Category Archives: Tuning

What you need to know about turbo modifications!

The article outlines the proper methods for modifying your car, ensuring money is well-spent, and collaborating with skilled tuners and tuning shops.

Choosing the right modifications for your car should be entrusted to a skilled tuner who can offer technical support and visualisation maps to assess the impact of parts on your power requirements, particularly in scenarios you encounter over 75% of the time. The remaining 25% or less pertains to your desires, which dictate the available efficiency for an occasional spirited drive.

Reference car:
Altitude: 3740ft (1140m)

– EJ25
– Manley Pistons 99.75mm C.R 8.5
– Blouch 1.5xtr 10cm
– Process West Verticooler
– Grimmspeed Cold Air Intake
– Perrin Turbo Inlet Hose
– HKS Equal Length Headers
– Grimmspeed Uppipe
– No name Downpipe
– Greddy Supreme SP Cutback

Determining the final performance of a car cannot always be accurately done on a dyno. Cars tuned exclusively on a dyno often do not perform as well on the road due to different load conditions and untested areas of the engine map. Consequently, dyno-tuned cars may excel in straight-line acceleration at full throttle but may not handle as well in other real-world driving conditions. It’s common for owners to be surprised by the initial performance, especially when compared to another car of similar power that’s been fine-tuned on the road, outperforming their ride in all areas. Moreover, these cars can suffer from inconsistent fueling, exhibiting areas that are either too lean or too rich, with optimal performance only achieved at full throttle.

Sometimes, relying on forums, other people’s experiences and dyno charts can be misleading. This can result in installing parts that are not optimized for your altitude and other requirements, leading to a waste of time and money. The following information will demonstrate cases where individuals become their own (google) tuners or rely on tuners with little knowledge of tuning. Standard modifications in the community or forums are then added and dyno-tuned with overinflated numbers, leading to further complications in the future for those who seek advice or want to experience more power.

Below is data taken from a car highlighting the incorrect decisions made when all parties have limited technical capabilities, previewing the creation of a performance platform.

Wastegate-boost to high-boost
Midrange-boost to high-boost with no gains
3rd Gear Dyno road pull shows increasing intake temperatures into the engine, reducing power and ignition
1/4 mile drag pull shows rising intake temperatures into the engine

The data shown highlights the mapping is way off the charts of a turbo’s compressor map, thereby demonstrating the need for compressor maps and the technical knowledge to calibrate the car with respect to the modifications and performance goals. As one can see, increasing boost did not lead to increasing torque and horsepower

Understanding the above, the key attribute, especially in boosting a car or enhancing the boost system, the following is a good visualisation when mapping a car’s performance with respect to the turbo used in achieving the performance goals:

Mapping at 18psi – 4000-6400rpm
Mapping at 23psi – 4000-6400rpm, showing reducing compressor efficiency the higher you rev
Mapping at 23psi – 4000-6400rpm, showing a broad range of efficiency for continuing boosting at higher revs
Mapping at 28psi – 4000-6400rpm continues to show a broad range of efficiency for continuing boosting at higher revs

Please remember that higher engine revs lead to lower efficiency unless cams are installed. To achieve optimal performance, aim for an efficient zone in the compressor map that suits 75%+ of your driving style and usage.

700whp+ Subaru Club – 2011 USDM STI 2.5 6MT

IAG stg 4 extreme block
14mm headstuds
Fire ring headgaskets
Pinned mains.
Garrett GTX3582R Gen 2
Ported heads, valves
Springs and Bc 280 cams
Ams intake manifold
TGV deleted

Full turbo back 3inch
Perrin big tube equal length headers
External wastgate 44mm
Grimmspeed 3Port boost controller

Injector dynamics 1700x
Radium in tank dual pumper
Dual AEM 340s Fuel Pumps
Perrin fuel rails regulator
PTFE line throughout
Radium -8 feed and return lines
Radium FPR 48psi base pressure

4bar map sensor -OMNI
Gm IAT sensor

Videos –

Raptor Supercharged 6Gen 2015+ Subaru Legacy 3.6R CVT

The 6Gen 2015+ Subaru Legacy 3.6R #CVT is a nice package, just like the 5Gen to be #Supercharged or #Turbocharged. The latter is the 5EAT for those who may not remember or now starting to love #Subaru. With indirect transmission tuning, there is no issue tuning this model for the performance you need but owners must remember this platform runs tight engine tolerances and does heat up pretty quickly, so it is important that you keep everything cooled – Engine Coolant, especially Engine and Transmission Oil. It would be advisable to run bigger oil and transmission coolers if you plan to run the car above average and in hot climatic regions. Besides heat, the only issue we see for SC operations is the belt, which is nothing new for any SC, and belt torque is very important.

Please note for any boosted application, we recommend cooling the Air-charged and running a BPV plummed back to the intake like in other Turbocharged Subaru’s. If possible, try to keep the MAF in the original location, if not, it would be a little more tuning but we advise full customised tuning and not drop-in-based maps or maps considered to be full tunes.

Xtreme Racing Tuning has been tuning Boosted-NA’s for 10+ years and is your trusted resource for your next project. We can safely say we have been sharing such results for years outside of customers’ own posts for global reference. For further information please search our forum and FB page for references and reviews.