dyno day results march 11 duals

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timbomoose · #1 Post by **timbomoose** » Fri Mar 23, 2007 9:27 am

Went to the dyno last week and got the long awaited results from the duals. We were hoping and planning to get a 3 pipe shootout,but everything was fighting us all day. So we did the best we could. For the shoot off we used speed1b's 478 drag quad. The shoot off was against the full hmf and the new dual exhaust. We were going to shootoff against the fmf also but problems that didn't allow this to happen,but from prior test dynoing the fmf and full hmf seemed to put out equal hp and torque. Here's the results to sum up alot of runs in short. Full hmf barely squeaked out the duals in tq and hp up to 7000 rpms.The hmf won by less then .5 hp and .5 ft lbs tq.I guess you could really call it a draw. From 7000 to 8000 rpms was dead even. From 8000 to redline 11,100 the duals won by 2.4 hp.This in reality adds up to about a true 1.5hp-2hp gain from 8000 to redline in the real world due to the extra weight 7pds =1 hp.The pipes were not weighed for exact,but is an max estimated senerio. Both pipes were tweeked to the gill for power in timing and fuel throught the entire powerband.We had 3 different length silencers and the short ones 9" (just like the ones being sold)won by a landslide.In comapisons against the long silencer the hmf was the winner.In my opinion the people who would benefit from the dual exhuast system would be drag racers, tt racers,i ceracers, or sand riders. Basically anyone who rides in top of the rpm range. For cross coutry or motocrosser I don't see these as being as beneficial becuase of gains are only at upper rpms. There could have been possibly a little more gains due to leakeage around the headpipe and the head caused from a stud cracking when changing pipes over. In my opinion and proven from the dyno these pipes do build MORE POWER. A true 2hp is the real world is well worth its $. Different size motors could result in slightly different gains but would expect it to be all in the same rpm range.The reason we didn't get to test the fmf in the shoutout was because the oneway bearing was going out in speed1b's quad and by halfway through the runs we were wondering if we could even make it through the dual test,by the time we got through the duals the one way bearing was completely spent.Here's the end results of the dual exhaust whopping 59.44hp and 37 lbs tq.

Blue duals red hmf

cannondale27 · #2 Post by **cannondale27** » Fri Mar 23, 2007 12:17 pm

Cool!Looks like he may have hit 60hp if the tires didnt slip right at peak.

Happyboy · #3 Post by **Happyboy** » Fri Mar 23, 2007 8:53 pm

I thought we saw like 61.5 hp?

Guy310 · #4 Post by **Guy310** » Sat Mar 24, 2007 6:30 am

They may even up on HP with the HMF but they way tip the scale in cool factor. I am ordering a set.

timbomoose · #5 Post by **timbomoose** » Sat Mar 24, 2007 2:32 pm

"I thought we saw like 61.5 hp?"

No the 505 broke 62 but had to stop because of noise and didn't get to the short cans which gave about +2 hp over the long cans probably would have seen 64-65hp. These charts were from speed 1b's little 478 getting this kind of power.Quite awesome.

mxracer776 · #6 Post by **mxracer776** » Fri Jun 01, 2007 7:37 pm

any chance of seeing a pic of these pipes mounted.

T-Rex · #7 Post by **T-Rex** » Fri Jun 01, 2007 9:41 pm

Looks good for the duals, there might be a 495 build in the future for mine with a set of duals!! Watch out Wistech???? You might have to fly down here to Texas and help me put it in, I have enough flyer miles for you to do that. I wait till we get into the 100 degree mark first....