[Z06 Rocket]

This was actually a small subtopic of another thread, but I figured I'd create a new thread since my question was buried and forgotten.

** Please disregard the "in any gear" part of the poll. I should have put, "for 2nd, 3rd, 4th, and 5th gear." **

Can anyone offer a somewhat technical explanation about how the fuel and power are directed/used when slamming the pedal down vs. squeezing it gradually, yet quickly. Basically, from a factual standpoint, which is better - quicky squeezing the throttle gradually, or just slamming it down?

Now the obvious poor traction issue should be involved somehow in the overall equation, lending less credence to the "slamming the throttle is better" assertion... but, I would think, IF the rear tires were able to somehow grab 100% pavement with a slammed throttle, it would take off quicker than just rolling on the gas. But perhaps that's not even worth debating, since I don't think there's any possible way to grab a full 100% of the pavement going WOT from a dig (using the STOCK tires). Also, let's leave out 6th gear out of the equation, since 6th and power simply don't go together...

I'm just curious of the optimum power/fuel flow etc in each case (slamming vs squeezing), but IMO, I still think traction has to be included in the equation somehow. Someone on the forum made a seemingly valid argument that slamming the throttle (to/from any gear) would cause an engine/fuel system "bog down". Basically I took it to mean that slamming it would inundate the fuel system, asking it to send too much fuel through the engine, and power to the rears too fast.... hence, there'd be a small power loss as opposed to squeezing it and gradually, yet quickly, attaining the power and minimizing power loss. Is this argument valid?

:cheers:

 

[OneQuickCoupe]

Rocket, The "in any gear" part of the question is what I don't understand. If you were in high gear, "4th", and rolling at 15 MPH and mashed or squeezed it fast just about the same thing would happen. Almost nothing.

You are a thinker?

D.J.

 

[01ZEE06]

I would think quickly squeezing would give you faster acceleration when traction challenged from a dead stop.

Or, when drag racing from a dead stop while into the throttle at say 3-4,000 rpm, perhaps slipping the clutch a little to improve traction rather than dumping it may prove faster.

On the street at 30 mph in second gear in my Z, mashing the throttle will produce lotsa wheel spin with stock 3.42's and 335x30x18 tires. Right now my car is at Dick Guldstrands getting Rockland 3.90 racing gears installed, so squeezing on the throttle will be even more necessary in this situation.

At 70 mph in third gear, I've always mashed the pedal to the metal, but I'll have to experiment now that the 3.90's are going in.

I plan on getting MPS Cups in 345x30x18 soon and this will change things as they really grip.

So, I would say bottom line is it DEPENDS on your rear wheel power, tire traction, gear, rear axel gear, tires, road surface, temp, speed, etc.

Generally speaking, a fast squeeze is probabily a better approach on higher powered cars, and pedal to the metal on stock powered cars.

You just gotta get out there in the real world and find what works best for you and your car :thumb:

 

[DJWorm]

The fastest and thus best race drivers greastest trait is that they are smooth. This comes from easing the throttle and brakes on and off. What this does is keeps the platform & suspension "loaded" and balanced.

This technique is learned and accomplished by looking ahead and squeezing the throttle on as the apex and straight appears at the A piller. Likewise brakeing is a firm and constantly increasing pressure as the braking point is reached.

Even letting off the brake and throttle is done progressively and smoothly.

All inputs, including steering inputs, are done the same way.

What makes a great driver and winner is that he can do this more smoothly...and faster than anyone else on a consistant basis. Senna was discribed as being Silky and Deaft with the controls. Mansel's speed in the rain was due to his smoothness.

Another mark of a great driver is that his technique doesn't change as he gets tired or the competition and emotion increases. Coolness and endurance.

 

[quickZ]

In our cars, slamming the throttle in lower gears with TC/AH off is almost a guaranteed spin. Learning to be smooth is helpful on and off the track, plus it causes less mechanical strain on the car. A broken car is not a fast car.

 

[RC45]

Depends what you are trying to acomplish.

If you road racing, as DJ says - smoothness is the secret to winning.

If you are next to a car and about to embark on a freeway roll from 50 or above... you better stomp that muffa throttle pedal like no tommorow... - other wise your picture and car will be all over the Supra forums the next day... with the byline - "SlowAss Z06 is blown away by BPU Supra..."

 

[RocketSled]

Ask the question slightly differently... does the engine make the best power with the PCM running open loop or closed?

WOT guarantees open loop operation from the moment you stomp the pedal.

IMO, unless the engine is in perfect tune, the car will pull harder closed-loop. Going to 95% of WOT until the last second might produce a stronger run-up.

 

[IT L GO]

Lets see

Will my car rev to 6000 RPM from idle faster if I floor it or push the throttle down gradually

Answer: Floor it.

Will my car pick up speed from 15 MPH in 4th (lug) if I floor it or gradually increase the throttle.
Answer: No real difference

In a computer controlled car such as the Z06, Full throttle application will increase RPM faster in every situation. In an old non computer carburetor 60S's car, finesse is needed at low RPM higher gear situations to prevent overwhelming (lugging) the engine.
:z:

 

[Z06 Rocket]

Rocket, The "in any gear" part of the question is what I don't understand. If you were in high gear, "4th", and rolling at 15 MPH and mashed or squeezed it fast just about the same thing would happen. Almost nothing.

You are a thinker?

D.J.

Sorry guys, I should have made myself more clear. Instead of saying "any gear", I should have excluded 6th, but I thought that was kinda implied because I'm talking about maximum power output - 6th gear and power output (at least for this car) is an oxymoron.
..technically, I should have said only 2nd, 3rd, 4th, and 5th gear - 1st is very debateable because of the traction issue - you can't really accurately test which way you'd get more power because if you slam it, 99.9% of the time, the tires will break loose.

I was mainly thinking from a technical standpoint... when you're in a situation where you can make a logical decision between slamming it down, or squeezing it (let's say, 60MPH in 3rd gear), which is better - slamming or squeezing? I guess the only way to find out is to test it...

 

[ScDFACHE]

This was actually a small subtopic of another thread, but I figured I'd create a new thread since my question was buried and forgotten.

** Please disregard the "in any gear" part of the poll. I should have put, "for 2nd, 3rd, 4th, and 5th gear." **

Can anyone offer a somewhat technical explanation about how the fuel and power are directed/used when slamming the pedal down vs. squeezing it gradually, yet quickly. Basically, from a factual standpoint, which is better - quicky squeezing the throttle gradually, or just slamming it down?

Now the obvious poor traction issue should be involved somehow in the overall equation, lending less credence to the "slamming the throttle is better" assertion... but, I would think, IF the rear tires were able to somehow grab 100% pavement with a slammed throttle, it would take off quicker than just rolling on the gas. But perhaps that's not even worth debating, since I don't think there's any possible way to grab a full 100% of the pavement going WOT from a dig (using the STOCK tires). Also, let's leave out 6th gear out of the equation, since 6th and power simply don't go together...

I'm just curious of the optimum power/fuel flow etc in each case (slamming vs squeezing), but IMO, I still think traction has to be included in the equation somehow. Someone on the forum made a seemingly valid argument that slamming the throttle (to/from any gear) would cause an engine/fuel system "bog down". Basically I took it to mean that slamming it would inundate the fuel system, asking it to send too much fuel through the engine, and power to the rears too fast.... hence, there'd be a small power loss as opposed to squeezing it and gradually, yet quickly, attaining the power and minimizing power loss. Is this argument valid?

:cheers:

Smooth transitions are always better in terms of automotive reliability and overall performance.

 

[ZeeOhSix]

I was mainly thinking from a technical standpoint... when you're in a situation where you can make a logical decision between slamming it down, or squeezing it (let's say, 60MPH in 3rd gear), which is better - slamming or squeezing? I guess the only way to find out is to test it...

Well, if the engine is very responsive and doesn’t “fall on its face”, then slamming the throttle would get you to the highest power point quicker. Once the throttle is wide open, you can't do much more from that point. Max power at any engine RPM is achieved with the throttle wide open of course. :cheers:

 

[ScDFACHE]

Well, if the engine is very responsive and doesn’t “fall on its face”, then slamming the throttle would get you to the highest power point quicker. Once the throttle is wide open, you can't do much more from that point. Max power at any engine RPM is achieved with the throttle wide open of course. :cheers:

The issue is not WOT, its traction as you pointed out. What is needed is a curve showing HP vs RPM, and traction vs. RPM - the point where the curves intersect is the point of maximal traction and HP efficiency and the poimt you want to get to in order accelerate as efficiently as possible. Smoothness is still important. If you are trying to accelerate quickly, just cranking the motor to WOT will have no result without decent traction. I have a 427 and if I go to WOT with a slap of the volume pedal, the rear end just does a 360 degree turn. The throttle blade of the Z06 is not fly-by-wire; its computer driven and can be controlled by program editing. I have learned that a 90 mm TB is much more sensitive to the effects of LS1 edit than the stock 78 mm TB.

 

[ZO6 AL-X]

Be smooth with transitions. This way you don't break the tires loose to easily.

 

[2002Z06Yellow]

Ask the question slightly differently... does the engine make the best power with the PCM running open loop or closed?

WOT guarantees open loop operation from the moment you stomp the pedal.

IMO, unless the engine is in perfect tune, the car will pull harder closed-loop. Going to 95% of WOT until the last second might produce a stronger run-up.

Very intersting point of view. why do you think it will run better under closed loop?


As far as the others i think the main question here(if you have read the other thread) refers to slamming the throttle at low rpms in higher gears. For example 40mphs in third 60 miles in third. If you havent tried it while racing someone(being in the wrong gear willingly ) slamming on the throttle causes you to fall back and 99% of the time.

 

[RocketSled]

A couple of reasons why I think this (though please note, I am only theorizing, I have no data to support my supposition)...

You get the best power when the engine is running it's leanest (provided of course you're not too lean). The PCM is "defaulted" to favor slightly rich at WOT as a "conservative" measure to prevent engine damage from preignition. That means that unless you've tuned the PCM, WOT will not be as lean as when the engine runs closed-loop and the PCM is actively managing the mix (at WOT, the PCM ignores the O2 sensors and uses the fuel trims and MAF to control the mix).

Peak power occurs at WOT and some "high" RPM. But the acceleration you get from your car isn't as much a function of the peak HP as it is a function of the shape of the torque curve on it's way to that peak.

In every WOT Dyno run I've done (the only way I've ever done them) the AFR curve tends to be richer at low RPM, leaning out only as the RPM gets near the top. So I have to wonder If instead I "managed" the throttle to keep the PCM closed loop as the RPM climbed, I would have a leaner mix down low, which would fatten the torque curve up some. If so, the car would definitely be quicker that way.

Not opening the throttle all the way does not necessarily mean the engine spins up slower. The engine only uses as much air as it displaces for the load and RPM it's turning. When I go to WOT at a low RPM, I'm not drawing anything close to the maximum airflow that the throttle body is capable of flowing. Logic dictates that I could close the throttle a bit and still flow as much air as the engine needs for the lower RPM. (example: Reducing the throttle by 50% when the engine is only calling for 25% of the throttle body's maximum flow rate has no effect on the amount of airflow passing through the motor). Doing so will let the PCM control the mix and theoretically give me a leaner mix and a better torque curve and so quicker acceleration (ignoring the question of traction, of course).

 

[Z06 greg]

The Z06 is a well balanced car,but gets unbalanced easily,if you are not smooth.Sqeezing the throttle smoothly may not mean you reach WOT any slower,just smoother.I can be smooth and fast at the same time.I have found the technique of smooth throttle,clutch and brake control,very effective on the track and my tranny doesn't heat up as fast.Slamming the throttle,is not good for your car and with 405hp it can get you into trouble real fast

 

[Z06 Rocket]

Very intelligent posts guys.. :thumb:

At first glance, one would surmise that just slamming the gas down would yield the best/fastest power output... but when you really look into it, and crunch some numbers, I'm betting it will seem that's not the case. After considering the arguments and assertions, I agree with RocketSled, and those of you that thought squeezing it will probably yield the best results.

Why don't we all just do some simple trials on the hwy to test it out, then post and compare the results here? Just to set a basis, we should all start from 60Mph in 3rd, and accelerate to around 100...? For the first run, slam it...and for the second run, squeeze it quickly. Of course, you should have someone time it on both runs; whichever method gets us to 100 quicker, is the clear victor.

I'd also like to see this test done on a dyno with actual numbers to see if the torque curve/peak is affected... there's no better way to prove/disprove a theory than with rock solid numbers. I wish there was a dyno nearby because I'd try it out!