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Thursday, September 8, 2011

Honda Civic LS-VTEC Journey
Over Bored Throttle Body

Next on my mod list was the Civic Type R Throttle body. Measuring in at 60mm the CTR throttle body was restricting the air flow to the Intake manifold and the VTEC engine is not "breathing" properly. So the next mod was to get it bored to 62mm to get a better air flow into the engine. It took 2 days for the machine shop to get it done. The Valve was also replace to accommodate the bigger barrel, as to ensure that there was no leakage. Feeling after installation was there was more torque in the mid to low RPMs. However more tuning needed to be done on the Greddy Emanage now that more air is coming into the engine, the Air Fuel ratio needs to be re-adjusted as well.

Piston INFO

Here are a few Compression Ratios relating to B16a heads on LS/VTECs courtesy of some calculating done by David Newman of the Hybrid Boards in an email he sent me...

"Well, first off, with what I've figured out in the past, compression ratios go for the following with LS/VTEC motors:
9.6:1 - P74 LS Pistons
10.0:1 - P72 GSR Pistons
10.8:1 - P73 US ITR Pistons
11.0:1 - P73 JDM ITR Pistons
11.5:1 - PR3 Pistons
11.7:1 - P30 Pistons
12.4:1 - CTR Pistons