When you are at the track do you shift your 700R4 or do you let the tranny do the work? If you let the tranny shift, do you put it in "D" or "OD"?

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92Z28
89GTA

 

I shift on my own, I wait til the tach gets to the stock red line, then shift. I don't know what the best shift points would be for your engine, but you want to shift into the next gear just where the power band starts.
I'm sure someone else can explain it better.

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89 RS parts car

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

You should leave it in D not O. That is a big advantage auto's have over manual at the track is the consistancy that you get from an auto. If you shift manually you lose the consistancy.
And winning is the track is all about reaction time and consistancy. Your ET is just how much money you have spent on your addiction.

 

Sorry dude I disagree, to get the best time you must shift manually. Just be consistent with how and at what point you shift. I think the consistency comes from the lack of a clutch, and the fact that it is very hard to miss a gear in an auto.

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89 RS parts car

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

I've left my car in D and OD and it shifts the same to me although others seem to disagree. You might be able to squeeze better times if you shift yourself but your going to be more consistant if you let the tranny/computer do it for you.

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j.wolfe
_ ____ _
91 GTA L98
Best time: 14.389@95.49 (VMP)
"...Deception..." Brandon Sloan * ...wounds heal and chics dig scars...

 

If you leave your car in "D" and it automatically shifts at redline, then what's the difference between letting it go automatically or shifting manually at redline?
I would think if anything manually shifting would be slower because if you wait too long to shift then your engine will be at redline longer and not accellerating.

 

Well I don't know about you guys, but at WOT my car will not take each gear to redline, it takes them about 500RPM short. If your car will take each gear to redline, then by all means leave it in drive, less margin for error.
I guess the importance of the shift point is what I'm getting at.

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89 RS parts car

Daily driver 91 RS auto LO3 63k

New project- 89 Formula 350 WS6
383 or 400 to come!

 

more important is knowing where the ideal shift point is for your car.
Bringing it to redline might not be ideal if you are not making power there and dropping too far into the powerband when you hit the next gear.
Personally I let the car shift on it's own, leaving it in 3rd. I have tried shifting it manually as well, but my car is very inconsistant and that run was slower, but it could have been something unrelated.

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Member of The Connecticut F Body Association
1987 IROC 5.7 - 14.21 @ 95
1988 Formula

[This message has been edited by Jay (edited September 13, 2001).]

 

The ideal situation is for the tranny to shift itself at redline. Stock vehicles typically do that, but if you've made mods to raise the powerband, you'll need to reprogram the tranny to compensate.

Automatic systems typically are more consistent than human-input systems. How many of you have an ignition advance lever on your steering column, for instance?

That said, most racers still shift the tranny. Ratchet shifters are a big plus over factory shifters in that operation.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. 2-1/2" cat-back, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 CC system w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker 2055 headers, 3" Catco cat & 3" catback, restalled TC, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Holley 750VS w/4150 conversion, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

As five7 says if the trans shift points are setup correctly for the power band of your engine then you can let the trans shift itself, there is however a large gap between 1 and 2 on a 700R4. You can gain some time by overreving first gear a little so you are at a more suitable part of you rev range when you go to second.

 

i can go about 4tenths faster shifting myself. i am much more consistant for bracket racing if i let it do it on it's own though.

later
tim

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91 Camaro RS-LO3,Auto.
14.209@95.46mph
Best 60' 1.917
Check Out The East Coast F-Body Nationals Home Page
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4 tenths by manally shifting? then explain to me the difference cuz i wanna know.

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86 IROC-Z
305 TPI
700R4 W/ shift kit
3.23 gears
T-Tops
maroon with gold stickers and rims/ black interior
43,000 miles
flowmaster exhaust, edelbrock headers, gutted airbox, converter, and MAF, K&N filters.

soon to come are 3.73 gears and subframe connecters.

 

If you have a stock tpi like me you are going to run faster shifting at 4400rpm than if you shift at 5000rpm. I leave mine in drive and have adjusted the transmission kickdown cable forward so that it shifts early and it runs about a tenth of a second faster than when it was adjusted back and shifted at 5000rpm.Not much difference but why wing your engine out for nothing?What large gap from 1st to 2nd? Horsepower peak on my engine is suppose to be 4400rpm and torque peak is at 3200rpm. My car can shift from 1st to 2nd at 4000rpm and not lose anything compared to shifting at a higher rpm.

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1990 formula 350 tpi dual cat auto 9 bolt posi 3.27 ratio

 

Loosening the TV cable like that is a good way to smoke your tranny.

 

shifting has a lot to do with where inthe power band the car falls back to when the shift happens.
with teh big 1-2 step in the 700r4 (3.06 first gear-1.63 second gear) you fall to far down the power badn to a less efficiant point. if you can hold out the shift a little further you can hit a better part of the power band.
keeping a car in the power band is the way to be quick

later
tim

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91 Camaro RS-LO3,Auto.
14.209@95.46mph
Best 60' 1.917
Check Out The East Coast F-Body Nationals Home Page
www.geocities.com/njspeeder

My MAFB.ORG Home Page
www.mycar.net/mafb/registry/detail.cfm?id=299

DSI Racing Home Page
www.geocities.com/foff667

 

I completely agree along with the few others that also have mentioned this point.

Ideally, you should have your tranny setup to shift at its optimum power point. If your engine is making power over 5,000 rpm; then having your tranny shift at 4,500 rpm does nothing for you. Coversely, having your tranny shift at 5,500 rpm when it should be at 5,000 rpm does nothing either.

As mentioned above, the wide 1-2 shift causes a problem. And like others, I have found that slighly "overrevving" past my optimum power point in first to bring me into second yields better results.

So, ideally you should have the govenors in your tranny setup so 2-3, and 3-4 shifts are done "automatically" at your engine's optimum and hold it slightly it longer in 1st so you don't drop too low in 2nd.

I also found, reworking the eprom so the shift light works on an automatic is a nice.

[This message has been edited by Glenn91L98GTA (edited September 21, 2001).]

 

Brent what have you been smoking?

 

I like to let the TV cable adjust itself the way it was supposed to. At the track I have tried everything possible to see what would give me the best results. The way that gave me the best e.t. was to shift it myself. If I was bracket racing I would leave it in D, because that gave me results within .15 every time. For me it was about .4 slower with it in D, but I guess everyones motor is not the same. Holding first gear a little more gave me better 60' times which would explain the better e.t.
I would go to the track and play with it. Try everything and keep track of what you did (launch rpm, shifting points, etc.) by writing it on the timeslip. Every car is different so it pays to try everything when you can tell for sure if it is making you faster or slower.
goodluck

 

There is no way holding your car in first gear longer gave you a better 60' time because if you let it shift itself it is not going to shift before 60'. It only takes 1.9 seconds to hit 60' in my stock car.

 

You better do some research over on the Tranny Forum. Decreasing line pressure via the TV cable is hazzardous to a trannys health.