:::RHMT::: Real Home Made Turbo

General Category => General Discussion => Topic started by: TheMadScientist on June 21, 2010, 09:03:10 PM

Title: Ever wonder how Dynojets figure horsepower?
Post by: TheMadScientist on June 21, 2010, 09:03:10 PM
http://www.factorypro.com/magazine/Sports%20car%20International%20magazine/Making_hot_rodding_Honest,1-5wNOTES.pdf (http://www.factorypro.com/magazine/Sports%20car%20International%20magazine/Making_hot_rodding_Honest,1-5wNOTES.pdf)

Well its all relative to a 1985 yamaha vmax and some imaginary number
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Joseph Davis on June 21, 2010, 09:10:49 PM
Common knowledge for some years.  A couple of the non-DJ dyno reps were handing them out, but honestly talking to the DJ reps themselves said everything about their product that needed to be said.

The best DJ's were the Drobeck designed 238C's, everything since then sucks mule cock.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Robb on June 21, 2010, 09:11:23 PM
Yeah I think we've been over this before on oHMT.  There's a reason they are called dynojunk numbers.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: TheMadScientist on June 21, 2010, 09:23:59 PM
Yeah I knew the formula was junk and had heard the story behind it but hadnt seen it in writing.

Learn young members ...... Learn
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Joseph Davis on June 21, 2010, 10:52:48 PM
It's interesting to note several high profile Dynapacks read 30% higher than local 224x's.  Both east and west coast.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: LS1pwNzJ00 on June 21, 2010, 11:11:17 PM
its also interesting to note that cars are balder on the east coast.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: bigdaddyvtec on June 22, 2010, 01:39:23 AM
It's interesting to note several high profile Dynapacks read 30% higher than local 224x's.  Both east and west coast.



ZING
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Stealthmode on June 22, 2010, 01:47:46 AM
So, then what would my dyno dynamics 478hp look like on the AWD dynojet? 
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: j.h.christ on June 22, 2010, 01:56:05 AM
So, then what would my dyno dynamics 478hp look like on the AWD dynojet? 

who cares, it's still a high 12 second car with almost 500 whp
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: sewell94 on June 22, 2010, 02:16:31 AM
What i've noticed is that the older DJ read way high, while the newer units seems to read about right.  We tuned a buddys 911 on an older DJ and switched to a newer one, and lost 80hp.    

The older DD units read very low, while the newer ones seem to be a little happier, i know something changed in the way they were calculating everything because a few buddies of mine all said they started to suddenly read higher after a software update.

 The mustangs seem to read on the conversative side(about right in my book),  new or old.  The land and Sea units(if set up properly) read about 1-2% higher than a mustang, but are very easy to munipulate to be made to read higher.  The superflow and mainline units also seem to read about right. I've never used a dynocom  or DP unit.

 All dyno owners think theirs read right, including myself. I can calibrate mine by hanging weights on it, last time i did it, with 1000lbs hanging on it, it was off by 1.14lbs. That's less than 1%, good enough for me.  A local machine shop has an engine dyno, using calculated drivetrain losses, were within a 1% or so of each other.

It is kinda funny that you menton those happy reading DP units, I hear that alot.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: LS1pwNzJ00 on June 22, 2010, 02:38:55 AM
So, then what would my dyno dynamics 478hp look like on the AWD dynojet? 

who cares, it's still a high 12 second car with almost 500 whp

Zing
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: jagojon3 on June 22, 2010, 02:40:46 AM
If I made a dyno it would be based on the length of my wang, strength of the Yen, current phase of the moon, and maybe BP's stock price.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: t_cel_t on June 22, 2010, 02:54:00 AM
i dont understand why its so hard to make an accurate dyno, it seems like pretty simple physics.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: lilpooh21186 on June 22, 2010, 03:07:12 AM
inertia dyno's are only acurate if all conditions are stock you dyno your car with 17in wheels and get say 250 hp put 14's on watch your number rise about 10-15% because you just changed your inertia as well as adding light weight flywheel and all other good things that free up rotaiting mass.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: crttaz on June 22, 2010, 03:41:33 AM
It's interesting to note several high profile Dynapacks read 30% higher than local 224x's.  Both east and west coast.

SLEW me a theory about Evans and Bisimoto.

118 whp DJ, 15% loss = 135 chp

change cam a slight MPG tune by Dave

121 whp Mustang, 20% loss = 145 chp

Timeslips showed the gains of 10 chp, know your tools :)
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Joseph Davis on June 22, 2010, 06:14:39 AM
inertia dyno's are only acurate if all conditions are stock you dyno your car with 17in wheels and get say 250 hp put 14's on watch your number rise about 10-15% because you just changed your inertia as well as adding light weight flywheel and all other good things that free up rotaiting mass.

Not all inertia dynos calculate the change in gearing that tire swap comprises.  Decent ones will compare wheel speed to rpm pickup to determine true gearing between crankshaft and tire interface, pulls in any gear (ASSuming traction) result in the same dyno output.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: lilpooh21186 on June 22, 2010, 09:25:56 AM
hmm good info Im still looking into 224xlc that or the MD Gladiator
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Joseph Davis on June 22, 2010, 10:40:25 AM
Common knowledge for some years.  A couple of the non-DJ dyno reps were handing them out, but honestly talking to the DJ reps themselves said everything about their product that needed to be said.

The best DJ's were the Drobeck designed 238C's, everything since then sucks mule cock.


hmm good info Im still looking into 224xlc

You're a fucking retard.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: lilpooh21186 on June 22, 2010, 10:53:39 AM
how so? JD ive done some research wont have my funds till after aug some insite will help
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: sewell94 on June 22, 2010, 03:19:38 PM
how so? JD ive done some research wont have my funds till after aug some insite will help

Buy my dyno, i've been thinking of upgrading.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Crackdown on June 22, 2010, 10:30:04 PM
You guys aren't seriously using a fixed percentage for drive train loss, are you?
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: HiProfile on June 23, 2010, 02:21:31 AM
You guys aren't seriously using a fixed percentage for drive train loss, are you?

Only when using a fixed boost step-retard.
Title: Re: Ever wonder how Dynojets figure horsepower?
Post by: Crackdown on June 23, 2010, 02:45:15 AM
You guys aren't seriously using a fixed percentage for drive train loss, are you?

Only when using a fixed boost step-retard.

Lol.