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#31 (permalink) |
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SRTforums Member
![]() Join Date: Jul 2003
Member Number: 2544
Location: San Diego
Posts: 394
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Quote:
Originally posted by jasfrmn
I was wondering how the lauch would differ on DR's....would you burnout still? I know you wouldnt lauch as hard, right? Depending on which DRs you're using, the BFG G-Force DRs - do NOT need a burnout, they're soft as it is, the wear rating is 00 (very soft). All is needed is a quick DRY scrub before staging... go around the waterbox, if possible. Whereas, Nitto 555R DRs NEED to be heated up to activate the sticky compound; their wear rating is 200. It's also streetable, hence the harder/higher wear rating. I wouldn't recommend driving on the street with the BFG DRs, they'll wear out a whole lot quicker, than if you were to only use it at the track. I've had both, I prefer the BFGs, as they are much softer and grab almost as good as slicks, almost... The RPMs to launch on DRs is significantly less than slicks, it also varies with track prep (good = sticky/ bad = wheel spin). So given that, reading around the forums, it ranges from 2000-2500 rpm. Remember, the 2.4 is a TORQUE monster, also the turbo spools up very quick. It'll take modulation of the throttle and/or clutch to get your launches down... PRACTICE, PRACTICE, PRACTICE... This is how I stage and prep for launch at the tree: After lighting up the first set of stage lights, pull up on the e-brake, but don't lock it; keep release button depressed. Then bring engine up to desired RPMs, it doesn't take that much throttle input to get to 2500. Next, slowly release clutch to the point of engagement and creep up to light up the second set of lights. As soon as the second set of lights come on, push the clutch back in just enough to stop your creep. At this point, you're "shallow" staged, which allows you to roll out a little before starting the clock. Now as the tree lights start, as soon as the last yellow lights, simultaneously let the e-brake down, pop the clutch and roll into the throttle. Watch the tach, if it shoots up in RPMs and bangs off the rev limiter, you've got wheel spin. Let off the throttle a little, don't let off too much throttle or you'll drop out of the powerband as soon as the tires grab. Get back on the throttle when the tires grab... After the light turns green, all the above happens in rapid succession, it seems like a lot to think about. Just like riding a bike, it'll all come together and become second nature. It takes a lot of practice... A couple things that are nice to have is a line lock (brake lock), instead of using the e-brake to keep you from rolling out of the staging lights and MSD 2-step (rev limiter) to set the launch RPM, to get more consistant launches and not worry about taking too much time by playing with the throttle to get the right RPMs; this is especially good when getting higher up in the RPMs... whew... gotta lay off the caffeine PRACTICE, PRACTICE, PRACTICE... to get your launches right. In drag racing, it's all about how well you do on the start, coming out of the hole and gettting the "hole shot"... reaction time and hookin' up the tires in the first 60ft... laters...
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#34 (permalink) |
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SRTforums Member
![]() Join Date: Jul 2005
Member Number: 31250
Location: Charlotte NC
Posts: 547
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Quote: Originally Posted by 2004NeonSRT4
what kind of burnout are you guys doing on slicks?
With M&H 24.5x8x15 mounted on Kosei 15x7 racing K1 wheels. We do about a 5 second burnout using second gear in the waterbox, 10.5psi in the slicks and launch at 5600+/- with a clutch dump. Best 60ft was 1.767 with that combo, but we did spin the rim in the drivers side slick about one inch off our index mark. (Avg 1.820 on four passes with different tire pressures) The car has solid motor and trans mounts and solid controll arm bushings also. We also added two 1 inch bushings (spacers) to the top and bottom coils of the rear springs to raise the rear about 1 inch and increase spring rate, there was little or no rear squat and no tire spin on launch. |
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#35 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2003
Member Number: 4577
Location: Oxford,PA
Posts: 6,657
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Quote: Originally Posted by Ram48
With M&H 24.5x8x15 mounted on Kosei 15x7 racing K1 wheels. We do about a 5 second burnout using second gear in the waterbox, 10.5psi in the slicks and launch at 5600+/- with a clutch dump.
Best 60ft was 1.767 with that combo, but we did spin the rim in the drivers side slick about one inch off our index mark. (Avg 1.820 on four passes with different tire pressures) The car has solid motor and trans mounts and solid controll arm bushings also. We also added two 1 inch bushings (spacers) to the top and bottom coils of the rear springs to raise the rear about 1 inch and increase spring rate, there was little or no rear squat and no tire spin on launch. almost the exact setup i have minus the spacers in the rear springs. exactly what i do to a T for a burn out but even on 13psi the car boggs out on the line with a 5.5k dump. any ideas?
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canadian_srt4 "as long as vednors keep making parts, my car will always be on a hoist."
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#36 (permalink) |
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SRTforums Member
![]() Join Date: Jul 2003
Member Number: 2345
Location: ...............
Posts: 4,611
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Quote: Originally Posted by 2004NeonSRT4
almost the exact setup i have minus the spacers in the rear springs. exactly what i do to a T for a burn out but even on 13psi the car boggs out on the line with a 5.5k dump. any ideas?
If your car hooks and bogs on 13psi, try a little higher psi. We do almost the same thing minus the spacers, but we have fully adjustable coilovers that will set to full stiff in the rear and full soft in the front. Very, very minimal squat. |
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#37 (permalink) |
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SRTforums Member
![]() Join Date: Jul 2005
Member Number: 31250
Location: Charlotte NC
Posts: 547
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Quote: Originally Posted by 2004NeonSRT4
almost the exact setup i have minus the spacers in the rear springs. exactly what i do to a T for a burn out but even on 13psi the car boggs out on the line with a 5.5k dump. any ideas?
What other mods have you made? We have quite a few, Water/methanol injection. stage 1, boost controller, elect exaust cutout, larger TB and spacer, two stage bov, etc. so that I think is why we dont bog off the line. Try another 1 to 1.5 lb of air in the slicks, You may get minamil spin but it should help20ft time if you dont bog. Keep playomg with tire pressure and launch RPM to find your best combo. Then use that as a baseline for your first pass or so on your next race then adjust from their for track and weather conditions. You will always be chasing traction. |
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#38 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2003
Member Number: 4577
Location: Oxford,PA
Posts: 6,657
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Quote: Originally Posted by Ram48
What other mods have you made? We have quite a few, Water/methanol injection. stage 1, boost controller, elect exaust cutout, larger TB and spacer,
two stage bov, etc. so that I think is why we dont bog off the line. Try another 1 to 1.5 lb of air in the slicks, You may get minamil spin but it should help20ft time if you dont bog. Keep playomg with tire pressure and launch RPM to find your best combo. Then use that as a baseline for your first pass or so on your next race then adjust from their for track and weather conditions. You will always be chasing traction. heres whats funny the car makes 400+ and ran a 12.0@120 on a big turbo kit. at 15psi (tire pressure not boost) with a 1.9 60ft. dropped down to 13psi it bogged out. will try 14 maybe next time. thanks for help i think its just all trial and error.
__________________
canadian_srt4 "as long as vednors keep making parts, my car will always be on a hoist."
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#39 (permalink) |
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SRTforums Member
![]() Join Date: Jul 2003
Member Number: 2345
Location: ...............
Posts: 4,611
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Quote: Originally Posted by 2004NeonSRT4
heres whats funny the car makes 400+ and ran a 12.0@120 on a big turbo kit. at 15psi (tire pressure not boost) with a 1.9 60ft. dropped down to 13psi it bogged out. will try 14 maybe next time. thanks for help i think its just all trial and error.
Just to clarify, you ran 15psi cold and spun, then went to 13psi hot and bogged... Is that correct |
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#40 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2003
Member Number: 4577
Location: Oxford,PA
Posts: 6,657
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Quote: Originally Posted by BlackDragon
Just to clarify, you ran 15psi cold and spun, then went to 13psi hot and bogged... Is that correct
yea very first pass was 15psi very cold tires then did a good burn out (brand new slicks to), waited maybe 30min in line with pressure dropped and checked to 13 just before running. then another good burn out.
__________________
canadian_srt4 "as long as vednors keep making parts, my car will always be on a hoist."
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#42 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2003
Member Number: 4577
Location: Oxford,PA
Posts: 6,657
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Quote: Originally Posted by BlackDragon
What was the pressure before you dropped it to 13?
15psi cold and 13psi hot are farther apart than the psi reading. alil over 15 hot.
__________________
canadian_srt4 "as long as vednors keep making parts, my car will always be on a hoist."
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#43 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2005
Member Number: 34303
Location: Palm Beach
Posts: 27
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Quote: Originally Posted by Ram48
With M&H 24.5x8x15 mounted on Kosei 15x7 racing K1 wheels. We do about a 5 second burnout using second gear in the waterbox, 10.5psi in the slicks and launch at 5600+/- with a clutch dump.
Best 60ft was 1.767 with that combo, but we did spin the rim in the drivers side slick about one inch off our index mark. (Avg 1.820 on four passes with different tire pressures) The car has solid motor and trans mounts and solid controll arm bushings also. We also added two 1 inch bushings (spacers) to the top and bottom coils of the rear springs to raise the rear about 1 inch and increase spring rate, there was little or no rear squat and no tire spin on launch. Nice mod. Where did you get the spacers for the rear springs? fabricate?
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04 Stage III w/t, AGP WGA, TXS MBC, AEM I, Mopar BOV, Mopar DP, Mopar Ex., 'clamped
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#45 (permalink) |
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SRTforums Member
![]() Join Date: Oct 2003
Member Number: 4577
Location: Oxford,PA
Posts: 6,657
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depends on the rest of the setup. size of slick. aftermarket clutch. the above listed is just general tips. practice will make perfect.
__________________
canadian_srt4 "as long as vednors keep making parts, my car will always be on a hoist."
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