When to shift?

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On my racecar I take it to a chassis dyno and do a all gear dyno.
This will give give you a ball park where to shift in each gear.
 
Chassis dyno. What's that cost? Half the parts in the motor? $500.
I test practically at the track, even if it takes me all summer. I don't trust the speed shop dudes, they are chebby boys. It would be stressful for me to turn over the keys. And besides they never know much about Mopars.
I guess doing all it by myself, is the fun of it.
Reaction times win the race in the brackets. I have run 16 a second Cougar and won first a place trophy.
 
aracer01 said:
Chassis dyno. What's that cost?
Click to expand...

As I said in my post, "there are other ways." Even I have a couple of G-techs that I've bought used, locally. I have less than 150 invested in the two of them. One is an older model, the newer one is new enough that it has data recording. 'S all you need to run a baseline, along, of course, with either a bit of track time, or a "stretch of road."
 
Stretch of road is freeway, or expressway, both have CHP. I do test fate once in a while just to see how it runs up to 6000rpms. Just so I can run it at the track, or to see if it will launch and stop in front of the house but, that brought out, a guy off work to see why the noise. Neighbors are changing to foreigners and might squeal to the police.
Nothing like Hiway 12 through Glen Ellen where we lived in the 80's, down the road from Marshall's Machine Shop in Whine Country Kenwood.
Your talking about software for the car and a laptop, that I can do. What exactly am I looking for? (search bing G-tech, nothing about dyno software)
Ok I found it on the forum.
 
You don't need to break laws, you can do this in "second gear" on the freeway. If you can get at least a partial run in all gears, so much the better. You need at least one good pull starting low, going "up and over" the peak and tapering off, so that when you plot gear ratios, you can get it to "cross.' You can do this on graph paper after you get accel / RPM data. Then compute the difference in gear ratio

Here is G-tech website. These have become more and more capable in recent years

http://www.gtechpro.com/

There may be other products that do this, I don't know what they are
 
I'm just lazy.
$250 at the chassis dyno and I have the info in each gear.
They want you in the seat when you do the runs.
Each gear will have a different tq spread because of the different ratio's of each gear.
Last time at the Dyno I moved my RPM chip to 7400 and let it fly.
Found out I didn't need to go over 6700 in 1st or 2nd.
I wouldn't do this with a stock anything engine.
That was my disclaimer.
 
When you build something special it makes sense not to waste time runs on tuning, all my competitors seem to have the car set before they show at the track, and I get beat to the 60', but i still get them off the line, and I dial according to the time runs. Tuning at home for the next time. The videos of the car give me the evidence for changes.
As long as your having fun do what pleases.
 
I have not been able to run the car or even drive it since I posted this. After getting called into work every day I am nervous to make the drive out to the shop :(
 
Got er out tonight. Put the Holley on it and drove it the same way I did before. Put it in d and go. Turned a 13.46 at 102. Second run I shifted the car myself. I was too excited to really pay attention to the tach but I was shitting on the street at 5000 into first and I'm pretty sure I was close to that number on the track. Second to third sounded around the same so I am guessing around 5000. Ran a 13.30 with the miss still at the big end. I backed the timing down to 33 from 36 and the miss went away but it took my 60 from a 1.90 to a 1.97 and shifted manually again by the sound. Ran a 13.38 after changing timing...i might need to look at my slip again to be posotive on that et.

That was my night. Car hooked great and ran great before the miss. I plan on taking the timing back up and throwing on a better fuel pump then seeing how that does. If I still get the miss then I'll spend the money on ignition junk. Any recommendations for pumps?

Car deffinAtly has some 12s in her I just need to beat it out of her :)
 
If you have alu head, head with a quench pad or a hart shaped combustion chamber. It my only need/want 33-34 degrees of timing.

If your 60 foot times slowed, you my need to re curve your dist to get more base timing in it.

Then again, it could just be a bad spark plug wire or coil.................
 
Buy yourself a log book. Summit and Jegs sell them, or get one of those composition books and do it yourself. For every run keep track of the engine temp before the burnout, the incrementals off the time slip, and the basic weather if you can (temp and sunny or not conditions is fine). If you can, join a local track rental group so you can get some repeating runs in. I prefer rentals myself to open test and tunes. Then, do one thing at a time. I would suggest you first set timing and do not alter shift rpm. Go up 2 degrees per run, see what it likes. Then go down and see what it likes. Then stick it where it likes it. Then concentrate on the carb and fuel delivery to make sure things are set right and you don't get the miss. Jet up two sizes, record the change. When it slows down, go back to where it was fastest. After that, then you can mess with shift points. Basically - put something in place to record changes, then make a bunch of runs changing only one thing at a time, then use the data to find shift points.
 
I have a log. I have everything recorded. I grew up with a guy that has more then a few notebooks full.
 
if you would like to continue just leaving the tranny in drive and running wot, you can tailor the shift point rpm to whatever you feel is safe for your combo. just pick a rpm number you want. by using a lighter govenor and a heavier 1-2 shift control spring and a little more line pressure, you can put it where ever you want. call A&A transmission for the parts and they will steer in the right direction
 
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