TylerT

iTrader: (1)

I have 5AT and I have heard people getting their first gears all the way up to 7000RPM redline, but mine always seems to shift at 6500 as demonstrated in this video here:


I have tried different ways of going through first gear ... starting in L ... still manages to hit 6500RPM and shift.

Tiptronic with VSA off (In the video), still shifts at 6500rpm.

Maybe the later TLs shift at 7k in first gear? I'm confused

Bearcat94

I think only '07 & '08 will hold first gear *all the way* to the rev limiter. You have to be in SS to do it. VSA on/off doesn't matter.

vinnier6

iTrader: (1)

i dont understand what the problem is...your car doesnt redline at 7k, its more like 6800rpm, you car comes damn close to redline...plus, you can never trust your tach and its acuracy...thoes things are notoriously off...looks good to me bro...

01tl4tl

Why are you shifting well past the torque curve optimum point?
Max rpm is not max power

And revving the engine that high is begging for trouble with valve clearance to piston top- if you were in the manual trans car, we would be reading about how your valves got bent all by themselves---- while you were minding your own business....

TylerT

iTrader: (1)

Just so you know, I don't push my car very often. If I pushed this car like that all the time, 71,000 miles would have gotten the best of it already.

That particular day I was practicing my launches for the 8th.

Max power is 6800rpm correct?

Bearcat94

No, redline is 6,800, Rev Limiter is at 7,000.

Max HP is @ 6,200.

Max Torque is @ 5,000.

TylerT

iTrader: (1)

After reading the racing & competition subforum as much as I do .. I always thought getting 6800 every shift would yeild the best performance.

Shifting at 6200 seems a little early if you're going for the best 1/4 time. Of course, I'm 19 years old and have a lot to learn ...

01tl4tl

To determine optimal shift point in each gear- spend $350 on the in car unit that measures times and g-forces-speeds- rpm etc.
It will calculate shift points based on g force changes as torque drops off and much more.
Records 60 foot- 1/8 and 1/4 times- roadrace lap times, pretty much anything you want to know-- it will do.
see G-Force as a web search for them, 2 models- get the better one

01tl4tl

another way is to find a dyno shop that has the new units
You can simulate full 1/4 mile runs with gear changes ON the dyno
It will find peak power in each gear on a graph- then you know what the car is doing at what rpm vs torque.

TylerT

iTrader: (1)

Theoretically, what is the best RPM to shift at?

juruki

iTrader: (2)

It looks like it shifted at 6,300 rpms... I believe the the car pulls stronger if it stays within vtec range while you go WOT.

dr_brains510

so to get a good 1/4 mile time, one should shift from 1st to 2nd at 6200 rpm and not 6800 rpm and keep shifting at the 6200 rpm throughout each gear? i'm talking in reference to the 07 TLS.

ib18c1

iTrader: (6)

even though shifting at 6800 is unnecessary, i beleive it's beneficial to thenext gear so you could land in the meat of the power band....shifting at 6500 or below can make you fall out of powerband which is 5at's biggest problem imo....

vinnier6

iTrader: (1)

thats wrong....the last thing you want to do when trying to accelerate hard is to push the engine past its peak output...once you go past peak output the hp drops off and you start loosing steam...upshifting before you pass peak output will allow you to keep maximum momentum so the next gear can achieve its max output quicker....

540idinan

I disagree, and agree with ib18c1. It is better to go to the redline so that when you shift into the next gear, your already in the powerband. The auto gear ratios are anything but close ratios. I believe vtec kicks in at something like 4800rpm(someone correct me if wrong), but when you watch the video the next gear starts at about 4500rpm. If he could wind it out to redline, he would land in vtec in all his gears, which would be most efficient. Also, I believe that if you look at a dyno of the power on these cars, it falls off after peak power a bit slower than it does gaining. So you keep the most power in all your gears.

To the OP, no idea sorry haha

vinnier6

iTrader: (1)

trust me, its never better to go to redline....always better to shift prior to power falling off...start watching alittle more racing, doesnt matter what kind, get yourself hooked on speed tv...formula one is the best for this kind of information, not to mention some track days with a motorcycle, with classroom as well....or you could just keep thinking you understand and do it your way....have fun either way

540idinan

You may be right, I'm just thinking about what seems logical to me. For example, if you look at this TL dyno sheet http://img258.echo.cx/img258/5590/ttpdynob9ff.jpg you will see that there is more power as a whole in the range 5000 to 6800 rpms. So looking at that, if you shift at redline, im guessing that you would land in the next gear at about 5k rpms (about 200whp). Then end at 7k rpms (for some reason this dyno doesn't take the car to redline, but judging by the graph, the curve is pretty level, and doesn't drop off significantly at 7k rpms.) So at redline you would be at about 220whp.

As compared to shifting at the peak hp 6200rpms (232whp) then landing in the next gear at about 4300 rpms (about 175whp)

This doesn't make sense to me. I have an open mind and am really curious to find the answer. So if someone else knows for sure, please chime in. Oh, and vinner6, I race motocross and spend a lot of time watching youtube/speed tv. haha

phee

iTrader: (5)

i agreee about shifting in the power band and not shifting to the redline. but i do know tha tmy 07 loaner would actually hit the rev limiter in 1st gear when i would floor it (huge loss of speed).

FORSITE

Shift points all depend on the engine's hp and torque curves. In our N/A hondas I believe it best to redline and push it to the limit so that we can stay in "VTEC" in the next gear. A turbo or supercharged car can be short shifted and still have plenty of torque to push the car up the powerband.

I wouldn't shift any less than 8200 rpms in my '99 civic si, and don't shift any less than 6800 rpms in my '05 TL. Would love to take it to 7000+

540idinan

vinnier6, do you know the reasoning behind your claim? I am really curious

vinnier6

iTrader: (1)

its not really a claim, its just fact...i have spent many years on and at the race track...ama motorcycle racing was my thing...all the engineers, racers all say the same thing...once power loss happens, you might as well be going backwards....cause your loosing ground....i am done here, you guys shift at redline if you want, i dont care....

Simba91102

This hits the nail on the head. A danger with short shifting (which is basically what all this talk about shifting at 6200 or some such thing is about), is that you'll fall out of the power band. This is especially important with Honda engines which are historically short of torque, and what's there is up high. My TSX shifts right at redline (7100), and it needs to (granted, it's a four banger). I'm really surprised that the TL doesn't too.

Bearcat94

Why is one better than the other:

1. Lose HP between 6200 and 6800 rpm in 1st and be in (or closer to) VTEC in 2nd;

or

2. Not lose HP above 6200 rpm and be just out of VTEC (~300 rpm) in 2nd?


IOW: Why is it better to be out of the powerband at the top end of the lower gear than to be out of the powerband on the low end of the next gear?

HONgDA

iTrader: (1)

how come mine shifts into 2nd automatically right at 3k rpm? i have an 05 if that matters.

tidus888

put it in L and you will see it redlining

Bearcat94

Because you're in full auto?

In full auto it should hold 1st longer if you are at WOT (not sure exaxtly when it will shift).

In SportShift it should hold 1st like the video above.

S PAW 1

EXACTLY!!
What Vinnier6 is missing, which is usually what happens before he stomps his feet, is the REV LIMITER. Most automotive magazines explain how they achieved their best times on their test cars, whether it be standing on the gas from a dead stop, feathering the throttle, or whatever. Most of the time, they achieve their best times by shifting just before the rev limiter kicks in. When the limiter comes into play, it knocks the heck out of your times.

That is the most efficient "sweet spot" for your next gear. From my own experience on my '07 TL-S, the rev limiter is at, or very close to redline. I may be off a couple of hundred, as I don't go there often.

That is one of the reasons why the 6MT is quicker than the 5AT. Because the gear ratios are closer together on the 6MT (although it is NOT a close ratio gearbox), the power dropoff is minimized.

vinnier6

iTrader: (1)

what your missing is that in order to shift before the redline or revlimeter you would need to anticipate the speed at which your engine is building revs...in order to achieve that you would need to start your shift way before your engine reaches its redline or limeter...which means your probably shifting around 6200-6500...if you hesitate you waited to long and missed your optimum shifting point...20 years on the racetrack, but i guess i dont know what i am taking about...i seem to be missing something....

S PAW 1

I've spent a few years at the track myself. My first experience was right about the time you were born.
I won't undermind your experience, so I'm sure you are aware that each engine is going to have its own unique powerband. The width of that band is the key, as well as your choice of transmission.

You are 100% correct that in order to explore the redline or rev limiter, you need to experiment somewhat as to what your optimal shift point should be. You don't want to hit the limiter, and this is what I stated. You are correct in the need to anticipate that point.

Most dyno charts that I have seen on the TL-S shows a sharp drop off of HP very close to the redline of 6,750. This would indicate the ideal shift point would be 6,600-- 6,700. Anticipation point at 6,400?
Again, small differences not worth getting upset or defensive over

vinnier6

iTrader: (1)

i see we had to drag age into the conversation as to say you out rank me...its all good...i am happy either way dad....

540idinan

I never said you were wrong man, I just wondered why. You obviously have more experience than me, so i would think that you know what your talking about.

HONgDA

iTrader: (1)

I am fully engaged in sportshift mode when it shifts from 1st to 2nd. When I am in 2nd and try to downshift into 1st it wouldn't do it. I think my tranny is starting to go out?

korrupted

So your in SS and it shifts into 2nd at 3K rpm, and won't let you downshift into first? Ewwww. take it to the dealer and get it fixed.

Before the get's out of hand, at what RPM is best to launch?

FORSITE

Unless you are at full throttle first gear will upshift automatically for you at different rpms depending on how much throttle you are giving. This holds true for < '07 models.

To downshift from any gear will depend on what rpms you are at, and will require a lift off of the throttle -> down shift -> and floor it again.

From my experience this holds true for downshifts from second to first at 30mph, third to second at 60mph and fourth to third at 80mph.

S PAW 1

No youngster, I dragged EXPERIENCE into the picture right after you dragged in yours. But, then again, you keep on making your point one way or the other. You are right..you ARE missing something.
v

[quote]20 years on the racetrack, but i guess i dont know what i am taking about...i seem to be missing something....

S PAW 1

WISH

vinnier6

iTrader: (1)

[QUOTE=S PAW 1]No youngster, I dragged EXPERIENCE into the picture right after you dragged in yours. But, then again, you keep on making your point one way or the other. You are right..you ARE missing something.
v

i am trying to be peaceful here brother...i guess you cant type in a little funny sarcasim when i was talking about the age thing....

S PAW 1

You don't seem to be inserting much humor, I guess I missed it. If you look at most of your posts on this thread, you seem pretty defensive, rather than trying to create peace.
I'm more than willing to offer my hand at peace back at you

BUT....you'll find as you get older, us old guys USUALLY miss the humor in those old man jokes.
Just the other day, one of the mods (that's right, a MOD) referred to something I said in one of my posts, and he called me PAW.
That's S PAW 1, SIR
I'm sure he was just kidding
Better get back on topic before he calls me by some other name.

screaminz28

iTrader: (1)

I have to agree with S Paw on this one. Since the TL's torque output is essentially flat from idle to redline, the best shift point is just past peak power where the output in the next gear will be more than the original. In the TL, that is right at or before redline, and surprisingly, in most modern cars. If you bring in old small block V8s, that was definintely not the case. Take the 5.0L mustang. The ideal shift point on a STOCK mustang was crazily below redline, due to the torque curve looking like the right hand side of a bell curve.