MattA 164 Report post Posted September 30, 2004 Was talking to a guy recently who reakons fitting an electric water pump will gain hp? sounded bit odd but his theory was that it takes power to drive the mechanical water pump so by-pass it and use a high volume electric pump therefore you re-gain the lost power. Anyone heard of this being done or of the theory? I don't think that i would be keen to try myself but if it worked and was reliable could be an easy external mod. Quote Share this post Link to post Share on other sites
Carl 3 Report post Posted September 30, 2004 Similar concept to using an electrical fan I guess...would only work if you're altenator can handle the extra power requirements...but I doubt it'll have much effect Quote Share this post Link to post Share on other sites
318is 0 Report post Posted September 30, 2004 Electric water pump - $125-00 Connectors and wiring - $2.50 Labour - $ 0 New motor when electric pump fails/power cuts off $3500-00 For the puny benifits its not worth it. :gay: Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted September 30, 2004 maybe for a 1 hp? Not worth it. Quote Share this post Link to post Share on other sites
gmccormack 0 Report post Posted September 30, 2004 Electric water pumps are only intended for serious drag racing applications, where no alternator is used.If you use it with an alternator in a street application you will lose power not gain it. The extra current the alternator must produce to keep pace with the load placed on it by the electric pump wastes more HP than driving a mechanical pump directly from the crank. Quote Share this post Link to post Share on other sites
MattA 164 Report post Posted September 30, 2004 As I suspected theory is better than reality... in the same basket as the electric supercharger.. the old saying "if it's too good to be true it probably is" Quote Share this post Link to post Share on other sites
Guest Andrew Report post Posted September 30, 2004 Electric water pumps are only intended for serious drag racing applications, where no alternator is used.If you use it with an alternator in a street application you will lose power not gain it. The extra current the alternator must produce to keep pace with the load placed on it by the electric pump wastes more HP than driving a mechanical pump directly from the crank. to stop it cavitating? (curious now) Quote Share this post Link to post Share on other sites
Guest Spargo Report post Posted October 1, 2004 Uh, race cars use electric water pumps, i guess they can afford to waste power then? Quote Share this post Link to post Share on other sites
bumpstop325 0 Report post Posted October 1, 2004 my suggestion is to underdrive the pulleys. increase the radius of the pulleys some the engine dosent have to work as hard driving them. simple lever physics. also use alloy pulleys, less weight to spin. i have read articlies about this, im not too sure on the thermo increase stresses on the engine. Quote Share this post Link to post Share on other sites
gmccormack 0 Report post Posted October 1, 2004 Uh, race cars use electric water pumps, i guess they can afford to waste power then? No. Running an electric pump from an independant battery as in a top fuel dragster= power gain. Running an electric pump from your cars battery & then having your engine working harder to replace energy the electric pump used= power loss.Every time you have an energy exchange there is a power loss.The more exchanges you introduce into the system the greater the loss.So, crank turning water pump via 1 belt = 1 exchange = low parasitic power loss. Electric motor turns pump, battery drives electric motor , alternator charges battery ,crank turns alternator= 4 exchanges = high parasitic power loss. Dragsters have an advantage over street driven cars in that they are running for such a short time they simply do away with an alternator all together and change batteries between runs Quote Share this post Link to post Share on other sites
318i Turbo 0 Report post Posted October 1, 2004 matta the guy that told you this is right, iv seen motors that have made very impesive gains from doing this its all in the same theory as people removing there a/c, power steering, rad fan etc etc, the less the engine has to turn the better and it dose take a fear bit of power to spin the fan, pump the water though the rad Quote Share this post Link to post Share on other sites
