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2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

General engine tech -- Drag Racing to Circle Track

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maxracesoftware
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by maxracesoftware »

Dragginwagon406 wrote: Tue Nov 23, 2021 12:50 pm
maxracesoftware wrote: Tue Nov 23, 2021 11:48 am Found it : https://dragymotorsports.com/

 
VortecPro_1970_MonteCarlo_1600Ft.jpg

 
Could you estimate my speed at 1/2 mile?

I’ve considered trying a 1/2 mile race.
Could you estimate my speed at 1/2 mile?

I’ve considered trying a 1/2 mile race.
i don't really know how accurate this is because i have no Database Data to compare for up to 2640 Feet ??
here's what it calculates :
VortecPro_1970_MonteCarlo_2640Ft.jpg
 
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by maxracesoftware »

it looks like this would be the maximum MPH you could attain w/ HPCF = 1.000

@ 4457Ft
27.221304ET
146.760890MPH
 
VortecPro_1970_MonteCarlo_4457Feet.jpg
 
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Stan Weiss »

I get this from my simulation.

60 Foot ET = 1.8935
330 Foot ET = 5.0774
1/8 Mile ET = 7.6995
1/8 Mile MPH = 93.9837
1000 Foot ET = 9.9455
1/4 Mile ET = 11.8308
1/4 Mile MPH = 120.3292

1/2 Mile ET = 18.651 -- 1/2 Mile MPH = 142.23
1 KM ET = 21.642 -- 1 KM MPH = 149.74
1 Mile ET = 30.263 -- 1 Mile MPH = 164.99

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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by dannobee »

It's not really accurate to call it "stock stall speed." Slipping a TH350 torque converter in a big block car was a nice (and inexpensive) way to get a higher stall speed with an otherwise stock big block back in the day. Put a tach on it and test the true stall speed when you get a chance, especially since it has 600 lb ft of torque. It'd likely flash over 3500 rpm.

Calling it "stock stall speed" would be like calling the 5700 rpm stall speed converter in a Super Stocker "stock." Yeah, stock 8" converter out of an Opel.
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by maxracesoftware »

i had a 1970 or was it 1972 dark brown Monte Carlo back then ( bought it brand new , can't remember the Year though :) 1970 or 72 Model :lol:
getting too old :lol:
i have a old Pic of it somewhere in suitcases in a closet
your Monte Carlo brought back a few memories of my Monte Carlo ,
i went visit my 1st Cousin in Sauk Village , Illinois near Chicago ,
got a Speeding Ticket on the way thru Interstate near a small Town in Illinois ,
offered to pay the Officer on the spot , but he refused,
instead he made me follow him to that Town's CourtHouse .

Also went up the Sears Tower ... felt it swaying :)
just like they said it would .
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

dannobee wrote: Tue Nov 23, 2021 2:36 pm It's not really accurate to call it "stock stall speed." Slipping a TH350 torque converter in a big block car was a nice (and inexpensive) way to get a higher stall speed with an otherwise stock big block back in the day. Put a tach on it and test the true stall speed when you get a chance, especially since it has 600 lb ft of torque. It'd likely flash over 3500 rpm.

Calling it "stock stall speed" would be like calling the 5700 rpm stall speed converter in a Super Stocker "stock." Yeah, stock 8" converter out of an Opel.
It’s the original converter that came with the 100K mile small block car. I’ve put 13K on it since I bought it. Call it what you want, I have a borderline 10-Second engine in a bottom-13-Second car.

I can tell you, no way it’s flashing 3500 rpm. I drove my other car with the 10” Hughes converter for 10 years, not even in the same ballpark. Maybe it flashes to 2500 rpm, but it’s tight, and that’s what makes the car enjoyable to drive (well that, and 600+ lb*ft of torque. I don’t want a sloppy converter.
Last edited by Dragginwagon406 on Tue Nov 23, 2021 4:45 pm, edited 1 time in total.
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

maxracesoftware wrote: Tue Nov 23, 2021 1:44 pm it looks like this would be the maximum MPH you could attain w/ HPCF = 1.000

@ 4457Ft
27.221304ET
146.760890MPH
 
VortecPro_1970_MonteCarlo_4457Feet.jpg

 
Well this certainly sounds more reasonable than 188 mph, based on gearing.

Thank you Sir!

You guys rock!
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

maxracesoftware wrote: Tue Nov 23, 2021 2:56 pm
i had a 1970 or was it 1972 dark brown Monte Carlo back then ( bought it brand new , can't remember the Year though :) 1970 or 72 Model :lol:
getting too old :lol:
i have a old Pic of it somewhere in suitcases in a closet
your Monte Carlo brought back a few memories of my Monte Carlo ,
i went visit my 1st Cousin in Sauk Village , Illinois near Chicago ,
got a Speeding Ticket on the way thru Interstate near a small Town in Illinois ,
offered to pay the Officer on the spot , but he refused,
instead he made me follow him to that Town's CourtHouse .

Also went up the Sears Tower ... felt it swaying :)
just like they said it would .
I can relate to your story...

As you can imagine, it's an easy car to lose track of your speed. 80-120 in drive is just a roll of the throttle away (no downshift necessary, no need to floor it). I've never had a ticket, I hope to keep my record clean [-X :mrgreen:
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

Stan Weiss wrote: Tue Nov 23, 2021 2:06 pm I get this from my simulation.

60 Foot ET = 1.8935
330 Foot ET = 5.0774
1/8 Mile ET = 7.6995
1/8 Mile MPH = 93.9837
1000 Foot ET = 9.9455
1/4 Mile ET = 11.8308
1/4 Mile MPH = 120.3292

1/2 Mile ET = 18.651 -- 1/2 Mile MPH = 142.23
1 KM ET = 21.642 -- 1 KM MPH = 149.74
1 Mile ET = 30.263 -- 1 Mile MPH = 164.99

Stan
Thanks Stan!

I think between you and maxracesoftware, I have a pretty good idea that I would be well-served to improve the aero before attempting a bonsai run...air pressure under the hood of a Monte Carlo could lift an airplane if left unchecked.
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

maxracesoftware wrote: Tue Nov 23, 2021 10:12 am for a Weather HP Correction Factor = 1.0000 i calculate 507.6 Peak HP occured at 733 Feet distance

if i understood correctly , it was in 2nd Gear thru the 1/4 Mile ??
 

VortecPro_1970_MonteCarlo_ZeroHPCF.jpg
VortecPro_1970_MonteCarlo_ZeroHPCF_733Ft.jpg

 
Is it normal that the car does not show 500 hp in first gear at all?

I graphed your data to give a visual representation of what is happening with the power going down the track. It graphically explains what I was explaining the other day. This is what I'm feeling in the car.
The challenge is, I’m in essence running three different races, and each is dependent on the other.

The first 150’ is pure torque, balanced with available traction, fighting to get up to the massive torque peak (more of a plateau). The next 950’ is riding that massive torque peak through two gears (and it feels amazing). The last 220’, is hoping you have enough top end horsepower to carry it out the back door.
MC Distance-Hp-0-60.png
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1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by maxracesoftware »

Is it normal that the car does not show 500 hp in first gear at all?

I graphed your data to give a visual representation of what is happening with the power going down the track. It graphically explains what I was explaining the other day. This is what I'm feeling in the car.
Is it normal that the car does not show 500 hp in first gear at all?
typically any DragStrip type vehicle with a Clutch or especially a Torque Converter ,
is Slipping , multiplying Torque , Shift time engagement , rotational inertia especially Rear Slicks or Tires,
eat up HP in 1st Gear a lot , then 2nd Gear a little less, this is result of Engine RPM/Second acceleration rate effects .

my Software becomes much more accurate around 330 Feet upwards, as all the above effects are being progressively reduced ,
and by the time the Race Car gets 500 or 600 feet out .... the ET Slip can be turned back into Engine Flywheel HP very accuratetly

what you are seeing is Tire HP or real RWHP applied on the DragStrip , and not Chassis Dyno RWHP
the curve of real HP down the DragStrip is different than Chassis or Engine Dyno
because of mostly varying Engine RPM/SEC acceleration Rates , Tire Growth Rates , Rolling Resistance rates ,
and Shift Times , actual Gear Engagement times , and Aerodynamics

example : suppose you made 600 HP @ 6500 RPM on an Engine Dyno at a Dyno Test Rate of 600 RPM/Sec or even 300 RPM/SEC
then the Engine in a Race Car going down the DragStrip does not stay at a constant 600 RPM/SEC Rate
it varying greatly in 1st Gear , especially with a Manual Trans/Clutch setup
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

PackardV8 wrote: Tue Nov 23, 2021 12:36 pm Those who want 2.56 gears and a TH400 to run on the strip, well good on 'em and they're going faster than most.

Those with experience, what would this combo turn with the optimum rear gear through a TH200-4R, TH700R4 or a TH400-GearVendors tranny setup?
Of those alternate choices, I like the TH200-4R. However, my transmission rebuild costs less.

The 2.74 first gear in the TH200-4R is still an issue with 225/70-15 tires, it would want to spin more.

The car is a great conversation starter :mrgreen:
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by Dragginwagon406 »

In-Tech wrote: Tue Nov 23, 2021 12:58 pm Back in '83 my '73 4300lb camino ran 11.86 at 129 with 3.42 gears, more tire, think it was pro trac's n50/15, don't remember if I got out of second gear T400 stock 350 furnace brazed convertor. 12"
I'm thinking you meant 119 mph, not 129, correct?

It would be one high-winding engine if you didn't get out of second gear turning a 3.42 gear.
1.88, 11.84 @ 119.27, 4100 lbs, 2.56 gears, stock stall, 225/70-15 Cooper Cobras
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by In-Tech »

I meant 129, the 468 had a solid street roller type cam and alum round ex. L88 heads, LS7 intake, I regularly turned it 7200. Race time I had it idling at 300 to get more flash out of the convertor and it would have been lucky to flash to 2200. She was pretty weak out of the hole and if you didn't get me there, it was shortly "all over but the cryin". Good times, I was 16 :)
Heat is energy, energy is horsepower...but you gotta control the heat.
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Re: 2.56 Gear, Stock Converter, 4100 Pounds, NA 11s?

Post by In-Tech »

Amazing, they still make the tire https://www.cokertire.com/tires/n50-15- ... ofile.html
I thought it was 29", they show roughly 28"
I had those traction action bars on it with the adjustable upper link and had different adjustment right to left. I had a set pressure setting for driving/cruising, then a lower pressure for racing. Man, that was many moons ago. I love this thread, it's brought back some good memories and congrats on how fast your car is =D>
Heat is energy, energy is horsepower...but you gotta control the heat.
-Carl
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