Phoenix from the flames - Porsche Boxster with an Audi 2.7T

[SuperCharged V6]

So pleased for you Tom, as others have said, you came across as a genuine car guy sharing his story with others. I was gutted for you when the fire happened, but total respect to you for cracking on with the new one, which by the way is even better, sounds great and goes rather well from what we have seen.

Loved your threads and it is what makes PH.

Thank you and look forward to the next updates

[Bob_Defly]

Just got through the entire thread, amazing stuff.

[Escy]

Thanks for the nice comments.

I've been using the car a fair bit over the last 2 months for sensible duties like the school run. Its been reliable other than one issue. I've had an intermittent non start problem before (when I needed to get it recovered a few months back), the ECU can't see the crank sensor signal when turning the engine over trying to start. I had thought it might have been heat related as I was thrashing it the last time it happened. This time, I was pootling along in traffic so the car wasn't hot, I nearly stalled it when I went to park, put the clutch in last minute, caught it, the revs picked up for a second but then it died anyway. After that the car wouldn't restart again from the starter motor. Luckily I was on a hill, I rolled it down and bump started it, drove it for 2 further 45 minute journeys that day and both times I stopped it wouldn't re-start (made sure to park on hills just in case). It doesn't make much sense, can't see the crank sensor when cranking but can read it fine when bump started. Pretty sure it's not voltage or heat related.

I talked it over with Baldur who built the ECU, he suggested removing a resistor on the circuit board that's used for different crank trigger set-ups, the idea will improve the signal for the ECU. I did that and it fired straight up and has been fine since. Hopefully it's the end of those issues now, time will tell.

Otherwise it's not put a foot wrong. I took it to the PistonHeads Sunday Service meet at Caffeine and Machine on the 12th. It was nice to get a chance to meet people and talk cars. It was also a cool venue.

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I think my favourite car there was this Alpina B10 V8, I'd love something like that.

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There was an Aerial Atom there, the way they do the intercooler ducting was interesting to me. The duct was just flat to the floor, not a scoop protruding lower than the floor in front of it. The difference in air pressure under the car is how it works. Not hard to rig something like that up, but on my car the issue is venting it out the other side. I really wish I could make an air to air intercooler set-up.

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[M22s]

This is possibly one of my favourite threads - your readers car Vlog a few weeks ago was fantastic too, OP! Would have loved to seen the car in the flesh at C&M.

[Dadof2]

I spotted you cruising on the m4 a couple of weeks ago, the car looks great moving along, really nice stance and just enough mods to looks different.

It was nice to see it out and about

[Escy]

M22s said:

This is possibly one of my favourite threads - your readers car Vlog a few weeks ago was fantastic too, OP! Would have loved to seen the car in the flesh at C&M.

Thanks. I'm planning to be attend plenty of car related things next year so maybe see you at something else.

Dadof2 said:

I spotted you cruising on the m4 a couple of weeks ago, the car looks great moving along, really nice stance and just enough mods to looks different.

It was nice to see it out and about

Thanks, I'm pleased with how it's ended up. The wheels were a gamble which I think paid off.

I'm pretty sure that would have been the day it needed to be bump started all the time. It's getting more use at the moment than I thought it would but I'm just taking it easy as the tyres aren't ideal for the current conditions. Just picked up a more suitable winter car so will probably SORN the Boxster in January.

[Escy]

I've not had the chance to look under the car for a few months whilst I've been driving it regularly as my garage has always had something else in the way. I knew it was still leaking oil so I was expecting it to be an oily mess underneath. It's not as bad as I feared. It's not seen lots of hard driving so that could explain it, I think it leaks the majority of oil under boost.

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I've got leaks on both banks but they aren't making a huge mess.

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My catch can looks a bit grubby and there was a drop of oil on the PCV valve next to it (it is a cheap ebay one).

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I'm going to make no attempt at fixing oil leaks on the engine until I get the PCV system sorted out. It's currently set-up like the OEM system with a one way valve on the inlet manifold and a pancake style PCV going back into my intake pipe. Blowby gasses go into the inlet manifold off boost, on boost they go into the air intake before the turbos. The problem is the pancake PCV valve has a hole in it by design so I'm drawing air in from my intake straight into the inlet manifold off boost. It's basically by passing my throttle body. My idle has raised about 200rpm. Off boost it doesn't pull a vacuum as it's drawing fresh air and as the boost comes in I get positive crankcase pressure as I guess my intake doesn't pull a vacuum on it until further up the rev range as it's going into a 3.5" intake pipe. It never pulls a vacuum even at the redline but it is showing less pressure than when I tried to draw it into my exhaust.

I think maybe I'll just run a large vent to atmosphere set-up and be done with it. That seems to be how most people do it. I'll get a big catch can with large ports and big filters and just run 3 separate pipes into it. I've found it interesting but ultimately I've over complicated things messing about with exhaust venturi's and PCV valves.

One thing that's surprised me is how quick things are deteriorating, driving it through the winter isn't doing it any favours. I've noticed corrosion on lots of bolts and fixings. Even stuff like my charge coolers are starting to look a bit manky.

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It also turns out that when I raided my scrap bin for bits of stainless to make up my intake I've used something a bit iffy.

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I did spot a small coolant leak.

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I was worried that something would go wrong with the car during the last few months (where I wouldn't get time to fix it) so I'm pleased it didn't let me down, nothing fell off or broke. I've enjoyed using it recently but I've got another car now so it takes the pressure off. I've got the MOT booked tomorrow, I expect it'll pass but I won't count my chickens just yet.

[Escy]

It passed the MOT as I expected it would. I've done 1500 miles in it over the last year.

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I needed to drop the roof the access the engine and nothing was happening when I un-latched it, usually the windows drop. I confirmed with PIWIS that the switch was the fault. I removed the latch housing and on the back of the switch there was a broken solder joint. Nice easy repair.

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I took the car out for a drive with the crankcase breathers disconnected, the pressure stayed at ambient the whole time so a large vent to atmosphere breather system will work. The problem is it smells.

[Escy]

I occasionally get a boost pipe pop off, it cost me a turbo before, I also had one pop off on the dyno which wasted a load of time. When I was in the middle of nowhere filming the Pistonheads video one came off and it ruined the plans for the day. I had one come off the other night when testing some stuff. It doesn't matter how tight jubilee clips are done up, they eventually work loose until one pops off. Being mid engine it's not always easy to get them back on so I finally decided to sort it out.

I bought some Murray constant tension clamps. I've known about them for years, I don't know why I didn't just buy them ages ago, bit of a mental block I think. I've used one before on my blue Boxster when I couldn't keep the pipe on the throttle body connected and it did the trick. They are popular in Motorsport, used on works WRC cars and stuff like that. The ridges inside the clamp improve the seal, the spring on the outside allows for constant tension with heat cycles. If anyone want's to see their promo video to see it explained properly it's here.



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Edited by Escy on Thursday 27th January 20:00

[Escy]

I've been doing some testing on my breathers, to try and find out exactly what's happening and where the restrictions are. First up is a run with nothing connected at all. As expected the crankcase pressure (green line) stays at near enough ambient pressure during a pull so that's my baseline. The calibration on my crankcase sensor has ambient around 1030mbar before I start the engine. When the engine is warmed up, it's around 1037mbar at idle.

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I then re-connected the lines where I had all 3 breather hoses merged into one pipe but left it open to the atmosphere. This is were people on some 2.7t Facebook groups where saying I had a restriction. It turns out that's not the case. It looks like it goes up on the graph but it's due to the scaling, it's raised about 5mbar (0.07psi in old money) during a pull which is insignificant.

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I then connected the merged pipe into my catch can but didn't attach anything to the outlet port. This time it peaks at 1066 which is around 30mbar (0.4psi) up on my baseline. I don't know how accurate these numbers are, I placed my sensor in the middle of the V, the numbers might be different in the cylinder heads, but they are good for comparisons. I'm taking that jump in pressure to be a bottle neck to address.

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I removed the drain plug from the catch can to do a run with 2 outlets on it. I don't know why I didn't put anything under the catch can before taking the drain plug out. It had a lot more gunk in it than I expected. Mainly water.

Edited by Escy on Saturday 12th February 17:19

Edited by Escy on Saturday 12th February 17:23

[Escy]

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My run with the drain plug out was a step in the right direction. It was around the 1040mbar mark so up on atmosphere but hardly. Looking inside the can, there was a metal gauze under the outlet fitting which is where the restriction was.

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I decided to try connecting up the catch can drain to my exhaust venturi's which were basically redundant the way it was rigged it up. I re-connected the hoses to the top of the catch can (go to a T piece, one side goes into the inlet manifold, the other to my intake pre-turbo, with a check valve and PCV valve). This run was a pleasant surprise, it briefly peaks at 1050mbar so 0.2psi up on my warm idle figure. It also drops down during the pull to 1037mbar which is the about the warm idle figure. It looks very much like the exhaust venturis are working, they are pulling a vacuum on the catch can as it's bringing the pressure down as the revs are rising, I'd expect the pressure to increase. I had these venturis connected to the outlet of the can before (T'd into the pipes running to my intakes), then I was seeing pressures of 1070mbar which didn't drop as the revs increased.

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This is how it currently is, just rigged it up with bits and pieces I had in the garage for a test. I might look to get a nicer fitting and a better hose to tidy it up as it sits a little low currently. I'm liking the idea of this set-up, the exhaust venturis do actually work so I didn't waste a time effort and money on them, also the water and oil collected in my catch can will now be spat out of the exhaust, which means it's maintenance free.

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I should have done these tests ages ago when I first thought I had an issue, pin point the issue rather than making wholesale changes then seeing what I end up with. Live and learn. I think I've got a good solution now. Over the next few months I'll fix all the oil leaks, hopefully that's it then. If it leaks again, that's it, going to ignore it as I'm not sure there is such a thing as a 2.7t without an oil leak anyway. It's a unicorn and anyone who says they do have one isn't looking hard enough.

[Escy]

Not sure why but I kept getting 403 forbidden when trying to post the last update all together.

[ReformedPistonhead]

Please keep posting, love the updates and your persistence. Great job.

[mwstewart]

Nice data-driven anlysis.

[Escy]

ReformedPistonhead said:

Please keep posting, love the updates and your persistence. Great job.

Thank you, I will do. Posts like the last one are probably boring for most people, it's a bit geeky and I might not explain stuff that well but I find it useful as a reference to refer back to, like a blog.

mwstewart said:

Nice data-driven anlysis.

Thanks, I should have done it ages ago.

[helix402]

I’d be very wary of Facebook knowledge/advice. Based on your thread I think your level of knowledge and investigative diagnosis goes quite a way beyond that on Facebook. Great work on sorting the project.

[Pupbelly]

Escy said:

ReformedPistonhead said:

Please keep posting, love the updates and your persistence. Great job.

Thank you, I will do. Posts like the last one are probably boring for most people, it's a bit geeky and I might not explain stuff that well but I find it useful as a reference to refer back to, like a blog.

mwstewart said:

Nice data-driven anlysis.

Thanks, I should have done it ages ago.

Keep it coming - love the geek element!!

[BrettMRC]

Fantastic work as usual OP, glad you've got it nailed!

[strombomb]

Hey Escy - great work as always!! To confirm, you think the restriction in the drain area of your catch can was to blame? Also, do you think you need a check valve on your line between the catch can and venturi to keep your intake from pulling exhaust during negative pressure (idle)? Maybe I misunderstood.

Great work and I’m taking notes!

[Escy]

Thanks. The restriction was the brass fitting with a fine mesh on it that was on the underside of the outlet port. Using the drain port as an extra outlet port meant I can keep this catch can. It only works as it's draining into the exhaust, I couldn't feed it back into my intake. I've got a one way valve on the exhaust venturi's, I bought a massive thing rated for high temperatures with a low cracking pressure. Took me ages researching that. If anyone is interested, this is what I bought, it's doubled in price since 2017, now £95. VSCCRO30412 - https://www.flowtech.co.uk/category/section-7-valv...

From what I've seen there aren't many good catch can options on the market, most have small fittings, most have more inlets ports than outlet ports and the ports are typically the same size for inlet.