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Loosing power/boost after driving after an hour or more
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1853
Location: MI

PostPosted: Thu Jul 04, 2019 1:39 am    Post subject: Reply with quote

These cars are actually a bit tricky to install an intercoller onto but has been done by many people here in many different ways..

CareraRSR put a 944 turbo intercooler under the nose panel like the 944 turbo which is a great setup but requires body work under the nose panel and he also changed his intake manifold a lot.. He might give you some links to check out..

Rasta Monsta did a pretty good one where he put an air to water IC in his battery box and the water to air exchanger in the front somewhere, which required little body work and other modifications to make work..

Here http://www.924board.org/viewtopic.php?t=28534 is another way to do it by RC that I think could be done with the stock turbo and intake.. A FMIC plumbed down by the headlight lifting bar..

Mine I like very much and requires little to no body work but will only work with an upgraded turbo. I don't think it will work with the stock turbo having the integraed BOV in the compressor housing..
It is more of a usual FMIC setup but you have to be able to turn the compressor housing upside down to blow toward the bottom instead of up..


You can see how I spaced the bottom of the radiator back to fit it and made a mount plate for it..



Can still get it here for $65 ON EBAY and fits perty gerd..

You can see it (somewhat) here..
https://youtu.be/X2jbkENELMk vid 1
https://youtu.be/1wk3QW90cbM vid 2
And my install thread but my pics are gone..
http://924board.org/viewtopic.php?t=41250&postdays=0&postorder=asc&start=0

Cedric did one pretty similar to mine in the middle of this thread http://924board.org/viewtopic.php?t=40495&postdays=0&postorder=asc&start=90

Morghen did a pretty nice FMIC that would work with a normal turbo but I think requires a 951 front bumper..

You can also do it the Porsche way with a top mount carreraGT IC and hood scoop..

Many ways to do it but none of them are super easy..

I admit that I like mine the best but I might be biased

While you are at it click the blue "slightly modified" link in my sig just under this line to hear the incredible sound (IMO) at the end to give you some inspiration
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chuck21401  



Joined: 20 Feb 2005
Posts: 192
Location: Annapolis, MD

PostPosted: Sat Jul 06, 2019 1:38 am    Post subject: Reply with quote

Fasteddie313 wrote:
These cars are actually a bit tricky to install an intercooller onto but has been done by many people here in many different ways..


Thanks for the information and links. I've been researching installation options. I'd prefer not to install a new hood with hood scoop, but that is an option.

The PWR Liquid to Air Barrel Intercooler looks interesting, I see that at least one board member is running one of those, but I also want to keep the pop up headlamps.
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chuck21401  



Joined: 20 Feb 2005
Posts: 192
Location: Annapolis, MD

PostPosted: Sat Jul 06, 2019 2:27 am    Post subject: Update - boost control line replaced - still too much boost Reply with quote

I had some time yesterday to work on the 931 so I decided to install the used boost control line.

The short story is that I was able to replace the line and that it didn't make difference...car is still generating 14psi-15psi after a short test run. I'm convinced that the answer lies within the wastegate.

Here's the longer version.

I have drive up ramps but they don't elevate the car high enough to provide adequate access to the wastegate area. I read a number of threads about jacking up a 924 and where to put your jack stands. I ended up putting the jack stands under the front cross member. I set the E brake and chocked the rear wheels. Also disconnected the battery.

Once I was convinced that I could crawl under the car without getting squished, I removed the boost bolt with a 17mm open end wrench. With the car higher in the air I found it a lot easier to get a wrench on it.

But first, here is a picture of the boost control line, there is a sharp turn, but the line is not kinked.



Here is the bolt and washers. One is copper and the other is steel (or aluminum?)...later I figured that the silver washer might not provide the best seal so I replace it with an other copper one. There's nothing magical about the Porsche sealing rings right? Looking up the part now, apparently the Porsche part is aluminum 90012304330

https://www.pelicanparts.com/More_Info/90012304330.htm?pn=900-123-043-30-OEM



But I don't think that this area is leaking...I didn't get bubbles when I tested it previously with soapy water and compressed air down the line.

Anyway, removing this line is not easy. There is a bolt that holds it to the block. To get to that bolt (and to make room to remove the line) I found it necessary to move some things including the distributor and the positive wire to the battery. Not a big deal, just took some time.



The bolt holding the boost control line to the block took many turns to get loose...but finally the line was free.

Here are the two lines side by side. The control line I removed was not clogged or anything.



So now it was time to install the used control line. As they say in the manual "installation is the reserve of the removal procedure." Well, sorta.

The revised part with additional rubber hose at the banjo fitting was a good idea. It was not easy to get the hard line installed. I quickly found that you have to start at the banjo bolt, then reinstall the bolt holding the line to the block, then attach to the intake and there is only one route for the line to go. Takes a while to figure that out by fishing it back and forth.

Once the line was connected I reinstalled the distributor and reconnected the wiring. I reset the timing based on the process detailed in a very helpful thread. I'll have to look it up again and post a link. Edit - Here is the link:
http://www.924board.org/viewtopic.php?t=37216

So now I was ready to try it out. I removed the jackstands and backed down the ramps I set up under the wheels just in case. The car started right up. I backed up and noticed that the car was leaving a trail of coolant. WTF? Turned off the car and opened the hood.

I had forgotten to tighten down the bolt holding the control line to the block. That bolt also holds down a flange related to the cooling system, I think there is a temp sensor there. In any case, coolant had leaked from that area. I was able to get a 10mm socket on that bolt without removing the distributor, etc. and tighten it down. Ran the car for a couple of minutes, no leaks, blipped the throttle, seemed OK. Now time to take a test drive.

Once up to operating temperature I gave it more throttle...and it boosted past stock boost. No change at all. I can't imagine that both boost control lines would be leaking...so the answer must be in the wastegate.

Not sure what to do next.
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1853
Location: MI

PostPosted: Sat Jul 06, 2019 4:23 am    Post subject: Reply with quote

I think it would take a hell of a leak, a lot more than a couple bubbles, in that line to raise boost that much like that..

So either you do your CIS testing and put an IC on to hold that boost or you do your CIS testing and go through your WG to lower the boost to a safe level, or just drive it easy till you figure out what you want to do..

I'm thinking that your WG has a stiffer spring installed into it, or some shims installed in it, or assembled wrong, or something..

My FMIC setup does not bother the headlights at all or the windshield washer tank..
It just requires a normal style compressor housing, grind a bit of a useless tab off the block, grind the steering rack a little, rebend the oilcooler lines a bit, move the horns a bit, piece of angle iron and some pipe for radiator spacing/IC mount/oil cooler mount, remove a couple square inches of sheet metal behind the front valance, and a bunch of hose, pipe, and clamps.. To do it again I would put the new BOV underneath like cedric did so the upper charge tube and that plumbing would stay completely the same also.. Stock radiator and fans and everything.. Still easy to service and replace the timing belt..
Quite non-invasive..
Even my V8 fuel distributor setup on top of the IC managed to clear the lights mechanism and OEM washer bottle..

If you have a 2664 turbo I have a spare comp housing that would work for you from an Audi (can put it on without even removing the turbo), or grab a cheap turbo from a 944 and swap the cold side of it onto your 931 turbocharger..

Mind you, if you have a 2660 turbo it is even more dangerous at the boost you are making..

Speaking of timing belts, you have a new timing belt on your car right?
If not, that is priority #1 without question..
Might also want to put in some NGK BR8ES plugs for safety too, and always run premium octane gas, and heavy 40 or 50 weight synthetic diesel engine oil, or car oil with a zinc additive to keep your cam happy, that you should check and adjust the lash on, and inspect the cam oiler tube and elbow..
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chuck21401  



Joined: 20 Feb 2005
Posts: 192
Location: Annapolis, MD

PostPosted: Sat Jul 06, 2019 4:48 am    Post subject: Reply with quote

The turbo is a 2664.



The timing belt is new. I had BPR7ES plugs in the car originally. They were gapped at .8mm which I think caused a problem at the high end. I tried B8EGV gapped to .6mm and they worked well.

Quote:
NGK BR8ES


...different heat range?

Yes, running premium gas. Oil is 20W50; I believe synthetic.

Quote:
you should check and adjust the lash on, and inspect the cam oiler tube and elbow..

I'll have to read up on how to do that.

Quote:
I'm thinking that your WG has a stiffer spring installed into it, or some shims installed in it, or assembled wrong, or something..


Has to be. Previous owner believed the WG spring to be stock. But without testing no way to know.

Quote:
So either you do your CIS testing and put an IC on to hold that boost or you do your CIS testing and go through your WG to lower the boost to a safe level, or just drive it easy till you figure out what you want to do..


At this point I'm leaning toward going through the WG. I think I'll have to take it somewhere. Even if I decide to add an intercooler, I'd still like the ability to run lower boost...maybe between 8 to 10 to 12 psi.
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peterld  



Joined: 10 Dec 2006
Posts: 768
Location: Noosa Heads QLD Australia

PostPosted: Sat Jul 06, 2019 5:50 pm    Post subject: Reply with quote

It would seem that your issue must now be wastegate related. Seeing as you have been able to accomplish what you have so far, removing the wastegate is very doable, though a pain in the arse because of space constraints.

The wastegate itself on the 924 (actually a 930 unit) is probably the most rudimentary piece of equipment I have ever seen on a car! The only biggies are not to break the diaphragm (or maybe it is torn or pinched) and for sure one or more of the studs will break.
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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Sun Jul 07, 2019 5:22 am    Post subject: Reply with quote

peterld wrote:
It would seem that your issue must now be wastegate related. Seeing as you have been able to accomplish what you have so far, removing the wastegate is very doable, though a pain in the arse because of space constraints.

The wastegate itself on the 924 (actually a 930 unit) is probably the most rudimentary piece of equipment I have ever seen on a car! The only biggies are not to break the diaphragm (or maybe it is torn or pinched) and for sure one or more of the studs will break.


So what else could go wrong here?

I found some threads about wastegates on the 930 forum at Pelican.

This thread talks about rebuilding the wastegate and that one problem could be a worn out valve guide. A worn out valve guide could result in a leak, which means more boost is required to open the WG, right?

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/782170-wastegate-hammered.html

This thread details rebuilding the WG and led to the creation of service kit
http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/972314-930-wastegate-rebuild-nla-parts.html

Here is the kit: https://www.ebay.com/itm/Qty-1-Porsche-930-935-965-931-turbo-wastegate-essential-rebuild-kit/113805106100?hash=item1a7f501bb4:g:pj4AAOSw9~Jc4v7K

Here is my question...could I test for a problem by connecting a mighty vac to the boost control line? Seems like if the valve guide is leaking...it wouldn't hold vacuum or not as much as it should with a healthy valve guide.

Edit: Using a mighty vac to pressurize the control line is discussed on this thread: http://www.924board.org/viewtopic.php?t=15712&highlight=wastegate+valve+guide So it might be interesting to try that out and listen for blow by past the valve guide; but how much is too much...wouldn't really know until I get in there.

The previous owner rebuilt the WG but not sure about the valve guide. I'll ask. Also wondering about the gasket between the hot/cold side.

The WG service kit (includes the diaphram) is $305 from Patrick Motorsports. Ouch. https://patrickmotorsports.com/collections/exhaust-turbocharger/products/tur-930-123-210-wgs-pms

Some picks from the previous owner's rebuild thread.




New nuts/bolts all around so maybe would be easy to disassemble.
[/i]
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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Sun Jul 07, 2019 11:54 am    Post subject: Reply with quote

You just presurized it with your air compressor didn't you? How much do you think it leaked past the valve when you did that? Did it feel like it was loosing a ton of air or held a bit of pressure?
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chuck21401  



Joined: 20 Feb 2005
Posts: 192
Location: Annapolis, MD

PostPosted: Sun Jul 07, 2019 12:49 pm    Post subject: Reply with quote

Fasteddie313 wrote:
You just presurized it with your air compressor didn't you? How much do you think it leaked past the valve when you did that? Did it feel like it was loosing a ton of air or held a bit of pressure?


Twice. The first time was done in an effort to excerise the wastegate in case it was sticky. Did that a couple of times. Second time was an effort to see if the control line was leaking and the unscientific soapy water bubble test. In both cases there was a ton of noise with the compressor running and wasnít under the car to listen for any leakages...but used my cell phone to capture video. Seems like the mighty vac test would be silent, except for leaking air.
So I donít know...just trying to think through what could be going on. But probably will not know more until WG is removed and inspected.
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chuck21401  



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PostPosted: Sat Jul 13, 2019 11:32 pm    Post subject: Removing the WG Reply with quote

Today I'm going to start the process to remove the wastegate. Any tips? PB Blaster on the nuts and bolts?
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peterld  



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PostPosted: Sun Jul 14, 2019 12:17 am    Post subject: Reply with quote

It looks brand new. Can't imagine it should be a problem getting off and out, and given how it looks as it was going together, I'm now doubting there is a problem there, unless the diaphragm has been pinched and torn.
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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Sun Jul 14, 2019 1:58 am    Post subject: Reply with quote

Read the thread again..
chuck21401 wrote:

Quote:
NGK BR8ES


...different heat range?


Ah, I forgot this part..

chuck21401 wrote:
B8EGV plugs


Those are fine plugs. Same as the br8es but a bit better electrode material..
I just meant that it would be safer for you to go with some non-protruding tip plugs and a little colder, which you did..

We need to figure out a way to test your spring to identify it and/or maybe just ask on here if someone has a stock spring they can sell you and then just try that..

chuck21401 wrote:
Today I'm going to start the process to remove the wastegate. Any tips? PB Blaster on the nuts and bolts?


Yeah, what were they 12mm or 13mm?
Whatever size they are you want a socket to fit, with a swivel joint and extensions, and grab every wrench that size you have..

The J-pipe to manifold bolts are pretty easy but the downpipe bolts are also a bit of a pain and need a variety of tools to get them all, like socket and swivel and extensions of varying length..

The WG mount to the torque tube is hard to get.. I think I used a stubby ratcheting wrench on them way up at the tips of my fingers..

PB blaster is a good idea especially on the downpipe bolts that get super hot and the manifold bolts but like you said your bolts look like brand new.. Mine looked like old exhaust bolts, you know..

peterld wrote:
It looks brand new. Can't imagine it should be a problem getting off and out, and given how it looks as it was going together, I'm now doubting there is a problem there, unless the diaphragm has been pinched and torn.


Right..
I really hate to be sending him after the WG, but what the heck else could it be besides a heavier spring? Maybe the top port vent is plugged? Plugging my top port with about 3' of hose volume on it gives me a couple more pounds of boost so if it is plugged right at the top vent that might raise boost more..

While you are in there I highly recommend getting a hose set up from your top port and into your engine bay for future use with a boost controller so you won't have to pull the WG again to do that later on..
Top port boost control is where it's at, but you have to take the WG out to do it..
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Last edited by Fasteddie313 on Sun Jul 14, 2019 2:24 am; edited 1 time in total
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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Sun Jul 14, 2019 2:20 am    Post subject: Reply with quote

chuck21401 wrote:

The previous owner rebuilt the WG but not sure about the valve guide. I'll ask. Also wondering about the gasket between the hot/cold side.


Heard back from the previous owner, some lateral play was observed in the valve at the same time that the valve lapping was checked but they didn't have a source for the valve guide at the time. So the question is how much is too much? The gasket between the hot/cold side of the WG was coated in copper gasket material and reused.
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Fasteddie313  



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PostPosted: Sun Jul 14, 2019 2:27 am    Post subject: Reply with quote

[quote="chuck21401"]
chuck21401 wrote:

how much is too much?


I just don't know..
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Carrera RSR  



Joined: 08 Jan 2010
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PostPosted: Sun Jul 14, 2019 3:35 am    Post subject: Reply with quote

Quote:
Right..
I really hate to be sending him after the WG, but what the heck else could it be besides a heavier spring? Maybe the top port vent is plugged? Plugging my top port with about 3' of hose volume on it gives me a couple more pounds of boost so if it is plugged right at the top vent that might raise boost more..

While you are in there I highly recommend getting a hose set up from your top port and into your engine bay for future use with a boost controller so you won't have to pull the WG again to do that later on..
Top port boost control is where it's at, but you have to take the WG out to do it..


Top port of wastegate should have a vented plug. The plug to stop shit getting in, vented to ensure no air resistance on the diaphragm from bottom port.

You can screw in a top port from above when fitted. Itís tight but doable so WG does not have to come off. Top of engine ancillaries maybe.
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