Dyno results of 408 falcon today

**jamescomet** · 10-19-2009, 01:11 PM

Dyno results of 408 falcon today 10-19-09.

Picture of car: http://img34.imageshack.us/img34/290/1004420.jpg

Picture of motor: http://img10.imageshack.us/img10/3089/1004656i.jpg

Picture of dyno sheet: http://img237.imageshack.us/img237/7955/1004668.jpg

I was a little disappointed because I guessed around 400hp under a load. The dyno guy guessed 360 and was right on with the first run. The second run was 375 through the headers which was a 15hp gain and 370lbs of torque. Anyway not to bad for a sleeper looking car but the sound (solid roller) gives her away.

james comet/falcon

**job1bf** · 10-19-2009, 01:25 PM

That is one sweet looking bird....I bet is drives better than the dyno says!

**pass1over** · 10-19-2009, 01:44 PM

beautiful car

**kgordonl** · 10-19-2009, 05:50 PM

Hey James, tell us more about your engine specs. What kind of tranny and rearend do you have? As someone who was disappointed my first trip to the dyno and has been able to resolve a lot of issues, have you checked the simple stuff like carb linkage to make sure it opens all the way? Also, what kind of fuel system are you running?

That's a great looking Falcon!

**steharz** · 10-19-2009, 11:36 PM

beautiful car-
but something aint right,seems way down on power,but maybe they were just lookin for a return visit to there dyno......awesome falcon mate

**jamescomet** · 10-20-2009, 07:32 AM

Quote:

Originally Posted by kgordonl

Hey James, tell us more about your engine specs. What kind of tranny and rearend do you have? As someone who was disappointed my first trip to the dyno and has been able to resolve a lot of issues, have you checked the simple stuff like carb linkage to make sure it opens all the way? Also, what kind of fuel system are you running?

That's a great looking Falcon!

I have a quickfuel technology 750dp carb. Nine inch 31spline rear end with 4link Heidts system and coil overs. Holly blue electric fuel pump, A built c-4 with manual valve body. The car was running rich and and they changed the jets in the carb and in the front bowl they put two 72's in and in the back bowl I believe they put in two 82's. Btw, these guys are professionals and have a building at the Speedway race track here in Vegas. I also know them personally so they are not out to get me to come back.

One of the things you mentioned was checking the linkage which we did not do or consider but I will check it out. I also think your right about checking the little stuff. Even with the numbers I have they said the car should run in the high tens considering the weight. Can you think of anything else to check? Thank Ya'll for your comments.

James comet/falcon

**frdnut** · 10-20-2009, 09:04 AM

Hopefully some experts will take a look but I wonder why the lines start to go all squiggely at about 4000 rpm...I think this might be a sign of weak valve springs or possibly an ignition problem?

**kgordonl** · 10-20-2009, 09:09 AM

Quote:

Originally Posted by jamescomet

I have a quickfuel technology 750dp carb. Nine inch 31spline rear end with 4link Heidts system and coil overs. Holly blue electric fuel pump, A built c-4 with manual valve body. The car was running rich and and they changed the jets in the carb and in the front bowl they put two 72's in and in the back bowl I believe they put in two 82's. Btw, these guys are professionals and have a building at the Speedway race track here in Vegas. I also know them personally so they are not out to get me to come back.

One of the things you mentioned was checking the linkage which we did not do or consider but I will check it out. I also think your right about checking the little stuff. Even with the numbers I have they said the car should run in the high tens considering the weight. Can you think of anything else to check? Thank Ya'll for your comments.

James comet/falcon

What kind of heads, compression, cam specs, intake, exhaust, etc.? Do you know how much HP it is supposed to make at the flywheel?
Going through a C4 and a 9 inch, depending on the build, I would expect to see more at the rear wheels.
Definately check to make sure the carb is opening all the way when the pedal is on the floor. That was the easiest ~20 RWHP I found!

**jamescomet** · 10-20-2009, 01:40 PM

Quote:

Originally Posted by kgordonl

What kind of heads, compression, cam specs, intake, exhaust, etc.? Do you know how much HP it is supposed to make at the flywheel?
Going through a C4 and a 9 inch, depending on the build, I would expect to see more at the rear wheels.
Definately check to make sure the carb is opening all the way when the pedal is on the floor. That was the easiest ~20 RWHP I found!

Ok here is the build sheet in two parts.

http://img291.imageshack.us/img291/5080/1002078xz7.jpg

http://img263.imageshack.us/img263/7052/1002079ev6.jpg

And the following site is from my engine builder with a girl named missy that has the exact same motor as mine and it says in the article that she is putting out over 500hp and running in the 10's. So I really don't know what the problem could be? You also might want to read through the sight and tell me what you think of his engines. Thanks again.

Missy's hot '66

**dennis111** · 10-20-2009, 01:55 PM

IMHO, his build looks like it would be in the neighborhood of 500 or so hp at the flywheel. At the wheels will certainly be less. One of the major contributors could be the transmission. The build sheet says C6 flexplate and a C6 will rob more power than a C4.

It does look like Frdnut is on to something about the valve springs possibly falling out at higher RPM.

Irregardless, the dyno that was used is a chassis dyno and this one could be stingy. There are just too many variables and differences between readings. Do what Melissa does and run it down the track a few times if you want a more accurate measurement of HP.