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Dr. Dean

Dean finally got his Z tuned this week.  We’ve been so busy over here at SZ that we didn’t have a chance the last several months to get his monster the proper attention required.    His mod list can be seen here:  Dean’s Mod List

He plans to make the upcoming June 12th IDRC event, competing in the True Street Class.  The dyno graph below shows his race fuel tune on boost and also on nitrous.  One can see how well the nitrous works, it is only used to get out of the gate and shuts off at 5500 RPMs.  This should be enough to get him into the 9s.  Now go kick some ass!

No, that’s not Dean with the pot belly.

The Lone Star Z

Where do we begin this story?  Well its a long one and there’s no need for specifics.  We can say it has a happy ending.  I hope that didn’t spoil it for ya ;).  Dave brought us his red gem child from the big state of Texas for some fixin’ after the wrench hit the spokes in his prior builds.  Along the way to Z nirvana, this Z received some funky fresh mods.  It arrived at our door with a freshly built engine, larger CZP 2560R turbos aka “GT28Rs”, MSP Manifolds, SZ 3″ Down Pipes, Nismo “old skool” 555cc Injectors, JWT 400 cams, JWT Dual POP, etc… (the important mods).  We performed various seances to rid the evil spirits and added SZ 3″ to 2.5″ test pipes and SZ 2.5″ dual tip catback.  It had that nasty ole’ Borla catback and 2.5″ test pipes (good riddance).  Added some CZP silver I\C piping, Ash Massives, and Z1 T.B.s to round out the “charge” side.

The Z was dynoed back in Texas before we got our hands on it shortly after its latest build.  Depressed with the paltry results of 365 whp, its owner decided for drastic measures.

Loaded with some Texas 93 octane we kicked off the dyno tuning fun.  I forgot what “real” fuel smelled like from other non-smog Nazi states.  Hell would freeze over if California got 93 octane one day.  Its amazing how 2 octane points help.  Luckily we have quite a few local gas stations that offer 100 octane at the pump.

A little cleaner.

Just another day at the spa.

Here’s how the Z performed on 93 octane & Q16:

510 whp & 465 torque on Texan 93 octane and 587 whp & 545 torque on Q16.

In a week or two this Z will be on a trailer to go back to her owner.  Enjoy the ride!

Piston Selection (alloys)

This isn’t an end all on which piston is the best or a detailed discussion into piston design.  This is just something to be aware of when selecting pistons.  A big misconception on “built” engines or more precisely speaking piston selection can be misinterpreted.  A forged piston is by far stronger than a factory cast pistons but there’s more to it than just that.  What do you realistically plan to do with your engine? Will you be daily driving the car?  Can you put up with a noisier engine?  Carefully think about what you plan to do.  If your planning on competitively racing, run very high boost pressures and\or nitrous and can deal with servicing your engine more frequently;  than a 2618 forging would be up your alley.  Most factory aluminum pistons are eutectic and hypereutectic.  What’s important to know about this is that these pistons have a higher silicon content which allows the piston to have tighter clearances for a quiet, long lasting engine.  The amount of silicon is directly proportional to how ductile the piston is.  Meaning just how “hard” or “soft” the alloy is.  Pistons that have high silicon are technically strong since their alloy has a tighter bond at the molecular level, BUT they’re also much more brittle and don’t stand up to detonation as well as a forged piston with less silicon content.  Your piston also isn’t the only part of your engine that’s taking abuse from detonation.  More on that some other time.

Something in between a 2618 and a factory piston alloy would be the 4032 alloy.  These have more silicon content than a 2618 alloy but no where near as high as a factory piston.  The clearances on these engines can be tighter than a 2618 for less noise and wear than a 2618 alloy.  A majority of the wear seen on a forged engine is when the engine is warming up.  You may have heard of the term “piston slap”.  This is the term used for a piston rocking around in the bore until it gets up to operating temperature and expands.  This rocking causes wear on the rings and of course on the pistons themselves.  Clearances on a 2618 and 4032 alloys need to  be “looser” to accommodate the piston when it expands as it gets hot.  This would be when it finally warms up, sees boost, etc….  Its best to allow a forged slugged engine to warm up until piston slap can no longer be heard before driving.  The popular Wiseco pistons use a 4032 alloy for best of both worlds.  It still won’t last as long as a factory piston but it is stronger and won’t wear out as fast as a 2618 alloy.

Typically, Japanese engines have very tight tolerances from the factory to have a “sewing machine” like operation.  Nice, quiet, and reliable (long lasting).  Hopefully this has helped some of you make an educated decision when selecting your next piston forging, instead of simply choosing the strongest “best” piston.  The term best has a relative meaning.  What’s “best” for your application?

Back to Z

The last 6+ months have been hectic for me to say the least.  Health issues, work, and personal matters take priority when it comes to the Z.  My Z32 was down for over a year (Oct 08) and I was anxious to get it back on the road before my surgery.  I was worried that if I didn’t get to it before then (Dec 09) I may never have a chance to work on it again if something happened in surgery.  I was told I could have been paralyzed and\or worse.   My current Z32 didn’t and doesn’t have anything wild as some may think.  I wanted something tame on the street but with enough gitty up and go to get the job done.  In a time and financial crunch I got it back together with the help of some friends and my fiancee.  Knowing it was running before I went in for surgery was a big load off my back.  I could peacefully rest knowing it was running and safe in my own garage at home.  This past weekend I did some data-logging for a prototype part and since it was strapped down decided to tune it for 91 octane.  This was also a good baseline for when I upgrade to larger intercoolers & piping.

I didn’t upgrade much this last time the VG30DETT was out, but just enough for some small power upgrades and great reliability.  It currently has:

  • Stock Block\Ported Heads
  • Custom regrind camshafts
  • JWT Sport 500s
  • MS Manifolds
  • SZ Turbo Inlet Piping (replaces accordion hose)
  • Old School Nismo 555cc Injectors
  • SZ Built Automagic Stage Race w\ triple plate converter & SZ Flex Plate (I like the auto)
  • BDE Engine Mounts (In case the bigger turbo bug gets me)
  • Full SZ 3″ SS Exhaust (Turbos-all the way back)
  • Z1 Larger TBs (For when the time came for larger piping & I\Cs)
  • Stock Stillen Intercoolers\ Stock Piping
  • Electric Fans
  • UD Pulley & HI OD Pulley
  • SZ Oil Pan

Pretty basic nothing crazy.  I was curious to see how much power it would make with the auto since it robs a little more power especially when turning up the pump pressure.  This car, when it was first put together in 2002 with the same turbos made an impressive 487 whp on race fuel back then.  When I bought it from my customer a few years ago it was “well abused”  and worn.  I dynoed it when I bought it shortly thereafter with race fuel and it only made 430 whp.  I beat on it while road racing and that was the end of it temporarily (stock oiling system sucks).  Fast forward to today and we have a happier Z back on the road.  Road racing is designated to another vehicle in the fleet.  This baby will live its life as a weekend cruiser and occasional drag strip runner.  Hoping to beat my best 11.3 ET (done on lower power) now with funky fresh powerful mods.

and the results were…………

414 whp and 411 torque.  I was certainly happy with the results having only run it on 91 octane.  The first run was before and the last run 7 was its final tune.  This will give me\us good info when only adding larger I\C piping and intercoolers.  Stay tuned for more on my project Z32.

Sport 530 Terr(y)or!

We had the pleasure to work on Terry’s beautiful Z32 TT. He shipped it out to us from Florida for a little mechanical makeover. He brought it to us to clean up some loose ends and add a few more details to the package he had.

His Z32 came to us with the following mods:

  • Built Engine
  • JWT 400 Cams
  • JWT Sport 530 Turbos
  • SZ Inconel Exhaust Manifolds
  • Nismo 555cc Injectors
  • JUN Solid Intake Cam Gears
  • SZ 2.5″ Down Pipes & Test Pipes
  • B&B 2.5″ Catback
  • Greddy Intercoolers
  • Lightweight Flywheel
  • JWT Dual POP w\ low speed kit

We didn’t do a “before” dyno pull because it wasn’t running great when we got it.  We sorted out all the demons in the end though.

SZ 3″ Exhaust Piping

We did the following performance mods along with a plethora of other misc things not listed:

  • SZ 3″ Down Pipes & Test Pipes (cone to 2.5″)
  • SZ & 300Degree 740cc Fuel System Upgrade
  • Ash Massive Intercoolers
  • Larger CZP I\C Piping
  • Z1 Throttle Bodies
  • BDE Intake Cam Gears
  • Selin MAF Translator & Elbow Kit
  • SZ Clock Switcher w\ 3 custom tunes

The Selin Kit is truly a great product(s) to work with.  Fitment is great and looks great.

One clean engine bay

Our clock switcher to make changing programs on the fly easy

Like I mentioned in the mod list we made 3 custom tunes for his application.  We tuned for 93 octane, 100 octane, and Q16 Race Fuel.  It’s been awhile since we’ve seen a 530 car do awesome since we discontinued our inconel manifolds.  Knowing Terry had a set on his Z, we were curious to see what it would put down on the dyno.

We were pleasantly surprised to see it make this much power, however with the tender loving care and mods we provided it made sense (480 whp & 471 torque).  We peaked at 17 psi at around 4200 RPMs with the boost dropping to about 15 psi in the upper end.  We tuned his Blitz EBC (electronic boost controller) for as steady boost as we could across the range.  The 2554R turbos don’t maintain peak boost in the upper RPM as well as larger turbos do.  Luckily Terry doesn’t have to use 91 octane in Florida.

Up next was 100 octane which can be found around SoCal in many gas stations at the pump.  At least we have some way to get around shitty CA-91 gas.  After dialing in timing and fueling we ended up with 514 whp and 522 torque.  We hit peak boost at 21.7 psi at the same RPM with boost tapering to around 17 psi up top.

For the last tune we ran on VP Q16 and peaked at 23 psi.  This is all the turbos could muster.  No fault of the turbos or W\G actuators.  You see, more boost does not always mean more power.  A turbo is rated to run in an efficient area of boost that relates to how much air an engine can process.  The less boost one can run and achieve the same or more power the better off you are.  I know this sounds elementary, but most people have a belief that more boost equals more power.  Take Terry’s VG30DETT for example.  For him to make 480 whp like he did on 93 octane he had larger exhaust, cams, inconel manifolds, larger intercoolers, piping, blah ,blah blah.  If he didn’t have let’s say our 3″ exhaust or larger intercoolers\piping, etc..  for him to make 480 whp it would have required him to make more boost (22-24 psi) AND run race fuel.  Why?  Because we’ve eliminated more restrictions in his system and  made his setup more efficient.  Hence his VG and 2554Rs don’t have to work as hard to make the power.  Make sense?  More restriction can equal to more pressure or (boost) which can lead to compressor over-speed or choke.  As well as extreme back pressure and engine damage.  Learn to know the limits, and if you don’t know, learn to ask someone who truly does.  Class is over.  Back to Terry…..we made 536 whp and 543 torque.  Congrats Terry and thanks for the pleasure of working on your Z!  You have one amazing 2554R powered Z32!