My Carrera 3.2

[Peter M]

I like 3.2's. I didn't plan to buy another one, it just sorta happened.  The fact that it wasn't perfect and needed a lot of work was part of its appeal as I didn't feel like it had to be bought back exactly to standard or to become just another "paint by numbers" 3.2 equipped with a Wong chip, a set of Turbo tie rods, Wevo shifter and Monty muffler that my '85 was.  Nothing wrong with this but I think the world has moved on to the point where modern aftermarket ecu's are a viable upgrade.  Anyway, enough yakky yak, let's talk what's happening at the moment:

Cold Start Tuning

The weather has been perfect lately to complete cold start tuning that my professional tuner was never going to experience due to his location. Consequently I've been adjusting the Engine Cranking Fuel Volume Compensation and the Engine Post Start Fuel Volume Compensation to have sufficient enrichment at low temperatures that the engine would fire and then idle for a sufficient time for the heads in particular to warm up enough so that continued enrichment is not required.

How's this done?

With a Motec, the Engine Cranking enrichment is a simple table of cylinder head temperature (coolant temp in normal applications) and engine revolutions (up to 6 cycles) in which the desired enrichment trim as a percentage is tabled.  With the Post Start enrichment, a similar table is constructed of head temperature and engine running time (in my case, 0, 5, 10, 30 and 60 second increments):

 

Being blessed with a snowy morning wasn't to be wasted today for cold start tuning:

I'm happy now with the cranking enrichment as the engine fires quite quickly but I need to increase the enrichment in post start table in the sub zero cells in the first 5 seconds of start up as it still currently barely runs at head temps of about 5 degrees or less for those first few moments .  I'll probably go up another 20% or so.  After being used to using a screw driver to adjust carburettors, using a laptop is something of a novelty for me!

However I am amazed at how creamy smooth and toey the engine is when stone cold and it takes a lot of self control to keep it under about 3 grand until the oil temperature comes up.  Not like an old Motronic setup at all. 

[targa george]

Finally!

I'm glad you're up and running Pete.  Looking forward to seeing it in the flesh sometime soon.

 

[SteveF]

Congrats Peter. Great to see if finally running again. I also look forward to catching up and checking it out.

[targa george]

Ummm.......Pete

Was the choice of background in your 'winter wonderland' shot above deliberate?

 

 

[Mike D'Silva]

Nice going.. My AEM system probably needs some tweaking.. when can you fly up to Brisbane?

[Peter M]

22 minutes ago, targa george said:

Ummm.......Pete

Was the choice of background in your 'winter wonderland' shot above deliberate?

It's a bit loud now and just wanted to test it wouldn't wake the dead......

[SteveF]

Or you brought it back from the dead 😎

It really does look fantastic.

[TINGY]

10 hours ago, Peter M said:

It's a bit loud now and just wanted to test it wouldn't wake the dead......

So while you are talking exhaust, are you sick of it yet? Is it loud around 100kmh?

[OZ930]

I thought I heard a 911.    🤣

[TwoHeadsTas]

11 hours ago, targa george said:

Ummm.......Pete

Was the choice of background in your 'winter wonderland' shot above deliberate?

 

 

I did wonder that too 🙂 

[Peter M]

12 hours ago, TINGY996 said:

So while you are talking exhaust, are you sick of it yet? Is it loud around 100kmh?

Nah, sounds great over 4 grand and no drone at all so all good.

Turning down the idle speed (ie changing some numbers in a table in the M1 tuning software) from 1100 to just under 900 has stopped it sounding like a angry rotary and that has soothed my nerves a bit.

Admit the rawness was a bit shock after driving my overstuffed pillow XJ6!

[Peter M]

Exhausts for Carrera 3.2's

You would think after selling 76,000 3.2's there would be a ready source of accurate information on what are the best exhausts to use on these cars?  Except for Steve Wong's infamous comparison table - http://forums.pelicanparts.com/4082599-post49.html - that he later declared as inaccurate, there was nothing definitive that I could find.  After reading a million posts and dyno charts, this is what I uncovered:

• Porsche increased the size of the exhaust primaries from the earlier 1 1/2 inch OD to 1 5/8 inch with the introduction of the 3.2's in 1984.
• SSI's having only 1 1/2 primaries aid torque below around 2,800rpm and moderate it above.  Cabin heat still works well
• The standard 3.2 headers actually perform very well and any sensible owner would just change the primary muffler/ catalytic converter to a straight through pipe and change the main muffler to one of the better brands like Monty, M&K etc. 
• Eisenmann do a 1 5/8 inch version of SSI's in two versions ( F model fits the generic style Porsche 2 in rear muffler or the G model that has a Eisenmann propriety catalyst and rear muffler) but are eye wateringly expensive and there has been a number of posts on Pelican about poor fitment and fabrication.

I originally intended to only change my pistons and cylinders to the higher Euro spec compression ratio and run SSI's and actually bought a set of both.  I do like the SSI look and sound.  However a run up the grade of the Oxley Highway one Saturday afternoon inspired a desire for more horsepower as I couldn't keep up with a stock 996 let alone a Gallardo so these items were sold off and a set of 3.4 pistons purchased. 

Since heat was important to me I purchased a set of BBE stainless 1 5/8 inch primary headers with hot boxes that I had modified to work with the standard 3.2 air distribution pipe to keep a neat look and to avoid the 10 miles of flexible hosing that always makes me think of the "Danger Will Robinson!" robot in Lost in Space.  I topped it off with a Dansk Motorsport 2 in/1 out muffler as I got it cheapish from Design911 but would have bought an M&K otherwise.

EDIT:  Some interesting comments on how good the standard 3.2 exhaust discussed here: 

http://forums.pelicanparts.com/porsche-911-technical-forum/1074815-88-3-6-conversion-planning-exhaust-advice-requested.html

 

  

[Stepo]

Looks like a lovely example, nice and clean underneath as well. No doubt you will be pampering her to suit your driving style, you obviously have the skills to do more than most of us.  Enjoy 😉 

[Peter M]

Haha, amazing what you find on the web, the drive that inspired my poverty. Not enough go and a recalcitrant 2nd gear syncro meant I just pulled over in the end.

 But caught up when the road flattened out.  Check out the eyes in the review mirror!

 

Actually that was a great weekend away:  

27 minutes ago, Stepo said:

Looks like a lovely example, nice and clean underneath as well. No doubt you will be pampering her to suit your driving style, you obviously have the skills to do more than most of us.  Enjoy 😉 

 

 

Thanks Peter for the kind words but I actually bought this car because it wasn't perfect and I didn't want to feel constrained.  Anyone can have a drive if they wish!  As for skills, not really I was fortunate to find a mechanic I trust and a tuner who knows his stuff.

 

Tour of New England National Parks.  Just have to slow down for the cattle grids!

[Stepo]

1 hour ago, Peter M said:

Thanks Peter for the kind words but I actually bought this car because it wasn't perfect and I didn't want to feel constrained.  Anyone can have a drive if they wish!  As for skills, not really I was fortunate to find a mechanic I trust and a tuner who knows his stuff.

Maybe not perfect compared to your last 3.2 but still a fine machine and a nice hobby to tinker with.

[TINGY]

11 hours ago, Peter M said:

 

Actually that was a great weekend away:  

 

Tour of New England National Parks.  Just have to slow down for the cattle grids!

As you may already know Pete the talk has kicked off for another Bendy weekender.

[Uncle]

I was following at a polite speed/distance  

I've been thinking about MP4-12C's quite a lot of late. 

[Peter M]

Engine Rebuild

So in 2018 the engine was rebuilt to the usual 3.4 recipe with the expectation of achieving around 225 Dynojet rwhp:

• ARP rod bolts to allow 7000rpm safely
• Mahle Motorsport 98mm pistons that were further fly cut for more valve clearance
• Existing cylinder were over bored 3mm and re Nikasil'ed
• Twin plugged heads
• 993SS cams
• Balanced
• Cam position sensor and 30-2 crank wheel installed ready for later use. 

The original engine was generally in excellent condition for it's 245,000km with only the valve guides and stems being worn and leading to moderate oil consumption.  The pistons and cylinders were still well in spec and the bottom end was good as gold too.  All the head studs were solid.  The cams and some followers however were mildly pitted but not unworkable.  I certainly had the option of just reconditioning the cylinder heads and just slapping it back together for another 100,000km but that would been far too sensible!  Consequently everything that needed replacement was done and there was no expense spared.  I am certainly thankful that my mechanic was happy for me to supply all the parts and I certainly scoured the world for the best prices.  Once these engines are apart, let's just say every thing comes in thousand dollar increments!

Of course I spent a good couple hours at the wire brush wheel preparing all the nuts, bolts, washers and other steel fittings for yellow zinc replating.  Not sure if that was as tedious as then having to cut each item off the copper wires when they came back from the platers.

My smart idea of sending the cylinders to New Zealand wasn't the cleverest and ended up having to send them back to be redone.  Then being caught up in their Customers resulted in what should have been a 2 week job being a 3 month delay.

As for the G50, it needed some new bearings and synchos as expected.  Probably the only surprise was the 5th gear set where the bearing surface of the main gear had brinelled.  The main surprise was the $2,500 cost of it's replacement!

 

[Mike D'Silva]

curious, why did the cylinders need to be re-done?

 

[Peter M]

4 minutes ago, Mike D'Silva said:

curious, why did the cylinders need to be re-done?

 

Mike,

They were returned out of spec for roundness. They came back the second time absolutely perfect. 

[OZ930]

40 minutes ago, Peter M said:

Engine Rebuild

So in 2018 the engine was rebuilt to the usual 3.4 recipe with the expectation of achieving around 225 Dynojet rwhp:

 

 

So, was 225 realised ?  Or was that the $ spent x 100 ?

[81SC]

1 hour ago, Peter M said:

Of course I spent a good couple hours at the wire brush wheel preparing all the nuts, bolts, washers and other steel fittings for yellow zinc replating.  Not sure if that was as tedious as then having to cut each item off the copper wires when they came back from the platers.

 

Hey Peter,

Can you share who you used for the yellow zinc plating & were you happy with the quality?

I need to have most of the fasteners & assorted brackets on my car redone for my restoration, so I'm looking for a recommendation.

[Peter M]

On 14/08/2019 at 18:42, OZ930 said:

So, was 225 realised ?  Or was that the $ spent x 100 ?

Brian,

The most accurate answer is I don't know!

In the States Dynojet dyno's are very popular because they are very consistent but they are a rarity here in Australia.  (However just about every motorcycle shop here has a Dynojet bike one!.  Go figure!)

Here, just about everyone has a Mainline dyno that isn't as flattering as a Dynojet and from what I can gather a Mainline reads between 15 to 19% less than a Dynojet.  So if that factor is applied and a few hp is given for the fact I'm still using the standard restrictive airbox, then "yes" mine is a pretty representative 3.4 engine build.

What is really usual about my build is how flat and linear the torque curve is.  This has astonished me and I was not expecting this engine to be less peaky than a standard 3.2 and certainly orders of magnitude less peaky than my 993.  So I certainly have the option of retarding the current cam timing if I want to chase higher peak hp figures for brag purposes or even going to much longer duration cams.  However the current set up makes for a quick car in the hills.  Let me spend a bit of time on the Oxley and the Ebor to Dorrigo Road and I'll get back to you!

$ per extra hp?  Wow, let's just say that equation is eye watering! 

On 14/08/2019 at 19:50, 81SC said:

Hey Peter,

Can you share who you used for the yellow zinc plating & were you happy with the quality?

I need to have most of the fasteners & assorted brackets on my car redone for my restoration, so I'm looking for a recommendation.

Brett,

I used Hamilton Chrome in Newcastle and was very happy with the results.  Cost a couple hundred dollars even though I prepared each item on a wire wheeled bench grinder and lost a bit a skin off the odd finger.

I think is worth the cost and effort just for the improved appearance.

[Peter M]

Twin Plug

I think there are even less excuses not to go twin plug than ever before.  The old days when you had to use a special distributor or adapt that gawd awful 964/993 distributor are now long gone.  With a modern aftermarket ecu able to run 12 plugs just as well as 6 by direct fire and the cost of a few more coils barely registering a blip compare to the money being spent on rebuilding these engines, I can't see how anyone can justify not going twin plug.  There is no point denying the combustion chamber design on these cars is anything but bottom of the class nowadays. 

For me one of the  other motivators that rarely gets mentioned was to replicate the creamy smooth feel of my old 993.  I also had a twin spark Ducati SS1000DS at the time and that was a lovely engine as well.

I think Steve Weiner summarised it neatly recently on Pelican:

….Twin-ignition has zero downsides (besides cost) and plenty of benefits that make it very worthwhile if one has the resources. More HP, more torque, reduced cylinder head temps, easier starting, and of course, reduced octane sensitivity. The latter may allow more timing depending on CR (remembering that twin-plug engines need 1/3 less total for complete combustion).

….Porsche used twin-ignition for more power with the fuel grades of the day, using higher CR going back to the 4-cam Carrera engines. Emissions wasn't a consideration. 3.6 litre engines NEED twin-ignition to safely run high CR's with pump gasolines.

Full version here: http://forums.pelicanparts.com/911-engine-rebuilding-forum/1033435-twin-plug-not.html

 

For my build I used the Nippon Denso coil on plugs (Denso 90919-02234) that are commonly used in Lexus and V6 Camry's that the turbo boys on Pelican swear by.  Others use the VW/Audi CoP's (Bosch 0986 221 024) successfully which are cheaper and if the dwell is kept less than 2ms, very reliable.  I also think the VW/Audi ones would be easier to mount as the height of the coil top is less and that I think would mean less bending and reshaping of the RSR plug holders to hold them in place.  Both these CoP's have built in ignitors and are readily available from eBay.

There is also an earlier suitable VAG CoP the Megasquirt guys use due to their higher impedance:

http://forums.pelicanparts.com/porsche-911-technical-forum/1066575-x-faktory-3-2-a.html#post10942504   

For my lower valve covers, I found I could buy a set of aluminium 964 overs cheaper than I could modify my stock ones.  Just had to enlarge the holes to fit the larger studs that the 3.2's use in comparison to the 964 ones.  Also allowed me to use the modern molded and reusable rubber cover seals.

 

[Peter M]

Oxley Highway today.

Magnificent.  Engine is just right how it is. Revy, responsive, smooth and fluid.  Could even be described as joyous. G50 is now a gem going up or down and the standard ratios seem better matched to the new engine too.