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Old 08-14-2008, 11:33 PM   #21
Jamestwilliams
junior member
 
Drives: Grand Am
Join Date: Aug 2008
Location: canada
Posts: 534
Quote:
Originally Posted by radz282003 View Post
There was a GMHTP buildup on an LS1 WS6 (that was eventually bored and stroked to 383 ci) wherein they swapped the OEM manifolds, SLP Y-pipe, and B&B catback with Dynatech LTs, QTP QTEC, and Borla CB. After tuning, they ran N20 runs with the cutout opened and closed and only gained ~ 8 RWHP, but something like ~ 30 RWTQ! That was around 430 RWHP though, so those gains will likely be higher than on a stock SS with manifolds.

Okay to explain something here, the reason there is an increase of only 8 rwhp while adding 30 lb/ft rwtq is in how the drive train works. What the gear reductions of the transmission and rear end accomplish is an increase in torque at the rear wheels. To move a car from a dead stop requires thousands of lb/ft of torque (for example based on the tranny and final drive of the ss you should get about 4000lb/ft of rear wheel torque. Some custom rockcrawler 4X4s are so low geared they get up to 30000lb/ft of rear wheel torque). So the larger torque number is due to the effect of gearing making a small difference a bigger difference at the rear wheels making an additional 30lb/ft of tourque inconsequential. That's why horse power was developed in the first place it accurately measures a comparable number as the gear ratios can increase or decrease torque. Even in sixth gear the new camaro will put out about 800lb/ft torque at the rears. So the moral of the story is don't fall for companies bragging about an increase in rear wheel torque that's why we use horse power.
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