I put in a EPI pink Spring and tried some VP ultimate 4 fuel over the weekend and the results were great. We set up a 300' test run on a dirt road and had a radar gun to use. We were timing the runs with a stop watch. I'm running a V force with just a Twin Air filter and a EPI pink spring installed. A freinds Raptor has a CT Sonic pipe a advanced timing keyway a 3+ rear swing arm. both bikes topped out at 52 MPH. the Raptor was a little quicker with a time of 6.47 seconds. The V Force was running about 6.74 seconds. The V force was having a problem keeping the front end down and we were having to let out of it. I will do some more runs on pump gas and post the results so you can see how much was gained. We did not have to rejet to run the VP Ulimate 4. The fuel burns clean. The only problem is the ordor it puts off setting in the garage. We were at about 1,000 above sea level.

 

damn i had a friend of mine time me on a kfx700 and my friend on a yfz450. my wheeler with a HPD plain spring and his with his baffel removed and air box lid removed and he started in 2nd gear. i got times right around 5.5 and mostly spun alot but so did the 450. his fastest time was only .09 faster then my fastest drag. all this done in 300 ft. sometimes i can beat him if i drag my best and he doesnt quite do his best but were close. the times done in same lane and same timer.. maby something with the mesuring was messed up on my drags or sometihng but the timer was on fine. i wana kno if anyone thinks this wrong. i dont kno the evelation but im in norwich newyork which is kinda in a vally so we aint that high of elevation.

 

The problem we were having was the ground was so dry we were spining the tires almost the entire run. the other problem was we were still having a problem keeping the front end down. We did measure the run with a 100' tape so the distance was accurte. We were on a gravel road. Next time we do some runs we found a dirt road to use and we think we will hook up better. I will post back and let you know.

 

A smaller rear tire will keep the front down but then you loose too much traction. We had to put the 22" back on to get back to 5.8 sec range.

 

but wouldnt having smaller tires give you more torque...making the front end come up even faster?

 

only if they hookup! More torque will spin the tires easier which is what you want to keep the front end down.