Will launching in second gear hurt the trans?
- Thread starter flyfish
- Start date
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It will generate more heat, but, it's been done over the years.
Run it like a glide.
Run it like a glide.
1968dartman
life is getting better!!
That's one way to slow it down!
75 Duster 360
Well-Known Member
I've done it quite a few times in my 8.20 in the 1/8 mile Duster that has a 3.55 gear and the low gear set 904 transmission with a TCI converter. Instead of stalling it to 2500 as I do when leaving in low gear, I stall it to 3000 and leave in second gear and run it through without shifting to high. It slows it down from 8.20 to 8.60. I've had the same converter for about 3 years and put around 1000 runs on it with no problem. I will do this when the track is bad and I spin on the line. Lately I have been disconnecting the secondaries on my 600 Holley DP and run it on the 2 barrells and still leave in low gear. It runs about 8.60 this way also but it is more consistant than leaving in 2nd gear and I can hit the tree just as good as when the 4 barrell is connected. I have to hit the tree slightly harder leaving in 2nd gear. I deep stage BTW.
dusterdragracer
Drag Racer
I use to burn out in 2 gear in both my 727 and 904 SB car. My tranny guy said it was better, less chance of rolling the sprauge when you let off.
pettybludart
Well-Known Member
I think the OP is talking about launching in 2nd gear instead of 1st.(not burn out)I think it would kill your 60fts resulting in slower times and a hot trans.JMO
805moparkid
Slant and AFX Guy
your just trying to wear out the trans leaving in second and as petty said killing your 60ft. if you want to run slower and less wear and tear reduce timing or even a throttle stop.
dusterdragracer
Drag Racer
@pettybluedart...Yes I got what he meant. I was just saying that if you can burn out in second, launching would be a similar stress on the tranny.
But thanks for catching that.
But thanks for catching that.
805moparkid
Slant and AFX Guy
umm not at all... during your burnout you have water on the tires and very low load till the tires warm up. on a launch you are putting all of the weight of the car, all the horse power at stall, then starting in 2nd (launch in third on your stick, yea right)
if your trying to slow down dont be stupis and ruin stuff, use a throttle stop, dial back timing, re gear to something numerically lower(3.55)
75 Duster 360
Well-Known Member
There is a bracket racer from VA by the name of Tim Griffith who has won tons of races. He has a small block Vega with a 3.08 gear and leaves in high gear. He definetely knows what he is doing based on his results. How hard do you think it is on his Poweglide or converter racing it this way? I've never seen him have a problem, just win races, track championships and World titles. As I stated earlier, I have put over 1000 runs on my $650 TCI converter and probally 50 of those runs was leaving in 2nd gear and have had no problems. It is actually easier on the tires, u-joints, axles, ring and pinion etc. than leaving in low gear. The only problem that I ever had with my 904 is when the track is no good and you spin and hook on the starting line and break the sprag in the case. Leaving in 2nd gear solves that problem as it will not spin, so it actually saves the transmission instead of ruining it. But I have found that it is more consistent leaving in low gear than in 2nd, so if I spin during the time runs. I just disconnect ny 4 barrell and the problem is solved as it kills my 60' time from 1.70 to 1.90 when deep staging.
67Dart273
Well-Known Member
I'm not sure I see a problem
You really think heat is a problem compared to, say?
A Great Big 440 Motorhome pulling a trailer on a hot day? Up, down curvy, back, mountain roads, or negotiating some town, etc. I don't think the converter "knows" what gear it's in, only that it's got a lot of torque on the input and "for some reason" LOL can't turn the output.
N' yeh. I know. Every once in awhile they kill a converter.
You really think heat is a problem compared to, say?
A Great Big 440 Motorhome pulling a trailer on a hot day? Up, down curvy, back, mountain roads, or negotiating some town, etc. I don't think the converter "knows" what gear it's in, only that it's got a lot of torque on the input and "for some reason" LOL can't turn the output.
N' yeh. I know. Every once in awhile they kill a converter.
805moparkid
Slant and AFX Guy
yep the tranny gets really hot and if you dont have a good cooler or multiple your gonna burn up clutches...
above post if correct its easier on SOME parts as its hitting softer, but your still putting a ton more load on other parts than normal...
as i said why take the chance and back off the timing or make a throttle stop? with no adverse effects to anything else...
67Dart273
Well-Known Member
Again, not sure I follow the logic of this. How is a launch any harder on the trans "other parts" than a 6K bang shift from 1-2?
805moparkid
Slant and AFX Guy
because at launch your not moving... during a shift the car is already under power and moving, even more so with a built auto as there is almost no power off time...
mshred
The Green Manalishi
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There is no problem leaving in 2nd with a 727...guys do it all the time....that is straight from the mouth of professional transmission builders too.
All the guys worried about the extra heat....I think you will be fine with just a 1/4 mile pass, not like you are driving it on the street like that everywhere
All the guys worried about the extra heat....I think you will be fine with just a 1/4 mile pass, not like you are driving it on the street like that everywhere
mopardude318
Well-Known Member
run it. you'll be fine.
75 Duster 360
Well-Known Member
What is your rear gear ratio? Think of all of the racers that use Powerglides. Two speeds. Their low gear ratios are in the 1.70 - 1.90 to 1 range. What is the 2nd gear ratio in your 727? 1.50 or so??? Not much higher than the low gear of a Powerglide, correct? So if you have a low gear ratio rear end such as a 4.56 or 4.88 or higher, you have in reality the same overall low gear ratio of someone running a Powerglide with a 4.11 or 4.30 rear gear. You can do the mathmatics running all of the exact numbers. Your rear tire size can alter all of these numbers also, which I'm sure you're aware of. I am no transmission or converter builder, but a few of my friends and I have tried leaving in 2nd or high gear when necessary due to varying problems, but no one that I know of has had any transmission related or converter related problems after doing so. I think that it is harder to dial your car in when racing it this way, as it seems your ET all depends on how the converter reacts to the launch. It is still consistent, but not quite as consistent as when leaving in low and shifting into 2nd. But it is a much better way to race than to spin. I have seen racers win races incorporating these methods instead of losing every round or breaking something. I've done it myself numerous times. But some people are scared to try something different or, God forbid, run slower!!! But to me, it's all about turning on the WIN light.
75 Duster 360
Well-Known Member
While we're on the subject of leaving the line in other than low gear, some excellent Footbraker racers such as Tim Griffith and Ed Talbert leave in high gear for a strategic advantage. I don't want to give away their secrets, but you should be able to figure it out for yourself using some logic. If not, try going to Scotty Richardson's Drag Racing School or use his White Board to see what I mean. See you in the staging lanes.
75 Duster 360
Well-Known Member
Thanks Tony. I couldn't remember the exact ratios. I know the Powerglides have 2 or 3 different ratios also, but I don't know them either.
tubtar
Well-Known Member
Factory are 1.82 and 1.76.
The 1.76 is the more desirable because the carrier / planetary is way stronger..........stock.
The way to tell them apart without opening one up is the length of the input shaft. I forget the exact length but if my memory still works , the 1.82 is about 1/8th inch longer.
Haha! Wow, all of the sudden I got a PILE of responses about a month later . Well, I've used this technique for 3 races now, works great and pretty consistent. I checked with a transmission builder friend of mine and he agreed that it should be fine. For those that don't know, this is one of the MANY things I have done to slow my car down enough to be able to run in Sportsman this year (bottom dial in sportsman is 12.0). I have the car right where I want it now, it currently runs 12.01-12.05 depending on weather....and this is how I got there if anyone wants to know:
1. Disconnect secondaries on carb.
2. Added as much weight to the car (safely) that I could.
3. Retard timing to 30°.
4. Short shift @ 5300.
5. Removed a good free flowing 14x3" air-cleaner and put on a dinky 10x1.25" air-cleaner.
6. Launching the car in second gear.
All that to scrub ~ 1.2 seconds, LOL.
. Well, I've used this technique for 3 races now, works great and pretty consistent. I checked with a transmission builder friend of mine and he agreed that it should be fine. For those that don't know, this is one of the MANY things I have done to slow my car down enough to be able to run in Sportsman this year (bottom dial in sportsman is 12.0). I have the car right where I want it now, it currently runs 12.01-12.05 depending on weather....and this is how I got there if anyone wants to know:1. Disconnect secondaries on carb.
2. Added as much weight to the car (safely) that I could.
3. Retard timing to 30°.
4. Short shift @ 5300.
5. Removed a good free flowing 14x3" air-cleaner and put on a dinky 10x1.25" air-cleaner.
6. Launching the car in second gear.
All that to scrub ~ 1.2 seconds, LOL.
75 Duster 360
Well-Known Member
Good to hear that you have your Barracuda dialed in the way that you want. As for the info, better late than never. Maybe some others on the site can learn a few things from this thread. I know that I have. I now know the low and 2nd gear ratios of 727's, 904's and Powerglides. Thanks for the info, guys.
goldmember
Well-Known Member
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Thought you'd like that trick for slowing down. Been doing it for years as have others and no the trans is not going to grenade.LOL I only use 2 of those tricks to stay 11.50 legal in my street small block car. Glad you got things working well.Haha! Wow, all of the sudden I got a PILE of responses about a month later
1. Disconnect secondaries on carb.
2. Added as much weight to the car (safely) that I could.
3. Retard timing to 30°.
4. Short shift @ 5300.
5. Removed a good free flowing 14x3" air-cleaner and put on a dinky 10x1.25" air-cleaner.
6. Launching the car in second gear.
All that to scrub ~ 1.2 seconds, LOL.
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