Turbo vs NOS

Thanks (or no thanks) to the Fast and Furious trilogy, now everyone is all crazy about turbo and nitrous oxide. Driving a turbocharged Toyota Vios myself, I often wondered what would it be like if I did not charged the car instead and went down the route of installing a NOS kit.

Well, I was fortunate enough to be able to gather and compile a huge library of dyno charts of various Toyota Vios that are either turbocharged or has a NOS kit installed. Hence, I would like to provide a compilation of those dyno charts to be shared here and a overall dissect as well.

Vios with turbo kit
Let's take a look at the various dyno runs of Toyota Vios with a turbo kit installed. All cars are running stock automatic transmission and the boost setting is set between 0.5 bar to 0.6 bar.

Dyno runs of various Vios equipped with turbo kits

The chart above shows nine dyno runs from different Vios, the average horsepower produced is between 130 PS - 140 PS and the average torque produced is between 17 kg-m to 18 kg-m.

Vios with NOS kit
Now, let's take a look at the various dyno runs of Toyota Vios with NOS kit installed. Identical to the setup of the Vios turbo, all cars are running stock automatic transmission and utilizing the same nozzle size as well.

Dyno runs of various Vios equipped with NOS kit

The chart above shows eleven dyno runs from different Vios, the average horsepower produced is between 110+ PS - 120+ PS and the average torque produced is between 16 kg-m to 17 kg-m.

Let's focus on the torque here instead of just horsepower alone, after all torque is all that matters when we are in for some spirited driving on the streets.

Let's first look at the dyno chart of the Vios equipped with turbo kits, most cars starts building boost from 2,500 RPM and some reached max boost before 3,000 RPM and some at a later stage of 3,500 RPM. This has a lot to do with the choices of turbo used and coupled together with other various reasons like bearings, A/R ratio, turbine housings etc. Most of them reached the peak torque of 17 kg-m to 18 kg-m around the 4,300 RPM range

Looking at the NOS dyno chart, the triggering of the NOS is at around 3,500 RPM and the torque readings surged all the way up reaching 17 kg-m at the 4,200 RPM range. For safety reasons most tuners will advise the spraying point of the NOS to be at a minimum level of 3,500 RPM and above.

Although the peak horsepower produced by the NOS kits is significantly lower compared to the turbocharged Vios, both cars achieved almost the same figures around the same RPM range. In order for the NOS equipped Vios to maintain power throughout the range, the spraying of NOS was maintained until RPM cut off.

Let's take a look at a dyno run between a Vios turbo and Vios equipped with a NOS kit.

Red: Vios turbo, Blue: Vios NOS

As you can see the figures for both the cars crossed path at around 4,000 RPM, and anything after that is history for the NOS.

Having said so, I'm not saying the NOS is bad nor I am against it. In reality, the NOS kit actually has the best bang for your dollars in terms of power gains as a typical standard NOS kit costs around RM 3,000 - RM 3,500 and it gives you the power close to a turbo car.

The only catch is that nitrous oxide refills don't come cheap, once you run out of laughing gas a typical refill will probably cost you between RM 180 - RM 200 depending on your refilling location.

So the choice is yours, if you're looking for some occasionally spirited driving without the hassle of bolting on a turbo kit and running all sorts of piping across the engine bay then the NOS kit is for you. It's clean, simple and straight forward and it gives you the power you need by a simple flick of switch or a press of a button. Just remember that the catch is that you will have to refill once you run out of laughing gas.

And if you're a more spirited driver like myself and you require constant power most of the time, then the turbo kit is for you. Think of it as you have unlimited supply of nitrous oxide in your car, of course the price to pay for it will be much higher compared to a NOS kit.

End of the day, the same principle applies regardless which route you're taking. Being reasonable and having a balanced tune is key to reliability of your engine and drivability of your car. Going blindly and solely just for the horsepower figures alone is shallow, you don't want to be a dyno whore.

There goes a saying which I can't agree more:

Cheap and reliable won't be fast.
Fast and reliable won't be cheap.
Fast and cheap won't be reliable.

Boost Spike

Yikes! It finally happened as I expected, I'm getting boost spikes.

Although its not happening in a big way since I'm only boosting 0.6 bar but its better for me to keep a closer eye for the time being. It only happens whenever there is a sudden kick down on the accelerator.

Well, at least I'm happy to report that the turbo builds up boost real fast.

Toyota Vios Turbo

(Update 26/06): The car made 153.01 PS & 19.45 kg-m, click here for more information.

After months of agony and pain of fine tuning with the tuner, the Toyota Vios turbo project is now finally complete. The previous work in progress pictures can be found here.

While the car was on the dyno machine awaiting tuning, coincidentally JUN Auto's President Junichi Tanaka and Chief Engineer Keiichi Hatanaka popped in as they were in town, and they started snapping pictures of the car.

According to JUN, they are currently embarking on a R&D effort to produce aftermarket parts for the 1NZ-FE engine such as camshafts, forged rods and pistons. If this is really true, then this is really good news for all 1NZ-FE owners out there. With proper researched and developed aftermarket parts, we will have a lot more things to play with.

Taking in to consideration the reliability for everyday driving, the engine compression has been lowered to a 9.5:1 ratio and I only went as far as 0.6 bar of boost. The stock injectors were already maxed out at 0.4 bar anyway so additional injectors were fitted to cope with the extra boost.

While a MAP sensor was added for a more accurate tune, the MAF sensor was retained and the voltage is clamped so the stock ECU would not throw a check engine code.

GT Auto tuned the car very conservatively considering the internals are stock standard and this small little 1NZ-FE now produces a usable 143 PS together with 180 N-m of torque at the wheels. Dyno chart indicates the turbo starts building boost around 2,300 rpm and full boost is achieved around 2,850 rpm.

If we do a backward calculation of 20% power loss at the transmission, the engine should be producing around 180 PS and 225 N-m of torque on the crank.

This setup should be just nice for city driving and some occasional sprinting with the car's weight kept at around 980kg.

My only concern now is the auto transmission gearbox, I am not sure how long can the gearbox cope with the additional horsepower before it starts to slip and give way. Oh well, when it does I guess it is probably time to swap it with a manual transmission then.

Modification Details

Stage 1 Turbo Kit

Lowered compression to 9.5:1 ratio
Garrett GT20 turbo with water cooled housing
Evo III intercooler
Turbosmart Ultra-Gate38 external wastegate
GT Auto Boost Controller
Greddy 3 bar MAP sensor
K&N air filter
Toyota metal head gasket
Addtional fuel injectors
Customized turbo manifold
Customized aluminium CAI piping
Customized aluminium intercooler pipings
Ceramic coating on manifold, turbo housing and down pipe
HKS Super SQV blow off valve
NGK Iridium IX spark plugs
ASR oil cooler adaptor with thermostat
ASR engine oil cooler
ASR ATF cooler
SARD MAG+ magnetic oil drain nut
TRD sport thermostat
DEI Radiator Relief
Thermotec thermal mat
All round Samco hoses
All round steel braided hoses
Customized oil catch tank
Customized 2.25' exhaust pipings
Customized dual exhaust mufflers with quad titanium tail pipes
Motul 300V Power 5W40 engine oil

4-Speed Automatic with Super ECT
Motul ATF 1A

VTTR Racing 6 pot aluminium brake calipers
VTTR Racing 330mm 2-piece slotted disc rotors
ProRS steel braided brake hose
Motul DOT 5.1 Brake Fluid

Hot Bits DT1 adjustable coilovers with canisters
17' Rays Engineering Gram Lights T57-RC wheels
Goodyear Eagle F1 GS-D3 205/45/17 tires
Ultra Racing front strut bar
Ultra Racing front lower bar
Ultra Racing middle lower bar
Ultra Racing rear strut bar
Ultra Racing rear lower bar
Ultra Racing rear anti-roll bar
Ultra Racing rear torsion bar

Greddy E-Manage Blue (Mutiara Motor Edition)
Innovate Motorsports LC-1 wideband controller
Innovate Motorsports XD-16 air/fuel ratio gauge
Blitz Dual Turbo Timer DCIV
Greddy Informeter Touch
Pivot Super Temperature Controller
Sun Auto Inazma Hyper VS
Sun Auto system up grounding kit

Performance (Wheel)
143.23 PS @ 6,000 rpm
181.55 N-m @ 4,200 rpm
Boost 0.6 bar

Fully tuned by GT Auto, tuner of Malaysia's fastest drag car.
Also mentioned on Turbosmart's website here.