image1 image2 image3

HELLO EVERYONE!|WELCOME TO ZHAPALANG MOTORSPORT|YOUR ONE STOP MECHANICAL WORKSHOP|FOR ALL YOUR ROAD CAR SERVICING|PERFORMANCE UPGRADES|AND RACE TRACK PREPARATION

4-1 vs 4-2-1 Header(Extractor)

4-1 is for high end power and 4-2-1 is for lower end. For auto we always recommend 4-2-1 because your engine rpm cannot reach as high as manual. It will change gear about 7k rpm automatically for most of the car. Manual is different, you can rev until 9k rpm (depends on your car setup). When 9k rpm, a lot of exhaust gas will be generated. So, 4-1 is working good here.

4-1 has bad respond at low end because of back pressure from your muffler. Imagine your engine is running at 2-3k rpm, the pressure from outside the car is greater than your exhaust pressure generated by your engine. So, your engine will have extra burden now. You will feel more heavier to drive ur car, then u will press harder on accelerator. At last, end up burn more fuel.

4-2-1 is reverse theory. It can give higher pressure at low rpm to push the exhaust gas out from the car.

Conclusion: a 4-1 will give move the powerband towards higher regions, suitable for high-revving engines while 4-2-1 give a broader powerband, punchier low-end and mid.

Share this:

CONVERSATION

0 Comments:

Post a Comment

We are a Garage Auto Mechanic Car Repair Workshop in Kepong, KL, providing the following services:
  • Power Steering/Rack
  • Replace Lights
  • Electrical
  • Fuel Injection
  • Clutch Repair
  • Brake Service
  • Exhaust System
  • Oil Change And Lube
  • Axle Replacement
  • Ssuspension
  • Electronic Testing
  • Radiator Service
  • Engine Repair
  • Aftermarket Service
  • Transmission Service
  • Computer Diagnostics
  • Air Filter Replacement
  • Air Conditioning Service
  • Battery Testing & Replacement
  • Vehicle Preventive Maintanence
  • Belt And Hose Replacement
  • Clutch Repair
  • Engine Modification
  • Everything Include Glass & Body