Modding Your Fg Xr6/g6E Turbo Take 2

[MattyP]

Modding your FG:

Everyday I see either on the Facebook or the Forums, How do I make X amount of KW or how do I get into 11s or 10s Or will this component get me too Y power level. So this is a basic guide on what engine mods you should be doing to get the most power efficiently. I'm not going to Definitively say this will get you 400kw or even 300kw but I will say when things start needing replacement. Before I begin a few things:

All statements and information contained within may or may not be up to date and all opinions are solely my own and not those of the forum administrators/moderators/advertisers.

There isn't actually a one size fits all guide to mods. Everyone wants something different in their cars and every mod you do will be a compromise in Performance, Economy, Cost, Noise, Functionality, Etc.

Future Proofing your mods is incredibly important. Do it once, Do it properly. I've learned this the hard way.

The most important performance Mod you can do is select a good tuner, Just because you've seen a video on youtube of them tuning a high HP car or they sell flash tuner and injector packages on Ebay doesn't necessarily mean they know what they are doing. Do your Research.

New products are always coming out onto the market just because I haven't listed them here doesn't mean they aren't any good, Once again do your research and learn if the product is right for you.

Lastly, I'm no mechanic or tuner. Im just an enthusiast with a love for the Barra and have spent hours upon hours researching and learning about these beautiful machines and if I can help anyone along the way then it'll be well worth it.

 

Stage 0

Start off with doing a full service. A good quality Engine oil, Oil Filter, Air filter, Fuel Filter, Spark plugs (pregapped to tuner specifications) and Coils if required. Check all your other fluids and service accordingly.

If fitted with a ZF it is also advisable to flush and service the ZF if around the 100xxx kms as this will extend the life of the gearbox and to prepare it for modifications. **Please note that the factory ZF heat exchanger is very prone to failure and should be replaced as soon as possible, Think of it like an insurance policy that's going to significantly reduce the chance of gearbox failure. Most common is the PWR heat exchanger. These are usually preferred because the ZF likes to be at a certain operating temperature which the heat exchanger can do more efficiently. Straight air to Transmission fluid coolers also work well and when fitted with a functioning thermostat and fan do the job nicely and totally eliminate the risk of the ZF Milkshake.
Factory ZF Heat Exchanger ->    Aftermarket Air to Fluid Cooler->   PWR Heat Exchanger fitted -->

If fitted with a TR6060 this is also a great time to refresh the trans fluid and flush and bleed the clutch system.

 

Stage 1

Flash Tuner

Most places tune with SCT and this requires a handheld flash tuner. If your workshop tunes with SCT you must buy one as its what actually writes the files to the ecu from the tuner. Some tuners use software like HP Tuners which doesn't require a flash tuner which can save on the total cost. SCT currently has more parameters however HP is becoming increasingly popular and more parameters will becoming available has time progresses. Neither is better than the other, Just different ways of tuning.

Fuel Injectors

These are the first bottle neck in the pursuit of power, They are a 440cc unit and typically run out of flow in the 275rwkw region. Once again some have seen more with them others have found they run out before this so If your going to be modding this is a good place to start. The two main aftermarket options for the 6T are Injector Dynamics and KPM 1000cc injectors. Both brands of injectors have excellent idling and flow characteristics and have seen 450rwkw on E85 in several cars. There are many other options available like 60lb Dekkas and 80lb Siemens however these injectors are outdated. They can be used but not recommended especially if your planning on going E85 or 400+kw.

Intercooling

(Johnny Tig vs PW Stepped)

The factory intercooler may have seen a power run of 300rwkw but it wont be able to do it again. The factory intercooler heat soaks quiet badly. Yes including the F6 one. The factory piping also has a tendency to leak or burst when boost is raised from factory pressures so it needs to be replaced. The Process west stage 1 cooler, Plaz 800hp and HDI kit are all good for 300+ and "Bolt On" but as I said above it's always a good idea to future proof as all will begin to struggle especially in the summer months with heat soak. The Process west Stage 3, Plaz 1800hp and The big Johnny Tig kit will outlast your wallet when it comes to how much power these units can handle. Do it once, Do it properly comes to mind again.

I'll go into the differences briefly:

Bar & Plate (Heavier, Holds more heat but sturdier) Vs Tube & Fin (Lighter, Better heat transfer but easier to damage)

Black (Removes heat better when static) Vs Polished (Removes heat better while in motion)

Process West use Bar & Plate while Plazmaman and Johnny Tig Use Tube & Fin

Exhaust

The standard FG Turbo exhaust is 3 inch the whole way. The first restriction is the Catalytic Converter. Venom make a widely used "Bolt on" cat which can go into 300s with correct supporting mods and tune however as we increase power demand the rest of standard exhaust becomes the restriction starting with the dump pipe. Xforce make a 4inch dump and cat that can "Bolt up" to the factory cat back Is an improvement however this will really begin to increase back pressure and cause a restriction the higher you go. A full system is not that much more expensive than a Dump and Cat which is why most people go down that route. Either 4inch dump and cat into a 3 1/2 inch Cat back or 4inch all the way are both popular choices and both have seen into the 450rwkw plus territory without too many dramas. Xforce, Nizpro or Custom seem to be the way most people go. People have had some issues with fitment with both brands mentioned so an Exhaust shop is highly recommended or have the appropriate tools/machinery.

Stage 1 Final Thoughts

So if you get a good Exhaust, Injectors, Intercooler and Piping and a good tune it has been shown to go 300rwkw and 11 second 1/4 mile times have been achieved. On an F6 this is even easier with the upgraded turbo. This is a good place to start and getting to learn how to drive these things. Once you get started its hard to stop so with that in mind.

 

Beyond Stage 1

After those first basic mods it becomes all about preference and what you really want from your Barra but keep in mind you always need the correct supporting mods Ie if you buy a Huge turbo you want get any power out of it if you don't upgrade your fuel pumps to suit. So with that in mind...

Fuel Delivery

The Fuel pump on the Fg is good for around Mid 300rwkw on 98, Some have seen (My car personally) 350 rwkw on E85. But some have failed at much much less so its always a good insurance policy to change them out anyway. The most common kit is the walbro 460. Relatively cost effective, Suits E85 and can go 400rwkw+ on E85. If your wanting even greater flow KPM and AI do Twin intank fuel pumps with either twin 300lph or twin walbro 460s both E85 compatible and can go into the 500rwkw mark. These systems are both still relatively new to the market and have been some issues with fuel lines around the pump failing with E85 however reports of these failing haven't been heard of for a while know.

External surge tanks have also been used and are also good for supplying 500rwkw cars utilising Walbro 460s, Bosch 044s etc and have been proven fairly reliable. However they can be very noisy, Relatively complicated and have legality issues as externally mounted fuel systems can be illegal depending on where you live.

One final consideration is the Bosch 044 is not rated for continuous E85 usage where as the Walbro and KPM is.

The fg Fuel rail has been used to 450rwkw plus. If planning on going 500rwkw a Fuel rail upgrade will be required. However the factory rail will suffice for most applications

Intake

The Fg intake system is fairly unrestrictive compared to the BA/F but as you climb closer and closer to the 400rwkw bracket it becomes a restriction.

An intake muffler delete adds extra sound however it hasn't been proven to add power.

Cutting a hole in the factory air box has been done with moderate amounts of success and has been used on a car with 400rwkw.

Cold Air Intakes like Herrod and KPM do look nice and add some extra sound haven't been proven to be big power adders either.

The main restriction in the intake is the factory crossover itself. Removing that with a turbo side intake and battery relocation kit allows the engine to breath alot easier but be warned a turbo side is incredibly loud compared to the standard setup. Lots and lots of turbo noise. One thing to consider with Turbo side intakes is to try and stay with the maker of the intercooler kit as Process West intercooling piping may not line up with a Plazmaman turbo side or visa versa.

The Intake Plenum in the fg is far better designed than the BA/F and has gone 450rwkw+ with ease however is going beyond 500 the plenum can be upgraded with most people opting for custom plenums.

Turbo Upgrades

This will probably be the most political topic on here but we will start with the very basics

Here is the specs on the FG XR6-T T04S/GT35R:

Compressor cover: .50 A/R.

Compressor wheel: T04S/T04B. Inducer 53mm, Major 76mm. 7+7 Bladed Cast wheel.

Turbine Wheel: GT35R. Major 68mm, Exducer 62mm.

Turbine housing: GT35R. 1.06 A/R

Here is the specs on the FG F6 GT35R:

Compressor Cover: .50 A/R

Compressor Wheel: GT35R. Inducer 61.4mm, Major 82.0mm 6+6 Bladed Cast wheel.

Turbine Wheel: GT35R. Major 68mm, Exducer 62mm.

Turbine Housing: GT35R. 1.06 A/R

So as you can see the Standard FG turbos cold side is smaller than the f6 but the hot side is the same. However as you do your upgrades proper boost control will be necessary. Totally unmodified FG turbos have gone into the 350rwkw however to push any higher than that or boost issues are occuring modifications may need to be done such as actuator upgrades, Porting of the waastegate and bigger flappers fitted.

The standard FG runs out of puff roughly at around 320rwkw on petrol and 360rwkw on E85. The f6 Turbo begins to run out at around 370rwkw on 98 and 410 on E85 with correct supporting mods. There are plenty of "bolt on" options for turbo upgrades for the Barra and here are just a few.

Upgrading the cold side. GTX3576r, GTX3582r And GTX3584r complete cold sides can be bought and fitted to either turbos above. These turbos mimic the specs as those turbos. This is a relatively cheap alternative compared to a brand new outright turbo. Places on ebay like mamba or kinugawa have been used with success by forum members but professionally fitting/balancing is recommended.

GTX3576R: Ridiculous spool, Has seen mid 400rwkws on E85. This is the turbo for someone whom loves the standard turbos 'punch'

GTX3582R: A fair bit laggier than the standard FG turbo but can get mid to high 400rwkws out of it. Was the go to turbo but becoming outdated

GTX3584R: Similar to the GTX3582R however by Mamba not Garrett and has a T04Z 11 Blade billet wheeled cold side

PTE6235: Spools a little later than the GTX3576R but has been getting more power than the gtx3582R

PTE6466: New kid on the block, Spools a little later than the 6235 but has been into the 500rwkw zone. Also water lines need blocking

MTA750: Similar to the GTX3582r

MTA900: Bigger than the MTA750 so a fair bit laggier however has run into the 9s

There are plenty more T3 footed turbos not mentioned and countless others available if going aftermarket exhaust manifolds. The Borg Warner EFR series turbos get a notable mention however the people who use them are fairly secretive on their setups and are very expensive.

Valve Springs

The standard FG valve springs are very hit and miss some lasting in the 350rwkw + stage and some needing to be changed straight away. Valve springs themselves don't add power but they are necessary if you begin to get valve float

Speak to your tuner and find out what they recommend.

 

Final Thoughts

With any modifications your going to cause stress on the drive line. The ZFs aren't happy above 350rwkw and clutches in the tr6060s start to slip at that level as well. Don't Forget too you'll need to be able to stop so invest in a decent set of pads, discs and lines and that'll make your trips much safer.

To all of you who made it this far thanks for reading

Happy modding and leave any questions/comments below.

Edited 26/08/16 06:44 AM by k31th

[South man]

Good stuff, The old one needed updating a long time ago, worth a sticky I reckon.

[Rab]

Worth keeping it open for MattyP to continue editing if possible too

[Ralph Wiggum]

large

font

A+ for effort. Matty PM me updates and I'll add to the first post.

[Rab]

font

[camo86T]

Nice write up matty

Maybe could add that twin 2.5" exhaust will flow pretty much identical to single 3.5" as it's a very common option with sellers

Also less likely to drone than a big single

[MattyP]

All good points

If you want the font changed go for it ralph.

Im sure I will have missed a thing or two so ill pm you haha

[Tocchi]

MattyP - valve springs probably should be mentioned

[MattyP]

Yes ill add that as well

Good catch mate

[ratter]

Fuel pump needs to be upgraded long before mid 300's if you want a correctly operating fuel system