dhughes Posted February 25, 2010 Share Posted February 25, 2010 I was just wondering why l28et make so much more TQ than HP, I always noticed on other engines it was the other way around? Quote Link to comment Share on other sites More sharing options...
19762802+2 Posted February 25, 2010 Share Posted February 25, 2010 HP = TQ*RPM/5252 Looking at the formula, HP is ALWAYS lees than TQ when the RPM is below 5252. When TQ is larger than HP, it just means that it makes the power at a lower RPM. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted February 25, 2010 Administrators Share Posted February 25, 2010 As already stated, Torque is measured, HP is calculated, (amount of torque produced in given time frame, RPM). As for why this is so with the EFI L-6, partly due to cam timing, partly due to this is an old engine design that was a state of the art 2 valve OHC design back in the '60's when this engine was introduced. Personally, I feel a bigger reason for the nice torque production, yet lacking relative HP figures is the stock EFI intake runners. These runners are only 53% the area of the intake valves themselves. Other intake manifolds, including manifolds for carbs, tend to allow the engine to breathe better in the upper RPM range (more torque above the 5252 RPM cross over), allowing for more HP production for a given peak torque figure. Maybe TonyD, Timz, JeffP will chime in as well. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted February 25, 2010 Share Posted February 25, 2010 I'll add that the stock cam/head combinations for the L engines usually have torque peaks in the 4-4.5k rpm range and then fall of pretty rapidly afterward. Add a more aggressive cam (which will shift the torque peak to a higher rpm)and do some headwork to improve flow and the HP peak can exceed the torque peak. Quote Link to comment Share on other sites More sharing options...
dhughes Posted February 26, 2010 Author Share Posted February 26, 2010 ok thanks, so basically, by opening up the intake manifold and heads/cams will even out the hp/tq.. Quote Link to comment Share on other sites More sharing options...
MAG58 Posted February 26, 2010 Share Posted February 26, 2010 You also have to think about what you're doing with it. The advantage of cute lil' ports especially on the exhaust side is that port velocity will be high. This leads to lots of nifty off idle response and it will spool a turbo a little quicker than a comparative head with bigger flow numbers. That means that below 5grand (where you spend 90% of your time, well for some people it's more like 30% of the time, but to each their own) everything runs better and it will hustle the car a little better than a monster flowing head at the same RPMS. Quote Link to comment Share on other sites More sharing options...
jc052685 Posted February 26, 2010 Share Posted February 26, 2010 ok thanks, so basically, by opening up the intake manifold and heads/cams will even out the hp/tq.. If your on the stock turbo it runs out of breath pretty fast too. Just a cam otherwise will balance it out. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.