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I previously purchased Turbo valves because I thought they'd be a direct swap & probably superior to the NA.
As most of you know, the turbo exhaust valves are SODIUM filled.
I did a brief visual comparison of the 2 because I wanted to know how compatible they were. What I found surprised me.
In the photo: LEFT is factory valve from Rebuilt NA head.
RIGHT is factory valve from non rebuilt head.
Look at the profile difference. (The one on the left looks like it would breathe better at lower valve lift)
-keep in mind the valve on the left has been "back cut" 30 degrees. I don't know if a stock NA valve normally has the same profile as the mighty turbo. Maybe someone can chime in.
First impressions: Nice to rev it up to 6500ish & no longer worry about valve springs failing. Also notice the mid-upper power band is better on the butt dyno. Part of this would be due to less advance on the cam and obviously better breathing when it's working.
I have a problem with running too d**n RICH however. The car stalled 5 times on me yesturday at idle. WB02 reading 10.5:1-12.5:1 and fluctuating. I think it's just too rich!
In the spring it was too lean. Fixed that with changing to .5 bar increase of fuel pressure... then have had more and more problems of running rich.
I suspect electrical gremlins. BUT ALSO, I need to ask myself "what has changed"?
Answer: temperature & with it air density.
Proposed solution #1:
-Remove Wilks Race Chip & install OEM chip (because Race chip doesn't read o2 sensor).* *
-Wire up my WB02 to the OEM narrow band 02 harness so the ecm can do it's job & adjust for elevation/temp; air density.
Yesturday I was going to do the wiring adaptation to narrowband, but didn't feel like jacking Wilson up. Instead I made a "coarse" adjustment by swapping in my 2.5 bar(regular) fuel pressure regulator. Adjusted the DME to +6% fuel.
Realized I had made an error with the clicks on the dme, thankfully I carry FRWILKS reference sheet & corrected it.
I brought my camera, but batts died. Shame because we got in 7 hours of adventuring... 4 hours of that included some of the most scenic driving I've ever taken Wilson on.
Honestly, the car was nearly spot on in terms of fuel tuning. With less fuel pressure, it's get up an go in lower rpms was notably better. Stop & start resulted in zero stalls. Also better fuel economy & less stink.
...all to be expected. Just happy about that. I'd rather work on improving other things right now. Enough engine business. I want to improve the interior & finish my headlamp conversion. BUT MOST IMPORTANTLY: seal the cab from the damn rain!
The drive I consider my "usual drive" with great scenery, minimal wildlife, first class roads, and winedy route is quite busy right at this time of the year. Typically it ends where Kananaskis mountain park begins (but is gated & sealed from entry in the "off" season, which is when I like to drive).
I took this road today because it was open. The gate was lifted to the mountain parkway & from Mountain range to mountain range the roads were accessible.
It was the most incredible drive. The colours and texture of Mother Nature's backyard were a prize for the eyes to behold.
The road was somewhat busy, but only in the way to make it more interesting with a lower powered sportcar... requiring a manual gearbox & a heavy right foot & proper planning to pass people at the right time.
It was one of the few times I was not annoyed by other drivers, but rather enjoyed them being there... adding to the overall experience, rather than limiting the fun.
Visibility was 100% on this clear day. Green, yellow, red & blue... summer was in full bloom. The positive energy of the real mountains could be breathed in & surrounded Wilson & I.
I drove by a couple of American hot rod types, motorcyclists accounting for over 60 riders... truly this road was being enjoyed by all types. It really felt like peace on earth.
...but the cracklin'-fire breathing-confident pissed off and angry four cylinder lightweight champion named "WILSON the great" was celebrating this day in the sun, in the MOST TRUE fashion.
Wilson is being Wilson. He doesn't have to act or pretend. He comes from a place where a select few remain. A place that no longer produces new champions by the likes of him. His design is 30 years old. Porsche no longer makes these cars.
For some of us privileged enough to drive the 944 the fire is not out. Some of us are stoking the fire.
Feeling like I'm living a "post card moment"... something European, I don't know maybe Swiss Alps or Italy... going around the bends. Looking ahead into the corner that continues to evolve in a tightening or loosening fashion. Traction could not be better in this balanced machine on the perfect black top. Road conditions are incredible.
Sure there is signage warning "do not stop - avalanche area". And there are the motorcyclists & large trailers being pulled up hills behind pickup trucks. And there's the occasional small group of young goats licking salt off the road, without any consideration for the rest of us; they don't even seem to care that cars are delicately trying to pass them.
At one point the main road is closed for construction and so we wined around on a dusty gravel trail to bypass that business. Upon re-entry onto the tarmac there is a long stretch of hill to climb. First gear turns to second, then third and so on... Wilson opens up his AFM flap to suck in more & more of that delicious air and simultaneously forcing out compressed exhaust gasses out of free flow pipe... sounding so good... kind of a "sport bike" motorcycle sound, but from bigger components. The sound of freedom.
Soon there is a option to turn left and for some reason I took it.
Almost instantly I was regretting taking this turn. "Why'd I do that?" I was already on the best road possible. Now we are putt putt putting, one after the other to a 4 way intersection. When it was Wilson's turn I noticed a sign to my right "Canmore 64 kms". Really?
For those that don't know Canmore is a small mountain town, a good neighbour to Banff National Park; like 30 minutes away to Banff. Canmore is incredible because it's situated right in the heart of the mountains and there is a real local-relaxed feeling. And the small businesses are happy to serve you. Need gas? Canmore has it. Need food? Many choices. Canmore would be a dream place to stay & in many ways is better & more accessible than the town of Banff. Don't let the stories of cougar attacks & bear attacks dissuade you.
So we hang a right without much hesitation. Surprised to see that it was all gravel road.
Adventure is front of mind. There are no dividing lines on the gravel obviously but traffic passes one another.
Wilson doesn't like breathing the dust behind the SUV's... so when polite to do so, he passes one, then another and so on. The speed limit seems really quite low and the ability to get on the stupid pedal seems easy enough. The road had some bald patches where the is smooth dirt tracks form from heavy truck tires pushing the gravel off to the side. I speed up a bit. And a bit more. This is fun! A popular turbo powered all wheel drive Japanese car is going below the speed limit and I thought it was strange that I passed him when safe to do so.
The thing about driving is, it's 100% attention. But even then I can screw things up.
Why did you want to advance the cam seven degrees?
cam advance really wakes the car up, a lot...dont know at what point the returns start to diminish though, but i intend to find out slowly..
Originally Posted by H.F.B.
At first you shaved the head and then want to use a thicker head gasket?
this one didn't make sense to me either though lol.
Originally Posted by Pizpot
I usually look at adjustable cam gears as being useful for helping to dial in clearances on a fresh engine rebuild where some deck height is lost rather than being a tool to dial in arbitrary amounts of advance at whim.
definitely a good idea to know where you're starting at clearance-wise before messing with advance/retard.
but the engine can safely run with the belt a full tooth off in either direction (9 degrees) so even with a mild shave 4 or so degrees of advance shouldn't hurt anything.
ive been running my car with 2* advance for a little while now and it runs harder than ever...going to try 4* soon.
I'd be all over them headers bro... if I didn't already spend $1000 on some already. Those you have look good.
To clear things up: The idea of shaving the head was to go for my ideal: a shave & standard gasket. The proposal for the thick gasket after the shave the merely to consider all options. In the end I consider myself very lucky (because I got what I wanted: big cam, head shave & standard gasket).
"Lucky".... yeah right. $1600 cdn for head work / head parts. And 30 hours of labour to get the combination just right and repair completed.
07-17-2015, 11:44 PM
