First pass- Garbage.

Car was like the 6th car down the track and it was cold. Spun the hell out of the slicks but HOLY SMOKES LOOK AT THE MPH.

14.38 ET-100.56 MPH-2.71 ST

The only difference between the car today and two weeks ago is the headers and the H-pipe is gone. Car picked up a solid 5 MPH.

Second pass- Slowest of the day disregarding the first wasted pass!

Car ripped off a mid 13 like it was nothing. Car was left in drive just like 2 weeks ago.

13.49 ET-100.19 MPH-1.93 ST

Third pass- Jetted the primaries one step richer, manually shifted 400 rpm higher.

13.31 ET-101.42 MPH-1.91 ST

Fourth pass- This was a lost pass that got my teeth on edge, best short time of the day! When I was shifting from second to third I missed and went into neutral! I instantly lifted, popped the shifter into third, waited for the trans to engage and mashed the gas again.

13.30 ET-100.09 MPH-1.86 ST

Fifth pass- I know I was running out of time (3:11PM) and the track was packed so I decided to go for broke and drop the exhaust. Dare I hope there was a 12 second pass lurking? The prior pass with a 1.86 ST should have been a 13.0-13.1. The track was a little slippery again and I could hear the slicks spin on the launch.

13.12 ET-104.14 MPH-1.95 ST

Sixth pass- I lowered the slick pressure in an attempt to get some more hook which is why I lost some MPH. Dropped from 12 PSI to 9 PSI. Best ET of the day (4:37 PM)

13.08 ET-103.4 MPH-1.88 ST

Seventh pass- Last of the day.

13.10 ET-103.5 MPH-1.88 ST

I could have made another pass but felt I didn't have anything left in my bag of tricks to get that last tenth. The car is over a full second quicker than its last outing. If I had a set of 4:10's out back the car would be flying in the 12's all day.

Took the car on the scales, 3675 lbs. which is where I calculated it should be with the addition of the 44RH overdrive trans and I'm sure the owner has gained 20+ pounds compared to 5 years ago when it was last on a scale with a 904. I do have an aluminum rear bumper reinforcement from a Feather Duster and might know where a front one is too. Both would shave a lot off the car.

Also the cam seems to make power right where Comp states it will, 5400 RPM. I do have a set of 1.7 roller rockers that might be able to extend that up a bit more.

Calculated HP is almost identical for ET/MPH 324/322

I'm very satisfied with the cars performance, it exceeded my expectations.

Gary

Very nice! You picked up a lot of steam just from headers. Nice to see true back to back comparisons like this

[video:youtube]https://youtu.be/-UsnjIIlsaE[/video]

13.08 pass from dash cam

One error on the front page- The slicks are 26" inches tall, not 24.5"

So I'm not running as much gear as some might think, sorry about the error.

Too many sets of slicks around here! I do have a set of 24.5" I was thinking of giving a go.

And I treed the hell out of everyone, best reaction time was a .009

That really made my day.

Calculated hp 2 weeks ago = 250 hp (average between ET/MPH)
Calculated hp yesterday = 323 hp (average between ET/MPH)

Adding 18% for drivetrain losses, that works out to 380 hp or so flywheel which is in line with several dyno articles on the 5.9 with a good cam, intake and headers. 18% is a touch low I think as I know from a Chrysler engineer that 18% was observed from them going from a 300+ hp 2.2 on a dyno to in car testing with a manual transaxle, 20% with RWD and a auto would be closer I think.

Track was packed yesterday, I think we averaged about 1 pass every 1.25 hours and this was with me getting right back into staging after a pass.

All 7 passes on Youtube.

1) The the flag on the right side of the track, hell of a headwind most of the day.

2) At the 2:50 mark you can hear when I missed a shift and get back on it.

Gary

P.S. I'm not liking that 2-3 shift, could be a tad stouter. I'll have to pull the trans this winter and see if I can tighten that up a bit.

Nice shot!

Very nice, headers really woke it up. Doesn't look like the OD trans is slowing it down much. I am thinking of getting a 5.9 magnum on the engine stand to freshen up.

I'm thinking a set of 1.7 roller rockers, pulling the steel behind the bumpers and another trick or two and I'll be in the 12's. Have to work on it over the winter.

Some header extensions might help too, give it a tiny bit more torque.

Drag radials might help too assuming they have the same hook, less rolling resistance.

Any suggestions for drag radials? Looking at the following..

M/T 275/50R15 (26.1")

Nitto 275/50R15 (25.7")

I just put some M/T 255-60-15 on my dart, they hook well. My dart runs very close to your car, low 13 high 12's with open headers. The Nitto's should work also and I think are a little less $.

I like the Nitto's as they are a little shorter.

I'm considering building a spare 8.25" rear with 4.11 gears but for the cost of kit, ring and pinion and decent locker diff I'd rather buy drag radials, skinny tires and 4" front rims.

$800 vs $1000 and I can use the drag radials and skinnies on my Dart.

Take a few hundred pounds out of the car, less rolling resistance and let'er rip.

FYI- There is a Carter 750 AFB on the Duster that is pretty well sorted out as you can hear in the videos but I'm willing to give a Holley 780 vac-secondary carb a try for a back to back comparison.

It came installed on my Dart when I purchased the car and is fairly new (I even have the box) but has to be re-jetted as it was redone for the altitude where the car was located and seemed lean when I drove the car home from the transporter in CT.

A subject for another posting! This will be a chance for the Holley fans to chime in for best settings and see if the Holley can beat out the Carter in a back to back comparison.

I'll setup the carb before hand and road test and then swap back to the Carter. Hit the track, make a few passes and then install the Holley and have a go at it.

Well shoot, lost out on the aluminum Feather Duster front bumper reinforcement.

Anyone have one for sale or a complete front '73 bumper with brackets?

I removed the front reinforcement out of mine and cut windows in the bumper brackets, the rear bumper weighed the most if I remember it was over 80lbs with the 5mph shock bumper bracket still on, I got it down more than half by removing the bumper behind the bumper and made some 5mph shocks (fake)out of aluminum and painted them black. I will probably die if I get in an accident but there still stronger than fiberglass i guess. I saw a guy at the strip that had a pair of carbonfiber bumpers that were chrome plated, would of never new they weren't steel if i didnt hear him telling someone else about them. Glad you got your duster to run some better times.

Nice post. I like real world in car back to back testing.

Over the years I've done a fair amount of dyno testing on motors running stock manifolds, and was often shocked at how poor the power output was for the level of effort involved with the build.
I don't know how mild of a combination you would have to put together to only see an 8hp improvement in going from 318 manifolds to headers, like the numbers reported in an earlier post.
We used to build some 350 Chevy oval track motors that required non-HP type exhaust manifolds, max pipe diameter of 2". They had to use oem iron 2bbl intakes, stock heads with 1.72 intake valves, stock rockers and had a CR limit of 8.5:1.
On our dyno a good one made around 280hp. Even on those things just bolting on a set of 1 5/8" headers would pick up the power 40+hp.

I get calls pretty often from people wanting to build strokers, wanting to make some power, and want to run manifolds. I still tell them one of the best bang for the buck parts they can buy are a set of quality headers.

Was only a 300 hp crate engine and thats at the flywheel I assume.

80+ hp might make a tad bit of difference.

I'm still doodling over the numbers, doubt I'll race it again this year but I do have an event at Cecil in November and I'm wondering if I can make the Duster the back up car if the primary doesn't make it.

hmmm.

Nice! Congrats. Nice pic too!

Which mufflers do you have on the car? I am a little surprised that you picked up 3-4MPH by opening the exhaust, at least with a 2.5" exhaust and the power level. I wonder if the jetting is not optimal, and opening the exhaust is helping with that and reducing restriction....

They are just Summit "turbo" mufflers that come with the 2.5" mandrel kit.

I have to say I expected more restriction. Back in the 90's my GTX would pick up 4 tenths with the crappy "crimp bent" system with flowmasters was disconnected.