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808 DUSTER

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Took my 72 duster to the track for the first time, I was a bit disappointed to say the least. Mabey my expectations were to high, but I feel like my combo is off.

Specs.
1972 duster
383 hp block
906 heads, bowl work and gasket match
1.6 roller rockers
Comp cam 280h grind
3000 10inch turbo action converter
3.55 gears
26 tall street radials

Best result of the day
60 foot- 2.25
330 et- 6.20
1/8 et-9.47
1/8 mph- 75mph
1/4 et- 14.69
1/4 mph- 93.76
Around 5200 rpm

After talking to my engine guy his suggestions, while keeping it treatable are
Manual valve body
Moar performance leafs(replace worn out stock ones)
Gas shocks to replace the air shocks
Slicks 8x26 for track days
M1 intake to replace eddy performer.

I would like to see low 12s. Mabey someone has a similar set up they can share or some ways to get to where I want to be.
 
Low 12s....needs a speed of 105+.....

next to check timing and timing curve...what carb are you using?

Does the converter flash to 3000 rpm or what?

and Street Radials...not the best for hooking up at the track....
 
well lets put it this way... my slant runs faster than that...

on the 60ft is the car just feeling slow, bogging, spinning the tires?

as 70 said timing curve and carb probably need work.

If your not running something other than stock springs your really shooting your self in the foot. I like S/S springs with the CE shocks, ride good and work.
 
Not sure on the flash, I'll check tomorrow
Using a Holley 4160 been reworked anb flows 952cfm with #85 jet
Total Timing is 38 at 2500 using msd dizzy, 6al box
 
It did feel a bit sluggish on the get go. I am going to fix the rear suspension and get the manual valve body next. I will get slicks set up for next spring. Any other ideas on what is off with this combo?
I forgot, was running 87octane...last min track idea and had already filled up.
 
808 DUSTER said:
It did feel a bit sluggish on the get go. I am going to fix the rear suspension and get the manual valve body next. I will get slicks set up for next spring. Any other ideas on what is off with this combo?
Click to expand...

slicks should come before the VB. i dropped 1/2 a sec when i went to slicks. i would get the rear setup and run it again, see what she does.

as for the sluggish you could not have enough timing in down low, fuel issues, kinda a host of things... What compression and can you post the rest of the cam card?
 
You need to make sure the car hooks up on the starting line because that is where a lot of the time is lost. Slicks would be the first thing then I would go 3.91 gear ratio.
 
A68DART360 said:
You need to make sure the car hooks up on the starting line because that is where a lot of the time is lost. Slicks would be the first thing then I would go 3.91 gear ratio.
Click to expand...

he is talking driveability and you can see that with the 3.55 and 26" tire. if he was going to do a gear change he needs to figure out what rpm he can live with and then figure out what tires will fit.
 
have some one video the car from the side, while also having the rear of the car and tire in view. ( a white stripe/ mark on the tire), helps to see if it's spinning or hooking.

to really see what it is doing, play the video in slow motion..
 
A 4160? Vacuum secondary? Secondary metering block or metering plate?

It's not making any power with that MPH.

The carb and ignition would be the first place I would look. Getting more than 850cfm from a small 1 11/16" blade carb take a bunch of work. Call me a doubter. Might have way too much jet in it.

Low compression and the cam being installed in a bad ICL won't help.
 
Slicks first 26x10x15 on 15x8 wheels, you need to be hooking up to make tuning judgements. I'd replace the Performer with a Performer RPM, not an M1. Use premium fuel 91 oct. If cam wasn't degreed in during build, get it degreed in. Total timing at 38-40 degrees. You didn't mention exhaust system, but if its anything less than 2.5 its costing you power. I won't run less than 3" on anything performance intended. I doubt the suspension work would do anything for you at this point. Now if you put in a 4500 8" converter and 4.56 gears then suspension work would do something for you.

good luck
 
808 DUSTER said:
Took my 72 duster to the track for the first time, I was a bit disappointed to say the least. Mabey my expectations were to high, but I feel like my combo is off.

Specs.
1972 duster
383 hp block
906 heads, bowl work and gasket match
1.6 roller rockers
Comp cam 280h grind
3000 10inch turbo action converter
3.55 gears
26 tall street radials

Best result of the day
60 foot- 2.25
330 et- 6.20
1/8 et-9.47
1/8 mph- 75mph
1/4 et- 14.69
1/4 mph- 93.76
Around 5200 rpm

After talking to my engine guy his suggestions, while keeping it treatable are
Manual valve body
Moar performance leafs(replace worn out stock ones)
Gas shocks to replace the air shocks
Slicks 8x26 for track days
M1 intake to replace eddy performer.

I would like to see low 12s. Mabey someone has a similar set up they can share or some ways to get to where I want to be.
Click to expand...



that 280H likes more then a 3.55 gear i believe.

don't waste the money on a manual valve body. its not needed to run where you want.

the 60' time need to improve big time.

the car doesn't have the MPH that it needs for some reason..

my dart went 1.69 60' with beat leafs and air shocks. but doing the rear suspension would be a nice modification.

slicks would make a difference..


how is your driving? could be some time in your driving.
 
here ya go.. the cam specs.. says right here that it wants 3.91 gear..
 

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If that carb flows that much cfm its to big for your combo. Total advance also is a little high for my taste and would double check cam timing. As for the intake it would be like the valve body no way I would change it untill I was happy with the way it ran.

We had a 383 std bore that ran that same intake with a 750 dp, trw 284/484 and 3.91 gears went 7.90's. Daily driver in a hevier 73 duster. Its their you have to find it. Good luck.
 
1970 La said:
If that carb flows that much cfm its to big for your combo. Total advance also is a little high for my taste and would double check cam timing. As for the intake it would be like the valve body no way I would change it untill I was happy with the way it ran.

We had a 383 std bore that ran that same intake with a 750 dp, trw 284/484 and 3.91 gears went 7.90's. Daily driver in a hevier 73 duster. Its their you have to find it. Good luck.
Click to expand...

man, that`s where I`d start first, u either set in the light or spun all the way thru, sounds like to me ----tha`s terrrrrrible---------bob
 
IMHO you're going to be hard pressed to get into the 12's with 3:55 gears. I realize that this is far from the only problem , but a gear chage is a necessity.
 
crackedback said:
A 4160? Vacuum secondary? Secondary metering block or metering plate?

It's not making any power with that MPH.

The carb and ignition would be the first place I would look. Getting more than 850cfm from a small 1 11/16" blade carb take a bunch of work. Call me a doubter. Might have way too much jet in it.

Low compression and the cam being installed in a bad ICL won't help.
Click to expand...
find out why it is not making the proper hp before you start buying parts mph should be over 103.
 
IfItsGotWheels said:
IMHO you're going to be hard pressed to get into the 12's with 3:55 gears. I realize that this is far from the only problem , but a gear chage is a necessity.
Click to expand...

yup, shave that 60 ft down. It's yield 2x gain on the big end.
 
Before you get too crazy
1) What was your reaction time?
2) Did you leave it in drive? Or start off in 1st?
3) How much tire pressure?
4) Did you spinn the tires?
5) If you are running a Vacuum secondary carb I bet you did the run on a 2 BBL and the secondaires never opened up.
 
ET has nothing to do with reaction time. The ET clock doesn't start until the car leaves the beams. You can sit in the staged lights for 5 seconds after the green comes on, leave and run a 5 second ET.

It's got a short tire on it so he can get away with his current gear. Would more gear be better, yes.
 
dwire67 said:
Before you get too crazy
1) What was your reaction time?
2) Did you leave it in drive? Or start off in 1st?
3) How much tire pressure?
4) Did you spinn the tires?
5) If you are running a Vacuum secondary carb I bet you did the run on a 2 BBL and the secondaires never opened up.
Click to expand...

Probably but I just read in another thread you should NEVER run mech secondaries on an automatic car and that Holley's are junk. :D
 
Crackedback agree 100% , just fishing wanted to see what it was.

Probably but I just read in another thread you should NEVER run mech secondaries on an automatic car and that Holley's are junk

Well this part true- you would not run a 750 double pumper on stock or almost stock engine with a stock converter and 3.08 gears

I have been racing since 1978 and never have any problem with Holleys
Very easy to tune . Try rejetting a AFB or Thermo quad
 
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