Team GTI

Improving Improved Touring
Off-season Upgrades

Winter 2004 - Spring 2005

It is officially the off-season and time to continue development of the PhilsTireService.com Team GTI. We have a number of improvements planned and progress will be documented on this page. We haven't prioritized or budgeted completely but the list of likely modifications is substantial:

>> Transmission - lower final drive gear ratio, limited slip differential, maintenance rebuild, and ring-gear bolt kit - Done

>> Engine - IT-spec rebuild with raised compression, replacement of service parts, and optimization of internal parts (balancing and blueprinting)

>> Engine Management System - research continues on what changes might be incorporated in the fuel injection and ignition systems - Begun, probably won't ever be done!

>> Intake and Exhaust - street-legal exhaust system with muffler, race-spec catalytic converter, and aftermarket header - Done

>> Suspension - additional adjustable rear antiroll bar, revised spring rates and alignment, wheel spacers, and camber plates - Partially done

>> Cockpit - upgraded instrumentation, improved mirrors, and a driver's foot well plate with dead pedal rest - Partially done

>> Brakes - removal of all ABS system hardware, re-plumbing of hard lines, and addition of a balance proportioning valve - Done

>> Safety - installation of an onboard fire system and upgraded rollcage padding - Done

This is the improved seat mount fabricated by Competition Cages. The multiple holes facilitate installation of a choice of two Recaro race seats, depending on the size of the driver running the car.

The driver foot well needed to be repainted after 13 hours of abuse at the VIR enduro, and 4 hours of testing the day before that event. The gritty VIR paddock dirt acted like sandpaper under the drivers' feet, taking the finish down to bare steel in places. An aluminum floor plate is planned to prevent this problem in the future.

That yellow plastic tube is part of the vacuum-actuated central locking system - one of the compromises on competitiveness yet to be removed from Project GTI.

The lower seat mount and a thinner bottom Recaro cushion made the quick-release hub used last season unnecessary, and allowed installation of the original horn button.

Doesn't your race car have floor mats? That item actually comes out for race events but keeps the interior clean while the car is being worked on.

Also visible here is the black, textured ABS plastic dash panel cut to fit the space originally occupied by the radio. Switches for the enduro auxiliary lights are mounted here.

The hand-held Halon extinguisher has been augmented with a 5-pound on-board fire system, also using Halon extinguishing agent. This is a push-release type system, so the trigger button and cable mechanism must be mounted handy to the driver and on a sturdy bracket - in this case, the piece that originally supported the interior center console. Release cable routing is also important, with large bend radii to prevent binding.

The hand-held unit is retained for incidental fires outside of the car - like sometimes happen when dry grass is ignited by a hot exhaust, under a car stuck out on course.

Interior wiring has also been rerouted and bundled out of the way. It is not permitted to simply remove unused wires under the Improved Touring rules, although the stock antilock brake sensors and passenger compartment wiring have been removed.

Click image for installation detail photos

Chief technician Cameron Conover of Greensboro, NC replaced the stock exhaust manifold with this original-equipment fabricated tubular unit out of a New Beetle. It is a direct bolt-in replacement for the original cast iron lump (below). While only dyno testing would prove that it makes more power, it sure seems to be a better design.

In addition to being 4.5 pounds lighter than the original part, this manifold should be stronger than an aftermarket racing header - an important consideration on a car that runs rallycrosses, endurance events, and for the first time this season, a tarmac rally

Click image for full-size image of the old manifold

A custom chip was also installed in the GTI's electronic control unit (ECU), recurving and advancing the timing, and increasing the rev limit from less than 6000 all the way to 7500rpm. The engine may not make more power at those higher revs but it will give the drivers more latitude of gear choice between turns.

The remains of the old exhaust system, most of which was hacked off at the VIR enduro last Fall, have been replaced by a custom-made 2.25" system built by J.R. Tire & Automotive of Creedmore, NC.

One interesting feature of the system is the compact, high-flow catalytic converter installed to replace the original unit (below). It incorporates both O2 sensors, preserves the Golf's road license status, and - as an unanticipated bonus - results in a cooler floor, due to increased air space in the tunnel.

Click for a full-size image of the old catalytic converter

The system also incorporates a muffler (not pictured) that quiets the car sufficiently for on-road use, like rally transit stages. Randy of J.R. Tire & Auto engineered a flange separation that allows the rear exhaust section to be easily removed and replaced by a simple turndown pipe, for roadracing events where the minimum sound threshold is sufficiently high.

We took advantage of an open Saturday afternoon and fabricated this floor-plate/dead-pedal unit, out of .063" aluminum tread plate.

I guess that we could have not used the polished stuff but who can resist a little bling on a race car?

PS - On-track data acquisition testing strongly suggests that the GTI is faster with the new muffler than it is with just the turndown! It will take actual dyno testing to get quantitative data so stay tuned for more.

We finally have a proper Improved Touring-spec gearbox in Project GTI, combining the better acceleration afforded by a 3.94:1 final drive gear set (from a MkII Diesel VW Golf), and a limited slip differential (LSD), manufactured by KAAZ in Japan and sold in the US by Bildon Motorsport.

The transmission was assembled by Charlotte-area VW gearbox guru Geoff Zimmer. Feel free to contact us by email if you want to get in touch with Geoff about work on your 020 or other VW 'box.

The function of a LSD is to force both front wheels to drive the car forward. With the stock "open" diff, the car turns easily as the differential gears allow the wheels to spin at different speeds, but the car tends to spin one wheel when accelerating hard - particularly out of corners, where the inside, unloaded wheel just whizzes away.

The numerically higher - but "lower" ratio - final drive (FD), makes the car slower in all of the gears than it would be with the original 3.86:1 FD. However, this makes the car accelerate more quickly, decreasing lap times, by the same action that lets all cars accelerate more quickly in low gears than in higher gears.


It's not much to look at but the new brake master cylinder, junkyard vacuum booster, and used fluid reservoir replace the much heavier and more complicated equivalent parts that came with the stock GTI antilock brake system.

Note that the front left port on the master cylinder is plugged (the bright fitting on the right in the image). One line comes off of the other front port and runs to the back of the car, through a driver-adjustable proportioning valve, to a tee junction, and then to each rear brake caliper.

Project GTI has also received extensive service in preparation for the Summit Point 12-hour endurance race, scheduled for the first weekend of June.

Since Project GTI ran originally in Showroom Stock trim, it was required that we use the stock alloy wheels. They were fine, as far as they went, but a switch to light alloy racing wheels will save a whopping 9 pounds per wheel!

The Hoosier tires illustrated here, as installed by PhilsTireService.com, are also lighter than the Toyos that we've used to this point, and can be expected to be marginally grippier as well.

We will debut this package at the 12 Hours at the Point enduro, the first weekend of June.

Rear suspension alignment has been modified with 1.5 degrees of negative camber (where the wheels are tipped inward at the top), through the use of shims from 247-parts.com.

These specially ground parts fit behind the stub axle, and align the tire tread more optimally with the track surface. This should make the rear tires wear more evenly and last longer, particularly in enduro events

The only downside to this change is that it provides additional grip at the rear end, aggravating handling that has tended toward understeer. New rear spring rates are expected to alleviate this situation.

Next New rear spring rates, additional service items, and the addition of accessories to prepare the car for its tarmac rally debut in September.

Last updated 8 May 2005
All photos K. Knestis unless otherwise noted

Project GTI is headquartered in Greensboro, NC


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All text and images © copyright 2003-2011 Kirk Knestis unless otherwise indicated. Other copyrighted images used with permission.