Engine Strengthening by a4darkness

[Casius]

I have a ton of tranny whine coming through the Stern mount, think I'm going to pull it. Now I'm wondering if there are OE alternatives to the stock one? Maybe a B6 S4? They've used the same bell housing for like 2 decades so it's probably the same but the mount might be different.

Another question for everyone, does anyone know of an additive that might alleviate gear whine? It's not a blown bearing or anything, just regular whine like you would get in reverse, but with the harder mount is pretty loud. Thought there was some additive I've heard of before that helps a lot.

[a4darkness]

Any updates?

Hopefully will do it this weekend, will let you guys know how it goes. Coincidentally I just did my front O2 as well - only needed an ordinary adjustable wrench. Took a bit of fiddling but it works: Loosen the airbox to shift it out of the way (or take it right out), spray a little penetrant on the O2 sensor nut, wait a few minutes, put on some oven mitts (to cover the wrists too) and flip the wrench to the right orientation that will give the most degrees of rotation with the handle facing the turbo, and you'll have plenty of leverage to loosen it. Mine was mummified with white crust when it came out. Original with my '02.

And I did the O2 Sensor swap this weekend. VERY pleased thus far with the results. Will add more details later but there has already been a marked improvement in both fuel economy and pep. Nothing too drastic on the power front, but I imagine if I was running 93 it would be more significant. However, this is the smoothest acceleration my car has ever had. Great stuff.

[audioclip]

Any updates?

And I did the O2 Sensor swap this weekend. VERY pleased thus far with the results. Will add more details later but there has already been a marked improvement in both fuel economy and pep. Nothing too drastic on the power front, but I imagine if I was running 93 it would be more significant. However, this is the smoothest acceleration my car has ever had. Great stuff.

Good to hear the o2 sensor improved things! For some strange reason after my MAF and front O2 sensor replacements, my mileage has actually decreased - I'm still trying investigate the cause. VAG readings appear okay (CH31 lamdas are within spec, CH32 long term trim corrections after clearing codes are minimal, within 10%). What's going on?

Been quite busy this past week, still have to get under the car to check those mounts (wish I had a garage..*sigh*).

[a4darkness]

"Improved" just might be an understatement. This is pretty drastic. After filling up Sunday afternoon, started commuting this week and was able to drain my tank by today. These miles were mostly freeway but a bit of city and backroads too. But still been givin her the beans when I have the chance. Regardless, this is some of if not the best mileage I've ever gotten in any of my A4's. For point of reference, I was getting somewhere between 250 and 280 p/tank before.

Needless to say, that O2 Sensor is gonna pay itself off rather quickly.

[audioclip]

"Improved" just might be an understatement. This is pretty drastic. After filling up Sunday afternoon, started commuting this week and was able to drain my tank by today. These miles were mostly freeway but a bit of city and backroads too. But still been givin her the beans when I have the chance. Regardless, this is some of if not the best mileage I've ever gotten in any of my A4's. For point of reference, I was getting somewhere between 250 and 280 p/tank before.

Needless to say, that O2 Sensor is gonna pay itself off rather quickly.

Wow, that *is* impressive. Shoot, in canada-talk that's over 600km(!) O_O That would be very nice to have. I'd say I'm getting around 400km now (250miles) if I'm rather gentle and add more highway to the mix, down from 450ish previously (280miles). Only change was new MAF + front O2. Hm.

Yesterday I increased my primary trim via lemmiwinks to reduce the amount of compensation by O2 sensor/MAF feedback. (Background - I was previously running lean, with 105% additive lamda and ~114% multiplicative). After trim adjustment, overall consumption seems a *little* better, the DIS reports about 10% less fuel consumption - I'm going to wait for the full tank results before drawing conclusions.

[a4darkness]

Okay, here's some info about my O2 Sensor swap.

Bosch 17090 Oxygen Sensor
http://www.amazon.com/gp/product/B000CF6020

These seem to go on and off sale on Amazon every week or so. So if it jumps up past $65, keep checking back to see if it's back down again.

Besides the O2 Sensor you'll need the crows foot ratchet attachment or something similar. I suggest you take the new O2 sensor with you if you're buying a new one like I did. The straight on, open sided ratchet attachments I found did NOT clear the O2 Sensor's wiring. Had to go with the crow's foot. Picked this one up at Autozone for $9 (#25249).

I read a few DIYs and posts that stated removing the airbox was necessary, but this was largely due to ppl who were using box wrenches or having extreme difficulty prying it free. Just buy the tool and make your life easy. Done.



Word to the wise, you will likely need to hose down the current Sensor with PB Blaster or something similar. I doused mine with multiple coatings over a few hours and that did it.

Yes, stuff like PB is flammable but using it is fine. If you do spray some on there and the cat is still hot it'll smoke so keep an eye on it... just in case. And no, if there's some left on the cat it won't combust. It'll burn off before hitting it's flash point. Yeah, I was paranoid so I searched. Safety for the win.

Used a ratchet + extension + u-joint to get at the sensor. This avoids that whole removing the airbox bit. Kinda nice.



You'll also have to snip the two zip ties holding the wire in place. Be careful not to cut anything else! Pull the coolant expansion tank 1st too.





From here, you can pretty much just pop out the sensor and feed the old one out / new one back in. Mind the paste on the new Sensor.




Bentley info...


And as you can see, it was certainly time for the old one to be replaced. I'm banking it came from the factory or it's really old.



And there you have it. If you really want to check yours out 1st, just get the crow's foot, extension and PB Blaster to check it out. But I'd be willing to bet we're all pretty much due for these unless they've been replaced for some reason or another.

[-Thread Navigation-]

[Casius]

In the summer, highway driving will get me around 800km to a tank, I really wish I could translate that to normal driving conditions

[A4OrlandoB6]

can we sticky this?

[a4darkness]

Stepped away from the internets for a while due to that whole school thing. Turns out a compressed summer schedule does not leave for much mod time. Nor sleeping. But that's a different story. Going to try and crank out a few between now and the start of fall term.

Trying to catch up a bit, I came across this post from OG and feel inclined to include it here.

While many have been successful in removal of the VAC / SAI / check valve system, there have been more than a few others that continue to have issues. Frankly, unless you've got a seriously in depth knowledge of the interworkings it might lead to more issues than successes. That said, I've always harbored a theory about those ppl w/issues returning a few of the more core elements of such to avoid said issues in the event of post-removal headaches. Furthermore, I am more a fan of the late 03 system (metal crankcase tube + pancake valve in the rear of engine) than the 02 or 04 and on.

So then, if you're having issues or just want to reinforce what's already there perhaps looking to replicate the 03 system is a good starting point. Might not be for everyone, but could be of help. Especially if you're a co-founder of the Rogue European Car Club. Maybe.

If you intend to retain the block breathing system (which I think is a good idea) my recommendation would be to use the late 2003 set-up. Following are my reasons for making this recommendation:

The early system found on the '02 and early '03 models actually had a few less hoses. This set up routed the PCV line from the lower block breather through the SJP for the brake booster vacuum amplification. This exposed the SJP to all of the hydrocarbon vapors and blow-by gasses which could be detrimental to the efficiency and longevity of the SJP. The later two versions got around this problem by adding a fresh air supply from the TIP to the SJP. A much cleaner arrangement.

Another difference between the first version and the later versions was an additional breather from the PRV connection to the downstream side of the PCV. In the second and third version it connects directly to the PCV housing. The second version does it with an in line check valve and a simple nipple off the PCV whereas the third version (as in your current set up) has the check valve and PCV all in one housing. This additional breather line was added at the same time the sludge issue was recognized and the VAG recommendation went to the larger filter and Synthetic oil. Consequently I feel this connection is worth having for sludge control.

The third difference is in the materials used. The first and second version utilized a metal pipe connection for the pressure equalizing line connecting the upper and lower block breather ports. The later version replaced the metal pipe with a plastic one that seems to break rather easily.

You may choose to use a combination of the second and third version by utilizing the all in one PCV/check valve housing rather than the separate PCV and check valve as found on the second version but retain the additional breather hose and metal breather pipe.

Hope this has been helpful for you.

Cheers!

Source


Right now on my check list...

* new pass rear window (effing SF crackies)
* rear brakes
* injector o-rings + plugs
* brake light switch
* Podi Stepper Boost Gauge (that's been sitting here in my room since I last posted ITT... eeesh!)

[boostedAvant]

Or the guy in the flannel jacket.

[vhstejskal]

Props to the detail as usual!!! Needs to be Sticky for sure. I'm going to be doing my O2 sensor in the next couple weeks also think my fuel mileage is a little lower then expected especially after doing my coils, plugs and the usual maintenance (OCD)...

[boostedAvant]

Can I haz window?

[IMG][/IMG]

[a4darkness]

Props to the detail as usual!!! Needs to be Sticky for sure. I'm going to be doing my O2 sensor in the next couple weeks also think my fuel mileage is a little lower then expected especially after doing my coils, plugs and the usual maintenance (OCD)...

You bet man. I'm realizing the O2 sensor swap is a pretty damn good addition. Kinda scratching my head why more ppl in the past haven't touted its positive effects more loudly. Good stuff!

[a4darkness]

Can I haz window?

ROTFL, I look so damn homeless.
Still haven't swapped it out yet. I am sooooo in post-finals decompression mode. aka lazy ass

Or the guy in the flannel jacket.

Seriously, F that guy. But he got his.

Was debating weather to post it or not, but everyone keeps telling me it's a pretty cool story. But it's an Audi window so I guess that counts for something. Although it's too much for this thread, I'll make a new thread for it here:
http://www.audizine.com/forum/showth...-by-a4darkness

[boostedAvant]

Hahah its so good. You'll get it done. And yes. F that guy. I wish I found the guy that broke into mine.

[alexza4]

great thead! some of the best shit you can do is to get rid of all that junk though (PCV, EVAP, SAI), much more less crap to break!

[wazzu70]

This thread is great! Thanks for putting all the effort into it. I removed all the hoses from my car, and now that I plan on selling it I want to make sure it can pass emissions.

I already waded through a lot of this by myself finding part numbers and where they go, ect. I wish I would have found this earlier! Just imagine trying to tackle this only going off those diagrams....not fun.


I need some help tracking down a few part numbers though to finish this off. From Post #335

What is the part number for the hose after the check valve under #24. Can't seem to find a PN for it anywhere. Also, do I need #32 on a 2004 (After 8E-4-000-001)? I don't think so.

Could I also get a picture of where the hose plugs into over by the PS reservoir?

Sorry...I still need a lot of help!!

Thanks a ton!

[diagnosticator]

great thead! some of the best shit you can do is to get rid of all that junk though (PCV, EVAP, SAI), much more less crap to break!

Not junk.

[A4OrlandoB6]

So I've had a nasty (vacuum?) leak for about a month that I was able to temporarily remedy with some shrink tube. Now that the hose has completely failed, I need a new one. However, the part number is slightly faded and I want to make sure I buy the correct $80 rubber hose. It runs from the valve cover to the crankcase bleeder valve seen here - crankcase bleeder valve

the part number is 06B 103 217 ?

It looks almost like an S but im not sure. pics for your clicks



where it goes


another temporary shrink tube block off fix


can anyone confirm this?

[boy412]

There's no way that hose is $80. The one I see in ECS includes two hoses, a check valve, some heat resistant wrap, etc. I'll bet you could just use a length of (4mm ID) silicone hose. I'll see if I can pull a part number off my car when I get home. Looks like you have a late 2003 also!

[A4OrlandoB6]

But I have an engine swapped from an '04 and bits and pieces were used from each engine so some systems are newer and some are what the car came with originally. my ETKA shows me that the '03 part would be a few pieces, including another check valve. I was able to confirm the part with the dealer back home in Orlando, and got the part for $46 on GAP

My main question is, having the valve blocked, how OK am I to drive?

[boy412]

Mixmaster! Nice...

[a4darkness]

This question keeps coming up so I just went out to my car to see if I could lift a PN. Always forget there's a jacket on that hose and the lettering is all worn off on mine anyway.



Short of pulling the hose and removing the jacket to see if there's anything underneath, unsure what to do here. I've scoured ETKA but don't seem to have that hose listed anywhere as it seems to be an addition of some sort.

As for running / using something else, I would stay mindful of the bends in the hose as a replacement prone to kinking might foul things up. IIRC, Spector was messing with those hoses and tried something else which kinked and make his car run funny.

If it were me, I would find a temp hose solution from Autozone rather than just block it off. Did this w/a large Dodge truck radiator hose for a leaking FMIC coupler and it worked great.

[A4OrlandoB6]

I did just that with the thickest rubber hose I could find that fit correctly on each end and the car whined like a pissed off mouse...assuming theres a slight kink thats barely letting air shoot by, causing that whistle. WOO WOO!!!


Thomas, the picture you posted is of the system that's on the '03 right?

[a4darkness]

I did just that with the thickest rubber hose I could find that fit correctly on each end and the car whined like a pissed off mouse...assuming theres a slight kink thats barely letting air shoot by, causing that whistle. WOO WOO!!! Thomas, the picture you posted is of the system that's on the '03 right?

Yeah David, sometimes allowing those breather lines to pinch will result in the no muy buenos. Also, Bubb Rubb is dissapoint.

And yes, the pic I posted is from my 03, but I'm fairly certain it's in everything past 03 when the changes to the vac system were made. Found a better pic of the hose shown here with the 3rd set of cutting pliers I lost to the confounded one time clamps.




Had an idea though to get you through. Basically, you need a short hose w/the appropriate bends or a longer one to compensate for the curves. But perhaps there's something easily accessible you can cannibalize.


The hoses underneath the intake manifold here:



You might be able to use the bottom section of the longer hose shown here to suffice for the time being (and obviously replace this one with a longer, curving piece of heater hose or something). Make sense?

[pkfinn]

Thanks for a very informative thread. It'll come in handy when I get my engine put back together. Every time I look at the bin full of hoses, check valves, solenoids, etc., I wonder if I'll ever figure out how it all goes back together.

[a4darkness]

******************************
EDIT
Synopsis on basics of DVs
Synopsis on Standard vs Reversed Orientation
710N install Pics and Tips
710N DV Dissection

******************************-

(continued here)

You bet man. And it will. When my buddy blew a rod and had to pull the engine in his B5 I was like... ummm, where does all that stuff go? Turns out it does all go back together with some ease, you'll get it goin.

I was actually going to post an update here as well.

Been noticing a bit of very mild fluttering while accelerating. Nothing serious, first attributed it to some wonky gas or something but it remained so I started with the basics.

I'll stop right here and reiterate that had I already installed my boost gauge, which is STILL sitting in my garage, I'd already have a solid answer. Jace/BoostedAvant keeps HeyTelling me about how much of a lazy assclown I am concerning the lack-o-installation of said item. Like, daily. Can't argue cause he's right, this is stupid that I don't have one yet. And more importantly, our cars should have came with one. Ridiculous. Anyway, looks like it's gonna happen on Friday. I'm gonna take a crack at it. Brace yourselves.

And if you enjoyed that pic, do let him know.

So then, about a week ago I swapped in a new set of plugs. I am a huge fan of the Iridium BKR7EIX's and got those again. However, I have been toying with the idea of going with MKV CPs and different plugs. But I'm not quite sold on the whole thing yet. Need to see some long term results from guys not running BAT engines. I have faith, but still want more info before switching over. We'll see about that one in a few months.

Anyway, I've getting plugs from this guy for a few years now. Always uber low prices and ships out w/in one, maybe two business days at the most.
NGK IRIDIUM IX Spark Plugs BKR7EIX # 2667
http://myworld.ebay.com/ebaymotors/i...id=p4340.l2559

Got the plugs in and they certainly helped smooth things out and bring up my MPG a bit, but the fluttering was still there. Started to think it might be the DV.

My current one is an OEM 710N (reversed). While this is a more than fine setup for a Stage 1, I figured that it might be weakening a bit (installed back in April 2010). They work great, but certainly don't last forever... especially when reversed and running more than stock boost. Well, just a bit more. Lets not get carried away here.

I kept an eye on the classifieds and audi_nightrider was trying to move a Samco Sport (#DVR-1P-001) w/a medium level spring so I picked it up. Side note, great guy to buy from. Props Francis.

Using his pics since my camera got jacked a while back.









(thx for the pics francis)


As I understand it, this DV was designed by the same fella who made the Forge 007 valve. More info via the old group buy here. Figured Samco is trustworthy enough and more importantly, a bunch of guys here picked them up a while back and I've not found any complaints.

So I popped it in today, reverse style as well. Tried to take some pics but the camera phone was not having it. At first, there was even more fluttering at the low RPMs... kinda made me think I didn't tighten something down enough or maybe the DV wasn't still good. But since it's only got 4k on it and I even added a 2nd worm clamp to the smaller end figured the ECU just needed some time to adjust. Maybe my old DV was indeed that weak?

Went out for about 3hrs to pick up some supplies and was both in town and did plenty of freeway driving. Temps were high and I drove in plenty of different situations (fast, slow, downshifting + accelerating, cruise control etc). After some time had passed, I noticed the freeway acceleration was a LOT smoother and held quite well getting towards 6k. Maybe even a little faster too. Yeah, all from a simple DV swap.

The low end improved after a bit so I'm hoping it was just an adjustment of sorts. But, once the boost gauge is *finally* installed we shall see. I even got a little bonus in the form of a DV 'pssssh!' sound. Never had that before, I kinda like it. Not too loud like a BOV or anything and I can't hear it with the stereo on but it's a nice little addition to the engine sounds. Good times. That's all cool and everything, but I'm obviously more concerned about the low end fluttering. If it completely vanishes, cool. If not, we start tearing things apart.

Nutshell, if your 710N DV is a year old you might want to think about swapping it out.


EDIT 02/22/12

A few ppl have asked me to describe what the DV and piping should look like once it's installed. Before I understood all of this, it really confused me as well. Below is a pics of the Bosch 710N reversed. (pic of standard vs reversed here) Also note the absence of the silver Helmholtz Resonator aka The Cow Bell, shown here..

We've always called it 'reverse' as it's the opposite from what comes via the factory but calling it the "Push Orientation" provides more clarification. In the Push Orientation, pressure goes under the DV's diaphragm and the side outlet recirculates (blue tape is on the side port which is connected to the TIP).

[-Thread Navigation-]

[diagnosticator]

That Samco DV is a piston type DV. The arguments supporting running the DV in reversed orientation, are based on the physics involved when running a diaphragm DV. The same physics may or may not be applicable to a piston type DV depending on the shape of the internal piston surfaces, and the surface areas that result. Diaphragm DVs are a lot quicker reacting to changing pressure levels and respond to smaller pressure changes, compared to piston DVs, and don't need any maintainence. The only trade off that exist with diaghragm DVs is the chance for failure of the diaphragm, with the failure rate increasing with age of the DV diaphragm. IMO, I prefer the faster responding diaphragm DV over a piston type DV despite the risk of diaphragm failure. With quality aftermarket diaphragm DVs the diaphragm is easily replaced. On OEM Bosch DVs, they are cheap enough to replace as needed. BTW, I running an OEM 710"P" DV, and it so far has been a better DV than the 710N.

[a4darkness]

Yeah, the P has crossed my mind every so often John. By 'better' do you mean in response or durability? I recall you mentioning it's brass components in another thread. Maybe I'll try one out someday. Hmmmm...

The piston style DV vs diaphragm thing occurred to me when I was driving, but I was actually thinking more about possibly using the next spring up to compensate accordingly. But regardless, I wanted to swap orientation to see if there's any difference. What's your vote?

[diagnosticator]

The response of the 710 N vs the 710 P is very similar. The spring rate in the P is slightly stiffer. The durability seems improved witht the P version.

Regarding spring rates, remember that a stiffer spring, or a spring with more pre load, will cause the DV to open later and close sooner, in relation to intake manifold pressure. Installed in the factory orientation, only the spring stiffness determines if the DV behavior is right for the dynamics of the charge air system, with minimum delay opening and quick closing as long as the DV does not open late and close to soon. (while boost air flow to recirc is still occuring)
This is one reason reversed orientation is functionally superior. Also, if the N249 is still hooked up controlling the DV independantly of the intake manifold pressure, (and there are good reasons to do this, as well as trade offs, ) it can be involved in the fluttering noises you are hearing.
I vote to reinstall the DV in the OEM orientatoin and try that out. Can't harm anything and you will gain more insight as to what setup is best, with the DV you have now.

[a4darkness]

The response of the 710 N vs the 710 P is very similar. The spring rate in the P is slightly stiffer. The durability seems improved with the P version.

Okay then, if for some reason the Samco doesn't cut it I'll order one up rather than another 710N.

Regarding spring rates, remember that a stiffer spring, or a spring with more pre load, will cause the DV to open later and close sooner, in relation to intake manifold pressure.

Herp derp. Kinda forgot about the opening later part. That grounds my stiffer spring = better response rate theory. Dunno what I was thinking there. Been a while since I rolled this one around my head.

Installed in the factory orientation, only the spring stiffness determines if the DV behavior is right for the dynamics of the charge air system, with minimum delay opening and quick closing as long as the DV does not close to soon. (while boost air flow to recirc is still occurring) This is one reason reversed orientation is functionally superior.

Understood. Taking this into consideration, and since this spring is stiffer than the 710N's diaphragm + she's showing less than peppy characteristics at low boost levels, this would support a reversal to the standard position.

Also, if the N249 is still hooked up controlling the DV independently of the intake manifold pressure, (and there are good reasons to do this, as well as trade offs, ) it can be involved in the fluttering noises you are hearing. I vote to reinstall the DV in the OEM orientation and try that out. Can't harm anything and you will gain more insight as to what setup is best for you, with the DV you have now.

Okay, that sounds like a plan. This convo is reminding me of a similar speculation concerning the effectiveness of reversing a piston style DV. Oh duh, that was here. It seems we never really answered weather or not a piston style should be reversed. While it certainly can, this new info seems to provide logic for diaphragm style in reverse and piston style in standard.

Now about the N249... really glad you brought it up. Oh and I should specify, these are fluttering noises I'm feeling during acceleration, not hearing. Only hearing a mild psssh from the DV from time to time.

I rarely eliminate or alter anything of this nature (no diode mods, emissions removals etc) so it is indeed still hooked up. I've always passed on the N249 Bypass Now that I'm running a piston style DV, it seems that looping the N249 could be an advantage to move the responsibility of DV operation away from the ECU and to the DV via manifold pressure.

Did some quick searching to brush up on the Loop Mod and ITT here found your related comment:

The difference in performance may be subtle, but enthusiasts like me and most others, are sensitive to changes in the behavior of the engine. Most average drivers won't notice but that isn't a factor that has any relevance for me. And just to clarify, the N249 normally provides the function of allowing the ECU to control the state of the DV, either open or closed, regardless of the intake manifold absolute pressure value, to reduce pumping losses at low load cruise and during cat heat up. The N249 can also be activated by the ECU to open the DV if the boost pressure increases above the maximum allowed boost pressure value due to failure of the N75 boost pressure control. But that is an unlikely scenario. Turbocharged engines without a backup boost control like the N249 are not more likely to experience overboost damage as a statistical matter.

(side note, part of the reason why I'm posting all this is for others whom might be tracking this thread for related info)

So then, piston style in standard orientation (with N249 standard) would be my plan as of now. But the addition of looping the N249 sounds interesting and it sounds like you're a fan of it. But if I were to do so, would it still be best to keep the Samco reversed or again back to normal orientation?

Would be cool to have your take on this addition as well. TIA

[diagnosticator]

I can't say off hand if the Samco DV would function better in the factory stock or the reversed orientation. With the DV reversed and closed, the square area of the inlet is a lot less than the square area of the top side of the piston, so with equal boost pressure applied to the inlet port area and the same boost pressure applied to the larger area of the top side of the piston, is the same situation as a diaphragm DV. Regardless of boost pressure, in the reversed direction there is always a lot more force holding the DV closed. This allows for the use of a light spring tension compared to a DV installed in the factory postition. Combined with a light spring tension, the forces that open the DV are mainly generated by the boost pressurized air acting on the different areas of the diaphram/piston as the DV cracks open. Since the boost generated forces don't have to oppose a stiff spring force to open, the DV opens quickly, then as the thottle is opened after a gear shift, boost pressure is reapplied to the DV aided by the closing spring force, closes the DV at the same rate that boost pressure increases in the intake manifold. With the piston DV, as soon as the DV cracks open, the bottom side of the pistion is exposed to boost pressure as well, the difference between the square area of the bottom vs the top of the piston determines the net force as opening or closing force, then the spring force is added to find the total net force opening or closing, with the DV open vs closed. Examination and measurements will show if the bottom side or the top side of the piston is larger in area, or equal. With the DV in the factory postition, with equal areas top and bottom, the only force holding the DV closed is the spring force.
I think a stock or light modded street driven car should have the N249 hooked up and working as designed. As long as the implications of disconnecting the N249 are understood, then it is mainly what is most sensible to the owner, if the N249 is hooked up or bypassed.

[Kittrell]

What is your address? I need to get some fingernail clippers to you asap!

[a4darkness]

What is your address? I need to get some fingernail clippers to you asap!

I kept an eye on the classifieds and audi_nightrider was trying to move a Samco Sport (#DVR-1P-001) w/a medium level spring so I picked it up. Side note, great guy to buy from. Thanks again Francis. Using his pics since my camera got jacked a while back.

These are not the hands you're looking for, but your concern for my nail length is quite kind.

I can't say off hand if the Samco DV would function better in the factory stock or the reversed orientation. With the DV reversed and closed, the square area of the inlet is a lot less than the square area of the top side of the piston, so with equal boost pressure applied to the inlet port area and the same boost pressure applied to the larger area of the top side of the piston, is the same situation as a diaphragm DV. Regardless of boost pressure, in the reversed direction there is always a lot more force holding the DV closed. This allows for the use of a light spring tension compared to a DV installed in the factory postition. Combined with a light spring tension, the forces that open the DV are mainly generated by the boost pressurized air acting on the different areas of the diaphram/piston as the DV cracks open. Since the boost generated forces don't have to oppose a stiff spring force to open, the DV opens quickly, then as the thottle is opened after a gear shift, boost pressure is reapplied to the DV aided by the closing spring force, closes the DV at the same rate that boost pressure increases in the intake manifold. With the piston DV, as soon as the DV cracks open, the bottom side of the pistion is exposed to boost pressure as well, the difference between the square area of the bottom vs the top of the piston determines the net force as opening or closing force, then the spring force is added to find the total net force opening or closing, with the DV open vs closed. Examination and measurements will show if the bottom side or the top side of the piston is larger in area, or equal. With the DV in the factory postition, with equal areas top and bottom, the only force holding the DV closed is the spring force.
I think a stock or light modded street driven car should have the N249 hooked up and working as designed. As long as the implications of disconnecting the N249 are understood, then it is mainly what is most sensible to the owner, if the N249 is hooked up or bypassed.

Excellent info here John, thank you.

Looks like both sides of this DV are of equal size so that potential advantage isn't really apparent. As for the N249, seems like a good idea to stick with what I've been doing and leave it be.

Strangely enough, the slight fluttering while moving thru the RPMs has vanished. While my initial thought was direction orientation it appears that there's a decent enough amount of air being reclaimed by the Samco that the ECU needed to make some adjustments. Today on my commute (even more so on the way back) there was far better throttle response and strength throughout the RPMs. Even have more umph while cruising in 5th! Haven't had that in a while. Acceleration is FAR more smooth and it feels like I've gained a nice amount of power back. Who knew all this time it really was my 710N faltering a bit. Really stoked.

May just leave it as is, although I am curious to see if the standard orientation would be an even greater benefit, although I can't really see it being all that dramatic. Regardless, we are good to go.

[Kittrell]

These are not the hands you're looking for, but your concern for my nail length is quite kind.

Well we know what to get Francis for Christmas.........

[a4darkness]

Apparently so. Heh.

After putting some more miles on the car with the Samco in it's reversed position, I'm actually starting to like the behavior and it's effect on driving. Contrary to my initial thought that there was a leak or something was wrong, the ECU seems to have adjusted accordingly. I believe diagnosticator's theory above to be true. A piston DV reversed will require a bit more pressure to open the DV. The byproduct of this is that acceleration is a tad less *sudden* and far more smooth. I'm really liking this, feels more refined.

Additionally, it's pretty obvious that my 710N wasn't holding pressure at higher levels b/c now in the higher RPMs some power has been regained. The addition of the Samco has actually made for a fairly significant improvement. Granted, we're just talking about a DV swap here but I'd be willing to bet most here would notice the same changes and appreciate them as well.

Also, the Podi is in! And man is it nice. Will post up about that soon.

[boy412]

Also, the Podi is in!

Hallelujah! I just installed a new gauge in my pod (had one of the earlier versions with the annoying speaker). I like the absence of the beeping, but the color temp of the LED backlighting is a bit cooler than the rest of the gauge cluster. I'm also not sure I like the anti-reflective lens. After all the back and forth we had about the stepper motor gauge vs. the mechanical version I think I actually like the look of the mechanical one better! The lighting matches, and the lens is not anti-reflective.

Interesting read on the DV. Next time I'm under the car I may reverse my Forge 007 and see how it feels. On a related topic, how frequently should these piston-style DV's be "serviced"?

[a4darkness]

I know right? Took me long enough. This whole commuting for school thing is no muy bueno. But, that'll happen. I'll live.

So you really like the mech better? I'm pretty stoked on the electric, it made for a pretty damn easy install and it looks so incredibly OEM. It really does. As for the color-match, it's a bit off. But that's b/c I keep my instrument cluster, stereo and radar very low. Clandestine status FTW. So when you turn the Podi down almost all the way, it starts getting a very mild hint of blue in it compared to the OEM gauges. Granted, if you go up one more notch it's gone but for some reason at this setting where it matches the level of my interior lighting it's a hair off. I snapped a pic with my camera and was going to post it but it's not at all an accurate representation of the color difference. It looks 10x more blue in the pic than IRL. Regardless, I love it. Oh, and no beeping here. I never turned it on. But I do love when it goes RED, kinda reminds me of this...



So are you gonna switch back to the mech gauge then? Damn... after all that. Ha ha ha.
Oh, and this is something we totally discussed. The black vs silver bezel, remember how I was all about the black. Yeah, took me all of 2 minutes to realize that once it's in front of you opinions can change rather quickly. Silver is in.

The whole DV thing is kinda splitting hairs but still fun to discuss and mess around with.

Side note, I'm certain my 710N lost a good amount of strength a while ago but I had always attributed the power loss to a boost leak. Well, an intercooler piping boost leak. But now that the Samco is in and whatnot, I'm thinking that it's a safe bet to swap a reversed 710N at least once if not twice a year.

As for the servicing, anywhere from quarterly to bi-annually is a good idea. I'd go w/quarterly. Also, if your DV is old then you might want to think about getting a new Forge Valve Spring Tuning Kit. I picked up a Forge a while ago and got that kit from NA MS but wound up selling the DV and going back to the 710N. Probably should have toyed around with the Forge more to get it right. More than anything it seems like using the proper spring and spacers (w/the Forge) is key. But considering your setup, I'd recon you're not suffering in the low end torque dept. Reversal could be beneficial, nothing outrageous of course but it's the minor changes that sometimes make all the difference.

How much boost are you seeing anyway?

[boy412]

Nah...I'll keep the stepper motor version. I'm DONE with re-wiring this gauge!

[wazzu70]

Where does the end of the T'd off hose go to? The one that has the plastic black piece at the bottom of the picture?



Another question. On the Vacuum tank in the driver fender there is one side of the tank that goes to a spot under the intake manifold that connects to the two solenoid valves. Where does the other side of the tank go to? I don't have the system in my car so I have no idea. All the diagrams I have seen just show the connection off the solenoid valves.

Thanks.