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Minotaur Automotive Tuning Software Tune your own 7.3L Diesel! If you have a question or comment about Minotaur? Post it here. Also, check out our Facebook group: Facebook - Minotaur Tuners |
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#11
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Edit: SO also if i'm reading this correctly that means you could have the truck in Drive, and if you burn a position on the chip that when selected you would be starting out in 3rd gear? |
#12
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I would assume you'd like Bill to answer those questions but I can give some insight as a transmission tech.
Yes, you'd be switching tunes as you run down the track. One hand on the wheel, one on the hand throttle, and one on.......wait a minute! Whether or not the converter is locked depends a lot on the truck itself. With a lower power rig or one with a huge, laggy turbocharger I can assume that having a locked converter (especially early in the pull) would be a detriment. Heat shouldn't be too much of an issue because you're not running for 15 minutes with an unlocked converter....more like 15 seconds. The problem lies in the torque multiplication characteristics of the torque converter. Once the input shaft speed gets closer to the engine speed, the torque multiplication factor goes away. Once you reach redline (not hard to do with an unlocked converter) and the torque multiplication goes away, the input torque to the transmission input shaft is very low.....and so is the power to the wheels at that point. Your best bet is to try out Bill's suggestion and practice with shift/TC lock points.
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Tuning, flashing, burning chips, and repairing all aspects of 7.3L Powerstrokes. SEVEN 7.3L-powered vehicles in the driveway. Two didn't come that way from the factory! |
#13
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Yes, you could have the trans switched to third gear and start out in third. For a pulling truck this may, or may not, be a big deal.
My personal preference is to have the converter locked once the RPMs hit 2400-2500 and then keep it locked form there. Some folks prefer to start out in 1st, and some in 2nd. It seems a little easier to spool in first, but maybe that's just me. Hope this helps.
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Bill Cohron - The Mad Doctor ![]() ![]() ![]() Power Hungry Performance - The ORIGINAL in Ford performance tuning... Since 1997! (678) 890-1110 www.gopowerhungry.com - Home of the Hydra Chip, Minotaur Tuning Software, and the new Orion Reflash System for Navistar! Bring back ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Much to my surprise, I'm actually quite enjoying Linux! ![]() |
#14
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Just wanting to verify so i don't burn out my TC. EDIT: it was late and forgot to mention exactly what i was going for. I'm going for a manual shift, example, pos. 1 is first gear, pos2 is 2nd, pos 3 is 3rd gear, and pos 4 is 4th. Then i'll be able to have an almost 8speed. with having my manual TC lock switch i can drop it in and out of lock, Not really somthing i'll probably use but hey, whatever lol. Ive always wanted to hack into the selinoids in the trans and put push buttons on the steering wheel so i could shift like the flipper shifter cars, but this is close enough and alot less work. Thanks andy Last edited by mustang_gt_350; Thu, June 17th, 2010 at 12:34 PM. |
#15
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OK is it possible to leave the chip in one position and have the truck start in 2nd gear and get up to say 15 mph and shift into 3rd and stay there? Also possibly lock the TC at say 10 mph and unlock at the 2-3 shift? (Some power tracks or heavy sleds wont hold 3rd and a locked TC) How are the shifts points controlled on 4x4 low? The actual vehicle mph or is there a conversion factor? Thanks
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#16
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There are a lot of things going on there.....and quite frankly, depending on the year of the truck in question, may or may not work just the way you want it to. In either case, you are looking at a TON of trial and error with the tuning to make it work just right.
The 4x4 low shifts are handled the same as the high range shifts....only divided by 2.7.
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Tuning, flashing, burning chips, and repairing all aspects of 7.3L Powerstrokes. SEVEN 7.3L-powered vehicles in the driveway. Two didn't come that way from the factory! |
#17
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Well I got to hook on a real loose track thursday night. I tried playing with shift points to get the truck to start in 2nd which it did. I set it to shift into 3rd at 38 to 43 mph (Which should be appro. 14 to 16 mph in low range) and throttle postion around 3/4 to full pedal. However i was up around 20 to 21 mph on the speedo and 3200 rpm and full throttle and it never shifted to 3rd. Any thoughts? Something I may have missed like a delay or something else? Thanks Edit: Its a NVK4 truck with PMT1 programming
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#18
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Any changes to the truck such as differential gear ratio or tires size? Might be enough of a change. WOT/WOT 4x4 shift rpms changed? Just some thoughts, I'm not on my computer with Minotaur or I might of had a few other ideas.
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Thomas H. '97 F-250 CCSB 7.3L Auto, Gauges, Modded H2E, 285/200% sticks, 7.3L IC, Stealth Dual HPOP, Pheonix chip '03 F-250 CCSB 6.0L Auto, Gryphon CTS, FICM tuning by PHP, Powermax |
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