Topic: My FIRST dyno, ever! [WESTERS / RESULTS]

[snaponbob]

According to Lyndon, dyno's show POSITIVE numbers on the way UP, and NEGATIVE numbers on the way DOWN. The dyno operator needs to be asked to retain data in BOTH directions. Then the data is used from a few places in the curves to do the division and POOF, a percentage is achieved. BTW, he found the 13% figure rather ....  ummm ............ curious. His basic statement was that NO automobile, front, rear, or all wheel drive is that efficient, period. And, that assumes manuals as automatics are worse.  And don't shoot the messenger.

[Critterman]

it all has to do with the fluid molecular structure of the kineveling pin download shaft in relation to the coefficiency of drag of the muffler bearing.

In other words JFM

[snaponbob]

Cool matched spark plugs and blueprinted battery terminal help, too. But don't tell anybody about my secret weapon -- balanced hazzelflam air management spreaders.

[Kelu]

It is me or idk  I didn't understood too much from SOB's reply 

In did 2 dynos on a european dyno where they let the car to break by itself and the dyno measures how fast the cars slows down and than makes an estimation for drivetrain loss, that dyno showed I have only 12% loss 

[snaponbob]

Ask Lyndon. He is who I am getting info from.

[tazz]

I would like to see how he gets 13% also.  

Im talking about a totally different vehicle NOT THE SOL.
But I am wodering and very curious how the heck a 5200lb truck with a huge ass tranny and 2 split drive shafts has a 13% drive train loss vs the Sols 18%?  Like I stated Ive got Hundreds of dyno sheets from all over the US that bear that out for the 99-03 L's and 02-03 Harley trucks.  The only explaination I can comeup with is that FORD actually UNDERATED the power ratings and they are actually higher than what Ford states or that tranny is really that efficient or most use Dynojet dyno's which could also be why instead of Mustang dyno's?  BTW info from National Lighting Association, Lightning Rodder and National Harley Truck Association which Im a member of all three.

[MGar]

I thought it was well known that the 5.4L S/C engine was underrated along with the 4.6L S/C '03-'04 Cobras, and LS1 (rated in the vette at 345, rated in F-bodies at 300) '98-'02 F-bodies.

[Kelu]

tazz: don't forget Kappa has also a truck gearbox

[kennysabarese]

Every dyno thread has a debate about which dyno sucks or drivetrain loss. *sigh*

[2.0 tspeed]

It's not rocket science, why all the debate, everybody cries if it's lower or higher then someone elses

[snaponbob]

It's not rocket science, why all the debate, everybody cries if it's lower or higher then someone elses

Why? Ego. Meaningless. With a good tune and 93 octane gas, any LNF Kappa will have 2nd gear traction issues at 5K rpm regardless of what a graph shows. Beyond that, it's "dyno racing". More power? Spend $7/gal and refresh the tune and you'll melt the stock rubber in second gear and have traction issues in 3rd. Bigger turbos? More power but less low end and more traction challenges. Want more? Buy a Z06 !!!!!!!!!!!!!!!!!!!!! Drivetrain power loss? Honestly, who cares? Want less loss? Change the trans and diff lubes to lower viscosity, do the dyno run, and change it back !!! More "dyno racing". Bottom line, what any particular car puts to the ground is unique, tunable to a certain extent, and is racing - drive better. No matter what the power output is, if it isn't used well, it's wasted, isn't it? After all, beyond print outs, how the car performs is the result of the total package.

[Critterman]

All of it is useless unless you have a base run to compare it to, and even then it won't be exact, temp, humidity, what color socks you are wearing all are factors in the results.

[Sol Asylum]

GJ isn't wearing any socks so how does that affect his dyno?  Maybe that's why his car isn't running properly.  You hear that GJ, put some socks on you hippie!

[Graywolf]

I suspect just taking a stock lnf gxp makes260 hp at the crank[assuming Gm isn't lying] subtracting the rwhp from the 260 will give you a very close number. Based on wester stock dyno runs=35 horsepwer lose at the rear wheels. My car just dynoed @ 355rwhp add 35hp for crank hp=390hp. If I used percentage my crank hp would be higher since engine rwhp dynoed higher.

[snaponbob]

I suspect just taking a stock lnf gxp makes260 hp at the crank[assuming Gm isn't lying] subtracting the rwhp from the 260 will give you a very close number. Based on wester stock dyno runs=35 horsepwer lose at the rear wheels. My car just dynoed @ 355rwhp add 35hp for crank hp=390hp. If I used percentage my crank hp would be higher since engine rwhp dynoed higher.

OOOPS !!!!!!!!!!!!! Math fail !! The assumption that a 35 whp loss from stock equals ONLY 35 whp loss from a higher horsepower tune of the same engine may not be true. Power loss will not DECREASE at higher power and rpm. Why should it? Only true measurement can reveal what is REALLY happening at the crank and then at the wheels. Anybody want to yank an engine out of their [fill in the blank] and toss it on an engine dyno?

I predict crickets.

[Gentleman Jack]

SOB,

I pulled my engine tonight after dinner.  I threw it on the engine dyno and came up with 317.8 hp and 381.8 ft lbs.  After that, I put the engine back in the car, changed the oil while I was underneath and redid a dyno run on the other dyno.  Came up with 274.4 hp and 329.2 ft lbs.  If my math is correct, that would equal about a 16% driveline loss.

So, there everyone has it.  For my car, and my car only, with an automatic transmission, I deal with 16% driveline loss.

Thanks,

GJ

[snaponbob]

WHAT ?!?!!?!? Terrific. Folks, THAT is selfless dedication to the membership of this site. Jack, my question is this ---


where are the  disclaimers ???????

Funny stuff. Thanks. Not THE best way to start the morning, but a good chuckle is a close second.

[old goat]

Like Bob said drive train loss is NOT a fixed number, it is a percentage and even that is not constant, it will be different in different gears and at different rpm. Therefore BHP numbers are stupid, and mean nothing, they are just a way to sell cars. Most race teams have the ability to dyno and engine, and do when they are designing headers and setting up injection, ask them what the BHP numbers are they have no clue, because the numbers are useless. They usually don't know what the RWHP numbers are either, it's about the curves! Gardella Racing can get 600rwhp out of there Solstice with a LSJ, they have it running at just over 500 rwhp to get the best torque curve for what they do. I have dynoed my car many times, numbers are irrelevent, Lyndon took the data and my car with TC off will kick the back out in any corner which is exactly what I wanted, I like driving sideways.

[snaponbob]

Actually, some race teams DO dyno drive train components. In the 90's, RCR opened up their Friendly, NC campus for a (first ever) tour that was exclusively for Snap-On. They had JUST finished a chassis dyno a month earlier. While there, they were just returning from a race and was strapping down Dale Sr's car for an after race run to see what changes in drive line losses they experienced. Since the install a month earlier they were SO shocked by the high driveline losses that they were modifying engine dynos as well as creating transmission and differential dynos to check for losses. According to employees that were doing the studies and working with the various shops, their goal was to reduce to 13-15% from the OVER 20% losses they were seeing. Beyond that, they were rather tight lipped other than to say they had crate loads of bearings, u-joints, and gears  they were working with. You can bet that auto manufacturers are more concerned with production costs than a couple percentage points of drive line losses.