Building a Rally Car

You have decided to take the plunge and transform your car into a rally car. Here are a few pointers to help you in the process on a budget. Most of the information is based on our experience with our Subaru RS, WRX & STI mostly GC & GD chassis (check the PrincesSTI, FrogSTIr, Le Toad and Le Toad 2 pages).

First thing is to check the rule books of the series you want to run with:

Check our Scrutineering rules page for a summary of rules and classes of these sanctioning bodies.

Team O'Neil rally school has a good introduction video about rally car build here: 

New vs older cars

Older chassis do not have the same rigidity as newer chassis that use more elaborate materials such as high tensile strength steel and have crush structures designed to absorb larger amounts of  energy.  In the pictures below taken around 1994/1995 in Rally Australia, you can see a Subaru Group N spec car, built by STi, seam welded shell, welded in cage, no sill bar. It was ‘just a roll’ but the bottom slammed a tree of only about 6-8 inches wide, the bottom of the car hitting first mid roll. Occupants survived but hurt necks. (Thanks to Jeff Denmeade for pictures and information about this incident).

Consider that you might have to plan for more safety improvements on older cars..

Buying or building

You should also consider the option of buying an already prepped car which is usually much cheaper. Check our Buying a used rally car  page  to make sure you  are  checking all the safety aspects of the car you are planning to buy,.
Racer Dave has a good video on the tradeoffs (check out his channel too, lots of good stuff):

Rollcage building

This is a major undertaking and will require careful attention to get it right. First step is to check the rule book, but basically if you follow the FIA rules you will pass with any organization.

Check our dedicated Rollcage page

Car preparation/build

Engine, turbo restrictors, air intake, fuel lines:

Check our Engine prep page

If you are new to the sport, you don't need to go crazy and a stock engine will most likely be the more reliable option. Eventually get a mild tune but more importantly stay on top of the maintenance schedule and replace fluids and all wear parts in time. If you have a turbo car, you will most likely require a restrictor: Read all the details in the Engine prep section

Brakes: 

Since most gravel tires are only available in 15", stock STi Brembos have to be replaced with smaller brakes. The go to setup is a 06/07 USDM WRX 4 pot front, 2 pot rear caliper setup and matching rotors. Note that if you have an STi, the rear brake drum for the ebrake is bigger and you'll need special rear rotors (see below).

Wheels

Check the Wheels / Tires page for more info.

We also recommend upgrading to ARP long studs (https://www.amazon.com/gp/product/B001O065FY) with long open lug nuts (https://www.amazon.com/gp/product/B004QHMS5S).

Suspension 

Check our DMS suspension page for setup and maintenance information on DMS 50mm coilovers. Also check the Samsonas installation video below it will show a comparison with the DMS struts. We now also have a dedicated Samsonas suspension page.

Great thread here: https://www.facebook.com/groups/1649355358677665/permalink/1670084879938046/?comment_tracking=%7B%22tn%22%3A%22O%22%7D):

Start with a cheap suspension like the KYB/King Springs and then upgrade to DMS or better when your budget allows. Most of the entry level suspensions are marginally better than the KYB setup. Buying used higher end suspensions can often be a great deal, just keep in mind the cost of rebuilds and who can service them so that you don't get stuck with unserviceable suspension. 

We also recommend using socks/covers to protect the coilovers from dirt/sand/water that can produce corrosion or damage seals. We recommend using SealSavers ProSeries Coil Savers (see video below). they come in pair so you will need 2 to cover the 4 shocks. You can find them at https://sealsavers.com/product/proseries-coil-savers/

The Outerwears sock covers don't really hold up do rally duty (for DMS shocks use https://www.amazon.com/gp/product/B003TPYUQI).

Don't overthink your suspension setup, more caster is better if it's adjustable. 0 toe front/rear makes the car very neutral (on AWD). Don't put too much camber, the tires don't have racing slicks level of grip on gravel. Swaybars is a matter of preference, we just run stock sway bars on our cars and the balance is great with stability at higher speeds. You might find a little bit more grip without sway bars especially on lighter cars but it will be a tradeoff for stability at higher speeds. Experiment and see what works best for you. Below is a cheat sheet from Whiteline to adjust your understeer/oversteer balance:

Strut tower reinforcement 

To prevent struts tower to mushroom or even complete tear off, weld-on strut reinforcements are a must ($30): http://rally.build/subaru-impreza-gd-weld-on-strut-top-reinforcement/

 Skids plates

 ($390) Primitive full rally armor skid plates front and back to protect  the engine and drivetrain in the most rugged conditions. (check http://get-primitive.com/3-protection-skidplates)

Rear subframe reinforcement

The rear subframe on the STi GD chassis is prone to cracking with the loads applied on the rear axle. To prevent the cracking, welding a reinforcement plate to limit the flex around the holes for the diff carrier bolts can go a long way. See the video below:

Underbody protection 

The underbody protection protects other portions of the underbody like the gas tank from rock projections and other road debris. We have successfully used UHMW-PE plastic sheets of 2x4ft (0.125in thick) that you can get on Zoro tools with free shipping. You will need 3 sheets to do one car. In our first iteration we tried to secure the pieces with the strongest zip ties we could find but they get ripped  under impact, the only way to go is to weld either nuts or bolts to hold your pieces of underbody protection. Using zip ties in the rear on moving lateral links is fine. Write your name on the pieces in case you lose them, sweep might bring them back to you if they know who they belong to!

Fender liners 

Stock fender liner replacements can be found for cheap (~$20: https://www.amazon.com/gp/product/B004GD40GM) but  in case it gets ripped off the car, it exposes the engine wiring harness to road debris. A simple protection using UHMW-PE (same material used for underbody protection above) can protect your wiring harness. See the video below:

Hydraulic ebrake

Requires replumbing the brake system and using an aftermarket DCCD controller if you don't have a mechanical center diff. There is a detailed thread on the Facebook Rally page at https://www.facebook.com/groups/1649355358677665/permalink/1663650153914852/?comment_tracking=%7B%22tn%22%3A%22O%22%7D

The stock ebrake will be fine in most situations, just remove the spring and replace the button with one that has a lip (oftentimes called drift button). See video below for the install:

Interior

Most of the time, the stock rearview mirror is usually enough, however the vision can be limited on the street with the cage and halo seats which can be an issue in transit or if you use the car for other activities like wheel to wheel racing. You can use a cheap clamp-on panoramic mirror that is very easy to install but add weight to the original mirror mount which might not stay in position during the stages.The rollcage mounted mirrors are more stable but can be tricky to install depending on your roof bars configuration and they will instantly break if they are hit by a helmet (which can happen if you get in/out in a hurry). After breaking multiple rollcage mounted mirrors (and it's a mess to clean the broken glass), I am happier with my clamp-on mirror, never broke one and very reliable on the street (don't really need it on stage anyway!).

For night stages, interior lights are necessary. While you can get by with a flashlight, the navigator needs a good light to read the notes, find the time card and so on. 

Rollcage padding

Door cards

 We recommend keeping the stock door card and only doing minimal cuts to clear the cage. First the stock door cards don't weigh much and there are not much weight savings to be made there. Second you won't have to relocate door locks or window controls. Third it will provide padding for your elbows and extra storage at the bottom for a tire gauge, paper tower, etc...

Seats

Bimarco Phantom (less than $500+shipping each directly from the manufacturer. The seats have to fit you well, make sure you try them before you buy them, there is a lot of difference in terms of size and fit from different brands and models. Check our Seat installation page for more details.

Seat mounts: Consider having your cage builder weld square tubing for you seat mount. Alternatively you can use a Planted seat mount using the stock mounting points ($140 a side): driver (http://www.amazon.com/Driver-Bracket-Sparco-Recaro-Bride/dp/B0087OYCGO) and passenger (http://www.amazon.com/Passenger-Bracket-Sparco-Recaro-Bride/dp/B0087OYCZA). Check our Seat installation page for more details.

Harnesses

Check our dedicated Harness installation page for instructions on choosing and installing your harness properly.

We are currently using Schroth Flexi 2x2 belts that we got from Stable Energies (https://www.stableenergies.com/Schroth-Harness-Flexi-2x2-6pt-Belt-FIA8853-2016/productinfo/SC-SR9453/)

Steering wheel

Getting in and out of the car with the cage and racing seats can be very challenging, adding a removeable steering wheel will make your life much easier:

Most regulations ask you to remove the steering column lock (also check kill switch install in the Safety equipment section below). Here is a howto:

Roof scoop

Do yourself a favor and keep all the stock venting/blower/heater in the car, even AC if you can. Rally.Build has a nice Evo style roof scoop with vents to direct air where you need it (https://rally.build/collections/rally-build-fabricated-rally-parts/products/carbon-fiber-evo-style-roof-scoop?variant=6807567269934). If you go for a traditional roof scoop and vent like the one offered by Primitive Racing (https://get-primitive.com/exterior/5-rally-roof-scoopvent.html), it will only blow air below the vent but not on the sides. If you want air to get to the driver and codriver, get a floor vent from the hardware store and glue it to the bottom of the roof scoop vent as show on the picture below. You can also use additional safety wire to secure it in place if needed.

Exterior

Hood pins

 (~$30): Sparco (http://www.amazon.com/Sparco-01606AA-Blue-Hood-Pin/dp/B001SIDI70) or Rally.Build (http://rally.build/competition-quick-release-steel-hood-pins/). This makes maintenance easier and can prevent the hood from hitting the windshield in case of a hood pin failure.

Hood struts 

($65): Tein hood struts (https://www.ebay.com/itm/NEW-Bonnet-Hood-Lift-Gas-Strut-Shock-Damper-Kit-Impresa-STi-WRx-GDB-GD-GG-GGA/273038708236)

Mud flaps

Rally Armor UR mud flaps ($135): http://www.amazon.com/Rally-Armor-UR-Mud-Flaps/dp/B004PBAF4Q

Decals 

Decals for driver/codriver names, kill switch, fire extinguisher ($20): http://rallygrafix.myshopify.com/collections/decals-rally-competition
The graphic packages with the windshield banner and door cards are specific to each series. Check their current provider for their visual package as it might change every season.

As Imprezas are pretty nose heavy, you can shave some weight by installing a lightweight bumper beam from Oswald Performance (https://www.oswaldperformance.com/products/gd-front-rear-beam-set?variant=1157639532)

Light bars / Light pods

Stages at night will be very challenging with just the stock headlight, adding a LED light bar has become a pretty inexpensive solution. Some of them can be mounted directly on the hood or roof of the car but a bumper or light bar is usually a better option:

Check the document below if you want to wire your LED bar with your high beams (required if you are running under CARS rules). If you can't see the document, the direct link to access it is: https://drive.google.com/file/d/1q5f4InXo51GgUw4eoSUkR_jkbOEnMOeQ/view?usp=sharing 

led bar wiring.pdf

Safety equipment

We are able to store most of the safety equipment in a toolbox that sits on top of the spare tire. The tie down keeps everything secure and in place. Make sure you don't get a cheap box that will be crushed as soon as you ratchet the strap and also make sure objects are secure in the box and are not flying around, causing damage to the box and eventually ending up flying in your trunk!

A better but more expensive option (~$300) is to use a Cartek GT solid state kill switch (https://rally.build/collections/rally-build-fabricated-rally-parts/products/cartek-gt-solid-state-battery-isolator-kit), much safer as you don't have to run high gauge wires through the car (see video below and check the  kill switch page):  

Kill switch wiring on a 2004 Subaru Impreza.pdf

If you can't see the document above, the direct link is: https://drive.google.com/file/d/1q5f4InXo51GgUw4eoSUkR_jkbOEnMOeQ/view?usp=sharing 

If you can, try to get basic first responder training or training in fire extinguisher usage. In case of an accident on stage and the need to quickly extract a person from a car, check the useful FIA Safety Extraction Guide, especially the section about the quick modified Rautek maneuver. 

Spares

Inevitably things will break during rallies even with the best possible prep. It is necessary to carry spares with you so that the car can be fixed at service. Here is a list of spares we carry with us:

Check with Wali at https://jdmracingmotors.com/en/ for great deals on spare packages.

Of course you will also need all the tools necessary for service. Check our service crew training video below:

Car reprep between events

We have a checklist of things to check between events or during long/overnight service at rallies. This makes sure that all the critical points have been checked out. The list is this Google spreadsheet: https://docs.google.com/spreadsheets/d/1W_J6Qzcyn3-gM1T_rI3spfpWSrJIEidTGCO91UJIva8/edit?usp=sharing

For each event, we make a copy of the template in a new tab and we change to green every point that has been checked with possibly comments in the cell if some action has been taken or something has been observed (worn part, loose bolt, etc...)
There a rea also wear items that need regular servicing or replacement. Here are a few of our maintenance schedules:

Driver/Co-Driver equipment

Some safety equipment can be bought used (but it is sometimes hard to make sure that the equipment is safe and has not been involved in an incident). Some overseas companies like Demon Tweeks or Murray Motorsport have substantially lower prices on new equipment even with shipping and tax duties factored in. 

Safety gear

Check our Safety gear page for information about helmets, gloves, shoes, Hans devices, arm restraints, etc...

Intercom

You can go with the standard Peltor or Stilo intercom that are widely used or go on a budget with a motorcycle intercom:

Budget intercom: Sparco IS110 amplifier (~$90) that has both a 9V battery power and 12V from the car for seamless power transition. You can get headsets for open or closed face helmets for about $45 a piece at http://www.demon-tweeks.co.uk/motorsport/intercom-headsets/sparco-headset-kit-for-is-110-intercom. The regular audio jacks are not very reliable and will fail quickly especially if you forget to disconnect them when getting out of the car. 

Higher end intercom: Sparco IS140 is a nice high end Peltor compatible intercom that has both a 9V battery power and 12V from the car for seamless power transition. It turns automatically on when the codriver connects his helmet. Stilo helmets will require a Stilo-Peltor cable, other helmets can use a comm kit like this one: http://www.rallynuts.com/helmet-headsets/rosso-racing-advanced-pro-open-face-headset.html 

Recce wheel

If you need to write your own pace notes, you will need to get consistent notation for the turns. Getting a used steering wheel and adding marks to it to indicate the angle of corners is a good practice used by WRC drivers (see video below).  Check the pdf document under the video below of the page to calculate the right angles for your car.

Recce steering wheel angles.pdf

If you can't see the document above, access it directly here: https://drive.google.com/file/d/1M9kx3j6CpJr-H9Xh20U4XaXVf4B0ulUD/view?usp=sharing

RallySafe

Check our RallySafe page for installation video and instructions

ARA and select CARS events have switched to RallySafe for timing and tracking during events.  You can purchase the permanent kit from https://shop.statusas.com/shop/category/rallysafe/

Rally computer

We have had great success with a very simple Android tablet and some apps for both car telemetry and rally computer. Alternatively you can use a modern phone, what really matters is that you have a dual GPS/GLONASS receiver for accuracy. Note that the use of a rally computer is not really useful beyond recce when using RallySafe, since the RallySafe unit provides similar features to a rally computer.

Android apps available from the Google Play store:

Video and telemetry:

Check out our dedicated pages:  Telemetry and Videos