What do you think?

[Redog]

OK I ran a 15.415 @ 88.72 MPH in the 1/4 in Feb. The temp was 61. I ran that with no spare and jack and 3/4 tank of gas.

I'm may be going to Acto this Sunday for a T&T (hopefully it doesn't rain) and I was wondering if it's possible to run a 15.20 or better with the same mods, no spare/jack and say between 1/2 and 1/4 tank of gas.

The car weighed 3306 when it ran the 15.41. I guessamate that one gallon of gas weighs about 6 lbs. So running with 5 or 6 gallons as opposed to 10.

Any thoughts :unsure:

[Naich]

its possible, but track conditions really play a big role in it. Also, are you going to run on your new wheels? They could slow you down a little. The weight of the gas is a small issue, but it won't help you .2 sec.

[Redog]

Originally posted by Naich@Mar 30 2004, 05:22 PM
its possible, but track conditions really play a big role in it. Also, are you going to run on your new wheels? They could slow you down a little. The weight of the gas is a small issue, but it won't help you .2 sec.

I ran the new wheels with the 15.415

when u go back and run in the summer time u will be running 15.7-15.9 guarenteed

[Oldsman]

well you might drop 15 lbs but you won't drop .2 in the 1/4. depending on humidty and air temp and track temp, i would shoot for hoping the same ET but maybe a little faster mph.

[Daytona]

Several factors will determine how quick you go. The differences in absolute altitude is negligable between Atco and RP.

1. The less gas you have, the more your weight distribution is skewed towards the front of the car. This is important for fwd cars like ours. This will help slightly with ET but more importantly (& significantly) it'll help with launching the car with less front wheel spin.

2. Humidity. The temps are supposedly to be cooler this weekend but the humidity level should be higher. Fuel-injected cars act adversely to higher levels of humidity. You'll see greater changes in ET based on changes in humidity than you would with the same amount of change in temp.

3. Track conditions. RP has a better starting pad than Atco does (IMO) so your launches will probably be a littler more consistent at RP. To minimize issues with the track, line your tires up in the "groove" - meaning find where the most rubber is laid down at the starting line and align your front tires on top of that. This will effectively give you the least slippery area for launch.

4. Shift points. Did you manually shift last time or did you leave the car in gear to shift on its own? Shift points are a huge factor in ET. If leaving it to shift on its own, keep the trans in 3rd gear. If shifting it yourself, find out where your engine peaks in HP and then shift 200 rpms above that.

woah..... did u just say when "manually" shifting the automatic to shift 200RPM's above peak HP spot on the tach? because the alero 3400 peaks HP and torque around 4200RPM's but redlines right about 6000 so ur sayin some1 should shift at roughly 4500RPM's (1500 less than redline)?...maybe that is right but to me it sounds like it'd be bad

[Daytona]

^Sorry, I'm used to my racecar peaks. Didn't realize the Alero peaks were so low on the band. Probably would need to play around with that to see exactly where to shift. Make subsequent runs shifting in 200-500 rpm increments until you found the sweet spot.

Although the redline is 6k, I don't think you should hold it out that far as you ultimately want to shift in the power band. You don't want to keep it revving far past the peak as the numbers will then start to slope downward . If someone has hp/torque printout for a stock engine I'd like to see it. Should give you a better idea of where to shift best.

Charts of the 3400 (LA1)


There are some

That's strange, the dyno chart doesnt go beyond 5500rpms, so you'd think they'd have the computer shift the car at 5500rpms at WOT. Anyways.. shifting at about 5000rpms looks to be best, but in order to make your tranny shift to a higher gear before redline, you have to let off the throttle some, because at WOT it always runs it to redline. Good luck with that...

Off topic and probably a stupid question.. but I was curious looking at those charts how do they get the xtra 10hp w/the Impala/Monte Carlo??

Actually, even if you shift...say from 1st to 2nd gear "manually" with an automatic at 4300RPM's it wont shift...it'll still stay in 1st till it hits redline (5800ish) THEN it'll just shift by itself into 2nd. So manually shifting an automatic is POINTLESS unless ur downshifting..like if you are goin 34mph and u gun it..it just stays in 2nd gear and slowly accelerates (dead spot)..but if you manually drop it into 1st..it'll shift and jump to about 5000RPMs and you get a very nice downshift and good acceleration. That is about the ONLY time I'd manually shift and auto.

Originally posted by mlcroy20@Apr 6 2004, 12:32 PM
Off topic and probably a stupid question.. but I was curious looking at those charts how do they get the xtra 10hp w/the Impala/Monte Carlo??

I believe its in the exhaust

[Daytona]

I don't know why there's an issue with the trans shifts from 1st to 2nd. My Daytona is similar except that I don't even have a choice of shifting out of 1st. It'll only let me shift from 2nd to 3rd though it will shift at whatever rpm I tell it to out of 2nd.

True non-computerized transes like in my old Camaro will allow you to shift wherever you want.

[Redog]

These times are shifting from 2nd to 3rd. I was talking to a guy at work and has says it would be best start in 1st to 2nd to 3rd.

Will that work better?

^ yes, it puts more torque to the wheels

[BLK03GXS]

Daytona is right, you need to shift just above the peak of your powerband... where-ever it may be, reason being simple...
It doesnt matter if the car redlines at 6K, or 10K, if the power is only their till 5K then its pointless to rev the shat outta the motor to get a slower et... cus thats what will happen...
I Sometimes post on www.pontiacdude.cc , the guy Ken has a 8 second T/a ... he and other ppl on that site have noiced better Et's by shifting lower, simply because their is more power there at the lower rpms, same applys here.
If i remember correctly some of them got better ET's by shifting around 4500-5000rpm's or less simply because thats where their powerband is....
Shifting at 6K seems like a harder shift... but just because it seems harder doesnt mean a hill of beans refrance your Et.

And if you start out with the shifter in 1, 2, 3, 4 at a stop... and floor it the tranny will shift into 1st untill the Tb tells it to shift up, thats the bottem line... your not going to get any more "torque" by putting it in 1st.. your only going to assure yourself that it is in fact in 1st gear.

you actually do get better torque from manual shifting because when the car is either in 1st, 2nd or 3rd, it does not have the overdrive gear engaged. I'm not entirely sure y this is but whatever the reason it gives mildly more torque to the wheels when you shift manually throught the gears. I'm not trying to say it makes the car produce more power, but rather use some of the power the tranny is normally sucking up.

Uh, an "overdrive" gear is simply a gear with a ratio lower than 1.00... "overdrive" is 4th gear in the automatics, and is something like a .68 "overdrive" ratio, and that has nothing to do with the first 3 gears

[Redog]

Should I shift into 4th (D) at the end or leave it in 3rd to finish the race?

A guy in work thinks I sholud leave it in 3rd. I think he's right. What does everybody else think