i know alot of people use desktop dyno. i liked it, but it got annoying since our trucks should peak trq before 2k, which is where it starts.

i downloaded the trail for dynomax, however it is wayy over my head as far as what i know about our motors. head flow numbers, rod lengths, valve sizes spring weights, im lost lol

any body use it before?

 

"Well folks, as promised I have the dyno data for my truck. It is a bone stock, lovingly maintained 1996 4.9L I-6 with over 145,000 miles. I am the original owner, since October 1995. The data is an average of two pulls on a DynoJet rear wheel dynomometer. Please, let the discussion begin."

Torque
1800 rpm = 224 lb / ft
2000 rpm = 228 lb / ft
2200 rpm = 238 lb / ft
2500 rpm = 231 lb / ft
2700 rpm = 227 bl / ft
3000 rpm = 222 lb / ft
3400 rpm = 200 lb / ft
3500 rpm = 195 lb / ft

HP
1800 rpm = 83 hp
2000 rpm = 88 hp
2500 rpm = 113 hp
3000 rpm = 127 hp
3300 rpm = 132 hp
3500 rpm = 130 hp
4000 rpm = 111 hp (I assure you, I've never seen this figure on my tach!)

That infor was taken from here: https://fordsix.com/forum/viewtopic.php?f=2&t=64144 Those are chassis dyno figures on one particular truck.

Also, There may have been some differences in published RPM peaks at various times. Sometimes 1800 RPM and sometimes 2000 RPM. There is no indication anywhere that I know of that says peak torque 'should' be under 2000 RPM. Notice that the TQ curve is basically flat from 1800-3000 RPM.

 

I was thinking ford had the engine peak at 1600, but I'm mistaken on that. My bad.

That's actually really helpful seeing those number like that, I'm going to go back to my hole and play with my cam profiles again.

 

Stock set up, I can't even see peak hp...that's kind of sad. Maybe I just do my have the man to go that high, I've gone 2800 at most aha

 

Like any computer model a DD program is garbage in garbage out. Without accurate, precise data inputs the models are speculation at best.

If you hunt around over on the big six board at fordsix most every technical spec you can imagine for a 300 has been posted at some point.

Chassis dynos bring another set of variables into the equation so comparing a run to engine dyno (or simulations) is futile.

 

I found everything I could to make it as accurate as possible for desktop dyno.
I spent atleast a weekend looking for a mild p&p flow numbers.
My numbers all have been within a hp or three of actual dynos and the curve matches what I've seen from 2k and up.
The other program was based on an engineer's level building a motor, while dd is more of a hey what will this cam do to my hp. The exhaust is a little screwy since you can't adjust it, however it does prove how important exhaust is on an engine

 

You may be right, if your engine is carbureted rather than fuel injected as would be the 1996 represented in the graphs.

 

Ford 300 Inline 6

That shows carbed engines rated at 1600 RPM for torque and EFI engines rated at 2000 RPM for torque.

 

Is there a can difference between the efi and carb? It's advanced if I'm correct? The airflow might be greater too.
Because I would be happier with a 2k peak instead of 1600.

 

With the flat torque curve in this engine I don't think there is enough difference to make a difference whether it peaks at 1600 RPM or 2000 RPM.

 

It's bout a five mph diff, diff from lugging at 35mph and not. Road to work is 35 mph for 15 mins.

 

It's the fuel injection - i.e. spraying fuel directly at the intake valve vs. mixing in a carb 12-18" away from the valve - that accounts for the difference. Plus you can tune fuel delivery and timing much better with an EEC pulling data from the distributor, MAP, TPS, intake temp, water temp, knock, etc. sensors.

Where peak torque happens is less important that how much torque there is at a given rpm. Just because an engine has a torque peak 1,000 rpm higher than stock doesn't mean it isn't also making more torque than the stock engine at 1,600 rpm.

 

Ahh okay. That's what I thought, just wanted to make sure.

That is very true, and that is why I am fine with a peak at 2 or 2200 rpm

 

The fuel injected engines have higher flowing exhaust which would only move the powerband higher. That's part of what you're seeing there.