Going to take a crack at Index racing next year

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RockinRobin

RockinRobin

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Thinking about trying Index racing next year. They have 7.0, 5.8 and 5.0 index. I tried it a few years ago when they had a 6.60, but I was always late at the light and there was no buyback.
I just assumed that all classes were .4 pro tree, but noticed on the flyer that 7.0 index is on a .5 second pro tree with a buyback. Now I just need to figure out how to slow my car down by a half a second.
I have a friend who raced 11.0 and 10.0 1/4 mile with the same car and won both. He slowed his car down a full second by starting in 2nd gear on a 3 speed torqueflite, so I'm thinking if I do the same thing that should slow me down 1/2 second in the 8th mile. Test n Tune next year will confirm it. I'm not a transmission expert but I don't think starting in 2nd gear would hurt the transmission.
 
Maybe ok of you have 5.13 rear gears.

I wouldn’t do it to my car.

And what does this 2nd gear launch do to your lights? Seems it would really slow down the reaction time quite a bit.
 
413 said:
Maybe ok of you have 5.13 rear gears.

I wouldn’t do it to my car.

And what does this 2nd gear launch do to your lights? Seems it would really slow down the reaction time quite a bit.
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4.56 gears and 29" slicks. sounds like I need to look into a throttle stop then. I don't think lowering shift points would do it, not in an 8th mile race.
 
My car runs 6.70s. It will run our 7.10 index racing on cooler days by just unhooking the secondaries. On hotter days it will only go about a 7.15 or so. I bought an ET genie and use that now as it's easy to adjust.
 
moparstud440 said:
My car runs 6.70s. It will run our 7.10 index racing on cooler days by just unhooking the secondaries. On hotter days it will only go about a 7.15 or so. I bought an ET genie and use that now as it's easy to adjust.
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Can you show me a link to that ET genie? Thanks!
 
Starting in second will build quite a bit of heat, leaning hard on the converter. Okay with the gap in early rounds, but when you start getting closer together in the later rounds you’ll struggle to cool down. Restrictor plates or smaller carb to chop your top end, and maybe dropping some timing will kill quite a bit of top end, and still have good response to wamp the stripe. Will the 7.0 class allow throttle stop/electronics?
 
I used the unhooked secondaries too. When the track personnel were giving me grief about not having a license, the unhooked secondaries slowed me from 6.30s to 6.50s.
You may need a mechanical throttle stop. You know... a bolt on the throttle linkage.
 
RockinRobin said:
Didn't realize it was a restrictor plate. Too much trouble constantly taking it on and off to run index then bracket then index, etc. Need to find a throttle stop for 4500 carb size. Everything I've seen so far is for 4150.
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You could just use your index setup for your bracket dial-in.
 
33IMP said:
You could just use your index setup for your bracket dial-in.
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Well I enjoy going in the 6.40's when I bracket race so I don't want to give that up. Since my timing is electrical in this car and not distributor maybe detuning it for index is the way to go. I think I'll try that first. It would be easy to load the old tune back into the box for bracket and it would be accurate.
 
RockinRobin said:
Didn't realize it was a restrictor plate. Too much trouble constantly taking it on and off to run index then bracket then index, etc. Need to find a throttle stop for 4500 carb size. Everything I've seen so far is for 4150.
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They make one for 4150 and one for 4500. It’s more or less a 1” spacer that’s an adjustable restrictor plate. When I installed it on my car and left it wide open the car ran the same as it had with a normal 1” spacer. I have the 4150 version so I would think the 4500 version would be the same. Only takes a few seconds with a 1/2 socket to adjust the restrictor plate.
 
moparstud440 said:
They make one for 4150 and one for 4500. It’s more or less a 1” spacer that’s an adjustable restrictor plate. When I installed it on my car and left it wide open the car ran the same as it had with a normal 1” spacer. I have the 4150 version so I would think the 4500 version would be the same. Only takes a few seconds with a 1/2 socket to adjust the restrictor plate.
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I'm going to try taking out timing first, and look into the restrictor plate if that doesn't work. This car will be doing both, and ran in the 6.40's tonight at a bracket race.
 
moparstud440 said:
They make one for 4150 and one for 4500. It’s more or less a 1” spacer that’s an adjustable restrictor plate. When I installed it on my car and left it wide open the car ran the same as it had with a normal 1” spacer. I have the 4150 version so I would think the 4500 version would be the same. Only takes a few seconds with a 1/2 socket to adjust the restrictor plate.
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My intake manifold is pretty tall, (Mopar drag pak) I don't think I have the clearance on the top to add an additional 1", plus some tracks or racing series may not allow a restrictor plate, but they can't say anything about how I tune my car. Going to try taking 5 degrees out next time I can get to a TNT night.
 
I really like index racing as I have been running it for about 12 years now. I really like the pro tree ( I was runner up at a pro tree race a few weeks ago and went rounds just yesterday ) I tried the E.T.Genie as well as the Willys adjustable restrictor plate and found in my application it killed too much mph for my liking and I end up going back to my “ bolt system . I am slowing down from 10.90 / 11.00s to 11.50s , with my other motor I was slowing from 10.60s to 11.50s. Keep in mind weather conditions affect how your stop is to be set. On my set up my secondaries are barely opening and disconnecting the secondaries slowed me to much. I m running 11.50s at 115 with 60 fts 1.48 - 1.52 shallow ( 1.58-1.62 deep ) on the stop .Leaving at 2,000. I deep stage on a pro tree so I am actually set up for 11.40s due to deep staging. I am no expert but the car has Won two track championships with my setup. I believe the e t genie is no longer being made or available but there is a guy in Pa making a similar set up called the “ Marko System “. I have also heard of the adjustments on the Willys plate moving because the adjusting system vibrates and moves resulting in needing a way to secure the adjustments better. BTW you don’t remove the restrictor plate assembly itself you simply remove or replace plates in the set up

CED32F82-FF83-400C-B15F-F48A0DFEEF05.jpeg
 
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BVoelzke said:
I really like index racing as I have been running it for about 12 years now. I really like the pro tree ( I was runner up at a pro tree race a few weeks ago and went rounds just yesterday ) I tried the E.T.Genie as well as the Willys adjustable restrictor plate and found in my application it killed too much mph for my liking and I end up going back to my “ bolt system ). I am slowing down from 10.90 / 11.00s to 11.50s , with my other motor I was slowing from 10.60s to 11.50s. Keep in mind weather conditions affect how your stop is to be set. On my set up my secondaries are barely opening and disconnecting the secondaries slowed me to much. I m running 11.50s at 115 with 60 fts 1.48 - 1.52 shallow on the stop .Leaving at 2,000. . I deep stage on a pro tree so I am actually set up for 11.40s due to deep staging. I am no expert but the car has Won two track championships with my setup. I believe the e t genie is no longer being made or available but there is a guy in Pa making a similar set up called the “ Marko System “. I have also heard of the adjustments on the Willys plate moving because the adjusting system vibrates and moves resulting in needing a way to secure the adjustments better. BTW you don’t remove the restrictor plate itself you simply remove or replace plates in the set up

View attachment 1716005180
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Is this the restrictor plate that is 1" tall?
I'm not running a carb, EFI.
 
RockinRobin said:
Thinking about trying Index racing next year. They have 7.0, 5.8 and 5.0 index. I tried it a few years ago when they had a 6.60, but I was always late at the light and there was no buyback.
I just assumed that all classes were .4 pro tree, but noticed on the flyer that 7.0 index is on a .5 second pro tree with a buyback. Now I just need to figure out how to slow my car down by a half a second.
I have a friend who raced 11.0 and 10.0 1/4 mile with the same car and won both. He slowed his car down a full second by starting in 2nd gear on a 3 speed torqueflite, so I'm thinking if I do the same thing that should slow me down 1/2 second in the 8th mile. Test n Tune next year will confirm it. I'm not a transmission expert but I don't think starting in 2nd gear would hurt the transmission.
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Slowing down half a second in the 1/8th without the use of a throttle stop will be tough I'm betting you find out, I have ran 6.0 index before and not only did very well in it but enjoyed it and had to scrub off .2 so that I could just run flat out and even with taking some timing out, short shifting and such these cars are hard to slow down. I have done a second gear launch before on a horribly prepped track and going by memory it may have scrubbed .1-.2 off but nowhere near .5 , good luck in your endeavor and I see they are doing 5.8 index around here now instead of 6.0 so I may try it again this upcoming year.
 
dusterbing the peace said:
Starting in second will build quite a bit of heat, leaning hard on the converter. Okay with the gap in early rounds, but when you start getting closer together in the later rounds you’ll struggle to cool down. Restrictor plates or smaller carb to chop your top end, and maybe dropping some timing will kill quite a bit of top end, and still have good response to wamp the stripe. Will the 7.0 class allow throttle stop/electronics?
Click to expand...
Since I'm running EFI it would be a pain to swap to a carb for index 1 week, then back to EFI the next, then back to carb, etc. Intake is too tall for a 1" restrictor plate. The plates are allowed but no electronics. I haven't been able to find any bolt type throttle stop for the 4500 size Throttle body.
 
RockinRobin said:
Since I'm running EFI it would be a pain to swap to a carb for index 1 week, then back to EFI the next, then back to carb, etc. Intake is too tall for a 1" restrictor plate. The plates are allowed but no electronics. I haven't been able to find any bolt type throttle stop for the 4500 size Throttle body.
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What does your linkage look like to the efi? are you using a Mopar stock style throttle cable ? does your linkage attach to the refi unit like it does a Holley carb? if it is you might be able to use a bolt system similar to my setup. Mine basically just keeps the linkage on the throttle blades from opening all the way and I move the bolt in or out for faster or slower.
 
It's a great challenge if your up for it. Helped on a SuperGas car and the only I can tell is data, data, data. It really disciplines you in your race program because of the repeatability factor.

JW
 
RockinRobin said:
Since I'm running EFI it would be a pain to swap to a carb for index 1 week, then back to EFI the next, then back to carb, etc. Intake is too tall for a 1" restrictor plate. The plates are allowed but no electronics. I haven't been able to find any bolt type throttle stop for the 4500 size Throttle body.
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Slightly more redneck approach, how bout you restrict air at the filter, instead of the throttle plates? Quick testing would be duct tape over part of it, then cutting a metal strip as a more use-able/easily removable primary killer, then trim the timing in your EFI table to fine tune. Basic example (numbers are made up), say you have a 3" tall, 14" dia. round filter. Tape off half of the circumference and see how much ET you kill...add or remove tape to get you in the ball park of where you want to be. Then cut a strip of sheet metal/aluminum/SS/unobtaneum/whatever to the height and length of tape you found that worked. Then like I said, pull timing to get the last few hundredths you need...as @SLOPAR72 mentioned you'll need lots of data to get the timing dialed in relative to weather. Then, when you're running your normal brackets you can pull the filter restriction and reload your primary tune. Maybe simply dropping filter height will restrict enough, or getting a restrictive paper type filter? Dunno...just throwing some ideas out.
 
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