Proper Launch RPM and Procedure?

[stonecoldcrazy663]

Ok, I am worried about hurtin my Transmission, so I need some help. What is the proper way to launch an Aurora, mines a 98 too. What RPMs should you launch at? What Gear is best? Can I hold the brake in and rev to the launch rpm, and what is it? Is this bad for the tranny? Thanks

[bLACk AurOrA]

if you're talking about normal driving... start out in drive. hit the gas when you wanna go and i guess it depends if your in a hurry or not? i usually shift about 3k or 3500.

[stonecoldcrazy663]

i mean for drag racing. I just wanna kno if im gonna hur t the trany by holdin the gas and revin it to 1500-2000.

[bLACk AurOrA]

ooo ummm.. im not sure. i got 195k miles on mine and i sorta build it up with the brake on. dont do it all the time but im sure it will be fine. start out in drive tho. cause if your at a stop your car will already be in first

[auroralover]

In my opinion, brake torquing these cars at any rpm is just not a good idea. I think they are fast enough as is without doing this. Trannys are too damn expensive to repair. I've beaten plenty of cars without brake torquing mine. This is just my opinion, of course, as I don't want to drop thousands into a repair job for something like this. Or, maybe I'm just old.......

[OldsMike]

stonecoldcrazy663 said:

Ok, I am worried about hurtin my Transmission, so I need some help. What is the proper way to launch an Aurora, mines a 98 too. What RPMs should you launch at? What Gear is best? Can I hold the brake in and rev to the launch rpm, and what is it? Is this bad for the tranny? Thanks

Brake torque is the procedure of holding the brake, giving the engine gas increasing the RPM's and thereby loading the torque converter toward its stall speed.

I do this all the time....... at the dragstrip.

Doing this on the street has no value. The road surface is not sticky, the tires are not optimized to stick, the road is dirty. Increasing your launch RPM on the street will only result in spinning the tires.

As for tranny damage, when using GM's TH350 or TH400, there is nothing to break in the torque converter. On AOD transmissions, the torque converters have clutch discs similar to the main core of the transmission. The question is, are these clutch packs moving at all when brake torquing? I can't answer that, frankly, I don't know. If they are, they would be prematurely worn out by excessive use of brake torque.

A trans brake is the correct method of launchng a car at the drags and I certainly would never put one on a Aurora. A line lock wouldn't necessarily work on a front drive as you would have to put the line lock to activate braking on the rear tires. The front tires, potentially, would just pull the rear of the car.... I'm just guessing on that.

IF, I were to take my Aurora to the dragstrip to see how it performs, I would probably brake torque around the 1800 RPM range (for starters). I would mix the RPM's, plus/minus 300 RPM or so to see the best combination. I would start in first gear and shift at engine redline (my 99 is 6200). I would also mix the engine shift point. The engine redline is not necessarily the quickest value down the track. If that number is too far from the torque curve, a higher RPM shift point will slow you down. I would also put Drag Radials on the front to optimize launch and use fresh, synthetic oil in the transmission and engine. A fresh set of plugs as a "mitaswell".

Hope this information is helpful to you...

[Aurora40]

Mike's right on. I don't think moderate brake torqueing to under 2,000 rpm would be hard on the tranny, but I personally wouldn't make a habit of it. That is what I do at the strip, though.

I typically roll onto the throttle for the best street launches.

As for shift points, the 4.0 seems to hold power well to the redline, or at least doesnt' drop significantly. It will make more power above the power peak than it does at where the revs will be after a shift. Plus, the higher you can get in one gear, the closer to the power peak you start in the next gear. I think our powerbands are suited best to pushing the revs to the limit. Of course, you can't make that decision, the PCM does. I've found the way to get the PCM to do this is to make sure the car is fully warmed up before you begin any monkey business, to make sure you put the pedal to the floor early on, and putting it in 2nd gear will help, though mine will often run to 6400 rpm in "D".

[stevensolds]

6400rpm, wow. My redline is 6000 cause its a 95.

I brake torqued to 1500rpm when racing some punk kid in an integra. I beat him off the line but i think he was spraying cause i had him the whole time then all of a sudden he blew by me.

Great ideas and theories. Letitroll is right about the tires not sticking on the street though, so there isnt anypoint to do it really.

[bLACk AurOrA]

mines a 95 and it shifts at 6200. the red line is just a little past the 6

[stevensolds]

Thats bad, you could float a valve. I think in 97 there were bigger springs or mounts or some stuff, so it could withstand it then. Mine always shifted at 6000.


Maybe yours shifts higher cause when it was new, the ppl that had it drove it harder, so then the PCM would "learn" how they drove.

[bLACk AurOrA]

i couldnt tell ya. it might shift at 6 exactly but the red bar starts after the 6 on the tach. ill have to try it next time i drive it