Ok, here is a question that i thought would have an easy answer but the more i look into it, the more complicated it seems to get so hopefully someone on here can help me out.

When doing a run down the strip, i.e. accelerating as fast a possible, is it best to absolutlely mash the right pedal as soon as i have traction, or should i gradually push it down as the revs build?

I used to drive a lancer with a the carbie 4G15 in it and i was told the cos its a carbie, if i mash the right foot then it will have too much petrol in the engine and i will loose power, and practical experence seemed to prove as much (not sure if it was all in my head or not but the fastest time i got was doing that, might have been the launch or something else).

Now i drive the V6 TS with fuel injection:D and figure that cos it has the computer running all of that type stuff i can just plant my foot and the ecu will do the rest for me.

so am i assuming correctly or should i still gradually apply the gas? this is for maximum acceleration, not fuel effec. I know the further down the right foot is the less the economy is.

floor it with traction
the reason you can't do it with carbies is because they'll flood the combustion cyl making the mix too rich
efi doesn't have this issue :D

floor it with traction
the reason you can't do it with carbies is because they'll flood the combustion cyl making the mix too rich
efi doesn't have this issue :D

Word. drop it at 3 grand and floor it

can anyone give a 3.5 ltr V6 Semi automatic a hand. on the street i can spin my wheels by just punching it, but on the track last night it did almost nothing, the worst starts ever, and very terrible times. help me if you can.

Are you saying your car can do standstill burnouts on the street??? Or are you saying you take off fast on the street but you cant do it on the track???

Autos are hard to control ive found, in my car planting it isnt the best option for taking off fast, i also use the gears, sometimes i whack it in low, ease on quickly before the revs start coming up then move it up the gears into drive on the lever. I found that planting it wasn't good at all for a good takeoff until your up and going. (In an auto), also found this was true when we were doing time trials in my mates mums 320i or whatever it was.

on the street i can take of with a little wheel spin, not so it squeels but you get the point, but on the track, it was a no go.

probably because the track is stickier than the street.

wheel spin doesn't help you go fast.

cheers,
.wook

Track conditions? The tarmac on the tracks was probably better and you were getting much more grip on the track compared to the roads. Weather conditions play a part as well, could have been many things.

yeh but the revs stayed low, so i was VERY SLOW of the start and started catching again once the revs were up, i need help any tips

EDIT: sorry to hijack thread, didnt wanna take up room by making a new one

Do you just plant the throttle full? As i said i found in autos that doesnt work when you wanna build up speed quickly.

yeah, efi cars can handle full throttle at low rpm, but often you won't actually gain anything as less throttle will still supply enough air to keep accelerating as fast as it can. so it doesn't really matter.

if it is higher rpm that you are getting traction at then just floor it.

technmiue i used was: brake on little bit of throttle, light goes green, foot flat on the throttle, and used my tippy gears to six thousand. to show how bad it was i didnt even get out of second

Using tiptronic as well hrm... you kinda have to know your own car to be the judge of that, for all we know you could have been going fast but you felt slow compared to the others.

Have you noticed a decline in your cars performance recently apart from at the track?

well your speed at the deep end has more to do with power and how long you hold gears rather than how clean you get off the line. in my manual i ran a mid 16 second pass (launched in 2nd to try and cut down wheelspin and just ended up with clutch slip) and my MPH was only a 1 or 2 MPH slower than my 14 second pass.

does 16.27 sound fast?

here are the conditions of my car = full tank of petrol, amp and sub in the back, wheel alignment was not so good i found out this morning when i went to tyre place to get rotated.

conditions of the track = ambient temp: 16.5 degrees/ track temp= 19.3 degrees/ dew point 9.2 degrees

what MPH was you pass?

86.37mph/139kph
reaction time .888
60 foot time = 2.654

that's not too bad for a stock-ish auto with all that junk in the trunk.

a stock manual will only do about a second quicker than that.

cheers,
.wook

would the pacies, hi flow cat and straight through muffler made much of a diff, i would of hoped they did

probably, but it might not be as much as you expected.

I thought pacies come on song above 3k rpm, so you would expect to lose a bit down low which would affect your 60' time. from the AMC Quarter Registry, your 16.27 is right about where I would expect you to be. take the sub and amp out next time (and maybe a bit less fuel)... you should be happy if you can break 16 seconds.

the fastest auto car I see on that registry is only 1.5 seconds faster than you, with a 12km/h faster trap speed.

the exhaust would've made more difference than the extractors. i didn't really notice a gain with the pacemakers i put on my last magna.

i ran a 14.84 @ 93.**mph with a 2.187 60ft with just a cat back system

the wheel alignment would've had a VERY small affect on your time/speed.

i probably wouldn't bother too much with the brake/accelerator trick. that is better used on rear wheel drive cars, and if you aren't good at it you can end up dragging the brake for the first few meters of your launch. if you do want to do it use the handbrake and wedge the button in so all you have to do is just drop it and gravity will do the rest.

also jack the car up and make sure none of your brakes drag. if your handbrake is adjusted too tight, or have a sticky piston that will hurt your MPH

ok thanx guys for your help maybe next time ill go hopefully get into the 15's without all the extra weight

yeah ditch the extra weight, pump your rear tyres up a bit harder, and maybe try changing gears a touch sooner. once you get up to high rpm the car can start to choke so it may be worth changing gears a bit sooner.

also, what air filter are you using? if it is a paper filter it may be worth changing to a better flowing filter.

K & N panel filter

ok. well just go out for a drive and just accelerate (in an area with a 100kmh speed limit of course) and just see what rpmthe acceleration starts to slow down. with your mods it should be around 5500rpm. you won't notice it so much in first but in second you should notice it a bit more. and if you rev well past this you will notice that when you grab the next gear it feels like it is pulling harder than it just was. this means you revved past it's optimum shift point in the gear before and you were just wasting time satying in that gear.

just another quick question, what width tyres do you run?

18*8.5

ok. well just go out for a drive and just accelerate (in an area with a 100kmh speed limit of course) and just see what rpmthe acceleration starts to slow down. with your mods it should be around 5500rpm. you won't notice it so much in first but in second you should notice it a bit more. and if you rev well past this you will notice that when you grab the next gear it feels like it is pulling harder than it just was. this means you revved past it's optimum shift point in the gear before and you were just wasting time satying in that gear.

just another quick question, what width tyres do you run?

almost, but not quite... you actually need to look at the gear ratios to see what rpm you would be at for each change, and then a dyno graph to see when the power in the lower gear is passed by the power in the higher gear. you might be decreasing in power, but it may still be more power than too low rpms in the taller gear. the perfect shift point is where the power is equal between shifts (I hope that makes sense).

oh yeah, don't rev your car out to 5500rpm in 2nd. that'll be about 145km/h, which isn't legal anywhere in Australia (except at the track of course).

cheers,
.wook

oh yeah, don't rev your car out to 5500rpm in 2nd. that'll be about 145km/h, which isn't legal anywhere in Australia (except at the track of course).
i can claim ignorance on that one cause i have a manual and they won't even crack 100kmh in second. the auto ratios are friggin tall! a v6 commodore will only do 130kmh in second at redline.


18*8.5
i wanted tyre size not rim size.

i can claim ignorance on that one cause i have a manual and they won't even crack 100kmh in second. the auto ratios are friggin tall! a v6 commodore will only do 130kmh in second at redline.
yeah, the 4 speed auto is super tall. I've had mine up to *indicated* 165 in 2nd at Wakefield. that's at about 6500rpm (I think redline is 6200 - I've never hit the limiter though). it's probably between 155 and 160 actual speed due to speedo error.

just think, the tippy auto will happily take off in 2nd, so that's 0-160km/h in one gear!

that is taller than 3rd gear in pretty much most manual cars on the road.

Haha yeah, my mums Honda CRV sounds like its going to blow up going 130... in 5th!!!

i just looked up the gear ratios. the 5 speed tippy is almost the same as the manual (just a fraction taller), so it won't go to 160kmh. here are the ratios (manual and 4 speed auto is TH, the tippy is TJ)

Transmission description Five speed manual
Transmission type 5 man
Ratio 1 3.333:1
Ratio 2 2.015:1
Ratio 3 1.407:1
Ratio 4 1.031:1
Ratio 5 0.804:1
Reverse 3.416:1
Final drive ratio 3.736:1

Transmission description Four speed automatic
Transmission type 4 auto
Ratio 1 2.842:1
Ratio 2 1.495:1
Ratio 3 1.000:1
Ratio 4 0.731:1
Reverse 2.720:1
Final drive ratio 3.274:1

Transmission description Five speed automatic, electronically controlled, sequential shift control.
Transmission type 5 auto
Ratio 1 3.789:1
Ratio 2 2.057:1
Ratio 3 1.421:1
Ratio 4 1.000:1
Ratio 5 0.731:1
Reverse 3.865:1
Final drive ratio 3.684:1


so yeah, 2nd gear in a 4 speed auto is taller than 3rd in a manual.

235/40 ZR 18 i think

so yeah, 2nd gear in a 4 speed auto is taller than 3rd in a manual.
maybe I'm reading that wrong, but it looks to me that it's actually slightly shorter than 3rd in both the manual and 5 speed auto box.

I also thought the 5 speed auto had a shorter top gear than the 4 speed, but according to those they're the same :shrug:

the actual gear for 2nd in the 4 speed is shorter than 3rd in the 2 5 speed boxes, but look at the final drive ratio of the 4 speed. it is 3.274 and the 5 speeds are close to 3.7 (tippy just under and manual just over)

also goes to show that the 4 speed would suck towing a heavy weight compared to the 5 speeds.

and look at how tall reverse is in the 4 speed.

My old auto TF if left in D would shift into 3rd gear at 120kph. I can't see a 4 speed auto reaching 160 without revving past the cutout. I'd be more then happy to be proved wrong though. :P

TF 3.0L gear ratios

Transmission description Four speed automatic, electronically controlled by Smart Logic INVECS II adaptive system (Intelligent Vehicle Electronic Control System).
Transmission type 4 auto
Ratio 1 2.842:1
Ratio 2 1.495:1
Ratio 3 1.000:1
Ratio 4 0.731:1
Reverse 2.720:1
Final drive ratio 3.735:1

the final drive ratio is about the same as the TH manual's and the gear ratio is similar too, so it wouldn't go as fast as the later 4 speed.

My old auto TF if left in D would shift into 3rd gear at 120kph. I can't see a 4 speed auto reaching 160 without revving past the cutout. I'd be more then happy to be proved wrong though. :P
I guess I need some in car footage then... although there are at least four other AMC members that have first hand knowledge of this.

after looking at the gear ratios i would believe it is high. not quite sure about 160, but close, and at that sort of speed you start getting speedo accuracy errors as well. but i certainly believe it 150 is within its reaches

reaction time .888
60 foot time = 2.654

Good luck at traffic light derbys :P

The reaction time delay was probably holding the brake....:bowrofl:

Good luck at traffic light derbys :P

Why whats your best Reaction Time??

Admittedly .88 isn't fantastic, but it's better than what I usually pull. So put your money where your mouth is Keyboard warrior.

Why whats your best Reaction Time??

Admittedly .88 isn't fantastic, but it's better than what I usually pull. So put your money where your mouth is Keyboard warrior.

... easy chief. I haven't been to a track, hence don't have a time slip and therefore can't back it up.

Just saying nearly a full second is pretty slow, considering they have the .4 second amber warning lights, and a .88 reaction time won't win many traffic light derbys.

... easy chief. I haven't been to a track, hence don't have a time slip and therefore can't back it up.
Just saying nearly a full second is pretty slow, considering they have the .4 second amber warning lights, and a .88 reaction time won't win many traffic light derbys.

0.4 is a perfect launch (at most drag stips), so 0.88 means he's leaving the line 0.48 seconds after the light went green. For most people that means they are starting to launch on the 2nd last amber light. Personally, I don't think you can compare reaction time on a drag strip to "traffic light derby" outcomes. My RT's are almost aways 1.0+ because I start to launch on the 2nd last amber.

And I am "easy" mate..... I just don't think the bloke deserves to be bagged out about his (presumably) first visit to the raceway. Especially by someone who hasn't been themselves. :cool:

yes it was my first time, hopefully i get into 15's next time

i'm a bit shady on the specifics of any magna but where does your motor make peak torque?
it is at that point or just below this that you should "stall" up the car to and then on the launch you just jump off the brake
good for launches but bad for the whole drivetrain
also you'll more than likely find that you don't need to rev it to 6500rpm to get max power as that's where you should be shifting
basically when the acceleration slows is when you change
holding to redline will hurt both your times and ya motor
for the record a .88RT is about average for a "non reg" racer
and b4 anyone asks no i have never been to the strip with my own car BUT i used to work at heathcote park dragstrip

i'm a bit shady on the specifics of any magna but where does your motor make peak torque?
it is at that point or just below this that you should "stall" up the car to and then on the launch you just jump off the brake

Peak torque is made at 4,000rpm, the stock stall will not go much over 2,000rpm.

I guess I need some in car footage then... although there are at least four other AMC members that have first hand knowledge of this.

In car footage would be nice, not because I don't beleive you, but because it'll be interesting to see. :P

i might be going again next week, i can try to get footage if i rememeber, but i doubt i would be able to do it

I have a vid of PhilsTH going down the strip in his auto 3.5 TH, doing a 15.84, on the line his changed into 3rd. He left it in D all the way, you can tell cause of the D light being on, on the dash. His is not a tiptronic.

The vid's floating around here somewhere.

i know that 1 of the strips in NSW you can run a 0.000 reaction time and not red light. they have it set so it goes off the green light, not the last amber light. so their 0.000 is the same as a 0.400. i think at my first outing i ran in the 0.8s all the way up to 1. but then i didn't care too much about the lights. i was more concerned with launching well since your reaction time doesn't affect your ET.

i know that 1 of the strips in NSW you can run a 0.000 reaction time and not red light. they have it set so it goes off the green light, not the last amber light. so their 0.000 is the same as a 0.400. i think at my first outing i ran in the 0.8s all the way up to 1. but then i didn't care too much about the lights. i was more concerned with launching well since your reaction time doesn't affect your ET.

Yeah that's what I thought, but if black beard is right depending on the type of timing system then his reaction time is fine.

I have a vid of PhilsTH going down the strip in his auto 3.5 TH, doing a 15.84, on the line his changed into 3rd. He left it in D all the way, you can tell cause of the D light being on, on the dash. His is not a tiptronic.

The vid's floating around here somewhere.
wheres the vid of you doing a 14 with no air filter dragging that R31?? That was classic

Yeah that's what I thought, but if black beard is right depending on the type of timing system then his reaction time is fine.
yeah i know willowbank uses the old timing system where 0.400 is a perfect light.

i got a mate that can run 0.4xx times all day. i don't know how he can do it. but then he did get to the finals at jamboree a few times in his NA 31, and has been to the strip a heap of times.