Launching an auto properly

*THT* · 05-09-2004, 11:21 PM

Hey everyone, this is my first post in the Racing forum as I've never raced my Max seriously. I'll be attending a meet later this month at a "local" track and wanted to know the proper/best way to launch an automatic Maxima. If it makes a difference, my car's got the following mods: Y-pipe, high-flow cat, Greddy SP2 catback, Technosquare ECU. I'm also running on lightweight 15" rims and Yokohama Avid Touring tires. I'll deflate them to 25psi before running and I'm also familiar with flashing the TC. Should I just floor it when the light goes green or what? And I'm sure everyone hates this question as it's very hard to give a good answer but approximately what times should I be expecting? TIA.

~THT

**deezo** · 05-10-2004, 04:37 AM

Before you line up to your mark, spin the tires just a bit to clean of the debris. Don't smoke them!

Soon as I line up, I torque brake and on the second yellow, I mash that bish to the floor while releasing the brake. When the auto is ready to shift, I feather the accelerator to allow the gears to drop faster. I run good times shifting like this.

*THT* · 05-10-2004, 07:19 AM

Feather means let off slightly?

~THT

**deezo** · 05-10-2004, 07:56 AM

Quote:

Originally Posted by THT

Feather means let off slightly?

~THT

Yes. Practice to see how quick you can get the shifts to drop then floor it after it drops into gear.

*THT* · 05-10-2004, 09:33 AM

Do you watch the tach or go by how the car feels? I do the latter but I'd like to know which way is better.

~THT

*THT* · 05-11-2004, 09:29 PM

I just realized, all my techniques need to be refined because I've modded it. Time to hit the road and find some deserted strips (not that hard in IA)!

~THT

Magikone69 · 05-11-2004, 09:53 PM

good luck man, i want to head out to the track to compete this weekend after i get my custom/magnaflow cat-back installed. i already have my injen clone, UDP, and Y-pipe installed.

*THT* · 05-12-2004, 09:32 PM

Another question: OD on or off? Intuition tells me "Off" but I'd like verification.

~THT

*waveridr85* · 05-13-2004, 07:28 AM

what do you mena by flashing the TC?

*THT* · 05-13-2004, 09:13 AM

Flashing the torque convertor. Hold your brake just enough to keep the car from moving forward. When the light goes green, hit the gas and you'll get the best possible response from your torque convertor.

~THT

*Jime* · 05-13-2004, 09:49 AM

Quote:

Originally Posted by THT

Another question: OD on or off? Intuition tells me "Off" but I'd like verification.

~THT

It really doesn't matter unless your car goes fast enought to shift into 4th. All the O/D off button does is prevent your car from shifting into 4th, nothing more.

I now leave my O/D off and manually shift into 4th when necessary.

*waveridr85* · 05-13-2004, 09:55 AM

Does flashing the tc or power braking provide better times?

*Jime* · 05-13-2004, 10:02 AM

Quote:

Originally Posted by waveridr85

Does flashing the tc or power braking provide better times?

There are too many variables to answer that question.

You just have to try and see which does best for you. I always torqued, but last year started just nailing it about 200 rpm above idle and it seem to work better. Traction is the biggest issue as to which works best.

*THT* · 05-14-2004, 11:42 AM

What's power braking?

~THT

wunfstmax · 05-14-2004, 02:05 PM

power braking is when you push both gas and brake... thats what i do up to 2000 rpm and never break traction

*THT* · 05-14-2004, 02:42 PM

Can't possibly be good for the car...I'll give it a try!

~THT

*cw96* · 05-15-2004, 10:12 AM

You can also unhook your drop resistor which will give you full line pressure shifts if you haven't already done it yet.Just pop the hood and unhook the connector it's on your right inner fender near the strut tower.I would only leave it unhooked while you are at the track because you don't want the tranny shifting that hard cruising around town.You will have to reset the ECU when you are done because it will throw a cel if it's unhooked for more than a few minutes.I ran a micro switch to my gas pedal so it would only work a WOT that way I don't even have to think about undoing then redoing the wires all the time.

oTranscendental · 05-20-2004, 02:41 PM

you better watch that feathering technique, I blew my 3rd gen auto doing that. Get a Valve body upgrade, and it will always shift fast. Its more expensive to replace all sorts of hydraulics, and the input shaft than to get the VB.

*THT* · 05-21-2004, 11:27 AM

What gear did you blow? Isn't 3rd an especially weak gear in the 4th gens?

~THT

*Broaner* · 05-21-2004, 11:52 AM

I'm curious about this feathering technique. Does it work for DR'ed or VB'ed cars? It doesn't make sense to me that it would. Anyone with experience to back this up or technical theory?

oTranscendental · 05-22-2004, 05:50 PM

I blew it up shifting from 1st to 2nd

Max-2-GTR · 05-22-2004, 08:15 PM

Quote:

Originally Posted by oTranscendental

I blew it up shifting from 1st to 2nd

Serious?! Man...how many times did you use that technic before blowing it? Sounds like a very bad technic then. Anyone else got probs after using the feathering technic?

Max-2-GTR · 05-22-2004, 08:18 PM

Is there a good combination like using D and brake torquing or maybe using 2, brake torquing then switching to D or withouth brake torquing and using 2 then switch to D or just hold brake till light then floor it on D? If you guys get what I mean

BadKarma99-4spd · 05-22-2004, 08:53 PM

Quote:

Originally Posted by broaner22

I'm curious about this feathering technique. Does it work for DR'ed or VB'ed cars? It doesn't make sense to me that it would. Anyone with experience to back this up or technical theory?

feathering as its being called(dont know what other terms it goes by) does "work" if your trying to make the tranny shift faster. my brother does it to great effect in his ls1 auto t/a. there is a huge difference in his shifts when he lets off the gas slightly just before it shifts.

doing anything to our crappy 4gen autos other than driving like a granny is bad for them

*Broaner* · 05-23-2004, 08:07 AM

Quote:

Originally Posted by BadKarma99-4spd

feathering as its being called(dont know what other terms it goes by) does "work" if your trying to make the tranny shift faster. my brother does it to great effect in his ls1 auto t/a. there is a huge difference in his shifts when he lets off the gas slightly just before it shifts.

doing anything to our crappy 4gen autos other than driving like a granny is bad for them

As I mentioned before in another thread:

Quote:

I also wonder why everyone hates this tranny. I don't like the fact that I have an auto but it is a good auto IMO. Lets think about this. When your in a relaxed mood the tranny does a very good job of being luxurious and discrete. But when you want it to kick your @ss it will do that with ease if you take the steps to drive it. Downshifting is one of those steps that helps a lot. IMO, it isn't extremely bad for it and it eliminates the lagging that you guys hate but was actually designed to do. So, depending on your mood the tranny can make the max very comfortable or a easy to drive beast.

That said, I've been thinking about this feathering thing and can't see its value in Maxima tranny's. Please do not bring LS1's into this debate. An LS1 is a totally different animal. In the case of the DR, the tranny is already shifting at 100%. This would mean that it cannot shift any faster no matter what driving style you use. I also cannot understand in working on a stock tranny because at lighter throttle the TCM is more compelled to inject as much of the luxury feeling as possible. If you're DR'ed you'd understand what I mean. You'd know that 1/2 at part throttle is the hardest shift. This would lead me to believe that the line pressure during the same shift in stock condition is very low(like 25-50%). So, IMO, letting off the trottle would only decrease line pressure, thus slowing the shifts. If someone showed me track #'s then I might have to reconsider but as of now I don't believe someone's perceptions. I definitely understand that is may produce a more dramatic shift but does it make you faster. If it does work, the time you save during the shift would be negated by the time that you were off the throttle.

BadKarma99-4spd · 05-23-2004, 09:10 PM

i still maintain my discontent in nissans 4gen maxima tranny

my 3gen tranny seemed much better, as well as many other cars ive driven.

most of this stems from the trannies apparent inability or reluctancy to leave 4th gear.

in general maxima auto is always in the wrong gear

and also 3rd gear just plain sucks.

*THT* · 05-23-2004, 09:29 PM

Well at least at a 1/4 mile track, you don't have to deal with the downshifting reluctance of the auto. Doesn't Mercedes Benz make a really good automatic tranny?

~THT

joeyicu · 05-24-2004, 08:19 PM

merc makes beautiful trannies, id think feather the shift would make the car slower, as line pressure is decreased, like the one guy said before, if it were me racing an auto maxima, id tq her up at the line to around 2k or more, meaning brake in, revs at 2k, then when the light goes green mash it and left off the brake, leave it and d and let the ECU do its thing, upping the line pressure all the way make it shift very quick but may not be nessicarily good for the tranny

*Broaner* · 05-25-2004, 07:36 AM

I must inject my opinion of the benifits of the DR mod. If the tranny shifts at FLP it spends less time slipping. The reduction of slippage results in a reduction of heat and therefore increases tranny life.

joeyicu · 05-25-2004, 04:17 PM

yes im not talking specifically this, just that with some, chips that up the line pressure to much, it can shorten the life of the tranny, the shift kit on my thunderbird does exactly what you descibed, i was thinking funny, i was thinking alone th elines up upping the pressure to unsafe points with like a unsafe dyno tune or such