Friday, May 20, 2016

NA Brawler

Words & Snaps by Ben

The Honda Jazz, or Fit, as it is called in certain markets, is wildly popular for being an amazing grocery-getter. It's small and easy to park, fuel efficient, and zippy enough for everyday traffic, and has enough room to haul a small family.

Yet while most see a common econo-box, others see potential.

Laurent is one of the latter, and inspired by the potential showcased by Spoon Sports' Fit, he started his new quest for power with this Jazz GD1.

At first sight, Laurent's Xiao Bai (Little White) looks only lightly modified. If it wasn't for the lowered stance, Honda Factory Type S kit, and the Spoon duck bill, she would hardly stand out from the many Jazz and Fits on the supermarket's carpark.

Yet this GD1 is not like its brethren. Laurent wanted to show the world that all Honda Jazz were not just grocery-getters, and decided that 150whp would be a bold enough statement to make his point.

This power target meant the standard intake-exhaust-ECU mods would just not cut it. He was going to have to dive elbow-deep in his engine and add in some extra oomph.

Getting down to work, he stripped off the block and set the canvas for his creation by over-boring the cylinders by 0.5mm to ensure they were nice and straight. He then slotted in custom high compression forged pistons, and tied them to the crankshaft with K1 forged conrods. The new pistons would give him a new compression ratio of 12.8:1, an increase of 2 full points from the stock CR.

Laurent then sent the head for CNC porting and polishing and crowned it with a custom stage 4 race cam. Right underneath the camshaft, Laurent fitted Bisimoto valve springs and retainers to make sure the valves would not linger open and hit each other, or the piston, when climbing up in the revs.

He then finished his work on the block by tightening everything together with ARP studs.

With his power target, Laurent addressed fuel starvation issues thanks to a Walbro 255LPH fuel pump and ditched the stock injectors in favour of 310cc ones taken from a K20.

With the uprated air flow of the ported and polished head, then next step was to make sure he wouldn't limit the power with a restricted air intake. For this, he chose to go with Weapon R's eye-catching intake manifold, mated to a Super 90 throttle body. The setup sucks the air in from an HKS Racing Suction Reloaded kit.

To let the engine rev faster, Laurent added an M Factory lightened flywheel, which he matched to an Exedy racing clutch, to avoid losing any ponies on the way to the wheels.

As the Jazz was originally designed to be an econo-box grocery runner, the long gear ratios were the next hurdle of his build. As he was building his car for the short track that is Johor Circuit, he needed to hit the bulk of his power band fast. He thus tossed aside Honda's gears 3,4 and 5, along with the final drive, and replaced them with close ratio counterparts, and a shorter 4.7 FD.

With the heart of his brawler almost ready to fight, Laurent shoehorned the package in his engine bay and secured it firmly with reinforced engine mounts. He then installed a Fujitsubo full exhaust system to let the pulses of spent combustion bellow their way out of the engine.

Surprisingly, the stock radiator proved to be efficient enough to handle the requirements of his new powerplant, and all Laurent had to do is swap in a mandatory low-temp thermostat, and install a fan switch, to make sure his car cools off properly after hot laps at the track.

His engine was ready, and Laurent gave it a new brain in the form of a Haltech standalone ECU.

However, before the tune, he felt like something was missing. He needed to add one more little touch as an insurance to hit his power target. The solution came in the form of Coolingmist's methanol injection kit.

He rigged the methanol injection to his throttle body so that it would automatically engage when Laurent would stomp the accelerator to the floor.

The parts were installed and ready to spring to life, thus it was time to tune the Haltech ECU, and see if his power goals were met. His Jazz found its way to the rollers and it was the tuner's turn to work his magic.

The results? A whopping 173bhp with 184Nm of torque.

He had met his target. But as power is nothing without control, and Laurent had some track side action plans, he had to make sure that his car would handle the corners like it took on the straights.

Thus D2 coilovers with custom spring rates of 8kg and 10kg at the front and rear respectively found their way at each corners of the Jazz. Lightweight 15'x7 Enkei RPF1 shod in sticky Advan AD08R rubber filled the wheel wells, with the front wheels sitting on 10mm spacers to make way for the Exzess 282mm big brake kit.

To wrap up the handling side, Laurent tightened up his GD1 with a front strut bar, echoed by a front undercarriage brace, and a room and boot bar.

He then ditched the back seats because weight reduction, bro, and swapped the factory front seats for Brides's hugging Low Max bucket seats so that he would stay firmly behind the seat when attacking the corners.

Out went the factory steering wheel, and in went an OMP steering wheel mounted on an NRG quick release.

Behind the wheel, staring straight at Laurent is Linear Logic's Scan Gauge II digital display to keep him informed of his engine's vitals.

Laurent then added more personal touches in the form of a Type R gearknob, Mugen pedals, and a fire extinguisher for safety.

While Laurent surely made his point about all Jazz not being simple grocery getters, he still has plans to further reinforce his claim. Maybe, just maybe, oversized valves and individual throttle bodies would be a good way to do that?

The future will tell if this NA brawler will build up an even more serious punch than it already does...
For now, it sure as hell makes one serious statement.


2007 Jazz GD1
Drive Layout
Max Output
173bhp / 184Nm of torque

Power Mods
HKS Racing Suction Reloaded, Weapon R Intake Manifold, Super 90 Throttle Body
Low Temp Thermostat, Fan Switch
Walbro 255LPH Pump, Honda K20 310cc Injectors
0.5mm Cylinder Bore, Custom 12.8 Compression Forged Pistons, K1 Forged Con Rods, CNC Ported & Polished Cylinder Head, Custom Stage 4 Race Cams, Bisimoto Valve Springs & Retainers, ARP Studs
Fujitsubo Full Exhaust System
M Factory Lightened Flywheel, Exedy Racing Clutch, Short Ratio 3,4,5th Gears, 4.7 Final Drive
Haltech Standalone ECU
Reinforced Engine Mounts, Coolingmist Methanol Injection Kit

Enkei RPF1 15’x7jj
Advan AD08R 195/50R15
Exzess 282mm Big Brake Kit (Front)
D2 Coilovers With Custom 8kg (Front) & 10kg (Rear) Spring Rates
Front Strut Bar, Front Lower Brace, Room Bar, Boot Bar
10mm Spacers (Front)

Body Kit
Honda Factory Type S Body Kit
Spoon Duck Bill

Bride Low Max, Bride Railing (Driver), Miki Railing (Passenger)
Steering Wheel
OMP Steering Wheel, NRG Quick Release
Gear Knob
Type R
Linear Logic Scan Gauge II
Fire Extinguisher

Laurent would like to thank to his tuner Reggit from R Tuning for the countless hours spent on the dyno, and the perfect tune, and his group of car-crazy buddies for their encouragement and support throughout his modification journey.


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