Buschur Racing's 1991 Eagle Talon TSi - Diamond Star Tuning - Project Hugger

10.54 @ 133 mph ( street tires )
How fast can I go? Well, how much money do you have? This exchange is a common one between power-hungry enthusiasts and tuning gurus. Will the pursuit for speed break the bank? Depends on the platform in question.

The Diamond Star platform is an all-star caliber performer. The DSM can go really fast in street trim with moderate upgrades; the first generation platform is the standout. You get a better head than newer models and a dramatically lower entrance fee for a car that is a willing participant in the pursuit of power. But how far can you push it with simple off-the-shelf bolt-ons? David Buschur of Buschur Racing has an answer-the Hugger Orange 1991 Talon TSi that graces these pages. The car was conceptualized as a street/strip proposition that retained its street drivability mechanically but got a bit carried away in the interior, which looks full-race for safety reasons.

Block Party
The foundation for thrust is a Stage 3 Buschur Racing short block fitted with a knife-edged and balanced crank, Crower con rods and 9.0:1 JE pistons. The block was bored 0.020-inches, honed and hot-tanked. Perched atop the 2.0-liter is a Stage 3 head that has been pumped for high-rpm duty.

Stainless-steel stock-spec valves, titanium retainers and shimmed springs react to special Buschur-spec camshafts as the 4G63 spins wildly to its 9000-rpm redline. Pressure is sealed in via ARP hardware and a stock Mitsu gasket.

Pressure Point
The stock TD05-14G has been discarded in favor of a Buschur Racing BR-57 Garrett-based T3/T4 hybrid. The turbine housing of the unit has been designed to Buschur Racing's specs and the wheel's trim and other details are proprietary. The turbo is positioned via a trick cast manifold and is regulated by a Turbonetics Deltagate and a Hallman manual boost controller.

The manifold looks like a nice piece of work, with thick flanges, large primaries, excellent turbo location and good placement of its external wastegate flange. Intercooling chores are handled by a Buschur Racing front-mount kit that utilizes a 33.5x13x3.5 inch core and 2.5-inch diameter inlet piping and 3-inch outlet piping to deliver the chilled charge air.

No Fuelin'
Air is only half the equation. Fuel, in the proper proportion, has to be present to realize the maximum potential of any engine combination. Project Hugger relies on a simple stock-based fuel system that retains the factory rail, feed and return lines and even the factory filter. Upgrades include 660cc Nippon Denso injectors, a high-flow fuel pump and an SX adjustable regulator with a Buschur Racing mount kit that joins the regulator to the rail.

Factory-Based Tuning Tech
The effort to keep the car streetable and simple is most evident in the tuning department. David Buschur elected to employ a ROM-tuned ECU and an HKS vein pressure converter (VPC) to oversee engine operation instead of a complex and expensive stand-alone engine management system.

The VPC tunes throttle response, idle characteristics and the entire fuel curve in 2-percent increments. It also replaces the restrictive Karman-style mass air sensor on the Mitsubishi. The tasks assigned to the mass air sensor are performed by the VPC, which works under the speed density banner. Speed density takes sensor information to determine the proper fuel maps for the engine. The maps, which are formulated using complex algorithms, are contained within the VPC's 16-bit central processing unit. The VPC uses different chips for different cars and for bigger injectors. In this application, Buschur Racing has designed its own chip. The VPC is joined by an HKS graphic control computer (GCC), which adds more precision to the tuning process. Where the VPC tunes the entire curve, the GCC affords tuning at five pre-set rpm intervals. The GCC interpolates the curve between the tuning points to ensure smooth fuel delivery.

The Bottom Line
The car has recently been tested in fwd form, generating over 550 hp at the wheels with more to come as this season's modifications are completed. An Advanced Clutch Technologies (ACT) clutch feeds the power through a welded factory center diff by way of a stock factory transmission. Our experience with Turbo's Project Talon is a testament to the woes encountered when one gets overzealous with the stick shift.

This has not been the case with Project Hugger. The car's regular pilot, Buschur's brother, Dan has been able to drive gently. His tender shifting and the fact that the car runs street radials at the track are major factors in the longevity of the gearbox. Despite this and a tame, street-lowered suspension, the Talon has clawed an impressive 10.54 at 133 mph. Look for the Hugger to be beaming at a strip near you. We hear it may be taken a few steps further in hopes of dramatically dropping e.t.s. Regardless of future accomplishments, the Talon vividly illustrates the potential of the first-gen DSMs and the potency of Buschur Racing.

Power Technik

Vehicle: 1991 Eagle Talon Tsi

Best e.t.: 10.54 @ 133

Engine: 4G63

Displacement: 123 CID

Forced Induction: Buschur Racing BR-57 T3/T4 turbo, cast manifold

Intercooler: Buschur Racing air-to-air front-mount

Nitrous Oxide: n/a

Fuel System: BR pump, SX regulator, 660cc injectors

Ignition System: Crane HI-6DI

Air Intake: BR sheetmetal manifold

Exhaust: Open

Boost Control: Turbonetics Deltagate wastegate, Hallman manual boost controller

Engine Management: Tuned ECU, HKS VPC, HKS GCC

Curb Weight: 2,758 lbs w/driver