Guide to Building Performance in Isuzu Automobiles
Dozens of people have E-mailed me asking how to improve the performance in their Isuzu vehicles. This is a guide to tuning your vehicle.
Index
Engine
Drivetrain
Suspension
Brakes
Engine Tuning
Everybody keeps leaving me behind, I want to keep up with everybody else.
An internal combustion engine is nothing more than a large petrolium powered air pump.
To make it work better all you have to do is make its job easier by improving efficiency.
To improve the efficiency of an air pump, you simply make modifications so that air flows through the engine more easily. The greater you make the capacity of air flow, the more freely the pump will work, the more power and torque the engine will produce.
Suggestions for a mild buildup:
Intake
Performance drop in air filter +3-5 HP
Ram air intake
Hot air induction pipe system +1-7 HP
Note: Tested with the hood open
Cold air induction pipe system +8-13 HP
Ported mass air flow sensor
Oversized MAF sensor
MAF to MAP conversion
Electronic air fuel ratio adjuster
Ported throttle body +5-7 HP
Ported air plenum
Ported/Extrudehoned intake manifold +3 HP
Fuel System for EFI
Remember: Fuel system upgrades beyond maintenance and
restoration to factory specifications are not justified unless
air intake modifications are suficient enough to cause the
engine to run lean. This depends a great deal on the safety
margin or cushion that the manufacturer designed into the system.
This varies considerably from model to model.
Clean and calibrate fuel injectors
Upgrade to higher flow rate injectors
Adjustable fuel pressure regulator
Fuel management system
Larger fuel pump
Larger diameter fuel piping
Fuel System for Carburated
Install larger carb jets
Upgrade to multi barrel, progressive carb, or multiple
carbs
Valvetrain
Performance cam or regrind +5-14 HP
Performance valve springs and retainers
Adjustible cam sprocket(s) +3-18 HP
Ignition
Performance plug wires
Performance spark plugs +1-4 HP
Advance ignition timing
Performance ignition coil
Supplimental electronic ignition system +1-3 HP
Computer
Performance EPROM chip or control module reprogram
+7-20 HP
TPS Recalibrator or other piggyback unit
Exhaust
Performance header +4-12 HP
Ported/Extrudehoned exhaust manifold +3 HP
High flow catalytic converter +5 HP
Larger diameter cat-back exhaust system +4-12 HP
Turbo style or high flow muffler
+1-2 HP if installed on stock exhaust piping
Cooling
Low temp thermostat
Oil cooler or larger oil cooler
Larger radiator
Supplimental electric cooling fan
Pulleys
Underdrive pulleys +5-15 HP
Drivetrain
Aluminum Flywheel +12-20 HP
For Turbo owners:
A reboost kit +35-40 HP
Bleed valve on the turbo system
Upgrade intercooler piping
Blow off valve
Adjustable wastegate
Install larger turbo
Install larger intercooler +10-18 HP
Ported/Extrudehoned exhaust manifold +3 HP
Custom welded pipe exhaust manifold (these tend to crack
from heat stress)
Larger diameter down pipe +17 HP
Fuel enrichment system
Fuel management system
Additional fuel injectors and controller
Suggestions for the more adventurous:
Engine work
Racing engine rebuild
Stroker kit
Ported cylinder head
Larger diameter valves
High compression pistons
Auxilliary oil cooler
Forced induction
A low pressure turbocharger or supercharger system on
a stock motor +20-100 HP
A high pressure turbocharger or Supercharger system
with engine rebuild to turbo specifications
+75-250 HP
Nitrous Oxide
Enough said +40-120 HP
Engine swap
Put in a bigger engine
Drivetrain
I side step the clutch and the engine redlines, but all I do is sit still smelling burnt metal and carbon.
Clutch
Performance clutch
Synthetic transmition lubricant
Stainless braided clutch hose
DOT 4 hydraulic fluid in clutch resevoir
Rear End / Transaxle
Limited slip or torque-biasing differential
Synthetic gear lubricant
Totota pickup truck rear end transplant
Suspension Tuning
I can go like spit on the straights, but every time I come to a turn, everyone I passed on the straight goes flying past me.
Performance shocks or struts
Coilover dampers
Larger diameter anti-sway bars
Stiffer springs or stiffer and lower springs
Very few people who cut their springs don't end up
damaging their car.
Strut tower braces
Urethane bushings
Plus one or plus two tire and wheel combinations
Larger diameter wheel with lower profile tire for same
overall diameter of tread surface
Light weight racing wheels and slicks for track use
Brakes
I go like spit and turn like I'm on rails, but I keep running into things because this thing won't stop.
Performance pads
Stainless steel braided brake hoses
Dot 4 brake fluid
Larger diameter rotors and larger calipers (Big brake kit)
Cross drilled or slotted rotors ??????
There are a good number of knoledgable people who state
that cross drilling and slotting rotors does nothing to
enhance cooling more than ten degrees over a 200-300 degree
range. Among these are Steve at SMC (he makes cross drilled
rotors, telling this to his customers costs him sales, but
he's an honest guy and I believe him). Cross drilled and
slotted rotors do reduce squeal by allowing the pad to pump
the dust produced by braking through the hole or slot as
opposed to floating the pad on a thin layer of dust. Aside
from this benifit, they are purely cosmetic.
Slotted rotors eat pads quickly and are most appropriate for
use on race cars.
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