DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Slowing down a fast car
Page 1 2 3 4 5 6 7 
Go
New
Find
Notify
Tools
Reply
  
Slowing down a fast car
 Login/Join
 
DRR Trophy
Picture of NC3x58
posted
If you were trying to slow down a car, what would be the best option?

1. adjust throttle pedal stop (or lengthen throttle rod) to close carburetor throttle blades to 50-70% roughly
2. under carb throttle stop, various options on opening/closing, but to keep it simple just fixing it at the same blade opening as you would with carb blades
3. adjustable restrictor plate style?
4. another method?

This is in a 5.40ish door car, 565BBC application. Standard powerglide etc.


Nick Craig

1971 Camaro Split Bumper
376ci LS3
 
Posts: 410 | Location: Ohio | Registered: December 28, 2013Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
Early shifting is my choice . I have shifted as early as 6400 on my 6200 stall and it slowed right at .300 and was very consistent


The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
 
Posts: 396 | Location: des moines iowa | Registered: January 10, 2020Reply With QuoteReport This Post
DRR Pro
Picture of CURTIS REED
posted Hide Post
I slowed my roadster from 5.80 to 6.50. It took 60lbs on the back, pulling 6° timing, shifting at .200 and running a 1.1875" restrictor plate.

It's harder than I thought it would be to slow one down. I can kill .400 just by running high gear only but I'm a footfeeder.



____________________________
2017 and 2018 Osage Casinos Tulsa Raceway Park No-Box Champion

2018 Div4 Goodguys Hammer award winner
 
Posts: 2916 | Location: KIEFER, OK. | Registered: August 17, 2007Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
You keep your mph to a large degree shifting early. I shift a hundredth after TB release.

It takes 2.5 hundredths for the shift to complete after that, 4 hundredths or so, at stall.

There's a dip after stall anyway, so visually the car looks no different, other than slow early in the run.

I run a converter that's 500-600 too loose also, for the fuel curve, to not to lug the engine after the shift 6700 stall.

This message has been edited. Last edited by: Mike Rietow,
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
I've been 112 on bias tires high gear only, radials don't grow so I can't run the gear I want to get the converter slipping 4-6% crossing at a reasonable rpm, so I'm going 110-111mph on radials crossing 6900 rpm,converter slipping around 10-12%.

It's the best path I think although I haven't perfected it yet to a degree to be Ultra competitive Super Pro racing, it's getting closer though every race with adjustments in between.

I think I'm just down to mixture now - jets & timing

 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Pro
posted Hide Post
Like Curtis wrote…… 1+2 transbrake VB would be my choice. Still have good mph with slower 60’ +ET.
 
Posts: 2441 | Location: 53056 | Registered: December 30, 2009Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
If this is a long term thing I'd suggest leaving in high gear. It kills .5 to .6 in ET (1/4) and about .060 in the box depending on the converter and gearing.


Denis LeBlanc

 
Posts: 462 | Location: Manchester, NH | Registered: February 03, 2006Reply With QuoteReport This Post



DRR Pro
Picture of CURTIS REED
posted Hide Post
How much are you wanting to slow it down?



____________________________
2017 and 2018 Osage Casinos Tulsa Raceway Park No-Box Champion

2018 Div4 Goodguys Hammer award winner
 
Posts: 2916 | Location: KIEFER, OK. | Registered: August 17, 2007Reply With QuoteReport This Post
DRR Trophy
posted Hide Post
Disconnect secondaries
 
Posts: 386 | Location: Natick MA | Registered: November 15, 2017Reply With QuoteReport This Post
DRR Pro
posted Hide Post
quote:
Originally posted by NC3x58:
If you were trying to slow down a car, what would be the best option?

1. adjust throttle pedal stop (or lengthen throttle rod) to close carburetor throttle blades to 50-70% roughly
2. under carb throttle stop, various options on opening/closing, but to keep it simple just fixing it at the same blade opening as you would with carb blades
3. adjustable restrictor plate style?
4. another method?

This is in a 5.40ish door car, 565BBC application. Standard powerglide etc.


IMO, out of the suggestions provided; I would use the one that best slows down the ET to what you want, while still retaining the most MPH. Out of your list, I would use #2.


1980 Camaro
Taking the Best Working Small Tire Shyt Box & making it Greater Than Before!
3000 lbs.
Pump Gas 436
 
Posts: 2501 | Location: NV. | Registered: October 20, 2006Reply With QuoteReport This Post
DRR Sportsman
Picture of Dave Koehler
posted Hide Post
Throw the chute at 100 ft.


Dave Koehler - Koehler Injection - http://www.koehlerinjection.com
Fuel Injection - Nitrous Charger - Nitrous Master Software - Balancing
99% of fuel injection problems are electric.
 
Posts: 351 | Location: Urbana, IL 61802 | Registered: December 03, 2003Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
i can shift from 7k to shift on time at .25 and slow down .4 in the 1/8.

ep
 
Posts: 757 | Location: dodging double wides... | Registered: November 28, 2007Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
Too many clutches will slow you down (drag),5,6,7 hundredths.

Intentionally, I have way too many clutches currently.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Trophy
Picture of NC3x58
posted Hide Post
For the purpose of this car, the owner is trying to get it to hit the tire a little easier and make the car just less violent all the way down really..


Nick Craig

1971 Camaro Split Bumper
376ci LS3
 
Posts: 410 | Location: Ohio | Registered: December 28, 2013Reply With QuoteReport This Post



DRR Sportsman
Picture of Bob Deniker
posted Hide Post
Can you run high gear only ?
 
Posts: 621 | Location: Latrobe Pa. | Registered: July 30, 2007Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
quote:
Originally posted by NC3x58:
For the purpose of this car, the owner is trying to get it to hit the tire a little easier and make the car just less violent all the way down really..


I've fought that from day one on a pizza cutter small tire.

Best thing I ever did for that purpose was put a TSI spragless in it, no slower, but smoother.

I think it's smoother because it flashes 200 rpm higher than drop back at the shift stall, in order to make up for less torque multiplication below stall than most sprag converters, also the phenomenon for why it's no slower,,, I think.

Feels slower though, smoother.

Traction control.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR Top Comp
posted Hide Post
A camshaft with a bunch of duration relative the engine combo will do a fair job in that regard as well, if you prefer a sprag converter.
 
Posts: 9398 | Location: Madeira Beach Fl. | Registered: June 12, 2018Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
quote:
Originally posted by NC3x58:
For the purpose of this car, the owner is trying to get it to hit the tire a little easier and make the car just less violent all the way down really..

Gear change will do that
 
Posts: 2591 | Location: at the track | Registered: May 09, 2007Reply With QuoteReport This Post
DRR Pro
Picture of CURTIS REED
posted Hide Post
quote:
Originally posted by green1:
quote:
Originally posted by NC3x58:
For the purpose of this car, the owner is trying to get it to hit the tire a little easier and make the car just less violent all the way down really..

Gear change will do that


Put a 1.64 gear set in it. Still have the RPM you need at the other end. Not sure about the violent all the way down part.



____________________________
2017 and 2018 Osage Casinos Tulsa Raceway Park No-Box Champion

2018 Div4 Goodguys Hammer award winner
 
Posts: 2916 | Location: KIEFER, OK. | Registered: August 17, 2007Reply With QuoteReport This Post
DRR Elite
posted Hide Post
quote:
Originally posted by NC3x58:
For the purpose of this car, the owner is trying to get it to hit the tire a little easier and make the car just less violent all the way down really..

sounds like a band aid approach to fix a car that don't work.
 
Posts: 13522 | Location: NJ | Registered: August 20, 2000Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2 3 4 5 6 7  
 

DragRaceResults.Com    Bracket Talk    Bracket Talk Forum  Hop To Forum Categories  Tech Talk - by Abruzzi    Slowing down a fast car

© DragRaceResults.com 2024