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.

Restrictor plates or add about 300 lbs, if possible. That way you don't have change the tuneup.

JMO

Zip.

Toss out the laundry a little early 8) 8) 8)

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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.

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

PUT LESS FUEL IN IT ---WHEN IT RUNS OUT AT 200 FEET IT WILL SLOW YOU DOWN !!!!!!! :? :roll: :roll:

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.

TS1955

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.

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.

High gear only should net you almost exactly what you need :)

Launch at 3600 and shift it at 4400 as a start. Go up on the launch and shift 200 rpm until you find your ET.

I run a toilet bowl,so changing air input I would have change to change complete tune up,no throttle stops are allowed in this class,car weighs about 2500# with me,taking off in high could be pricey after a while,have tried leaving easier and shifting early,can't seem to find a consistent combo,Iam considering buying another pumkin and starting with maybe a 4.56 ratio and working from there.Hey Lively if I was driving a ford I'd already be running a 5.90.

Here is a website with an innovative way to slow your car down.

http://www.etgenie.com/

I have to ask .. why would taking off in high get pricey after awhile ?

?
 

What GOOD is a PUMPKIN going to do?
Halloween is LOOOOOOOONG Gone!!
Later
G 8)

toms131,
A stop screw under the peddle (as Todd74 suggested) is not considered a throttle stop. We did this with Jimmy Smiths car (a member here on RJ) when he was running a stacks injection on Alcohol. The car would run .650's and he wanted to run the 7.00 class, so i'm sure it would work a toilet bowl, and it doesn't effect the 60' times that much.

JMO

Zip.

hammertime
 

Not knowing that taking off in high gear will hurt my trans for sure,but I did try it like 3 pass's in a row and noticed that trans temp seemed to get higher than normal every pass so I went back to low gear launches just to be safe.It may be o.k. for dragsters and cars lighter than mine,I just can't afford a trans and didn't want to risk it.

Re: hammertime
 

It should be a little more heat but not more then 20 degrees more then normal, its just slipping the converter more. A lot of 9.90/10.90 cars run high gear only. Car weight really has nothing to do with it, its generally how good or bad the parts are in your trans is all.

Re: hammertime
 

How do you use a tranny brake leaving in high gear?

TS1955

You leave in low gear and shift it within 600-800 rpm of the launch. You want the low gear launch so you still hit the tire to get out of the beam but you are shifting quick enough that you most likely won't get a full revolution out of the tire. When I do this with the dragster I can go from running 4.80 to 5.20-5.30. All out the car will mph 145-146 and shifting right away to high gear the car will run 141-142mph. I have done this 1/8 and 1/4 mile. No issues with heat and my converter is very loose.

If this is inconsistent for you, the launch rpm may need raised. Where do you normally launch and shift your car at? Is it a glide or 3 speed?

Normally launch @ 4000 rpm,shift @ 6800 rpm with power glide

Here is what I originally posted. You need to test for consistency.