The final test configuration in this session was to replace the short header system with the full length units. The full header system is an off-road-only modification, as the collector extends to well past the location of the stock cat. The "race" header, tested with the induction ram pipe still in place, netted a small increase in peak horsepower output to 116.3 hp. More significantly effected was torque output, with the peak now edging up to 119.6 lb-ft. With the full-length header, the lower and mid-range torque filled out nicely. Compared to the stock baseline, torque at 5,000 rpm was up by 21 percent with the long header and induction tubes; power that will make itself known when you're foot is on the mat. Even the "street" system, though softer down low than the long pipes, boosted torque by about 10 percent at the bottom of our test range at 3,000 rpm, and by as much as 19 percent at 5,000 rpm. These mods will really make the Neon engine come to life.
While our dyno numbers are based upon testing the SOHC engine, tti has developed similar upgrades for the DOHC engines. Preliminary testing has shown substantial improvements are up for grabs with those engines as well.
Torque LB-FT
2-liter SOHC Neon
DynoJet Dynamometer
Tested at Brother's Performance Warehouse
| RPM | Base | Short | Indct | Long |
| 3,000 | 102 | 109 | 112 | 116 |
| 3,500 | 101 | 107 | 109 | 113 |
| 4,000 | 102 | 108 | 113 | 118 |
| 4,500 | 102 | 110 | 112 | 118 |
| 5,000 | 96 | 108 | 114 | 116 |
| 5,500 | 95 | 103 | 108 | 109 |
| 6,000 | 82 | 93 | 97 | 97 |
Horsepower
2-liter SOHC Neon
DynoJet Dynamometer
Tested at Brother's Performance Warehouse
| RPM | Base | Short | Indct | Long |
| 3,000 | 58 | 62 | 64 | 66 |
| 3,500 | 67 | 71 | 73 | 75 |
| 4,000 | 78 | 82 | 86 | 90 |
| 4,500 | 87 | 94 | 96 | 101 |
| 5,000 | 91 | 103 | 109 | 110 |
| 5,500 | 99 | 108 | 113 | 115 |
| 6,000 | 93 | 106 | 111 | 111 |
Legend
- Base: Stock '98 SOHC Neon, 60,000 miles
- Short: tti "street" short-tube header; tti 2 1/2-inch exhaust system with high-flow catalyst
- Induct: As above, with tti ram induction pipe and high flow gauze/mesh filter
- Long: Full-length header; tti induction pipe and filter; tti 2 1/2-inch exhaust system w/o catalyst
The shorter header is equipped...
The shorter header is equipped with a bung in the collector to accept the upstream oxygen sensor. The downstream sensor mounts in the head pipe aft of the converter. With the long-tube design, the upstream sensor mounts in the number one primary pipe, while the second sensor threads into the collector.
DOHC headers are very similar...
DOHC headers are very similar to the SOHC units, however, the primary tube entry is modified to match the elongated shape of the head's exhaust port. The tti primary pipes smoothly transition the port shape into the primary tubes.
In conjunction with the aided...
In conjunction with the aided breathing on the exhaust side, Neons benefit from an improved air entry tract. TTI makes this air tube and filter system, which together with the short exhaust header and exhaust system ups the power of the Neon SOHC powerplant by 15 percent.
An underhood view of a prototype...
An underhood view of a prototype install at the tti plant illustrates the air induction system's layout and routing. note the nicely made strut brace bar, which transverses the upper suspension mounting points-another tti product for the Neon.
A similar bar is manufactured...
A similar bar is manufactured for the rear by tti to stiffen the chassis under demanding cornering situations.
A heat shield is manufactured...
A heat shield is manufactured by tti to keep the exhaust header from radiating heat to the induction.
To limit the engine's torque...
To limit the engine's torque reaction under hard launching or power shifting, tti has available a solid forward mount. The mount reduces engine deflection in the chassis to a minimum and doesn't impart the expected degree of harshness.