Can You Diagnose This Dyno Chart?

[nev62]

Hi People,

Can anyone have a guess at the Dyno Chart below as to why I have a drop in power and torque from around 2400rpm to 3000rpm? The blue lines are my early 6.5lt and the red is a later model that was just rebuilt before its dyno run. both are non turbo.

My dyno run was after the injectors and ip were rebuilt.

http://users.tpg.com.au/nev62/images/6-5lt%20dyno.jpg

[More Power]

The IP governor perhaps... or a fuel supply issue (plugged fuel filter or bad lift pump).

Jim

[gmctd]

Those look normal to me, for a n\a 6.5 - the blue was in dire need of help, unexplainable at this time as you cannot do the required maintenance for improvement with re-runs, the red shows what may have been accomplished by the improvements - fuel type, fuel supply, air filtration, injectors, IP, timing chainset, etc, as MP suggests.

The red is lookin' really good - try a turbo for improvement.............

[nev62]

The blue (my engine) shows it just after spending $4400 in having the tank cleaned and resurfaced, all filters changed and ip plus injectors rebuilt.

[gmctd]

My bad, then - even tried lookin' at it upside down, so's I could get a sense of the view you have down-under - looks even worse, that way, eh?

Say wha.......44 hundred bucks to drain and clean the fuel tank? And they call 'em 'stealers', here!

Are both vehicles comparable - same trans, same final drive, same tires, same exhaust, same intake, etc?

[nev62]

My bad, then - even tried lookin' at it upside down, so's I could get a sense of the view you have down-under - looks even worse, that way, eh?

Say wha.......44 hundred bucks to drain and clean the fuel tank? And they call 'em 'stealers', here!

Are both vehicles comparable - same trans, same final drive, same tires, same exhaust, same intake, etc?

Final drive intake and trans is the same. Don't know about tyres and guessing exhaust is different as mine is homemade.

A quick breakdown of the cost is

Clean Fuel Tank 130
Fuel 30
Reco IP 1450
Reco Injectors 850
Inlet Manifold Gasket 113
Tank Fuel Filter 25
Hand Primer 63
Fuel Filter Assy 120 (I had them replace my single filter for a dual)
Fuel Dumping Cost 35
Compression Test 150
Dyno 180

The rest of the cost was in labour charges.

[gmctd]

Effective final drive ratio in third would be the easiest explanation - he got 33" mudders?