GVR-4 Upgrade Path

The following is a suggested upgrade path as put out by Mike at Road/Race Engineering.

PLEASE NOTE that all prices are current as of 7/15/02, but they can change at any moment, so do not take them as gospel. They are a general guide only, to give you an idea of roughly how much the mods will cost.

This is the upgrade path that we recommend for the GVR-4. Here is the current list and prices. There is a reason that we are using the parts listed here - they work. They have not been chosen because they are in style or fresh, just proven. If you build an "all GReddy" or "all HKS" GVR-4, or if you want a Blitz BOV just because everyone else has a GReddy, your performance will suffer.

Since the GVR-4 is a very limited production car, you will find yourself on your own for some projects. We support this Do-It -Your-Self  attitude by offering many of the hard to find fabrication parts specific to DSMs and GVR-4s. See the RRE DIY Pages for more info.

Your car should be in top mechanical condition before attempting these mods. This means replace your timing belt at the recommended intervals and keep everything on the timing side of the motor in top shape. You should have no exhaust or oil leaks, no lifter tick, no strange suspension problems and great brakes.

Mike W

I N I T I A L   M O D S

ITEM Description Cost
Air filter Road/Race-Uni Foam Filter or K&N Filter $40
Install Air filter and remove the Boost Control Solenoid restrictor, which raises boost 2-3 psi $30 
Mail Order
3" Certified Muffler (Florida)

Mofugas  2 1/2"  

$  ??


Mofugas Downpipe  $225
Mofugas High Flow cat $125
Local Install or muffler shop
Exhaust @ Your local muffler shop

Road/Race 2 1/2"(Local installs only)
Road/Race 3" (Local installs only)
(1 resonator, straight thru muffler, simple tip, mandrel bent)


$450 $525 

2 1/2" or 3"  RRE Custom  Down Pipe


2 1/2" or 3" High Flow cat

$ 150

Fuel Pump Your stock fuel pump flows 100 liters per hour @ 43 psi @ 12V. This pump flows 150 lph.

Walbro In Tank Fuel Pump
Install Pump


Free Mods Remove Boost Control Solenoid Restrictor 

Play with the MAS adjustment screw  If you monitor O2 voltage and you don't mind a possible lumpy idle.



The GVR-4 is a little unique compared to the rest of the DSM line. The intercooler, while it is mounted in the front, is very small. Oil cooler sized. For making any serious boost you will need to upgrade it. The first choice for most DIY guys is to modify a front mounted I/C from a Starion turbo. They can be purchased from a wrecking yard for $75 to $150. They flow well enough for over 300 hp and look nice. After the I/C bottleneck is addressed you would then work on the piping. Stock piping is 1 7/8" diameter. Upgrade it to at least 2 1/4" or 2 1/2" if you are going for berserk hp.

ITEM Description Cost
 I/C Piping Includes all piping from turbo to intercooler, from intercooler to throttle body. Air filter assembly needs to be moved forward. Battery needs to be moved. This straightens out the inlet tract to the turbo. Piping Kit only assumes you already have an upgraded I/C and have the ability to adapt and modify our pipes and hose to your I/C install. We give 2" dia hose down thru the drivers side of the radiator in the stock area. We pick up with 2 1/4" hose at the bottom of the radiator support on the passenger side. The stock intercooler is the biggest restriction, that needs to be addressed before you worry about I/C piping

More Info


Install $180
Front Mount Intercooler RRE/Griffin top to bottom flow, 18" wide by 6" tall core.

I/C with end tanks only 
Brackets and adapting hose for RRE pipes 
Install (with our I/C pipe kit purchase)



T U R B O   S U P P O R T

ITEM Nicer Choice Cost   Budget Choice Cost
Boost controller GReddy PRofec-B $350   RRE Manual Boost Control $60
Install Prices: 
Controller only 
VDO 52mm mechanical boost gauge 
 GReddy Electronic (non peak hold) 52mm boost gauge 
 GReddy Electronic peak/hold 60mm boost gauge 
Mofugas Motorsports A-Pillar Mounting Pod
VDO Mounting Cup 

Spark Plugs and Wires Magnecor 8.5mm wires 
NGK BP7ES plugs
  NGK 7mm Plug Wires $45
Install plugs and wires $10 labor
Exhaust Gas Temperature Gauge GReddy Electronic Peak/Hold 60mm $225   GReddy Electronic 52mm $165
Install EGT 
Install probe only
$85 labor
$25 labor


ITEM Description Cost
Exhaust Flow Port Exhaust Parts
This is good for 15hp alone. The stock manifold flows well enough for up to around 400hp if ported. The exhaust housing of the turbo and the turbo outlet (O2 sensor housing) also benefit from porting.
Port Exhaust Manifold 
Port Turbo Exhaust housing 
Port Waste Gate 
Port Compressor Outlet
Port O2 Sensor housing 
Port All 
Wicked Port All
If Exhaust Manifold is cracked, new 2G manifold
$ 75
$ 75
$ 40
 $ 35
$ 75
$225 $300
Remove and install Assembly
Broken Studs (common)
 $ 40+
16-G Turbos If your turbo is dead, time to upgrade. With the 16-G, you can keep the boost down and need only an upgraded fuel pump. To run over 15-16 psi boost on pump (92) gas SAFELY, you will need more fuel.

Mitsubishi TDO5-16G-7cm.
This turbo is good for solid low 12 second 1/4 mile times.
It can sound manly to say you have a bigger turbo but this is all 98% of you need

Regular 16-G Turbo  
Big 16G Turbo 
Clip 5-15 degrees 
Porting (see above)
Gaskets (inc 7cm gasket) 
Broken Studs (common)
SS Oil Line 

$ 45
 $ 40+
$ 55
Serious Upgrades:
(For turbos larger than the 16G, you will
need an upgraded intercooler AND something to either upgrade the GVR-4 MAS to a larger 2G one or eliminate it by using a HK$ VPC)
Mitsubishi TDO6 cartridge and exhaust wheel Uses a Mitsubishi 7cm exhaust housing that has been bored to fit the TD0-6 wheel. The 20G style compressor housing is machined to fit a Garrett 46 trim wheel making it effectively a bolt-on T3-T4 turbo.
Price includes 10 degree clip and weld on 90 degree outlet elbow.
External Wastegate

An external waste gate may be required to control the boost if you are using one of the larger upgrade turbos, especially if you are running with no catalytic converter at "the track". 

35mm TiAL Wastegate 
40mm TiAL Wastegate
Install is custom 



A I R / F U E L

ITEM Description Cost
To take full advantage of all the air flow that you now have, you need more fuel and the ability to control it.
Air/Fuel Ratio Meter Jumptronix Digital O2 Sensor Voltage Meter  $85
Super AFC  
This allows you to modify the signal from the MAS (air flow meter) to the ECU to help trick the ECU so that you can lean things out to make up for larger fuel injectors. The AFC will also help compensate for removed honeycombs to make for a smooth idle. 

With the stock injectors (450cc/min) running out of capacity at 
15-16 psi boost on pump (92) gas, you need to swap them out with larger injectors. 550cc/min work well on pump gas up to around 16-17 psi on pump gas and with race gas up to 22 psi. With the larger 660cc and 720cc injectors, you can run more like 19-20 psi on the street and as much as your motor can take on race gas. 

Super AFC 
RC/Lucas 550cc injectors (set  of 4) 
Denso 550cc injectors        (set of 4) 
Denso 660cc injectors        (set of 4) 
Denso 720cc injectors        (set of 4)

Cams Web Cams - 546/ 547 grind cams
Lumpy Idle,    Big power
Install cams




ITEM Description Cost
Clutch Good: ACT 2100lb with the street disc
Excellent All Around: Center Force 2500lb Ball Bearing Dual Friction
Best but Strong Left Leg: ACT 2600lb with the street disc
(all prices include a factory T/O bearing)

Lighten flywheel and resurface (exchange)
Stainless Steel Clutch Hydraulic Line

$  20



ITEM Description Cost
Datalogger Don't even think you will be fast with out one. 


Advanced Tuning For applications over 275hp cut away lower MAS channel entirely or switch to 2G MAS or HKS VPC.
  2G MAS Install Flows more air than the stock air flow meter. Needs a 2G air filter and turbo inlet hose. Must be used with the AFC. You would need to relocate the battery.
Used 2G MAS 
2G K&N Filter 

$ 95
HK$ VPC Vein Pressure Converter, also known as the "Variable Performance Computer" because of the love /hate relationship everyone has with it. Eliminates factory air flow meter for less restriction before the turbo. Also gives you a little adjustability with the fuel. Uses the factory air box with air flow meter removed, or buy a K&N-type open filter & adapter to replace air box completely. Different programs available for stock injectors or 550cc injectors.

For larger injectors, we use the AFC to further compensate. In cold weather, it can cause poor fuel mileage and/or erratic idle speed at any time. HK$ never has them in stock, get a used one, much better value.

Install VPC 

$450-650 $160
Advance Base Ignition Timing Advance base ignition timing from 5 degrees stock to a total of 10 degrees. With 92 octane it is a waste of time, on 93-94 octane gas it can help some, usually you just end up back where you started after the ECU retards for knock. This is best done on high octane race gas.


ITEM Description Cost
Head Work Port Cylinder Head 
Remove and install head 
Valve Job 
Upper Gasket Set 
$300 and up
$250 to 400
Big Bore Throttle Body Bored Out Throttle Body (exchange)  $250
Install a bigger throttle body and port out the intake manifold inlet to match and adjust TPS 

Install a bigger throttle body and port out the intake manifold inlet to match and adjust TPS




Intake Extrude Hone  Intake Manifold (exchange)
Remove and install
Ignition MSD Digital DIS-2 (Pic)
Additional to connect 2-Step rev limiter




ITEM Description Cost
4 Bolt Rear Axle 
4 Spider Center Diff Speed Designs 4 Spider Gear Conversion
LSD Center Diff Quaife Center LSD $1500


ITEM Description Cost
Brake Pads and Rotors Power Slot Rotors 
Metal Master Brake Pads 
$ 55
$ 45
Install Brakes $80
Brake Lines Stainless/Braided Brake Lines
Brake Fluid Motul 600c (1 Liter)
Install lines and bleed brakes 
$ 18
Springs and Shocks H&R Springs 
Mofugas/Whiteline Springs
KYB GR-2 Gas Shocks
KYB AGX Adjustable Shocks 
Strut Tower Bars GReddy Front Strut Tower Bar
RRE Rear Strut Tower Bar 
Install Bars 


Sway Bars Mofugas/White Line Rear Sway Bar 
$ 90
Urethane Bushings Energy Suspension Bushings
Minimal  install
All installed


Prices good at 7/00. Prices are subject to change with out notice. Install prices are for local customers only. Install prices may vary if your car is a star in the Dope Show. All prices are doubled if you have a bunch of messed up parts from the 909 area code land that leak, fall off, or cause an injury. $100 charge for every time your alarm goes off, on a slow day we reserve the right to set it off just for the extra cash so be sure it will NOT work when you drop it off.



Questions, suggestions, comments, constructive criticism and/or corrections? Email me at talonts@vfaq.com.

This document can be reprinted for personal use or reference for your mechanic(s) with no prior permission needed. It can be linked to directly, as long as you have a link to the main VFAQ page of http://www.vfaq.com, though linking to the main page instead is preferred. This document can NOT be reprinted for profit/resale/redistribution of ANY type without expressed WRITTEN permission from me in advance. Bulk copying of this document onto your web site without prior permission will not be tolerated, link to it instead. 
Last modified: July 15, 2002
Copyright 2000, Road/Race Engineering, Tom Stangl