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-   -   Power drop just after shift (MK3 manual) (http://www.focusfanatics.com/forum/showthread.php?t=307552)

knapkin 01-25-2013 06:24 PM

Power drop just after shift (MK3 manual)
 
Driving a new 2013 focus SE hatch (near 2k miles) I have noticed that at launch and the 1st-2nd shift that often times I get a noticeable power drop after fully releasing the clutch pedal.

To be specific, while shifting from 1st to 2nd gears, I have (the feel of) more power with the clutch partially/mostly engaged, but once fully engaged, power to the wheels seems to momentarily dip.

There is no traction control light coming on, and I'm not doing anything silly with the throttle.

I have a few ideas, but I'd like to get some thoughts as to the cause, or if others see this as well. I'm thinking it's:

a) User failure (hope not after 14 years driving standards).
b) Traction control doing something 'minor' without lighting up.
c) Valve timing at the lower end of RPMs (shift usually happens to put 2nd at 1.5-1.75k or so).
d) Just bad torque at my shifting points which translates to a momentary blip until the engine revs up a bit (does not quite explain everything unless I always over-rev and slip the clutch at shift, which my previous 160k+ mile clutch would disagree with).
e) A problem that needs to be looked at.

So I guess I just need to know it's not e) (so we can avoid all the votes for user failure!). As a bit of background, the car previous to this was a 105hp 1993 del sol.

I have searched here and google for related threads, there was one that sounded similar regarding off the line starting, but was for 2012 models specifically and had a TSB issued, so as a 2013 model year, that would not be applicable.

Elizabeth 01-25-2013 06:58 PM

There is not much torque until over 2,200 RPM.
I usually shift at 2,000rpm 1,2,3.. and if at 25mph stay in 4. at 30 speed limit I cheat to 32 mph so i can go into 5th. This is wanting max fuel economy and not any even staying with traffic accelerating..

You may be used to a bigger engine where you can expect a bit of torque at 1,500 to 1,800 or so. NOT on the Mk3 Focus!!
I would say what you experience is totally normal for so small an engine.
When I am wanting to go in a bit more hurry... (driving like the rest of traffic does acceleration-wise) I will rev her up to 3,000 so it has some torque available.
When I want to REALLY go fast I wind her out to 6,500 before shifting.. that is when you can see this car can actually move fast (enough).
Most of the time at 1,500rpm or under 2,000 there is no 'step on the gas and go (anywhere faster..) You have to actually downshift if you want to move smartly.

So, from another lifetime manual driver (47 years driving)
It is not a problem with the engine/clutch.
You just expect way too much at the low RPM you are shifting at!!! [wiggle]

If you ever drove a typical, historical Honda engine?.. This car engine is way more like a typical Honda. no torque, needs revs to move.. Not like a Mustang. [bigcry]

It IS good enough to be a MPG miser using low RPM like you are.. But it cannot accelerate much more them a crawl using low RPM shifts.. Great for MPG.. bad for getting anywhere fast.
So i say rev her up to minimum 2,000 RPM to shift from 1,2,3 and only if stuck in a 25mph zone go to 4th.. for 30 mph it is pretty iffy to stay in fifth.. unless you can be on a flat road, no need to accelerate at all. 32 is minimum for 5th for me.. (I have a mile long flat bridge i can do 5th at 30mph.. but that is zero traffic.. and no headwind either..)

Hope this helps..

knapkin 01-25-2013 07:38 PM

Yeah, my previous car (for 10 years) was a severely underpowered honda del sol, but I did not notice this. It's really feeling like something is catching on late (even at sub 2k RPM) that the shift is complete, almost feels like turbo lag if that makes any sense.

On a side note I have noticed a significant increase in power at about 2.25k RPM which is right inline with your 2.2k, but this is not just about that, I'm really talking about the 0.5-1sec after shifting.

felixdd 01-26-2013 07:36 AM

What Elizabeth said

Theres little to no torque that low in the rev band. I shift as early as you -- 1800 rpm or so. The car inches forward. At least I'm "winning" the ECOmode though :/.

As well, there just isnt much punch in 2nd until at LEAST 5000-5500. I recall having to merge into a 80km/h intersection from a standstill and that was the time I truly punched it. I actually was surprised at the surge of torque and wheelspin I got in 2, but that was with the gas fully pressed to the floor. That brought a smile to my face too. However, the torque is nowhere near that even at 4000.

However, on the highway, downshifting to 4 and letting the revs climb to 4000-4500, the car accelerates smartly (as Elizabeth puts it). Closer to the surge at 5500 in second, and certainly enough to pass slower traffic.

knapkin 05-26-2013 02:13 AM

Sorry for the necro, but I figured this out. It has to do with two factors, how I was shifting and the throttle response time. A simple adjustment to my shifting has resolved this.

From stop to first I would often times start the shift rev'ed a little high. Then drop the throttle down to rev match my rolling speed, fully engage and then hit the throttle.

It seems there is about a 2 second lag between dropping the throttle and having the engine actually rev down, so what was happening is just as I fully engaged the engine (sometimes still in first, sometimes I've made it to second before this hits) the revs finally drop, and because I overcompensated my throttle release due to lack of response, I'm way too low and wind up in very low torque territory.

I'm assuming this is normal and can reproduce the lag pretty regularly in second by accelerating and then popping my foot off of the throttle and counting the seconds until the engine break kicks in.

All in all it seems to boil down to me getting used to my new car.


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