0-60, shifting, throttle engagement help!

[Dathaeus]

Hey guys, hope you're all well...

So last week I was at a stop light, and there was a luxury Lexus next to me, driven by an older gentleman and his wife. Usually I don't drag because most cars don't come close to being competition (you'll find this statement ironic later) so it is few and far in between, especially in the area I live in. Anyways, I had to start hard to cut over to the other lane to make a turn about 1/4 mile down, so I started a "conservative hard" start... then I noticed the Lexus busting out himself, so I said, might as well go go go... well I had some sloppy throttle control, and bad shifting, and in just over 1/8 he was a couple car lengths ahead and I was feeling well, like a shmuck really.

Now I have no doubt that car had more HP than me and he probably just put the petal to the metal in his automatic just for childhood thrills, good from him. However, this made me think, what exactly AM I doing with this, am I even using this car to its full potential? So late that night I went to an desolate strip of road and did a little 0-60 test. The result was absolutely appalling, if not embarrassing and an utter :facepalm

Just over 9 sec. Yes that is 9 and in nine, before 10. Now the specs say ~5.6, but I think definitely under 6 sec correct? I did it 3 times, every time, over 9s. Anyways this got me thinking, GET HELP.

This is what I know:


I pop the clutch around 4k RPM so I get a slight free spin for like a couple milliseconds, I think thats proper?
I did NOT floor the gas but came very close the first couple times... then the third time I did, no change in time. Each pressure was fast but gradual, never just slamming the gas to the metal, I think that's proper?
I tried twice getting into 3rd and once staying in 2nd... I discovered you HAVE to get into 3rd... lose way too much power at the end of 2nd by about the 40-50mph mark
Steering was pretty much dead straight, no wiggly lines there
Shifting was not the best and I did not double clutch or anything else, but 3+ seconds worth of 2 shifting mistakes?
Each shift was around 5700-5800 RPM I think


I am no drag expert, so I MUST be missing something vital here. The funny thing is, even the 9 sec doesn't really feel SLOW, but then again maybe I am just used to it and don't know any better.

Help?

[az3579]

At autocross, I found that I'd get the best launch at 2k. 4k is way too much to get a good launch since you'd just end up spinning the tire (yes, singular - we don't have Limited Slip Differentials) and losing time trying to regain traction. Spinning tires mean you are not going as fast as you could be, and this is the same reason why drifting through a corner, while satisfying, is not the fastest way around it.

Second, you're not going to be doing yourself any favors without fully depressing the throttle.

Third, you're shifting way too early. Shifting at a slightly later time will help drop the revs down exactly to where they need to be. Our gearing is still too long to take advantage of shifting earlier. The engine makes the most power at 5900 RPM. I'd say keep it at around 6500 for shifting and you should be good to go.

Fourth, you need to be a lot faster with your shifts if you want the fastest times. The faster you shift, the worse it is for your transmission synchros since they have to work harder to get the desired shift speed. It's a tradeoff; what's more important to you, the longevity of your transmission or a faster shift? Ultimately the difference between shifting fast and rev-matched shifting is somewhat negligible in wear, but since I personally drive so damn much, I choose longevity and wait for the revs to fall to where they need to. If I'm driving it like that, I'll probably do a 7.5-8 second 0-60 time. When I shift fast, I can usually achieve high 5's to 6 seconds consistently.

Fifth, it goes without saying that if you don't turn off traction control and you see that little flashing yellow light, you're not going anywhere in a hurry. For best results, fully disable the traction control.

Finally, the ZHP is slow, so it's totally pointless trying to race anybody with it.




Oh look, my post has 6 gears... err, points... in it. :)

[slater]

Finally, the ZHP is slow, so it's totally pointless trying to race anybody with it.

in a straight line, you mean? :) it's not a 0-60 car....

peter

[Dathaeus]

Hey az, some nice advice, I really appreciate it.


At autocross, I found that I'd get the best launch at 2k. 4k is way too much to get a good launch since you'd just end up spinning the tire (yes, singular - we don't have Limited Slip Differentials) and losing time trying to regain traction. Spinning tires mean you are not going as fast as you could be, and this is the same reason why drifting through a corner, while satisfying, is not the fastest way around it.

Second, you're not going to be doing yourself any favors without fully depressing the throttle.

Third, you're shifting way too early. Shifting at a slightly later time will help drop the revs down exactly to where they need to be. Our gearing is still too long to take advantage of shifting earlier. The engine makes the most power at 5900 RPM. I'd say keep it at around 6500 for shifting and you should be good to go.

Fourth, you need to be a lot faster with your shifts if you want the fastest times. The faster you shift, the worse it is for your transmission synchros since they have to work harder to get the desired shift speed. It's a tradeoff; what's more important to you, the longevity of your transmission or a faster shift? Ultimately the difference between shifting fast and rev-matched shifting is somewhat negligible in wear, but since I personally drive so damn much, I choose longevity and wait for the revs to fall to where they need to. If I'm driving it like that, I'll probably do a 7.5-8 second 0-60 time. When I shift fast, I can usually achieve high 5's to 6 seconds consistently.

Fifth, it goes without saying that if you don't turn off traction control and you see that little flashing yellow light, you're not going anywhere in a hurry. For best results, fully disable the traction control.

Finally, the ZHP is slow, so it's totally pointless trying to race anybody with it.

Really on the 2k? I thought every good drag start has the wheels slip slightly before forward boost, ad we are talking milliseconds, not like 2-3 seconds. But even at like 3-3.5k, it wont slip so why 2k?

Now are you barbarian slamming the gas all the way down almost instantaneously or is there an optimal acceleration on the depress?

Yea I was thinking of shortening the gears but wasn't worth it, esp sacrificing MPG at the higher end.

So by fast shifts you mean not waiting for it to fall into that gear but slamming the stick into the next gear? I remember some driving instructor talking about that but I guess all racers slam the stick into the slot?
And I don't drag race, and I haven;t even raced on my car on the track yet, this is all for learning for the day I find the time and funds to start doing that stuff, so honestly I guess I don't care as much about the longevity of things.
And wow, up to a 3 sec/40-50% different in time by shifting mercilessly? Wow. At least that helps me understand what components are important in achieving the times.

[az3579]

in a straight line, you mean? :) it's not a 0-60 car....

peter

Even in the corners, the ZHP is still considered a momentum car, just like a Miata.

[slater]

Even in the corners, the ZHP is still considered a momentum car, just like a Miata.

i guess i've never had a car that was fast enough to not be considered a 'momentum' car, LOL!

peter

[az3579]

i guess i've never had a car that was fast enough to not be considered a 'momentum' car, LOL!

peter


The reason I say it is because all the other cars in this weight range nowadays have a LOT more power. It may not be a momentum car when it's new but it certainly becomes one as time goes on. If you don't keep the "momentum" up, then you can't "keep up". ;)

[bshovers]

Okay so hypothetically speaking. Your doing a pull starting in first gear. Where is everyone shifting at going into second?


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[NickZHP]

BP when you say launch at 2k you mean dumping the clutch correct? How bad is doing this for the transmission?

[az3579]

BP when you say launch at 2k you mean dumping the clutch correct? How bad is doing this for the transmission?

Dumping the clutch is a bad thing. The only situation anyone should ever be "launching" a car is under competition circumstances, IMO. The only time I have ever launched my car is at autocross where every millisecond matters and I can't afford to get bogged down at the start. It depends on the tires you have as well.

Think about the shock you're sending through your driveline when you allow a clutch spinning at a significantly different amount of speed from the flywheel to just "hit" in an instant. No bueno.

[FL116]

I have still yet to launch the ZHP since I've owned it.... Is that bad??? Lol

[BMWCurves]

I haven't either, hasn't bothered me.

[Rovert]

I launched mine every week at least for aggressive starts for thrills and chills. It survived with no problems. If you do it right the transmission will last. If you don't, then it'll be expensive you will learn!

If I launched at 2K I don't think my car would go anywhere. Then again I had 265/30R19 rubber so maybe that's the culprit. My launches were around 3000-3500 so I could play with the clutch for a few milliseconds to get enough traction and just a tad of wheel slip so I had maximum energy to the ground and enough energy to bleed off as sound and friction from pushing in a little too much power. I always shifted at redline so the next gear would be closest to its peak power.

I did get really good at double clutching to save my synchros on all up and downshifts. Maybe that helped my synchros last as long as it did with 173K punishing miles. Before changing cars my ZHP grabbed hard, never slipped, and slipped into gears buttery smooth!

Learn how to get out of the gate aggressively and you'll really open up what you paid for and also discover things you didn't know about yourself. Live the journey!!!