I'm just curious as to how you guys get the best acceleration out of your cars. I'm not basing the following observations on anything but feel but here is what I have found.

1. If I floor it, it doesn't seem as fast as when I give it about 3/4 throttle. The shifts seem a lot more responsive and I don't get much lag at the start. This seems kind of weird to me, has anyone else experienced this? If I floor it with the VDC off, my tires don't spin at all.

2. If I am going very slow, around 10 mph and then I give it 3/4 throttle it accelerates a lot faster than from a stop. If I accelerate from a stop I don't really feel pinned in my seat at all, but accelerating hard from a slow speed does.

I saw someone mention in a previous post that there was a way to improve shifting performance for around $500. Are they talking about using a different ECU?

Does anyone else have similar findings?

2003.5 5AT G35s
Stock
Garnet/Sport/Premium

 

I agree to above as well... I also find it weird that I can't get any wheelspin with VDC off too...

Any ideas? Time to reset the ECU?

---------------------------------
Navi-Conversion Kits at Discounted Pricing
*Authorized AV Electronic Dealer*

2003.5 Desert Platinum Sedan
Premium, Navi, xBox

 

It's just physics. At a dead stop your HP has a great deal to overcome because your car isn't moving one bit. 3400 pounds of down force. Once it moves the "object is in motion and tends to stay in motion" and the horsepower/torque can devote itself to accelerating the forward motion more...that is of course until you start running into drag at higher speeds which is very debilitating to acceleration.

At 10 mph, you are also at 10 mph. As far as G forces go, you may as well be at zero. When you hit the throttle, your ponies don't have to devote as much to getting you moving. You'll always get a better jump from a rolling start.

Resetting your ECU will not change a thing. In fact, the ECU operates with totally different parameters at WOT than it does the rest of the time.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger

 

The technosquare chip will do a few things. I believe it will get rid of your speed limiter, then lean your fuel mixture at higher RPMs (ours are way too rich), it will increase your redline (pointless if you don't have mods because your optimal shift point right now is around 6400), and a couple of other things. Definitely of benefit, but even moreso if you have mods. Without any mods the only benefit you'll receive from the technosquare ECU, IMO, is the leaner mixture approaching redline.

2004.5 Coupe/5AT/Ivory/Everything but chin spoiler/Z Tube-Popcharger

 

It's my understanding that the AT Sedan ECM program has a limit to how fast the throttle body butterfly will open. Wouldn't want granny to spin the tires on the way to her bridge game, would you?

The TechnoSquare ECM program upgrade fixes it. IMHO, the improved driveability was actually worth the cost by itself. The performance improvement's were icing on the cake.


DaveO - 2003 G35 Sedan / DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TS ECU / E-Fans
Street Edge TC / B&M Cooler / Stillen Exhaust

 

DaveO has got the mods to back up the advice. PM him for more info as he has enlightened many of us before.

03.5 Sedan/B.Sil/Prem/Wntr/Aero/Tint/Rims/Hotchkis Sways--WHRER ARE OUR PARTS!
69 Chevelle Hard Top BB/4.11's/Posi

 

Sideburns, I have similar experience too
I have a 5AT stock. I have noticed many times that even if you are going 10-20mph and you slam the gas all you get is a very quick rev of the engine and not any real torque. There seems to be lag in torque. My previuos car an Acura Legend had lag too but that but that not much. A few times I was kind of in jam and had to take a quick exit but there were a couple of cars on the way so I have to quickly accelerate and go around them. Nowing I was driving a G with 260 ponnies I thought just slam it and go aroudn these cars, My wife ws sitting with me so I wanted to show her what this baby can do. So when I floored it the engine reved to about 5-6krpm but not much torque. I had to lay off the pedal in surprise I guess and also I did not want to redline it. Not to mention I missed the exit.
I seem to get better torque and rpm combination if i push the gas 1/2 to 3/4 only.
Any similar experiences or ideas how to have better control on acceleration?


2003 G35 Black Sedan

 

iafzal,

If my torque converter theory is correct, the very quick rev of the engine may be your torque converter's (TC's) "flash" stall speed.

Torque multiplication normally occurs during the "launch"... from a dead stand still to about 60 feet or so out and to some degree at extremely low speeds. Anytime the TC's turbine is turning faster than its stator, there is no torque multiplication and the TC's operating only as a fluid coupling.

If we add the stock TC's slip (fluid short circuiting the turbine and flowing back to the impeller) and stock ECM's program "limitations" to the above... well I'm sure you see the picture.


DaveO - 2003 G35 Sedan / DP / Willow / AT / Premium / Sport
350Z Engine Cover, T-Stat & Air Duct / Stillen CAI
GG 7-Wire H-G Kit / TS ECM / E-Fans
Street Edge TC / B&M Cooler / Stillen Exhaust

 

I concur with your findings.

Seems like if you floor it the ECU says "this punk ain't messing up MY nice tires!"

If ya ease into it and keep the pedal just short of WOT you can fool the ECU into running like it was supposed to.



On-On
S&S

 

Yeah i experience the same problem. So now whenever i wanna punch it, i just switch it to manumatic and downshift myself instead of WOT.

 

I notice the same. I seem to get great acceleration when I
depress the accelerator about half way or more.

2003 TwBlue 5AT Sedan, sunroof,
Graphite Leather, splashguards, HKS exhaust,
14 wire Grounding kit, 350Z duct, Stillen CAI
Underbody rear diffusers, Drilled alum pedals