Restrictor plates

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oldkimmer

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Are they the right thing to use to slow ur car down about a second or so. Smaller carb, less timing. Less converter? Throttle stop?. Or how would u go about it? Thanks. Kim
 
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I try and take it off the initial hit and lower the shift RPM just make things easier and everything...
Edit: "I would try" as in I've never had enough to want to slow down...
 
My son had to slow his Duster down over a second before he put his cage in the car. He wired the back barrels of the carb closed and added 100 pounds. Worked out perfect.
 
How much do you have to slow it down.

In my car I can slow it down a half second (11.7 - 12.2) by shifting overdrive instead of running through the traps 400 over shift light RPM.

I would not pull timing.

Firs thing I'd do is lower my shift points or try grabbing another gear.
 
I bet that 2bbl was still faster than mine...


When we built his 360 I had an idea where it would be but wasn’t sure so we talked to the tech guy. He gave us one pass to check it out. When it went a 10.70 he met us at our pit spot to have a talk about our plans. When I said we would disconnect and wire shut the secondaries he said to try it. I think it went just under the 11.50 needed. During the week we added 100 pounds till he could get his roll bar installed. They seem to be a little more forgiving on test n tune nights but race days they will chase you down at most of my local tracks.
 
Some people use a bolt under the gas pedal to restrict the throttle. For my wife's car it runs 10.70's but when she runs street/sportsman and is limited to 11.50 we just unhook the 4 bbl. Works good unless the air is really good than we add some weight in the trunk. They say 100 lbs is a tenth in the 1/4 mile.
 
Back in 2013, I put my 10.7 car into sportsman for the year (12.0 bottom dial). Unhooking the secondaries was worth about 0.4 seconds, retarding the timing to ~27° was worth about 0.3 seconds, launching the car in second gear was worth about 0.4 seconds (and short shifted it at 5200rpm with my 5k converter...basically shifting as soon as I saw the RPM change). Added ~ 100lbs was about 0.1 seconds.

The final piece was only used in the fall to keep it out of the 11's, and that was a dinky 1" tall 10" diameter air-cleaner that was REALLY dirty, LOL...that thing literally killed 0.2-0.3 seconds all by itself.

With all that installed the car ran 12.0x's....road that thing all the way to the division finals :)

Edit: This "tune" fouled 2 sets of spark plugs that year....ran like crap, but it was very consistent crap.
 
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