also the SAI system.
So, maybe the discussed RoW tune is different for the cable throttle, but maybe not for the 2001 or later 996's?
Just Pre-cat lambda sensors where fitted to RoW from beginning of production until and including MY1999. Perhaps MY 2000 too, I don't know for sure.
Cable throttle is a dead giveaway but c4 and earlier ones with PSM and/or cruise control had e-gas and could still be with just pre-cat lambda sensors.
SAI is dead giveaway for car having post-cat lambda sensors.
USA m96 3.4 cars were rated @ 296HP, Some ROW cars were rated at 300 HP. Some other ROW cars without cats were rated at 302HP. IIRR.
Don't remember seeing any posted specs for the Row M96 3.6 cars but it probably followed similar to the 3.4 numbers with a slight increase depending on exhaust systems used.
IMHO from my experience seeing dyno results over the years, Porsche HP #'s have always been underrated somewhat compared to most all other car manufactures that always 'round up'. there HP numbers.
Hello All, following up with this post as it's dealing with what I'm currently experiencing although the engine is a 3.6 X51 with the SAI deleted. There seems to be a lot of knowledge in this post.
A little backstory, I've been chasing a flat power curve over 3000 rpm. Durametric has shown that the deviation and cams are operating properly. I have a suspicion that its something to do with the resonance tube flap in the intake. I recently had to delete the SAI system due to cracked port in the 4-6 head which is not obtainable any longer (yes I looked for one for over 2 years!). So the ports have been plugged on the tops with the OEM plates and a plug has been installed in the SAI port in the head. I had the ECU set for ROW as well.
I tested the flap via durametric but I don't hear any actuation. I checked ohms on the solenoid and got 22.5 so thats good. I blew into the vacuum line that goes back to the flap, at first it took a lot of pressure to hear any movement. After that initial pressure, I can hear a clicking and feel some pressure in the line. I cant tell if the flap actually moves or we're just hearing something else. Currently the TB tube is off so I could have a look back there. I'm also considering pulling the resonance flap tube and setting the flap open manually, disconnecting the arm and driving the car to see if anything is different. If not, obviously I have an issue somewhere else, maybe cats.
Does the vacuum chamber need to be installed still? What is the required routing of the vac lines with SAI delete? I can't seem to find a good diagram that shows this option. I also do recall the flat power curve being present prior to the SAI removal so I'm wondering if the flap was potentially frozen/stuck. I do want to verify that my vac routing is correct before putting it all back together.
There's a lot to unpack here, I know. HAHA. Oh by the way this engine has 503,000 miles and its actually quite healthy.
Thanks a lot all!
Hey man, I've seen your various posts on facebook in reguards to the head issue you have. An oddball, but believable. Anywho, you do need the vacuum reservoir as another member pointed out - the engine doesnt produce enough vacuum at WOT to keep things working. You also need to make sure the black/white one way valve is installed correctly. I'm at work but when I have some time I can draw you a diagram.
Also, its a vacuum system so you wont be blowing on anything, you'll be sucking it. I highly suggest checking the flap out of the car with a mighty vac. They're known to seize at least on the non-X plastic intakes
Thanks, that�ll be helpful. Yes, I�ll pull the flap tube out. I used essentially just used positive negative pressure on the flap. Negative or vacuum seemed to have no affect on flap even through the direct line to it, no noise or clicking. As you said it�ll be easier to visualize the whole thing once it�s out. How tough is that one to get back in? Looks like it�ll be quite the ordeal.
see posts above for the drawing I did for another member. The part number for the SAI braket is on here too, can be ordered from any porsche center or pelican
ROW Vacuum Reservoir Bracket:
Qty. 1 - 99611314550
ROW Vacuum Reservoir Bracket Screw:
Qty. 1 -
99991911502
(Holds Reservoir To Bracket)
You might need one of these connectors and some of these and line if you don�t have that stuff.
Vacuum Hard Line:
00004320501
Vacuum Connector: Quantity UNK
9P1129487
Vacuum Connector Splitter:
92857372705
FWIW-
I am having Slakker rebuild my 3.6 and Brandon Clark has said that the SAI can be removed. No problem. How and what is deleted I do not know. When I asked about it he said it was simple "Just tap and plug some holes." Enough information for me, after all they will have the entire engine apart.
Perhaps give Brandon a call at Slakker @ [phone removed] and ask him for clarification? He has been very helpful with all the questions I had, and continue to have about a 4.1 build. Other folks there are not as knowledgeable as Brandon is (right off the top of his mind), and Brandon can bridge between task-required to parts to correct part names and so on.
Good idea or not? Dunno, but I would ask Brandon anyway. He (aka Slakker) answered a lot of questions for me B4 I became a customer. JMO.
YMMV
Everything anyone needs to know is in this thread with the exception of the blockoff plate numbers - those are only a google search away.
Brandon is a stand up dude, though. I'm a dealer tech and he handled the rebuild of our clients 4S, everyone was very happy. He also took care of an idle speed change on my personal car
Thanks for the vac routing and the parts list. I have most everything still but needed to ensue it was all routed properly.
But I'm quite sure I've found the issue today. I loosened the clamps and rotated the flap tube. I found the mechanism completely seized, the arm that attached to the flap plate is corroded and would not rotate in the arm. I tried to actuate the flap but the part where the rod mounts to the plate broke right off, its completely rusted in there. With the arm released the flap moves freely. Will be needing a new resonance tube. I did not fully remove it yet because it'll be a total bear to get it back in, I'll have to see if unbolting one the intakes will help.
For now, I've zip tied the flap open, connected all the vac lines and will drive it tomorrow to see if the power over 3000rpm has returned.
Will update if the power returns or not. If so there are several mechanics on my **** list.
As for Slakker, I'm definitely building an engine fund for this car. At some point, this 500k+ mile X51 is going to need an overhaul, but I�m not giving up on it until it finally gives out for good. I�d love nothing more than to rebuild
this
engine instead of just replacing it. This car, engine and transmission have already proven themselves far beyond anyone�s expectations, and deserve to keep going as long as they can.
Well that was it! That seized flap has been the culprit of low power for years. I recall the power loss happening intermittently around the 400k mile mark but I�m sure one winter hibernation seized it up all the way.
What�s far more frustrating is that several and �knowledgeable� Porsche mechanics have looked at the car. Had the engine out, doing guides and head work. Not one of them saw that corrosion or thought to consider the intake flap as the source of power loss. I can�t imagine the money that was thrown away to due bad mechanics. At the end they threw hands up and said guess the engine is just tired.
Anyways, thanks a lot guys! I�ll be ordering a resonance tube and getting this thing sorted out.
So happy to have this thing screaming again!
