When to shift?

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doogievlg

doogievlg

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I have been thinking about my disappointing 13.6 et. When I make a pass I always just out the car in drive and floor it. I'm not sure of the shift points because I'm not watching the tach. It's a 360/727 combo that has never had the shift points touched.

My question is would manually shifting the car help shave a few tenths?
 
It could. I shift at 5500.

I have a manual valve body. You want to shift and go thru the traps at close to the same rpm. Because of my gear and tire I only go thru the traps at about 4700... I have a stock bottom end so I don't want to get to much closer to 6000 as I'm afraid it will come apart.... If you have a good bottom end 6000 should be no problem.

If yours is shifting early it could be out of the power range of the cam/converter and will defiantly effect ET.

As you get more comfortable you will NEED to learn to watch your gauges... its very important. Get a shift light too... you cant miss your shift point then.
 
Oh my! some of these tranny's will shift at about 4200 rpm's. Some 4400 rpm's. If you have a bigger than stock cam, headers, and a 4bbl, your 360 might like 5500-5800 rpm's. You could loose almost a full second. I saw a guy drop .8 tenths by manual shifting it vs letting the tranny shift itself.....
 
Now I'm fired up. I have the mp .484 cam with 26 inch tire and 3:55 gears.
 
Manually shifting would probably help...putting your Holley carb on it would probably help even more.
 
flyfish said:
Manually shifting would probably help...putting your Holley carb on it would probably help even more.
Click to expand...

Honestly there is a story behind the carb. My dad gave me the Eddie. I run it on the street and if he is going to the track with me I run it. Right after he gave me the Eddie my friend have me the Holley. I feel bad putting the Holley on over the Eddie in front of my dad.

Next time I go to the track though he will
Probably not be there so I'll do the switch and see what happens. I'm convinced I can get this car down into the twelves without any more major investments.
 
I ran that exact same cam in my 360. With 1 5/8 headers I shifted at 5700 rpm's with stock J-heads. With a 10 inch street fighter converter and 3.91's (28 inch tall tire) I hit 12.9's at 104 mph. I drove it 1 hour to the dragway, raced it as I drove it. Never uncorked the headers, just ran it as I drove it.
 
doogievlg said:
Honestly there is a story behind the carb. My dad gave me the Eddie. I run it on the street and if he is going to the track with me I run it. Right after he gave me the Eddie my friend have me the Holley. I feel bad putting the Holley on over the Eddie in front of my dad.

Next time I go to the track though he will
Probably not be there so I'll do the switch and see what happens. I'm convinced I can get this car down into the twelves without any more major investments.
Click to expand...


I kinda know how you feel... When I got my scoop My dad wanted to paint it and he struggled and struggled to get it to come out nice... He finally gave up on it and it looks like horse **** IMHO... lmao.... I put it on the car and never said a word. It been on a couple years so I figure I'll take it off this winter and do it myself... He probably wont even notice.

Good luck, when are you planning on getting back to the track?
 
Dart Sport 360 said:
I kinda know how you feel... When I got my scoop My dad wanted to paint it and he struggled and struggled to get it to come out nice... He finally gave up on it and it looks like horse **** IMHO... lmao.... I put it on the car and never said a word. It been on a couple years so I figure I'll take it off this winter and do it myself... He probably wont even notice.

Good luck, when are you planning on getting back to the track?
Click to expand...

I'm hoping to hit the test and tune in three weeks. I'm going to be on call for work until then. I need to get this thing dialed in before the nats:).
 
In the mean time though here is the first burnout with the new slicks.

And no the track isn't usually that packed.

icon_smile.gif


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doogievlg said:
Honestly there is a story behind the carb. My dad gave me the Eddie. I run it on the street and if he is going to the track with me I run it. Right after he gave me the Eddie my friend have me the Holley. I feel bad putting the Holley on over the Eddie in front of my dad.

Next time I go to the track though he will
Probably not be there so I'll do the switch and see what happens. I'm convinced I can get this car down into the twelves without any more major investments.
Click to expand...

Ohhhh kay, well that makes sense....well, I mean, I can see not wanting to hurt feelings and such.

What kind of shifter do you have? Just curious since you are going to be shifting it by hand instead of throwing it in drive. Like the others have said, try 5500 shifts and see what happens.
 
Column shift. I'm not opposed to going to a floor shifter but when I was a youngin I got a hurst promatic 2 and took it up to a friend. He said that shifter wouldn't work with my 727? I was always skeptical but I have just been living wih the column shift.

If I keep shifting the car manually though I will deffinstly switch so I don't throw it in reverse.
 
Column shift would cool to see in a car running 12's.. Maybe if you can get use to it put a reverse pattern valve body in it.

I want to put a ratchet shifter in my console this winter... Its sitting here on my desk, calling my name...

Get back out there and see what happens... Don't expect too much, I always build things up before hand and then I'm slightly disappointed when the outcome is not what I expect.

I think your on the right track for sure.
 
I'm at the point where I'm just going to take my time and be happy with a tenth at a time. I'm going to throw the Holley on it and drive it like I normally do. Next pass I'll shift the car. Next pass I'll mess with the timing.

I know better then to throw the new carb on the car and fuel pump and ignition at the same time.
 
Yes you have the right idea. I'm like you and like to know how each change effects things.

What track do you race at normally? You should go to the Norwalk MMW race in September. Its a great race.
 
I usually stick around the cincinnati area. I plan on making my way up for that. I don't have a truck and trailer yet so it depends on if my friend is off work.
 
Always take off in 1, with the clutches and overrunning, vs the overrun by itself in Drive or 2. Shift at 5900 to 2, shift at 6000 to D. Then try lower @ 5500/5800 and see if it's quicker. Second always winds up to a higher RPM due to the gears spread. 26" tires will never grab, 27-28.5" or what will fit. The taller the better due to a longer foot print. Use this to see where the rpm is after shifting.
http://vexer.com/automotive-tools/speed-rpm-calculator
It makes sense to be at the torque peak at the start of each gear and just above the stall.
I think the higher rpm shift to high is needed since the torque converter has two input splines and different turbines. But that is just my guess on why it works. The reason I stated may be wrong. but the way it works isn't.
I use a reverse DC plate and modified tray as in the DC manual valve body notes, and column lever. It's safer since you have both hands on the wheel and shift with your fingers.
One time I forgot the tach and shifted by ear and won a first place trophy. Put the tach on the dash with a bent bracket so you get used to seeing it.
Engine has a note like a trumpet and you get used to the peak sound and shift. I collected 14 trophy's in the first 3 years of racing. Now the competition is running better and I have slowed down my alertness late in the day.
I have moved away from the track and it was 15 years before I started again with a car hauler, now it sucks driving home late on Bay Area freeways. Too many Aholes in the wrong lanes. Poor pavement or K walls on the East I 880 fog line.
[ame="http://www.youtube.com/watch?v=zM3IoEvbTtg"]1968 Cuda 340 drag racing in Sonoma CA.on 275/60x15 street tires @12.94.MOV - YouTube[/ame]
[ame="http://www.youtube.com/watch?v=JRYVArhYpjo"]1968 Barracuda 340 V8 at Infineon Raceway on Wed. Nite Drag Race 9/08/10. avi - YouTube[/ame]
Also my "movie".
 
I think you should install A Go-Pro for a pass or 2.
It's really funny watching what you do during a pass.
Also you will see where you are shifting at.
I've not had a problem Shifting small blocks at 6500 rpm's.
Even my stock bottom end 383 I shift at 6500.
 
I left the column shifter in just so people would ask about it.

 
I've run slower using 6500 rpm second gear **** point, and I can hear and see it on the videos, depends on the car and motor combo.
Also, the column shifter is removed, on my 74 with floor shift, drive the roll pin out and the spring and lever come out. Why do you want it in the way?
 
You don't need to guess where to shift, you can scientifically figure it out. You need either a dyno, or an accelerometer device like a G-Tech, or other device to measure RPM and engine torque. You could even rig a simple indicator on your motor mounts, and if you don't have a software driven logger, use a friend to "watch the gauges.

What you do is plot your accelleration curve VS RPM and all you really need is one gear, and from a "somewhat low" point "up and over" the peak on the way down the other side.

Then, you overlay plots based on the transmission ratios "Where the curves cross" is your shift points. You can use either RPM or MPH for the rotation, and either torque or HP or acceleration for the remaining factor

Here's an example, it matters not "what this is." This is an engine / trans/ vehicle combination of some type, "who cares." The point AT WHICH THESE CURVES INTERSECT is your shift points. They are not necessarily the same in each gear

GNLPhvUX.jpg
 
aracer01 said:
I've run slower using 6500 rpm second gear **** point, and I can hear and see it on the videos, depends on the car and motor combo.
Also, the column shifter is removed, on my 74 with floor shift, drive the roll pin out and the spring and lever come out. Why do you want it in the way?
Click to expand...

I was saying I'm not afraid to shift a smallblock or a 383 at 6500 rpm's.
It's always up to the combo where to shift,
 
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