Best launch/shifting methods

[Fastlanev6]

I'm going to hit up the track in 2-3 weeks, and i've been thinking about my car's powerband. I think if it shifted a little later than the computer does, i'd make better useage of my powerband and run slightly better. I read somewhere that putting the shifter in another gear besides OD will increase line pressure and allow you to rev past the auto shift point. Is this accurate? At what RPM will the rev limiter hit in each respective position, and from all your experiences, at what RPM should I shift at? Also, how do you launch when racing the 1/4? Any powerbraking? ETS on/off?

[Colin]

Try turning the ETS off and leaving the shifter in second (this increases line pressure) when you launch then manually upshifting shifting just near 5 grand . Forget power braking unless you like breaking parts ... :roll2:

[Fastlanev6]

is the pressure raised ONLY in 2nd, or is 2nd just reccomended? will it shift exactly when I shift it to 3rd at 5k rpm, or will it keep revving to the programmed shift point? 5k seems a little low to me.

[rabidpanda69]

It'll rev a little after you actually shift it. I suggest you try it out just to get an idea of you its gonna react. Dont want to hit that limiter at the track ;)

[Fastlanev6]

yeah tonight I was cruising around, got to a light where I was going to make a left turn, dropped it into 1 so I could manually shift it. Started going, didnt give it full throttle, shifted into 2 and it shifted hard....kinda caught me off guard. Now I know it increases the line pressure. Does anyone know where the rev limiter is before I try it myself, and at what RPM I should shift in each gear?

[Colin]

Originally posted by Fastlanev6
5k seems a little low to me. With the stock cam no more HP is being produced after 5 grand so revving past that point will do nothing but make noise . http://www.gaownersclub.com/images/engines/3400_gt_curve.jpg

[Fastlanev6]

yes, but looking at the graph, at about 3800rpm (which is about where the transmission engages after shifting from 1-2), the engine is producing about 150hp. At what looks to be the shift point (where the graph ends), it's producing about 160hp. If I was to shift earlier (at say, 5k rpm), the transmission would engage at a lower rpm (like around 3k rpm). At that engine speed, the HP curve is just beginning to pass the torque curve and HP is actually being generated.
It's true the power band drops off after the HP peak, but the question is what range of the powerband do you want to use when racing? You see my point?

[Colin]

Originally posted by Fastlanev6
You see my point? Yes , but what is really needed for drag racing is closer gear ratios so the revs don't drop so much between shifts. I see what you are saying and you could see if it helps by trial and error , but still no more power will be produced after 5 grand but it may help keep it in the power band dispite that .

[kickarsgrdam01]

i have a very good racing method i think, I powerbrake it, never had a problem, to a little under 2 grand and it gives a good launch, just a little bit of tirn squeel on city roads but you wont get any at the track. then, it taken practice but if u put it in 1st when u start and when it gets to about 5400rpm click it into 2nd and it will shift right at 5900rpm ( anything higher and u will hit the limiter, and then do the same from 2nd to third but click it into 3rd at more like 6600rpm. the reason is because the computer has more time to do the shift since 2nd is slower then first. that works well for me but it is had to get the 1st to 2nd shift right all the time, u will be early or late, both are bad so maybe just do the 2nd to 3rd shift, that is very easy and gives better results

[Bjornboy81]

6600 rpm's?!!! Isn't that a little high for these engines?

Hey, do you guys floor it right off the line or gradually (but quickly) get it to WOT?

[Fastlanev6]

I'd never rev my engine to 6600rpm...arent the Gen III 60 degree V6 cranks rated at like 7500rpm? Thats pushing it a little close, and theres absolutely NO power at that RPMI think for right now (unless my mods raised my powerband significantly), 6000rpm is THE latest i'd want to shift.

[Fastlanev6]

Ok I just tested a few things...with the shifter in 1, the rev limiter hit at about 5900rpm. I almost got to my shift point in 2nd but I saw a cop so I slowed down. Lets put all this info together so everyone knows.

[Bjornboy81]

I'd think it would be best to just keep it in 3rd and let the PCM decide when to shift. We have a computer that faster and smarter than us, so I'd say let it do it's job. You can always help it out by getting DHP though. :)

[Fastlanev6]

Originally posted by Bjornboy81
I'd think it would be best to just keep it in 3rd and let the PCM decide when to shift. We have a computer that faster and smarter than us, so I'd say let it do it's job. You can always help it out by getting DHP though. :)

Yes but the computer only does what GM told it to do. On the 4T60-E mated to a 3100 in a Chevy Beretta, the tranny shifts a bit too early to take full advantage of the powerband (see this link for more info on how Canada manipulates shifting Berettaspeed.com (http://www.berettaspeed.com/information/view_article.php?id=3) )

[Fastlanev6]

Ok...after doing some testing here are some conclusions i've reached...

1. Leaving the shifter in 2 or 3 when starting from a stop will not affect your shift RPM...it will shift at the same spot as if it was in D.

2. There is a rev limiter at about 5900rpm, and hitting it will screw you over in a race.

3. Since the RPMs climb so quickly and the rev limiter is only 200rpm past where the tranny shifts, its not worth letting it rev past the programmed shift point.

4. Transmission line pressure is increased in all selections except D (overdrive). It is unknown (maybe someone does know) if there is a difference in shift speed between the 3.

5. Powerbraking would probably cause you to run slower times, plus the stress on the tranny will just heat it up. It probably wont help you.

6. Make sure the ETS is off when launching.

Please leave your comments (for or against) these statements, and we can have this available for all to use once we get this perfected. Thanks.

[Bjornboy81]

Originally posted by Fastlanev6
6. It has been mentioed that it is best to have ETS off when launching. Does everyone agree with this statement?
That's a definet yes. The last thing you want to happen is the PCM to pull back the timing when you squawk the tires a little bit.

As far as torque bracking (powerbraking) I can't really tell if it's any better or not. I do use two feet when I'm taking off hard (I won't call it racing :lol: ) so I can get on the gas right away; but I do know that torque braking isn't good for the drivetrain so I stay away from it. Good observations Keith ;)

[Fastlanev6]

facts edited. Thanks for your input. I think the fact that I can gun it at a 3-5mph roll and still chirp the tires says that I dont need to powerbrake anyway...but you brought up a good point about hurting your powertrain (it significantly heats up your tranny when you do it, and as we all know.....heat is bad).

[Bjornboy81]

After I put on my SLP exhaust I noticed that I can't chirp the tires as much like that. But the high end gain is well worth it.

So does anyone know for sure if the transmission pressure is increased more having it in 2nd rather than in 3rd?

[Fastlanev6]

Originally posted by Bjornboy81
After I put on my SLP exhaust I noticed that I can't chirp the tires as much like that.

That could be a good thing when taking off from a stop, too.

[car audio dave]

this is all good info, im going to the track next month. i was planning to powerbrake it, but after reading herei think ill lay off that.my car might be slightly different since i have the ASE computer reprogram. ill post up any info i gain.

[Bjornboy81]

Sounds good Dave.

I'm suprised more people havn't chimed in with their methods and techniques. I know a lot of people around here have been to the track multiple times...so if you have a good launch method, please feel free to post up people! :D

[TA^Guy]

If your taking it to th etrack here are a few things to do to improve your launch....

Air down your front tires to about 26psi. The softer tire will grip better but not be too soft where it will incress rolling resistance and cause more friction. while your at it air the back ones up to 40psi. (return them to normal after racing)

Turn off ETS, A/C and any other acessories. Pull the shifter back into 3rd (still incresses line pressure). When both drivers are staged brake stand the car to around 1800-2000 rpms, I green just matt the throttle. You'll have to test various rpms to brake stand the car at given you r vehicle and track conditions. What your shooting for is a little squeel from the tires off the line. Don't hear it, means you can be launching harder, if it spins too much it means your loosing traction. Keep playing with tire pressure and engine speed while brake standing and you'll find your best launch technique.

[Bjornboy81]

Brake stand at about 1800~2000rpms?!!! Isn't that just begging for CV joint problems?

[TA^Guy]

For what the whole .5 second your standing on it?

Can't be any worst them the tires spinning and grabbing traction on a sticky track. Or not spinning for that matter.

It's not like the car makes 400ft/lbs of torque, it's only a wee bit over 200.

If anyone is affraid of breaking anything stay off the drag strip! Can't win if your not willing to push the limits.

[slowbird]

I find it's better to launch off of idle. Loading it up on the brakes isn't needed...but then again...it depends on how sticky the track is that day.

Warm the tires up a bit after the waterbox...get the crap off of it, and the hot rubber that the Big V8 cars lay down can help.

Pick a lane that all the big muscle cars seem to be launching well off of. Try and go right after one...keeping an eye on where they left the rubber patches...and try and launch off of that.

Keep as little fuel in the car as possible...remove any unneccesary items from car. (i.e. Spare tire, Jack, Subs, Toolboxes, Girlfriend etc) Be sure to keep the seats/interior in. Street Trim is the only way to go.

As said before....keep the front tires kinda low...experement and see how you are launching. Rear tires...pump them up to Max if not more. (I'm not responsible for blowouts or tire wear)

If you have an extream skirt package, or large spoiler...remove them if you can...you can gain a tenth or two from shedding that weight and friction.

Make sure all accesories are off...

[Rayz]

JATO
Jet Assist Take Off :lol:

[slowbird]

Originally posted by Rayz
JATO
Jet Assist Take Off :lol:

Good idea.

[04GASE1]

oh man i love the way my ga shifts when i manually shift from first to second, part or full throttle, kinda makes you think there is something under the hood after all, lol. personally i like to brake torque off the line, but i build a lot of heat in the tires for the show, if ya know what i mean

[Fastlanev6]

brake stand= more heat = slower shifts and more wear. Just dont brake stand for long.

[GAGT7386]

sorry off topic but what do you guys recommend for PSI to be for casual driving. i have toyo proxy z4 tires, right now i am keeping them at 38 front 41 in the back. possibly to high just wondering what your thoughts are.

[Fastlanev6]

go with what it says on the drivers side door...mine says 30psi

[Prospeeder]

we keep 35 PSI on all 4 tires when driving.

And brake standing isnt gonna hurt your car if you do it for a few seconds, its not gonna heat ur transmission up that much for that whole 2-3 seconds ur doing it, and with newer cars these days, it takes 30-40 minutes of highway driving just to get the trans hot enough to check fluid! Iv done brake stands in my car twice and at 2k it definatly helps you hook up, and with that turbo auto spooled it makes a nice quick 0-100 or what ever, i would expect my car to do low 15s if i went to the track, but ill have to find out

Iv done take offs in my moms car, but she has nearly bald tires and is due for new ones next month so the 225/50/R16's spin like mad

[Fastlanev6]

Originally posted by Prospeeder
we keep 35 PSI on all 4 tires when driving.

And brake standing isnt gonna hurt your car if you do it for a few seconds, its not gonna heat ur transmission up that much for that whole 2-3 seconds ur doing it, and with newer cars these days, it takes 30-40 minutes of highway driving just to get the trans hot enough to check fluid! Iv done brake stands in my car twice and at 2k it definatly helps you hook up, and with that turbo auto spooled it makes a nice quick 0-100 or what ever, i would expect my car to do low 15s if i went to the track, but ill have to find out

Iv done take offs in my moms car, but she has nearly bald tires and is due for new ones next month so the 225/50/R16's spin like mad

I dont know about you, but back home it was a good 20 min drive to the local drag strip. My engine got pretty toasty by then, even if I let it sit for an hour after getting there. Thats highways driving...if you drive in the city it would heat up even more (not beyond safe levels, of course). I just dont think you need to powerbrake in a GA...it gets enough wheelspin as it is, and you dont want too much. I found the perfect combo to be about 35psi launching from idle (I think thats what it was, anyway).

[Prospeeder]

Of course the engine gets hot! It has internal cumbustion going on, but a transmission doesnt, and takes quite awhile to warm up enough to even check it, hell, a quick run to walmart and back can have my car at 200 degrees coolant temp, but the trans fluid will still be cold to the touch

[Fastlanev6]

well sure...but keep in mind every little bit helps. The transmission has parts that spin pretty quick, and in city traffic especially it can build up heat. Tranny temp is very important in racing....thats one reason lots of the pro and super pro guys have some sort of tranny cooler. Point is...heat = bad. Anyway, we have our opinions and thats perfectly fine.

[Prospeeder]

Yea, if you want tranny heat, drive a Taurus/Sable, LOL! theres some tranny murdering without even trying!

[xxbackhillxx]

heat = bad is a stupid philosophy. running the motor cold is just as bad as running it too hot. same goes for a transmission.

[Fastlanev6]

k...explain to me why you think "heat = bad" is a stupid philosophy. Of course running a cold engine isnt that great either...but i'd rather have my engine below normal temp than above (for more than one reason). Heat is the cause/creator of most engine/transmission problems. I'd rather be running rich than have warped cylinder heads (exaggerated example, of course).

[Old Guy]

This pretty much sums up anything I would say. I ran my GA every week for about 2 solid years during the season and as John said, brake standing for a short period of time , and I would suggest doing it at when you see both cars are staged, won't hurt anything as long as you keep it between 1800 - 2000 rpms. Anything higher will not only put harmful stress on your tranny, but won't result in a better time.

My best times actually came within the last 2 months I owned the car so that's pretty good evidence that the tranny didn't show any ill effects from the brake standing.

Just a note for any SE owners: Start in 2nd gear in an SE and then do your final upshift at 5K which will be just before you cross the finish line. For some reason the SE tranny shifts from 2nd - 3rd a little early, or at least it did in my car.



Originally posted by TA^Guy
If your taking it to th etrack here are a few things to do to improve your launch....

Air down your front tires to about 26psi. The softer tire will grip better but not be too soft where it will incress rolling resistance and cause more friction. while your at it air the back ones up to 40psi. (return them to normal after racing)

Turn off ETS, A/C and any other acessories. Pull the shifter back into 3rd (still incresses line pressure). When both drivers are staged brake stand the car to around 1800-2000 rpms, I green just matt the throttle. You'll have to test various rpms to brake stand the car at given you r vehicle and track conditions. What your shooting for is a little squeel from the tires off the line. Don't hear it, means you can be launching harder, if it spins too much it means your loosing traction. Keep playing with tire pressure and engine speed while brake standing and you'll find your best launch technique.

[Old Guy]

Originally posted by Fastlanev6
k...explain to me why you think "heat = bad" is a stupid philosophy. Of course running a cold engine isnt that great either...but i'd rather have my engine below normal temp than above (for more than one reason). Heat is the cause/creator of most engine/transmission problems. I'd rather be running rich than have warped cylinder heads (exaggerated example, of course).

I agree. My best times were always when my temp was 180 degrees. If I was at 200 when I staged I knew I would run .1 - .2 seconds slower.

[slowbird]

Yea...my best time was the first run after I let her cool off a bit.

[Fastlanev6]

yep...its why some people ice their engines after making a few runs....why people (myself included) install lower temp thermostats, etc. Of course your engine should be at operating temperature....but it helps when you're at the bottom end of that spectrum :D

[slowbird]

Originally posted by Fastlanev6
yep...its why some people ice their engines after making a few runs....

http://img403.imageshack.us/img403/2959/picture0076qh.th.jpg (http://img403.imageshack.us/my.php?image=picture0076qh.jpg)

My old Turbo 2.0L Sunbird.

Ice is good.

[mygaathena03]

well believe it or not... i've got the new W-rated Dunlop Direzza DZ101 performance tire on a 17 inch Kazera wheel.... and I've been experimenting with a stopwatch and coned off area's at my dad's construction site, and i'm seeing 0-40mph times at least few tenths quicker using this method...

a brake-torque at about 2200rpm... ETS on.... and the shifter in first....

There's an intial squeal of one tire, but once the brake is tapped on that wheel to check the slippage and the power is transferred to the other wheel, the car takes straight off....

[JamaicaMeCrazy]

heat is bad....if i remember what i heard a while ago, every 10 degree increase in underhood temperature meant a 1hp loss...please feel free to correct me if i am wrong, just tryin to remember:???:

[Fastlanev6]

I bet its more than that...my car is noticably quicker in 60 degree air than 80 degree air

[Prospeeder]

Well a car will run and perform better at Operating Temprature then being ice cold. Of course the cars gonna run better at lower air temps,. Colder air is more dense air, more air = more power. Has nothing to do with engine temprature itself wich wouldnt make much of a difference because the engine will run a constant temprature most of the time

[Fastlanev6]

yes....but we're talking more about incoming air temps than engine temps. Once your engine reaches its normal operating temp, it takes a long time for it to cool down....but its the surplus heat that you can try to get rid of

[gectek]

the best way to launch a factory car, or a modified one for that reason, is to flash the converter which factory is about 1900 to 2K, really about 1895, but the tach on the IP isnt that accurate really, but to flash the converter is best, also use a sticky tire. there isnt enough power NA for the tires to break loose when standing at the line, and minimal wheel slippage is ok to provide a fast secondary flash for the converter, which will give u better times. now when u go with a higher stall, then you should try to stall out the converter to that speed and then run it from there, a WOT run from the line isnt necessary and can be counter productive if it is above the stall speed, because then the engine and trans have to take longer to equalize pressure/speed/and torque mult. but if it takes WOT for you to reach that speed and keep it, then by all means...full boogey, after you take off, then floor it and dont look back. tuning for the trans is necessary for you to see any amount of time subtraction in terms of just the trans getting you better times and more accurate/harder shifts. if you wanted hard shifts, just unplug the MAF, because when you run WOT for that long it uses a programmed spark table, so there isnt much changing that

[Fastlanev6]

Just for the record...DO NOT unplug the MAF sensor. It will cause your engine to run like crap. Besides, I dont know many people who can simply "reflash" their PCM to raise the torque converter stall RPM. If you want better transmission performance, get a drain/fill, install a polyurethane tranny mount, and possibly do a shift improvement kit (though I dont know if its worth it). The factory 4T-65E shifts pretty quick when its running correctly and if you have it in 2 or 3.

[gectek]

wait a minute...what are you talking about. first off the 99+ have the 4t4x in them, secondly i didnt say reflasht the PCM...it is a process called flashing the converter. reflashing the pcm will have nothing to do with converter stall speed...period. that has to do with the stator, how many vanes it has, the degree of the vanes, the amount of vanes on the hub and the degree those are oriented also. flashing the converter means to rev the engine until the speed between your engine and TC/trans equalize, you can basically hear it do that, its usually about 2k on the tach. unplug the maf if you want, itll just run speed density, which is max line press and hard shifts, but if you run it for a few runs then it wont matter that much. also no one sells a shift improvement kit for our trans. the 4t45 is a good trans as well, u just have to know how it runs and how to improve it...just like me 3.91 gears, high stall converter, and a few other things

[commie21]

i noticed when i went to the track for the first time, i got about 5 runs in. i tried a couple of different things. i tried manually shifting, letting it shift on it's own, i didn't power brake. i took my traction control off on all the runs. i got the tires wet, dropped it in first, lit em up. got em warm. when i did that, they just sat there and smoked. when i had it in drive, and tried to lite em up, it automatically shifted to second and i lost everything. when i ran, i noticed when it shifted into second, at about 5900 rpm's i lost a lot of my power. rpm's dropped to about 2700, but that was due to the stock pcm. i installed a new pcm and i can tell the difference when i run now. haven't been to the track with it yet but im sure my time will be better

[SikMindz]

1) WTF did you wet your tires for?
2) If (and I'm almost certain you are) you are running street tires there really isn't a need to "lite them up." The only reason why you may want to do a QUICK burnout out is to scrub the tires clean of debris. OUTSIDE of the waterbox I may add.
3) Manually shifting has already been proven to be problematic. Put it in 3 turn off ETS, power brake to about 2500-3K and punch it at the 3rd yellow.

[gectek]

well u cannot run the RPM up that high with most factory stall converters...they are only at 1895

[SikMindz]

Oops...1500-2K I meant. You're right.

[Fastlanev6]

Actually, in my experience using the wet box (even with street tires) has helped with traction. I would roll all the way to the forward edge of the wetbox, spin them for a few seconds and let off the e-brake. No water left on the tires, nice and sticky, and a cool smoke show :) Not to mention my better 60' times.

[SikMindz]

...although this goes against all conventional wisdom and track etiquette- whatever floats your boat man. A good quick spin of the tires to rid of debris is more than sufficient by most standards.

Picked up from various websites regarding the waterbox and treaded street tires:

I will assume you are on street tires. Your treaded tires will just pick up water in the treads, and when you do your burnout, it will sling water all over inside the wheel well. You will then track the water all the way down the track, and water will be dripping down onto your rear tires, making them VERY slick! If you do this, you make the track dangerous for everyone. The water is for slicks, not treaded tires. Back up slightly if needed. For street tires, a burnout does much at all. Street compounds are hard, and high performance tires are specifically designed to not heat up. Heat causes high speed tire failure, that is why you paid big bucks for "Z" speed rated tires. Now your trying to heat them up??? If I run my street tires, I do a quick, short burnout to clean the tires off. Buy a cheap set of slicks when you can.
;)

[Fastlanev6]

If I still had all of my timeslips from when I used to run my old Chevy Beretta, I would post them but I dont. My best 60' times HAVE been after doing a burnout in the wetbox. I had pretty good tires, so I couldnt just break the tires loose for more than a second without having transmission slippage instead (GAGT included). You do want to be sure your tires are dry, which is why you want it to spin for a few seconds after you leave the wetbox...but thats easy since you're going 40mph on the speedo leaving the wetbox. Just saying what I have found, thats all. I was skeptical at first, but you never know until you try...and I have.