Avoid these mistakes when modding your 997 Turbo Porsche! (1000hp and more)

After the release of our YouTube video “I blew up my Porsche! (We found the Weak Links on the Path to 1000whp and beyond)“, we received numerous requests for a 997.1 Turbo-specific version. The previous video was more focused on the 996T, so many viewers wanted to see a similar video for the 997.1 Turbo. The 997.1 Turbo is a great car that can be easily modified to make even more power. In this video, we will show you the many barriers or weak links you’ll run into on your 997.1 Turbo and how to improve and  strengthen them so that you can continue up your path to more power with the reliability you’ve come to respect in your car.

We’ve had plenty of failures for sure!  That’s what happens when you push the envelope!  Luckily, we’ve learned along the way how to avoid this and are making this video to share with you what we’ve found to help you save time and money so you can enjoy your passion with reliability built in from the start!

If you’re enjoying these videos, be sure to like, comment and definitely subscribe so you won’t miss any future videos.   Let us know in the comments what you think about this topic and if there are any additional barriers you may have encountered in your own build up.  

I’m sure you’ve already taken care of the basic maintenance issues such as spun cam sleeves and coolant bungs, so let’s jump right in and get started with some mods!

1. Tuning!    When you start your upgrade path, tuning a Turbo is the biggest bang for the buck you’ll see.  Not like GT3’s and Carrera’s that struggle for a few horsepower here and there, a turbo has a huge advantage in tuning, namely BOOST!  With a simple tune you can quickly find 60 to 80 horsepower and 100 to 150 foot pounds of torque!   That’s massive for doing nothing else!    Here are some things you’ll want to watch out for along the tuning path.
   1. This engine tends to be quite knock sensitive.  Much more so than the 996 Turbo even though Porsche lowered the compression ratio from 9.4 to 9.0 to 1.  California cars and other areas with low octane fuel will be on the lower end of the spectrum for power gains here.  While those with 93 octane (US) or even better European 98 or Shell super 100 can have a lot more fun!  Be careful you choose your tuner wisely and always log the car post tune to check the boost, timing and fueling.  Don’t trust that an off the shelf or generic tune has been thoroughly tested on all fuels and conditions.  Your tuner may have an awesome tune that was created on Shell super 100 over in the UK that may just melt your engine down in California!  Let us help you there and build an amazing tune for your car, your fuel and your local conditions while also verifying you have no misfires, bank to bank imbalances, error codes or other issues that may arise or may have always been there and you didn’t know about it!.
   2. Bricks!   While bricks are great for building homes, they’re not so good when your ecu becomes one!   Even though flashing ecus can be nearly 100% reliable, it’s not 100% reliable.  Your battery could die during flashing, your dog could pull the cable out of your laptop, you could kick the cable out of the obd2 port or have a freak lightning storm.  The 997.1 turbo ecu can generally recover a flash where the 996 turbo won’t, but that’s also not 100%.  So don’t put yourself in a situation where you’re flashing the car on the side of the road out in the middle of some desert and brick your ecu!   Always flash in a safe place, just in case…   
2. Exhaust…   The next barrier you’ll run into is the exhaust.   The stock exhaust performs well and is very quiet.  Maybe too quiet!   A lot of people like to upgrade the exhaust just to make their car sound like a performance car and not wind whistling through the trees.   Besides the sound, the exhaust becomes restrictive very quickly when upgrading the power since more power means more airflow and heat which ends up exponentially increasing the exhaust flow demand.  This is compounded again since the 997.1 turbo utilizes VGT turbochargers with Exhaust temperature sensors mounted in the inlet turbine flange.  These are there to protect the VGT vanes from going into thermonuclear meltdown.   With a performance tune and stock exhaust the temps will get to a point where the ecu senses the exhaust temps are too high and will lower the boost, dump in a bunch of fuel or back the throttle plate off.  Any of which will reduce the temps back to a safe point and your tune is now producing less power than a stock car due to the exhaust backpressure and temps.  There’s a ton of exhausts out there to choose from but of course we’re fond of our own for these cars 🙂   They sound amazing, have no drone and will stick with you along the way to huge power gains!   They’ll also lower the egts, keeping the ecu out of the protection zone and lower the backpressure to improve boost response and power.
3. Spark plugs…  Yes, something as simple as a spark plug can quickly become a problem when tuning your car.  As the torque increases the combustion pressure rises making it harder and harder for the plug to fire.   You can fool it for a while with an overly rich condition that makes it easier to fire the plug, but there will come a point when they will start misfiring.  And that’s typically right across peak torque which is a pretty broad range in a 997 Turbo anywhere from low 3000 to 5500 rpms.  So if you’re feeling a loss of power in the midrange and it’s not ignition retard from low octane fuel, it may be misfire from your spark plugs.  A fresh set of plugs gapped down to 23 to 25 thousandths should get you feeling good in the midrange again.
4. A lot of hot air!  Now that you’re running more boost, the turbos are producing hotter air simply from doing work on the air when compressing it.  It’s a pretty straightforward calculation to know what the outlet temps should be knowing your inlet air temp, compressor pressure ratio and compressor efficiency.  There are many ways to counter this problem:
   1. Intercoolers…   Intercoolers lower the intake air temps dramatically!   The stock intercoolers are pretty good on a stock car, but even Porsche knew they could be better.  The 997.2 turbo intercooler has a much larger core and revised inlet and outlet tanks for improved flow and cooling, but the end tanks tend to leak since they’re a plastic tank crimped to the core.  Protomotive intercoolers are nearly double again the size of the dot 2 turbo intercoolers which are already 25 to 30% larger than dot 1s.   But bigger is better can only go so far since intercoolers efficiency is directly proportional to the airflow through them.   Front engined cars have a huge advantage in this area, and semi-trucks even more!  Check out the intercooler in one of those babies if you ever get a chance.  They’re the entire front grill area of the truck!  But that’s totally necessary since diesels tend to always be in boost and also run much higher boost levels than gasoline engines.  Well, most gasoline engines, lol…  So, while better intercooling is a huge benefit to inlet air temps, exhaust temps, oil temps and mostly engine power through increased air density, too thick of an intercooler won’t allow the ambient airflow through it and they just become a brick.  They’re awesome when they’re cold since they are slow to heat up, but also slow to cool back down!   We’ve developed our cores with a large ambient airflow channel to vastly improve the efficiency of the cores and optimize the thickness for the available area having the net effect of high flow combined with great efficiency.   All of this combined makes for a cooler running engine with much higher power capacity.
   2. Air intake system…  From the air filter down to the turbo can have a significant effect on the air temps.  You may be thinking it’s just about airflow, but with turbos and compressors you need to consider the compressor pressure ratio like we just spoke about.  Using the formula above, you can see that higher boost makes higher temps.  But consider running the same boost with a more restrictive intake system.  A restrictive intake system lowers the pressure creating a vacuum in front of the compressor..   This has the effect of increasing the pressure ratio across the compressor just like running more boost!   So if you’re running 1 bar of boost unrestricted that’d be a 2 to 1 pressure ratio.  But with a restricted intake, in theory, pulling the ambient pressure down to -0.5 bar you’ll now be running a 4 to 1 pressure ratio and your inlet air temps will skyrocket due to the compressor having to compress the air 4 times vs. only 2!  We tackle this with our super low restriction fenderwell intake systems that we’ve run up into the 1500s wheel horse power range.   So you can be sure that it flows plenty well when you’re still down in the sub 600s.
   3. Meth injection kits…   If you’ve improved your air intake system and intercoolers but maybe live in a high desert area where you just can’t get any cooler, a meth injection kit is a great addition.  It not only cools the intake air but also raises the octane of the mixture to near race fuel levels.  On a properly installed and tuned setup you’ll actually see your intake air temps go down when on boost!  Now that’s impressive cooling!  We’ll commonly see 15 deg C below ambient temps in the one to two bar range.  There’s a lot of controversy about meth injection kits and a lot of shops uncomfortable with installing them.  But I really feel that’s more due to a lack of understanding of what’s going on there.  You are literally installing a secondary fuel system in the car!   I mean, no one would take it lightly replacing their fuel tank, fuel pump, fuel lines or injectors?  So why are people so complacent about meth kits and will just throw them in quickly to get down the road.  This I feel is more where the issues come in vs. a very nicely installed system, tuned properly can be a great addition to your car.  With meth your car can feel just as good during the hot summer months as it did during the winter.  And raise the factor of safety up a massive amount on cars limited to lower octane pump fuels….
   4. Turbo compressors…  When you’re pushing your turbos hard enough you’ll start falling off the efficiency island and start making a lot of hot air vs. more mass flow for your hungry engine.  You may keep raising the boost thinking more boost equals more power, but more boost with lower compressor efficiency and higher outlet temps can end up being lower mass resulting in less power.  The higher outlet temps not only reduce the density but also the tendency to knock which is already a problem on this engine.  You can upgrade your turbos compressors to help this.  The stock turbos have about 28lb compressors on them so 560hp at the crank is about all you’ll see from them.  With a nice set of compressor upgrades you can push the car with the previously mentioned mods up into the 700-710whp range or about 780 crank hp.  Running too large of a compressor will start having an adverse effect though since the turbine wheel is very small on the 997.1 turbo.  To go beyond this point we highly recommend swapping out to Garretts, Efrs, Xonas or just about any turbo family with a larger turbine wheel and more turbine flow.  All of a sudden you’ll be making very nice power without so much boost as the VGTs.
5. Clutch…  Even a good tune can go through a clutch when you have a turbo car.  While a brand new clutch disc and pressure plate will hold a nice tune, a high mileage one will probably start to slip on you.  A basic pressure plate and clutch disc upgrade is nice here if you would like to retain the oem dual mass.  FYI the sachs 764 pressure plate works with the dual mass while the 487 gt3 rs does not.  For those wanting quicker shifts and better acceleration the Euro RS lightweight flywheel is a great choice.  Even better because as you get further down this path you’ll be able to re-use all the parts for our dual upgrade and double the clutch holding power while having factory drivability!   The oem clutch can hold about 600 ftlbs.  A Sachs 764 upgrade is rated around 900nm or 675ftlbs.  The 487 bumps that up another 10% to about 750ftlbs.  All well above the capability of the stock internals.
6. Connecting Rods…   Now that you have all the mods above you’re getting into the zone where you need to be worried about your connecting rods.  These share the same rods as the 993, 993 Turbo and 996 Turbo.  They’re super lightweight and reliable at factory power levels.  But once you start pushing over 600+ ftlbs of torque the rods will just say NO….  So, let’s throw a nice set of Proto rods in so you don’t need to worry about them any more 
7. Head Studs…  Right about the same 600+ ftlbs of torque the head studs become an issue.  You’d think that blowing a head gasket out would be a head gasket issue, but that’s just the symptom, not the true problem.   The oem head studs are 10mm all thread rods with 170,000 ksi tensile.  They’re really nice pieces for a stock engine, but for big upgrades they become an issue pretty quickly.  Replacing the head studs with aftermarket 10mm drop in can get you pretty far since the aftermarket studs have 190,000 ksi to 210,000 ksi tensile strength and a larger cross section between the threads.  But don’t be fooled into believing the 1000hp on these studs or you’ll just be paying to pull your engine down again.  Yes, you can hit 1000hp with boost ramps and creating tuning.  Or get there quickly by just cranking it up, but your head gaskets won’t last long and you’ll be revisiting this before you’d like to!  So, while you’re there, go the extra mile and throw in a set of our 12mm inconel 625 head studs and be done with it.  Yes you’ll need to machine the case for the larger thread, clearance the liner carriers and cylinder head holes, but you’ll be doing it once and not coming back….  Our 7/16” head stud kit eliminates the need for liner carrier and head clearancing plus oem base and head gaskets fit over them, so it’s a nice way to go as well.  But the 7/16” head stud kit has a 70 to 75ftlbs torque limit vs. the 12mm inconel are torqued to 80-85 ftlbs and some shops push them to 100!   Be careful up there as the heads can either warp or crack if everything isn’t just so at the 100 ftlb range.
8. Fuel…  Wow, it took a while to get here!  On a 996 turbo you’re doing injectors and pumps around 560 to 600hp.  A 997.1 Turbo comes with 60lb injectors and nearly 1000hp worth of pump when running pump fuel not e85.   The 60lb injectors are good for low 700s, while on e85, you’ll barely hit 500!.  At this level we’d like some 1100cc bosch injectors for their precise fit, linearity of flow for nice tuning, compatibility with many fuels and the connectors don’t require goofy adapters that are prone to failure.  A set of 1100s are good for over 1000hp on pump fuels and low 700’s on E85.  When I say pump fuels I mean gasoline based fuels with a stoichiometry point of 14.7 vs E85 being down in the 9.7 range.  I’m not saying pump fuel to run to the gas station and expect 1000hp out of 91 octane.  Pump fuel can refer to ms109, Sunoco GT104+, Ignite racing fuel, C12, C16, and many more.  Any of these are basic gasoline fuels with a variety of additive packages for different applications.  Beyond the 1100s we like the Bosch 1650cc for flex fuel setups in the high 1200whp range on E85 and Bosch 2150 or 2200s for up and over 1500whp range. Of course this takes more fuel pump and chassis lines to move that much volume. Our triple in tank pump setup with upgraded chassis lines works amazing here. 
9. Airflow and volumetric efficiency…While we may have been able to reach 1000whp with a basic strengthening build, let’s do it better.   Improving the airflow path can lead to higher volumetric efficiency which will let us build an engine that’s not working so hard to be here.  Yes, turbos are the great equalizer and can push a ton of air through just about anything, but we love the adage of less boost more power!  A Ypipe, throttle body and plenum are great for basic upgrades giving you improved throttle response and maybe 15 to 20hp.  Where portwork and upgraded cams can net another 50 to 75hp.   Add a Gt3 intake manifold to this whole combination and we’re talking more 100 to 150hp gains all without raising the boost.  So for the same 1000whp power level we can actually reduce the boost, gain better power under the curve, improve response and lower temps.  This all leads to improved reliability at the same power level.
10. Valve train… With more airflow, we’re usually talking more rpm’s as well.  When upgrading your camshafts, you’ll also want to install a set of high rate valve springs to keep everything under control.  Higher lift and duration camshafts increase the acceleration and deceleration rate of the valves and lifters.  To keep the valves from floating and whacking your pistons, these stiffer springs will keep the valves and lifters in contact with your camshaft and not your pistons!   The 996 and 997.1 turbo share the variable lift intake lifters which are massive in size and weight when compared to gt3 lifters that are designed to rev much higher.  So, even with stiff springs, 73 to 7400 rpms is about all we like to rev these engines to with oem lifters.  An occasional 7600 seems to be ok, but too much of that and the lifters fall apart.  We’ve pulled apart engines running 7600-7800 rpms for a few years and couldn’t believe the lifters were in pieces when removed yet still running…   Vs. going full gt3, a neat trick is replacing the variable lift intake lifter with a flat tappet lifter that’s nearly ½ the weight.  Then regrinding the intake cam for a single lobe vs. multiple.  This also requires some tricky tuning in the ecu to remove the variable lift.  But with this combo, 8000 rpm is possible.
11. Displacement…  Like airflow and ve, displacement can improve the power capacity so much you’ll be able to reduce the boost again to maintain that 1000whp level.  By now, with all the mods we’re talking about and 4.1 or 4.2L we can reach this power at a mere 1.3 to 1.4 bar!  So rather than taking 2 to 2.2 bar on a basic build, 1.8 bar on a 3.8 basic build, or maybe 1.6 on a ported and cammed 3.8 we’re all the way down to 1.3 to 1.4 bar for the same power level.   And running these engines at stock boost levels, when built this way, can produce twice the original power level!.  Yes, I drive a 1000+whp 996T and am building a similar engine for my 2010 997 turbo.   And thoroughly enjoy being able to drive it around and track it at 0.8 bar while making 800whp at that boost. 
12. With the 996 and 997.1 Turbo engines being so similar, our video “I blew up my Porsche! (We found the Weak Links on the Path to 1000whp and beyond)” covered many scenarios beyond this point taking you all the way to 1850whp levels.  Make sure to check that one out if you haven’t seen it yet for some amazing engine builds!

While there’s so much more we could go into, we’ll need to save that for a future video and get back to work building amazing engines for you.

Thanks so much for watching!   If you’re enjoying these videos, be sure to share with all your car friends who I’m sure will like, comment and subscribe!

Let’s all have a great time building our dreams!