Dyno Results

Bom Dyno Pic
HR Drag Pipe VS. HMF Slip-On
Lectron48, HR Intake, TheBom mild port with 1mm larger intake/exhaust valves, A1/A2 cams, K&N in airbox on both

Bom Dyno 2 Pic
Lectron48 on Gas, HR Intake VS. TM45 on Alky, FTZ Intake
TheBom mild port with 1mm larger intake/exhaust valves, A1/A2 cams, K&N in airbox, HMF Slip-On on both

I was pleased

JMiller

 

Nice numbers!!

 

Thanks 1BigDSRider but HR and TheBom deserve all the credit

 

Yeah but you had to fork over the cash.[img]i/expressions/face-icon-small-smile.gif[/img]

One question about the dyno numbers. I know the ugly stick is designed for drag racing, but it seemed odd that it dynoed less on hp and torque around 3700 to 4700. Not knocking it because I will probably end up with it. But I wonder why it made less hp in that range than the hmf pipe? I wonder if its a back pressure thing.

 

I'm not even going to try to answer that question...I'll leave that for MisterHP or 222 if they care to chime in for I don't want to give a wrong answer. I do know that when I installed the HMF and no other mod I felt alot more bottom end but top seemed to suffer...perhaps I didn't have it dialed in correctly.

JMiller

 

Loosing low end power by installing a bigger bore exhaust is very normal. This happens because of the low flow velocity of a large exhaust pipe. Smaller diameter or longer exhaust pipes helps low down power because they keep the air velocity high. At high RPM these smaller pipes can become restrictions and prevent high end HP. Larger pipes are required for higher RPM flow, but then they can cause low end power loss.

Also, if these exhaust pipes are tuned, they are designed to flow air at a narrow RPM range. Tuned exhaust pipes sometimes also cause power loss due to bad velocity at lower RPM.

There is a way to cure this problem, but it will require some electronics and a special little “device” inside the exhaust pipe. Interested to find out how to make something like this???


PS. Can you tell us more about what compression piston you where running and how this motor is different that the 70HP motor form MR HP?

 

I'm sorry that I didn't post that the piston used in all dyno runs is HR's 16:1 stock bore.

JMiller

 

I didnt know that Eric had come out with a 16:1 piston. That sounds like its pushing the envolope. Or do you mean 14:1?

Gary

 

Alcohol piston.

222

 

one of the dyno results says it ran with gas. Assume since the 14:1 kit is ran on 110 octane, so is the 16:1?? Don't know.

jbt