Header, Chevrolet Colorado 5-cylinder
••• click the following link to See New BOLT-IN HEADERS
The JTR/Stealth Conversion’s long-tube header is designed to improve power and torque.
The primary tubes are 1-5/8" diameter. The lengths of the primary tubes are 29" to 34".
The collector is 3" diameter.
The performance improvements on an otherwise stock 2005 extended cab ZQ8 with the 5-cylinder/automatic and 3.42 gears are as follows:
0–60 mph, 7.7 seconds (average of three runs)
1/4 mile, 15.9 seconds at 89.2 mph (average of three runs)
Modified with JTR/Stealth ram-air intake:
0–60 mph, 7.5 seconds (average of three runs)
1/4 mile, 15.7 seconds at 90.4 mph (average of three runs)
Modified with JTR/Stealth ram-air intake and header:
0–60 mph, 7.2 seconds (average of three runs)
1/4 mile, 15.4 seconds at 91.6 mph (average of three runs)
All measurements were made with a Vericom 2000 accelerometer/performance computer.
All of the above tests were done with the outside air temperature at 45 to 50 degrees F, which helps explain why the 1/4 mile performance and 0-60 mph times are better than most other published information.
The outside air temperature has a very noticeable difference in the 1/4 mile performance — this is, in part, due to the high compression ratio of the stock engine.
When the truck was tested in 70 degree weather, the quarter mile times were lower by about .4 seconds, the trap speeds were slower by about 2 mph, and the 0-60 times were about 0.5 seconds slower. This also provides proof of the performance benefits of a cold-air intake.
All tests were done with a full tank of 87 octane gasoline.
Using a formula to calculate horsepower based on 1/4 mile performance, the header adds about 10 hp. The header and ram-air combined adds about 20 hp.
This header will not fit on the 4wd trucks or the Hi-rider, Z71 trucks (trucks with torsion bar front suspension).
Installation requires modifying the heater hoses to provide clearance between the header and the heater hoses.
On trucks with automatic transmissions, the dipstick tube will need to be bent slightly, and the bracket that attaches the top of the dipstick tube to the cylinder head will have to be bent.
The exhaust system requires cutting and welding which can normally be done by most muffler shops.
The header is not smog legal, and is for racing and off-road use only.
HEADER INSTALLATION INSTRUCTIONS
The basic installation will probably take three to four hours -- this does not include the trip to the muffler shop.
A muffler shop should be able to connect the header to the exhaust in less than an hour.