Launch video- thoughts on taming this a bit?
#2894273
03/01/21 06:37 AM
03/01/21 06:37 AM
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Joined: Jan 2003
Posts: 10,006 Frostbitefalls MN (Rocky&Bullw...
gregsdart
OP
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OP
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Iron block 550, 10.5x33 Hoosiers. 6000 stall, launch at 4200. Torqueflite, 4.56 gears in back. Front ladderbar bolt in bottom hole 5 3/4 inch off the track. Afco big guns in back, rebuilt Afco dbl adj in front. 106 wb, in this vid there was 47% on the back tires. My new block will drop 112 lbs off the car. With engine setback that will remove about 15 lbs from the back and about 98 from the front. Car and driver will weigh 2900. I already have the battery up in front of the radiator so moving wieght forward is not possible. The wheelie bars are 66 inch long and i do plan to lower them an inch or two. The hoosiers have no tubes and are on a 14 inch rim. I run 8.5 psi so far. 60 fts have been inconsistant and i am thinking a touch less launch rpm (3800?) and raise the ladderbars up to the third or top hole to slow wheelspeed at launch. Thoughts? https://m.facebook.com/story.php?story_fbid=10225104160328116&id=1142132673
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Launch video- thoughts on taming this a bit?
[Re: gregsdart]
#2894347
03/01/21 12:18 PM
03/01/21 12:18 PM
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Joined: Jan 2003
Posts: 19,367 Las Vegas
Al_Alguire
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I Live Here
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Las Vegas
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An aluminum block aint gonna help for sure. I think we have discussed this before but wheelspeed is your friend. Also running the launch RPM down will be a good bandaid, it will give the car a "run" at the converter, but may affect your ability to hit the tree some.
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Launch video- thoughts on taming this a bit?
[Re: Al_Alguire]
#2894396
03/01/21 02:17 PM
03/01/21 02:17 PM
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Joined: Oct 2005
Posts: 1,646 Ringtown, Pa.
Dartsport540
top fuel
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top fuel
Joined: Oct 2005
Posts: 1,646
Ringtown, Pa.
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Best thing that I have done for mine, was a custom built set of front shocks from Santhuff.
I have a chassis car with ladder bars. I have a solid set of wheelie bars. Ladder bar is in lowest hole. I can go from 4" wheelie to a 4' wheelie by adjusting the extension on the front shocks. About 6 to 7 clicks on extension. Tighter keeps front end down, looser gives bigger wheelies. Too tight and it will spin. I only have 2-1/2" to 2-3/4" of front shock travel. I didn't believe that I could calm my wheelies down by front shock adjustment, when I talked to Santuff. But it worked for me. I also have 51-1/2 % weight on rear wheels, 48-1/2 % on front wheels.
Last edited by Dartsport540; 03/01/21 02:21 PM.
548 cu. in., Bill Mitchell Aluminum Block, CRT 727 auto trans, Alston Chassis. 8.981et at 149.46 mph. 1.204et - 60 foot, So Far....
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Re: Launch video- thoughts on taming this a bit?
[Re: Al_Alguire]
#2894489
03/01/21 05:08 PM
03/01/21 05:08 PM
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Joined: Jan 2003
Posts: 10,006 Frostbitefalls MN (Rocky&Bullw...
gregsdart
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OP
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An aluminum block aint gonna help for sure. I think we have discussed this before but wheelspeed is your friend. Also running the launch RPM down will be a good bandaid, it will give the car a "run" at the converter, but may affect your ability to hit the tree some. Just the change in tires from the big 2078 Goodyears to 10.5s seemed to slow the reaction time at least .02. So my thought was to drop the launch rpm but hit the tire more with the ladderbars to gain consistancy. Since i race in a box class loss of vehicle reaction time at the hit isn't a big deal . Right now it looks to have too much pitch rotation? As i recall Al your Barracuda was in a similar situation? Dartsport i had my front afcos rebuilt and asked the guy to tighten them up. Also not sure what you are running for ET, but in my case adding enough power to go from 9.50s to 8.90s was a huge change in my car.
Last edited by gregsdart; 03/01/21 05:15 PM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Launch video- thoughts on taming this a bit?
[Re: gregsdart]
#2894495
03/01/21 05:20 PM
03/01/21 05:20 PM
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Joined: May 2004
Posts: 12,391 Taxes & Virus's R-US, NY
Dragula
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I Live Here
Joined: May 2004
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Taxes & Virus's R-US, NY
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Are you heads up or a bracket guy?
Because if your a bracket guy, why hit the convertor at 4200? You can lower that down...It will affect where you hit the tree, but all that can be re-tuned with front tire pressure and other little tricks like the front shock extension clickers...etc. I typically leave off the brake at 2k-2.4k, but last year looking for ET, I turned it up to 4k and then the wheelies were big enough to bounce the front end. I turned it back down the next weekend. Mines programable, and I don't need any chips. You just need to lift them a little to transfer all the weight.
If you have to run the convertor so high, I would defiantly lower the damn wheelie bars...Why have them if you aren't going to use them. Make sure you have fresh gr8 hardware on them too! From there, I would program a custom timing curve and back some of the timing down...This is probably the easiest way to manage the power and be able to adapt to track conditions.
I am not nearly as fast as you guys, but I plan on sneaking into the 9.30/5.80 zone this year, so we will see. I do not run any wheelie bars....So keeping the front down is kinda part of the game.
Last edited by Dragula; 03/01/21 05:24 PM.
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Re: Launch video- thoughts on taming this a bit?
[Re: gregsdart]
#2894535
03/01/21 07:06 PM
03/01/21 07:06 PM
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Joined: Jan 2003
Posts: 5,762 Hot Rod Ridge
FastmOp
master
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master
Joined: Jan 2003
Posts: 5,762
Hot Rod Ridge
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I'm an idiot lol
Forgot most of what I knew 😆
Last edited by FastmOp; 03/01/21 09:06 PM.
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Re: Launch video- thoughts on taming this a bit?
[Re: merpar]
#2894766
03/02/21 12:16 PM
03/02/21 12:16 PM
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Joined: Jan 2003
Posts: 19,367 Las Vegas
Al_Alguire
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I Live Here
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Posts: 19,367
Las Vegas
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My small tire Barracuda was only happy with the front end up in the air. Ladder bar car with a fairly high crank centerline and way to high of a ride height. All those factors contributed to its propensity to do wheelies. We also ran a MUCH smaller tire at 29.5x10.5". It was basically a small tire SS car and never meant to have 1300hp. We can do the same in the Vette, mile high wheelies for 150' if we choose. It is a ladder bar car as well but its 95" wheelbase and 32" ladder bar contribute there. Wheelspeed takes care of that issue in the Vette for sure, shock adjustment, launch rpm as used to reach that goal. We leave at the lowest RPM the conditions will allow, sometimes as far down as 3800rpm WELL below converter stall for sure. It gives the car a "running" start at the converter. We have not run that car since September of 2019 and now have new shocks all around in an effort to get it to leave as flat as possible. I am sure we will look like idiots here in a couple weeks with all the new pieces on the car. Different trans ratio(we run a proflite), different pump configuration, more rear gear, new shocks, more power blah blah blah. FWIW we are also at 56/44 on weight bias in the car. It is perfectly consistent this way as well. My TS car sees plenty of wheelspeed as well and we have no issues with consistency there either.
"I am not ashamed to confess I am ignorant of what I do not know."
"It's never wrong to do the right thing"
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Re: Launch video- thoughts on taming this a bit?
[Re: Al_Alguire]
#2894967
03/02/21 08:04 PM
03/02/21 08:04 PM
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Joined: Feb 2006
Posts: 474 Alberta, Canada
451Guy
mopar
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mopar
Joined: Feb 2006
Posts: 474
Alberta, Canada
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I realize it is sacrilege but maybe a Powerglide????
Thanx 451 Guy
512 cu in 71 Demon Super Street Car - NO LONGER - Broke Crank Best ET 9.57 @ 139.96
451 cu in Pump Gas - 71 Demon Super Street Car Best ET 9.99 @ 136.80
512 cu in 69 Charger R/T Best ET 11.39 @ 118.11
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Re: Launch video- thoughts on taming this a bit?
[Re: 451Guy]
#2895102
03/03/21 07:13 AM
03/03/21 07:13 AM
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Joined: Nov 2011
Posts: 287 PA
Harry's Taxi 2
enthusiast
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enthusiast
Joined: Nov 2011
Posts: 287
PA
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I realize it is sacrilege but maybe a Powerglide???? or pull a couple of plug wires off.....same philosophy.
'86 Maple Grove KOS Mopar low qualifier......true street legal with no power adders.
NOS-used when losing since 1940.
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Re: Launch video- thoughts on taming this a bit?
[Re: jwb123]
#2895181
03/03/21 12:34 PM
03/03/21 12:34 PM
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Joined: Jan 2003
Posts: 10,006 Frostbitefalls MN (Rocky&Bullw...
gregsdart
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I had the bars as high as they will go to see what would happen going from 15x15x33 to 10.5x15 x33 slicks. I understand the theory behind a low launch, but not all cars respond well to that. Mine seems to like at least a foot of daylight under the front tires on launch. Since my CG is too high and too far back that might be a big part of it. Then i opt for an aluminum block for this next season. Front end % will go from 53 to 51.5 That will drop the weight 112 lbs, about 95 off the front end. So that is why i have so much interest in what can be done to limit violent wheelstands, since i expect the loss of front end weight will hurt a lot. Fuel cell is up front, battery is in front of the radiator. Thanks everybody for contributing. I plan to drop launch rpm and raise the front of the ladderbars to compensate, and control it with Big Gun Afcos . Front shocks are DA afcos rebuilt and revalved stiffer so i can lock up the front rise if needed. I am interested in more feed back so fire away!
Last edited by gregsdart; 03/03/21 12:37 PM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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