More Track Builds

[Martin Donnon]

Looks like more and more GTR owners are catching the track day bug, and why shouldnt they these cars are quick. Heres a nice 400awkw build thats being carried out on a daily driver and going to Victoria where it will get to stretch its legs at PI, Winton, and Sandown.... lucky guy!

Plenty of folks want to know how to build a quick track GTR - which is different to a dyno or show GTR - this is a formula thats proven to deliver the times on several tracks around the country

Pull the engine to fit a high volume oil pan, as well as strip the turbochargers and convert them over to full ball bearing WR35TT. The gain in converting to ball bearing is via the fitment of a larger more power capable turbo to add 50kw plus at the wheels without adding lag which can kill a GTR off the corner, particularly when stuck with having to use a higher than optimum gear (too fast for second, not quite fast enough for third)

Larger low restriction WR35TT turbine wheel keeps turbo speed down and reduces backpressure at 18psi boost, which means that the tune has less chance of any detonation on the track, and that the exhaust temperatures stay lower

A lot of modifiers forget the hardlines. Retaining the stock hard steel water and oil lines is crucial to avoid both leakage and any chance of underbonnet fires. Rubber lines simply do not last in the GTR engine bay environment

Full titanium exhaust system removes some 25kg from the GTR as well as flowing more air than standard and once more reducing backpressure. An important track consideration. Both differentials are properly cooled as well. More to come over the next couple of days

[Martin Donnon]

More chance to work on this track GTR today, which started with fitting some low restriction turbocharger outlet pipes to the WR35TT turbochargers before putting the engine back in the bay -

Larger injectors are mandatory on any powered up R35GTR (bigger turbos) as the factory units are close to their limit on the stock turbos. A nice 750cc straight fit injector gives plenty of additional headroom to the project and ensures no lean outs at the track

Fitting the larger injectors requires the top half of the inlet manifold to be removed at which point it must be very carefully worked around to stop any foreign objects entering the lower half of the inlet manifold

The stock brake rotors have received some punishment from multiple track days already and as such are ready for replacement. This is not an uncommon sight for R35 stock brake discs that have done their fair share of work

The solution comes in the form of upgraded AP J-Hook brake rotors front and rear combined with Endless brake pads (W003) and WR35WS brake water injection system. This is - the - way to get the GTR stopping hard without burning its brake hardware

More to come tomorrow

[Deano 1]

Awsome detailed thread, keep it coming!

[Col-GTSX]

Yum, sexy brakes

[magic1]

martin, im intrigued by this water cooling on the brakes.

[Martin Donnon]

Intrigued? What would you like to know. We consider Brake Water Injection a necessary part of a race track brake upgrade in our neck of the woods as our local track - Malllala - is the biggest brake punisher in the country, and when you are on the pace a good solid three lap jaunt in a 35 (or most anything) will have the pedal in the floor. As verification Steve Glenney tried our brake water injection system on a GTR last week and could not believe how good it was in practice. Feedback like that makes me happy

[Beer Baron]

looks great. it will be great fun at PI. is it going to run on E85?

[Martin Donnon]

Thanks for the support on the build up guys

Yes Beer Baron it will be a mean thing over there in Vic thats for sure...now back to it

Today the braking system got fully put together and bled. The hat installation onto the AP discs is time consuming and must be carried out carefully due to the McLaren Spring bobbin design used by Brembo. Its good, but must be carefully tensioned

General service work was carried out in preparation for the track in the form of our 10w-60 oil and subsequent new filler cap. Make no mistake if you track with any less than a 10w-60 in the sump you are - definitely - wearing these engines at an artificially accelerated rate. Why do it?

Since this car will see race tracks in hot and dusty environments we stuck with the factory air filters. We have tested most of whats out there for GTRs in the way of aftermarket filters and there is virtually - zero - power gain, and big losses in filter efficiency to be had. Most of the foam types dont even seal properly around the edges and should be best avoided at all costs unless an engine rebuild program is in the budget.

As we upgrade and build a lot of GTR turbochargers for international clients I can tell you that compressor damage like this is common on sub-10000km GTRs with aftermarket elements. Most of the dirt then makes its way into the oil so its a lose, lose

The PCM connectors have been removed to allow the wiring of an external shiftlight, which is very important for shaving tenths on fast tracks where you a) dont want to hit the limiter, and b) dont want to take your eyes off the track

Last but not least is the WR35FS fuel surge tank system for R35 GTR. Not too many trackgoers realise that at under half a tank long right handers will have the engine leaning out dangerously and in some instances cutting out altogether. This system allows full fuel supply down to 0km to empty and can literally save an engine from high speed detonation. Will show completed pics of this installation tomorrow....

Hope everyone is enjoying this so far

[zebra]

I love those Surge tanks, But why dont you run bosch pumps?

Myself and others have had heaps of dramas with Walbros over the years.

[Martin Donnon]

There are plenty of reasons we do not use Bosch pumps in this application. The first and biggest problem is noise. The next issue is their relatively massive current draw of 40A combined peak, which is far more than we want to put back through the charging system of the GTR which is quite sensitive. Last but not least when using genuine Walbro pumps, in external configuration with accurate and controlled power/ground supply, free of inlet restriction we have never had an issue

18 months of tracking a GTR as hard as anyone in the world has delivered a perfectly clean bill of health for the Walbro(s) in this given application

[zebra]

Cool, Was just curious

Thanks for the straight forward answer

[Martin Donnon]

Cool, Was just curious

Thanks for the straight forward answer

No problems, ask away with any questions you might have and I will do my best to answer them

[ARGH35GTR]

As if aftermarket air filters dont work they make more power and filter better that is a fact for sure

[zebra]

No problems, ask away with any questions you might have and I will do my best to answer them

Cool I might give you a bell soon about some things for my 33

[magic1]

Martin,

Curious if it was a closed loop or spray application of water and if it was a spray, where it is applied.

I have look now on your website.

[GTAUTO]

Hey Martin

Look good another fast car on the way, the way things are going they are going to need an R35 section for next years superlap. However I really beg to differ on the filter what dyno do you dyno with? because i have seen definite gains from aftermarket filters on our Dynapack dyno all be small gains but definite gains, as well as improved boost responce. As for the turbo blade damage on the car just take a look at the filter it is clear this car not not been well maintained that filter is disgusting. If anything Pod filters yield less impressive gains, as people never air box them properly, you can beat those factory boxes for design and flow. Just my take on it.

dave

[Martin Donnon]

They way to measure whether a performance air filter actually achieves performance is via pressure logging behind the element. We can run a secondary presure probe there on our Mainline Dynolog AWD 1500 dyno and actually plot the restriction if ineed there is one. If there is no pressure drop there is nothing to be gained from a filter swap

[Martin Donnon]

Back to the build up......

The vehicle is now completely finished as a ground up installation and back in Victoria tuned and ready to hit PI this weekend. Here are the final photographs, and hopefully this thread gives the members here some good ideas how to modify their own cars for actual track effectiveness. All of the parts used in this installation are aimed at cutting lap times

The WR35FS fuel system is now finalised and the boot fully retrimmed. In operation the pumps are silent and easily accessed. Note the water tank for the brake spray system which can be removed when the GTR is not at the track

Note the interfacing of the fuel system to the existing GTR fuel lines is carried out in the engine bay using Teflon braided lines, and ensuring that the setup is reversible if need be

To run at our required boost level - 17 psi on the WR35TT Turbochargers - the factory blow off valves need to be modified. The bypass port needs to be blocked off which we achieve with a screw in fitting, which stops the blow off valves pushing open under high boost pressures.

Final race track preparation comes in the form of a Velo APEX seat mounted on a modified Bride rail. The Velo is a perfect fit for the GTR not intruding on the door trim and jamming, fitting perfectly into the relatively narrow GTR space. We also modified the harness to fit a crutch strap to hold the driver securely

Finally the engine management system was calibrated on the chassis dyno to deliver both optimum power and reliability. Track GTRs have very different tuning requirements to street or drag GTRs. Using the latest Cobb AP Beta development software we were able to achieve a smooth 17psi boost curve, and a touch under 400awkw on our Mainline AWD 1500. Thats a gain of 45% over the stock figure which puts it into perspective....also careful of dynoing on Toyo R888 tyres, they will knock your figures down 10% or so due to their soft traction index....as we found out

[handbrake]

Another great build Martin, well done

[Martin Donnon]

A little upgrade solution like this gives a genuine GT2/GT3 destroyer and leaves a lot of change in the kitty. The trick with these cars is not doing any 'backwards' or 'negative' mods as many are available for the GTR