We had the parameters set for 4th gear & pull to 6200 even though I was leaving 500 rpm on the table. Opened the borla partially and proceeded to make a run. The german doing the run had a hard time getting the thing in gear. Don't think a short shifter could be so short! Perplexed for a minute to say the least. Everyone is standing around the he guns it once in 4th. Error too great slippage. Looked at the chart and it came out to like 350 bhp. So we had 2 guys sit on the trunk after I opened it and they were at least 350lbs in total weight sittin on my back.
He goes through the gears again and gets it in 4th and just jams it. The sucker screamed and shot 2 nice puffs of black smoke. Sweat music to my ears baby. Looked at the reading and........................ eh-eh.

He never got it to 6200 rpm only 5620 before the dyno shut off from too much slippage w/a extra 350lbs out back! BHP was 420 and climbing, torque read 381 rwhp corrected @ 4920 rpm AND climbing! Not bad for a mail order tuned chip and still pig rich. My friend is thinking 420+rwhp easy esp if we had wound it out to 6800-6900 rpm. I got to find the conversion for bhp to rwhp and see what it is. I still don't think it's that powerful personally, I guess I've always downplayed the car since day one.
So what is the conversion factor for bhp for hp? Anyone know?


Silas,

 

Sounds like its makin some power I don't know the conversion formula for ya though...And damn, your sig is HUGE

 

To convert from rear wheel HP to flywheel HP, you need to divide rear wheel HP by (1 - drive train losses). I was able to run my engine on an engine dyno with the full intake and exhaust, then do a chassis dyno after it went into the car. I was running a T56, Street Twin, 3" chrome moly DS and a 12-bolt. Losses at 486 flywheel HP were 12.8%.

Conservatively, assume about a 13% loss for your HP level. So, you need to divide rear wheel HP by 1.00 - 0.13 = 0.87 to get flywheel HP.

Your post is a little confusing:

??????

 

Excuse me for my ignorance but I was speaking with a dyno tuner and he was trying to explain BHP to me. Unlike regular HP which simply reads the rearwheel HP levels the BHP is supposed to indicated what the most constant HP level is through the entire car from the drivetrain down to the wheels. Not quite sure what he meant but it's supposed to result is an all around better tune making your car more efficent as opposed to simply slamming as much HP down to the wheels.

A BHP is supposed to be a much lower number than you'd get from a simply RWHP reading but it uses a completely different system.

Email the guys at http://www.brgracing.com and they may be able to explain it better than I can.

 

Sorry for the huge sig. I know it's supposed to be 5 lines or less but it was just for the post only. Don't post my sig anymore.

Yeah I know it sounds confusing but they had a corrected rwtq readout but not for hp only bhp? Sounded skeptical to me as well but that's what their printout says.

As for the formula I'll try that out and see what I come up w/. Thanks for the help!

 

Here's an interesting article that I found on the subject...

http://www.grapeaperacing.com/GrapeA.../miscpower.cfm