Best way to slow car

Old 12-24-2011, 05:28 PM
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toms131
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Default Best way to slow car

I have a sbc w/pg and 5.13 rear that runs consistent 5.60's.I am thinking of slowing it down to run a heads up 5.90 class,what is best way to go,if changing rear how far would I go,thanks for any input.
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Old 12-24-2011, 09:12 PM
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zipper06
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Restrictor plates or add about 300 lbs, if possible. That way you don't have change the tuneup.

JMO

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Old 12-24-2011, 10:22 PM
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TheYellaBrick
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Toss out the laundry a little early 8) 8) 8)

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Old 12-25-2011, 07:14 AM
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markdunlap
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Default Best way

I have had this issue for 2 seasons.

Slowing a 5.90 car down to 6.40+ to avoid having to get a license again and the associated cost.

I went thru 10 ideas.

Finally used a homemade restrictor plate under the carb at a RJ members suggestion. Slowed to 6.28 with a 4 hole 1 3/4" plate for a 2" dominator carb. It works consistanly. Rather than making a few more to get slower and having to pull the carb each change, I bought an E Z Plate system. It has a 1" spacer with a cut out in the side to slide in 1 of 20 supplied plates. A simple 1 bolt cover comes off and a change can be made in 30 seconds. I haven't tried it yet, but a lot of Super class cars use them. It is very high quality looking, but is a little salty at $350. I think this will be the answer.

No changes to your tune up are required.
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Old 12-25-2011, 07:18 AM
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hotrod1994
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throttle stop the local engine builder will run a 7.20 flat in 1/4 mile but his chassis not certified for 7.20 so he puts the throttle stop on so he runs like a 7.40
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Old 12-25-2011, 08:29 AM
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lively
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PUT LESS FUEL IN IT ---WHEN IT RUNS OUT AT 200 FEET IT WILL SLOW YOU DOWN !!!!!!! :? :roll: :roll:
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Old 12-25-2011, 12:52 PM
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TS1955
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I used a pneumatic throttle controller to run IHRA Super Rod 6.40 index. I can slow my e.t. but still run 120 mph.

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Old 12-25-2011, 02:48 PM
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Tod74
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I have the same issue as my car will run in the 5's but is not certified nor am I licensed...just make an adjustable throttle stop to put under the pedal and play with it until you get it right....you could also use a solid stop up on the carb.....the threaded rod under the pedal is cheap and crude but effective.
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Old 12-25-2011, 07:00 PM
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TheYellaBrick
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Some sort of throttle stop under the pedal is something I put on every car i build. The main reason is when you're 'pushing' for that last ounce of speed, you are not stressing out any of the linkage or stretching the cable. I make sure that it is adjusted at WOT and then can have the option of slowing it down if desired.
A lot of stuck throttle issues can be traced back to over-centered, deformed linkage, stuck wide open throttle blades, or frayed cables from over stressing, and no solid stop on the gas pedal.
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Old 12-26-2011, 07:45 AM
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hammertime
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High gear only should net you almost exactly what you need
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