How much improvement will I see?

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Clelan

Clelan

Inferno Red Duster
FABO Gold Member
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Martensville Sask. Can.
I have a 74 Duster with a 360, A500, 4.30 gear. I run 275-60-15 drag radials. Approximately 3500 lb car, maybe more, I will weigh it in the spring. My car is primarily a street car and highway cruiser, but i want to make it as quick as it can be for what it is.
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My best time to date is a 13.36 @ 104.24 with a 2.08 60' time. I got in touch with a torque converter guy from TCS Performance Transmission in Burnaby BC Canada. It's a well respected shop here locally. His recommended converter should stall between 3200 and 3500. My question is, what could I expect for a 60' and ET improvement if I do say get a full 3500 stall from this converter? I know this won't be exact as there are way to many variables, but I'd appreciate opinions by the experienced racers here.

Thanks,
Cley
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Clelan said:
I have a 74 Duster with a 360, A500, 4.30 gear. I run 275-60-15 drag radials. Approximately 3500 lb car, maybe more, I will weigh it in the spring. My car is primarily a street car and highway cruiser, but i want to make it as quick as it can be for what it is.
View attachment 1716350554
My best time to date is a 13.36 @ 104.24 with a 2.08 60' time. I got in touch with a torque converter guy from TCS Performance Transmission in Burnaby BC Canada. It's a well respected shop here locally. His recommended converter should stall between 3200 and 3500. My question is, what could I expect for a 60' and ET improvement if I do say get a full 3500 stall from this converter? I know this won't be exact as there are way to many variables, but I'd appreciate opinions by the experienced racers here.

Thanks,
Cley
View attachment 1716350553
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What is the current converter? Current 60 ft is soft for the ET/MPH. It will be quicker with a better converter - IF you can hook it up.
 
I plan on shock upgrades and better tires to adress that part of it. Plan is for QA1 Double Adjustable Shocks on all 4 corners to go with my super stock springs and 6 cylinder torsion bars. Tires will likely be Hoosier Drag Radials.

Cley
 
Why is the 60' so slow with 4.30 gears?
Does it spin at the hit?

You better weigh the car before ordering a converter.
 
Clelan said:
The converter is here. It spun just a bit on the run shown. The converter was a super tight stock unit.

Cley
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you gained 22 mph the last 1/8, that's good for the area of ET you are at. A sign the 5.9 is making good once it's going.
 
Is that a Bracket master? If so what did it cost?

15.00 60 foot. MPH has a mid 12ish in it.

Good looking side shot of the car!
 
A GOOD converter can make "around" a second difference if the rest of the car is tuned for it.
 
413 said:
Why is the 60' so slow with 4.30 gears?
Does it spin at the hit?
Click to expand...

I agree that the drag radial tire, 4.30 gear and 2.08 sixty ft. does not make a lot of sense to me. Even with a stock/tight converter.

To the OP, how much track time have you had with the car? My gut tells me that as it sits, even with the stock converter, it should run a 1.9 sec. sixty ft. with practice. That in turn should get you to the 13.00s.

The other info that is important is the mph on the time slip. Once you have the car running consistently (goes to what I asked earlier about track time) the mph stays nearly constant, irrespective of the sixty ft.

The mph is generally a good reflection of power. If the 104-105 mph is consistently where the car is at now, the converter will not really change that, unless the current converter is junk.

So I’d guess that if the car hooks with a good converter, you are at a best of 12.70 or so.
 
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I would change the shocks first, then sort out how the car launches. The car has the capacity to really stick the tire with the power your are throwing at it. You could end up needing more flash rpm to get the most out of your combo. There is nothing in your combo that makes traction hard to achieve. I’m making more power flashing to 3500 with 1/2 the tire. I am a bit lighter, but I could see you needing more flash rpm to help get her moving. The years of higher flash equaling high % of slip at the stripe are gone. I’m slipping 3-4 % at the stripe. Also my 904 PTC 9.5” converter cost $700 US about three years ago.
 
furrystump said:
The car has the capacity to really stick the tire with the power your are throwing at it……..There is nothing in your combo that makes traction hard to achieve……The years of higher flash equaling high % of slip at the stripe are gone……Also my 904 PTC 9.5” converter cost $700 US about three years ago.
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Agree with all this
 
furrystump said:
I would change the shocks first, then sort out how the car launches. The car has the capacity to really stick the tire with the power your are throwing at it. You could end up needing more flash rpm to get the most out of your combo. There is nothing in your combo that makes traction hard to achieve. I’m making more power flashing to 3500 with 1/2 the tire. I am a bit lighter, but I could see you needing more flash rpm to help get her moving. The years of higher flash equaling high % of slip at the stripe are gone. I’m slipping 3-4 % at the stripe. Also my 904 PTC 9.5” converter cost $700 US about three years ago.
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That's probably less slippage than a stock old style converter.
 
Your 60ft time is EVERYTHING. Make sure there is ZERO tire spin. Look at your ignition timing and converter to get that thing out of the hole.
 
I have about 30 passes on this combo in 4 different outings. MPH was as low as 102 and as high as 104.5. My bestpass is the time slip pictured at the bottom of my original post.
I was having trouble getting it sorted out, it would either sputter or spin. I kept increasing my squirter size to get rid of the off idle sputter, but it was when I finally started going down to smaller squirters that the stumble started improving. I ran out of season before getting it sorted out.
My timing was 25 initial, 35 total, all in by 2500 or less. I did try timing locked out at 35 but noticed no difference.
Aa far as traction, I have 275-60-15 Nitto NT555R Drag Radials. I experimented with pressure and tried as low as 15 psi. Finally, I found 24psi where I got my best traction. Totally not what I was expecting. I will get better drag radials, likely Hoosiers. I won't go to slicks, at least not now. I drive the car to the track.

Cley
 
Drag radials and the bias slicks are different animals when it comes to tire pressure. Seen way to many with DR pressures in 14-16 and suggest 20-22 area for a car like your.

People stuck in the 80's along with converters thoughts in many ways. Usually there is a bunch of 60' locked up in the front of the car.

If you haven't run it with the new converter, I'd put the squirter back to stock or next size up.

What is the engine combo? Altitude? Saw a video and it lays over really badly when you step into it.
 
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It's a 74 Duster,
360 Magnum
Refreshed Stock short block
CNC ported Speedmaster LA heads w. 2.02,1.60
Advertised Intake Duration - 274
Advertised Exhaust Duration- 282
Intake Duration @ .050 - 224
Exhaust Duration @ .050 - 230
Intake Valve Lift - .538
Exhaust Valve Lift - .534
Lobe Separation - 110
Edelbrock Torker 2-340 single plane intake
Quickfuel 750 DP
Cheap headers and 2.5" dual exhaust to bumper with H pipe
MSD 6AL
Stock distributor with FBO limiter plate
25 initial, 35 total
A500 overdrive automatic
Was Stock low stall converter, now will be 3500ish stall
8-3/4 SG, 4.30 gear (all new, sg works good)
Super stock springs and 50-50 shocks in rear
/6 torsion bars and Stock wore out shocks in front.
No sway bars
275-60-15 Nitto Drag radials on 15x8 steel wheels
Running 91octane pump gas cause that's as good as it gets here.
Weighed 3400 lbs but I added interior from a Chrysler 300S and a 12" sub since then, so I'm guessing 3500 lbs or so.

Not sure what else to say

Cley
 
I am a big fan of a higher stall speed. I run an 8" TC that flashes to 5000 rpm at the track but putt-putting around town, you would never know it was a high-stall piece. At the track, the trans temp is roughly 160 when I leave the line and 180-185 at the end of the 1/4 mile. IIRC, the last time I calculated the slip at the stripe it was 5% or less.

I also agree with the others that your engine seems to be capable of high 12's/13 flat based on that mph. You just need to get hoofing getting out of the hole and a higher stall speed, coupled with that 4.30 gear, will do it.

So go as high a stall speed as you can. So long as it is a "tight" unit (meaning a small diameter for the stall speed, not a big diameter with a high stall speed), you'll never know it's a race piece.

Your comment on the squirter size put a smile on my face. Yep, too many people think they need a bigger pump shot when they really need a longer pump shot. A 50cc pump with maybe a 31 shooter and a good pump cam is a good place to start. You can also do this by filming over your carb and have someone stab the throttle (in Park!!). You can often see the stumble right after the pump shot ends.

My $.02...

BTW...good looking car!!
 
i would go at least 4400-4800 rpm stall. in my black R/T, i had a 4800 rpm stall and it was real good on the street. your 60' will drop with a higher stall. you will run high 12's
 
I would go with a convertor that stalls around 4500. That combination ultimately should be able to threaten the 11’s.
I had a stock short block 360 in my current car when I got it. Initially untouched eddy heads( so yours should be better) 750, airgap( I would ditch your single plane) 4.30 gears, and Hoosier bias quick time pro 28 by 10 tires. Low 240’s at 50 comp solid
Car ran 12.23 very first time I ever had it out at 108-109.
If you are truly wanting to step the car up, I would do those 3 things, more camshaft, more convertor, and swap to a good dual plane like an air gap.
You won’t have any issues hooking what you have with a good 28 by 10 tire( like a Hoosier)
You should be capable of making 450 horse with a few tweaks
This is the cam I recommended to my buddy who bought the 360 I used to have, and he has it installed. I had pitched that junk comp cam and switched to a bigger Howard’s that I still run in my stroker.
This cam, assuming those heads are half way decent, the dual plane and a real convertor, as I said should seriously threaten the 11’s and be fun on the street to drive. And yes, that cam would be plenty street friendly, just don’t wimp out on a convertor you will never be happy with. Get a tight 8 inch that will flash around 4500, and hang on.

Mechanical Flat Tappet Camshaft & Lifter Kit; 1964 - 2003 Chrysler 273, 340, 360 3000 to 6600 Howards Cams CL711262-08DL | Howards Cams
 
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Make sure your fuel system is up to the task. A 3/8" feed and return with a good electric pump is what I would run. Return system also helps with ethanol fuel problems on a street car. Definitely get rid of the torker manifold. Airgap with an open 1" or better yet 1" HVH Super Sucker will improve throttle response.
 
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