squeezing a little bit of hp from the old engine

shogun · Post by **shogun** » Thu Oct 12, 2006 10:03 pm

well im sumped, since the class im competig in autocross is for stock engines, and i play by the book, i looked for the best way to bolt on power so here is what i ended up with, an underdrive pulley, the original pulley was 1450 grams and the new one made from billet weighs 196, and it is 25% underdriven, i hope to get good results from this modification, in unothodox web page i read that every pound lost there yields about 2.5 hp the total weigh savings were 2.7 pounds

some pics of the process

Typrus · Post by **Typrus** » Fri Oct 13, 2006 12:42 am

How much was that?

Mac · Post by **Mac** » Fri Oct 13, 2006 3:22 am

watch out for those pulleys, my friend just took one off his car because it burnt out his alternator and wore out his serpentine belt because it was constantly slipping.

I've also heard mixed reports of spun bearings too.

shogun · Post by **shogun** » Fri Oct 13, 2006 10:01 am

i made it so it was cheap about 50 dollars i guess, since this is for a vbelt design there is not much trouble, as for the alternator the underdrive is just enough so it works properly

ill post pictures of the install

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Oct 13, 2006 11:28 am

Nice! I need something like that for my MR2.

Post by **ARCHINSTL** » Fri Oct 13, 2006 12:01 pm

terceldude wrote:...I need some for that engine swap I want to have put in or do the swap myself, depending upon the difficulty of the process.

I thought you were in Toyota's program to develop techs?
Which is your participating college?
Tom M.

shogun · Post by **shogun** » Fri Oct 13, 2006 1:41 pm

here are the pics of the install, the car feels like it revs a lot faster, but times on sunday will tell me

removed the radiator and lossen the old pulley

belt is off, then i used an extractor to get the pulley off

the pulley installed, just put everything back on

Mac · Post by **Mac** » Fri Oct 13, 2006 9:48 pm

shogun wrote:i made it so it was cheap about 50 dollars i guess, since this is for a vbelt design there is not much trouble, as for the alternator the underdrive is just enough so it works properly

ill post pictures of the install

check the voltage at the battery when its idling, his was about 10V, so the alternator was working at maximum capacity to charge the battery all the time, overheated and died. the slipping was a seperate issue that wore out his belt whenever he accelerated.

I beleive at idle you should have something like 13 volts.

shogun · Post by **shogun** » Sat Oct 14, 2006 8:46 pm

i get 14 volts from 800 upwards