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#1
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launching a 4 speed..
How do you manual racers come off the line? Do you slide your foot off the clutch and let the pedal fly or do you just lift your leg quick and keep your foot on the pedal? And,Do you bring up the rpms,hold,release clutch then floor it once in motion or Do you,Bring up the rpms,hold,then floor it at the same time you release the clutch? I'm trying to find a good way to launch my GTO. I either bog from not enough rpms or I smoke the tires from too much rpms.I have the same problem with drag radials and street radials.I also need practice.Just wondering how somebody else does it.
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#2
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I feel your pain!
I am still figuring it out but definately getting more and more comfortable with every pass. I think the hardest thing is doing a ten sec burnout with a stick!
I like to bring the rpms up to about 2500 rpms and then dump the clutch and letter buck! I have some suspension woes I am trying to figure out and when I do I will most likely be able to launch at a higher rpm...Hope this helps!
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434 CI TKO600RR 1969 Carousel Red RAII Heads...Pump gas 400+hp/450+tq at the wheels...life is good! |
#3
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I keep my leg on the pedal. If I feel the tires shake hard, I will slide the clutch back in and try to feather it a bit. It took us about 5 passes with our Catalina to find the right tire pressure and RPM launch to avoid bog and breaking the tires loose. My suggesting is to change only one thing. Get the tires at a pressure you feel is working and make 200 RPM changes to the launch. Not sure what type of clutch you are using, but the burnout will effect how the clutch grabs. 5 seconds in the water box is plenty.
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#4
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I keep my foot on the clutch pedal. Had a buddy scrape his leg up with the "slide the foot off" routine. As was said, you might have to modulate the clutch slightly for best traction and that is hard to do when your foot is on the floor board vs on the pedal. LOL! Depending on the launch rpm (for each combination) the clutch set-up is key to good traction and also the lack of broken parts. If you cannot set the "base" properly, get a different clutch. Wrong "base" breaks stuff.
Tom V.
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"Engineers do stuff for reasons" Tom Vaught Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward. |
#5
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I agree with they said. I launch at 2200 and floor it. Tires, clutch, track conditions, got to find the right combo. I change one thing at a time, hard to do at first. Keep at it you'll get better it takes time get to know it all . you got a good tire gauge for slicks?
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MudBird |
#6
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My GTO launched the best at 5000, "rolling" into the clutch it wouild spin slightly and then hook. I LOVE it, but it just costs too much to play that way. My best 60' was 1.72, the first trip down the track with the Continental Coverter was a 1.65 and now I am knocking on the 1.5's door-LOL. Goodluck to everyone racing a stick. -Jim
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#7
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Thanks guys.
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#8
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Launching a 4-speed is a blast. It's also very frustrating. Practice, practice, practice. Be patient, You have to play with YOUR combo. Like others said, change one thing at a time. I can launch up to 6k, foot on clutch(no dumping). Found that nothing was slipping so luckily I didn't break anything. Something has to slip, or something will break. Have dropped to about 4000 & playing with tires & pressures to get the tires to slip a little. Good luck and have fun
Dave
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New Motor: 6-13-12 P-Dude 67 GTO 406, 670 heads, RPM, 750 Holley P-Dude Cam, M-22 4-speed, Centerforce clutch, 12-Bolt 4.56 275/60R15 M/T Drag Radials Old Motor: New PB 4-21-11 : 12.460 @ 109.97 1.844 60' ' |
#9
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Don't side step the clutch. Might wanna consider a two or three step wired to the line loc, takes one more variable out. If your launch RPM is lower than burnout RPM some switch work will be required. I'd try 3rd or high gear burnouts.... Treat the car like it's stolen in the waterbox, first sign of smoke roll out and pre-stage.
Best advice is just play with it. There's nothing more fun than a stick drag car. Set up well they give nothing away to automatics! |
#10
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That's how I run mine...MSD 6AL box with 2step box pluged in...then to an adjustable rpm control box hidden in the glove box of my 4-spd console. Wired into my line lock. Turn the dial up to 5500 rpm (max on it), set line lock and do burnout.
Then turn the dial to rpm I wish to launch...typically 3500 to 4000 rpm. Stage the car. Set line lock (which is again also wired to the two-step). as the lights come down, clutch already to the floor, gas to the floor, engine speed runs up to what I set on the box (3500-4000) for that second or two...lift line lock button and clutch foot on last yellow. Might feather the clutch a bit if required to keep rpm up coming out of the hole. I like it as gives me fewer vaiables to think about... 1) Don't have to goof around looking at the tach trying to get my rpm right as the lights are coming down. (Things are happening fast as we all know right about this time) 2) with gas to the floor already with the lights coming down...I concentrate solely on clutch foot feathering off the line (if necessary) and the upcoming big kick of the all-important 1-2 shift (power shifting). Fun Later Mike |
#11
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Thank goodness for the "search" option. This thread answers a lot of my questions. I recently changed my clutch from a worn oem style to a Ram Powergrip. Without really testing any launches before track time at a local track's "street drags" competition, I thought my prior method of launching at 2700 rpms or so would work. With the new clutch, the car would spin and bog when it hooked. One of those frustrating nights on a cold track. After reading some of your suggestions above, I need to move my rpms up and think about line lock and a two step box.
Dan |
#12
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You can also adjust where the clutch engages... I would adjust it to engage "down low" and work it from there when street racing.. you have to find the sweet spot with rpm and engagement... no straight answer there as each engine is different...
I liked it to engage early so I could "slip" it if need be... I have burned the rivets off a clutching in one night of racing... |
#13
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i finally had success launching last weekend after not having the car out for about 3 years. I installed a soft loc clutch
https://www.summitracing.com/parts/m...xoC108QAvD_BwE now i can use the 2 step and rapidly release the clutch, my 60' times went from 1.9 to 1.64. https://youtu.be/zwdH6cpU1gI not sure its a real street friendly clutch though. seems very grabby when you are inching forward. now i just have to figure out how to hit all the gears..... my foot hand coordination was severely rusty.,
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1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard. |
#14
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There are centrifugal assist clutches you can also tune the "grab". I think a lot of the Stocker and SS cars run them. And maybe Tom S here?
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Skip Fix 1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever! 1981 Black SE Trans Am stockish 6X 400ci, turbo 301 on a stand 1965 GTO 4 barrel 3 speed project 2004 GTO Pulse Red stock motor computer tune 13.43@103.4 1964 Impala SS 409/470ci 600 HP stroker project 1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs |
#15
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Quote:
Awesome! Is the 2 step activated by a switch in your clutch? What rpm are you now launching at? Sent from my iPhone using Tapatalk
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1970 Tempest (428 Whitmore, Cliff Q-jet, Doug Nash Five Speed) slowly coming back to life 1965 Lemans (462 Butler, Cliff Q-Jet, Muncie M20 with 3.55s) |
#16
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Yes the 2 step is set by the clutch switch i use a MSD digital and set the launch at 5500. I realize that as cars go its not super fast at 11.90 and 1.64 60 aint pulling 10g's but holy frick did it set me in the seat, i had to move the seal up a couple of clicks. lol
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1970 gto (4spd) 462 500 hp 11.940@114.21 / 1.843 60'/ 3980 lbs 1964 corvette roadster 1968 corvette roadster 1962 corvette "equal rights, not equal things" if you want to know the future, read "atlas shrugged" I dont race a 4spd because it is easy, I race a 4spd because it is hard. |
#17
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Sweet! Nice addition for a hundred bucks. I have not added a roll control/line lock yet. Is that part of your setup?
Sent from my iPhone using Tapatalk
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1970 Tempest (428 Whitmore, Cliff Q-jet, Doug Nash Five Speed) slowly coming back to life 1965 Lemans (462 Butler, Cliff Q-Jet, Muncie M20 with 3.55s) |
#18
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Funny story from last years GTO AA Nationals in a tech segment given by Milt Schornack. He was talking about a car he built for a Canadian car dealer for his son to race and the guy was ticked off that the car wouldn't run the numbers he paid Milt to build it to. Milt went to Canada took the old man and his kid to the track to watch him run it. The kid came back and sure enough it was slower than Milt promised. Milt jumped in revved the car to some screaming RPM over 6,000 and side stepped the clutch. The car ran what he said it would and when he got back he told the old man his kid just needed to learn to drive it .
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#19
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This is an old post, kinda cool it was brought back up.
Through the years, our best 60ft times came with the wheels up when the clutch was soft and on the verge of slipping. The top end MPH would suffer. Calvin Hill Hill Performance 708-250-7420 |
#20
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Still
Need decent adjustable shocks. Just saying. 😜
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ECM member. 2008 Outlaw Pontiac Drag Series Champion MANDRA Do it now fool! Life is short. 69 Grand Prix/3163lbs / IAII 535 w/ Tiger heads by Gaydosh....9.35@ 144 so far.. through mufflers. 1.26 60'. Going back to track with pump gas engine.... My 60 Ventura retired to street/strip duty.. |
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