ransom
ransom GRM+ Memberand SuperDork
10/10/12 2:01 p.m.

One of my gripes with our 2012 WRX is that the softness of the power delivery.

I mean, it's got plenty of power.

I haven't been able to pin it down to being a bunch better if rolling on from at least midrange revs, already some load, or a combination. Some empirical data gathering would be good, but...

I'm just wondering whether this is turbo lag, or the computer's idea of how quickly the throttle should be rolled on, or... ? ('my brain' is also a viable option...)

Maybe a dumb question, but I'm unaccustomed to both electronic throttles and turbos, and I'm wondering why this car is fast, but not... eager?

sachilles
sachilles SuperDork
10/10/12 2:09 p.m.

drive by wire throttle It can be edited out.

ValuePack
ValuePack Dork
10/10/12 2:23 p.m.
sachilles wrote: drive by wire throttle It can be edited out.

+1. A friend edited the lag via OpenSource in his'07 2.5i, you'd never know there wasn't a cable there.

bigbens6
bigbens6 Reader
10/10/12 2:32 p.m.

Prolly lag, when i drove a WRX vs my MazdaSPEED6 is was unimpressive, and though i know they are comparably quick the MS6 felt MUCH faster due to how quickly that little K04 turbo this when you mash the loud pedal...

GameboyRMH
GameboyRMH GRM+ Memberand PowerDork
10/10/12 2:34 p.m.

A dual-mass flywheel could be a contributing factor.

SilverFleet
SilverFleet Dork
10/10/12 2:50 p.m.

The throttle response on these is absolutely horrid on the factory tune. My '09 had problems with rev-hang too. It was so annoying. Glad to see they came up with a solution.

ransom
ransom GRM+ Memberand SuperDork
10/10/12 3:34 p.m.

Thanks for the infos!

This may sound odd, and it's too much extrapolation to do anything concrete about, but my biggest desire here was to find out whether I hate turbos as I try to figure out details of my street/autocross BMW 2002 project...

I guess the way to find out about the WRX conclusively would be to do the throttle edit and find out where that puts me, feel-wise. But since this is a short-term car and my intent is to baby it for resale (including no dodgy behavior or tweaks, never mind how actually dodgy this is or isn't), I'm not going to touch it...

sachilles
sachilles SuperDork
10/10/12 3:44 p.m.

One of the grm advertiser offers a product intended to alter throttle response and is removable. The Name escapes me.

turbo subies can have lag, but if you are at throttle tip in, that isn't the lag.

ransom
ransom GRM+ Memberand SuperDork
10/10/12 4:10 p.m.

In reply to sachilles:

It could be that I'm expecting too much at too few revs (as low as 2500-3000, though I would certainly expect to be down there leaving corners at an autocross, so it seems applicable), but part of what I'm seeing seems like a soft delivery even if I bury the throttle.

A quick look for a graph suggests this thing should be making near as makes no difference peak torque by 3000 rpm (once the turbo is spooled up), and almost 80% of that by 2500 rpm...

I read a bit at one point about how the inline throttle quickeners help, and it sounds like it basically "pre-undoes" the computer's smoothing by saying you're asking for more than you are.

That is, if the Subaru's computer thinks it should give 40% throttle plate opening at 50% throttle pedal travel, the quickener intercepts the 50% throttle message and makes it something larger than should map to 50% actual throttle in the computer.

However, I don't see how it can get to 100% any quicker, because it can't just ask for a spot further along the map...

irish44j
irish44j SuperDork
10/10/12 8:30 p.m.

Sachilles, that is the Sprint Booster. I've heard both good and bad things about how well it works from various people over the years. Haven't tried myself.

As for the 2012 WRX - I assume it has the same factory tune as my 2009 (same engine, turbo, etc) . One of the main problems with the factory tune is that for emissions purposes it runs VERY lean to mindrange, and then pulls timing under full boost. I'll see if I can dig up my old baseline dyno, but the A/F is dreadful bascially everywhere.

You can do an OTS tune, but I picked up a used Cobb Accessport and just flashed the base stage 1 tune. This gave a much better A/F, timing did not pull, and didn't get the midrange hesitation I was used to. Also it made the throttle response better, or so it feels (actually, I think it can be adjusted via the AP manually, as well, but don't quote me on it).

MIght just also be a matter of getting used to the larger turbo (or any turbo), depending on what you drove before. In my first few months owning the car I constantly found myself off-boost, and the car is kind of a pig off-boost. After a while it became natural to drive the car differently from an N/A car to keep it "on boost." Now I rarely get caught in a situation where I'm lacking power to do whatever I want to do.

I'll also mention that I came out of a 2000 Maxima, which has an excellent CABLE throttle setup....so DBW was new for me as well and took a while to get used to. But the nice part about DBW is that it's electronic, so it is tunable (the way you could adjust a cable throttle by a screw, etc).

For a while I kind of hated the turbo 4-banger as well, coming out of a smooth, linear V6. But now I hardly notice or get caught with turbo lag. My driving style has subconsciously adjusted. Now when I drive my little e30 I'm constantly annoyed at the lack of turbo on the M10, lol....

irish44j
irish44j SuperDork
10/10/12 8:36 p.m.

ok, here's my baseline dyno: TQ (you can see the midrange hesitation where it pulls timing) HP look at this A/F!

here is one of my runs after Stage 1 tune. Not much HP gain, but a significant increase in TQ and it arrives about 500rpm sooner to boot. Plus MUCH better A/F

IDK if that will tell you anything, but there it is....

carguy123
carguy123 PowerDork
10/10/12 8:51 p.m.

The problem is a flat torque curve. There's no punch of torque or power to hit you at any spot.

Power delivery is very gradual in all parts of the rev range. I'm like you in that I want some punch somewhere. It makes me feel like it's going fast.

A BMW 6 cylinder has that gradual power delivery and magazines rave about it, but to me it's boring.

irish44j
irish44j SuperDork
10/10/12 9:14 p.m.

you guys need to use the "downshift" feature, which can be accomplished with your left foot and right hand

I frankly tend to not be in 5th very often unless I'm just highway cruising. In heavy highway traffic where I might want to make a move, I just stay in 4th most of the time under 65mph or so...

Ojala
Ojala GRM+ Memberand Reader
10/10/12 9:44 p.m.

I started to write a long winded brain dump about changing the accel/req torque tables on DBW roms and comparing that to req torque/throttle duty cycle tables.

But then i noticed that you don't want to make changes to the car so never mind. But to answer your original question, yes there is something in the stock ecu's rom that makes it feel laggy and over damped. I really don't know anything about sprint boosters but at least it is removable.

sachilles
sachilles SuperDork
10/10/12 9:51 p.m.

And you need to try a 2.0 turbo Subie to fully appreciate the torque of the 2.5 turbo. I have both. Night and day difference. The five speed gearbox paired with us turbo cars does feel like the gears are very tall.

irish44j
irish44j SuperDork
10/10/12 10:05 p.m.

All you need to try is an M10-powered e30 and you will appreciate the torque of pretty much any car built since 1980, including rotaries. :)

NGTD
NGTD Dork
10/10/12 11:29 p.m.
sachilles wrote: And you need to try a 2.0 turbo Subie to fully appreciate the torque of the 2.5 turbo. I have both. Night and day difference. The five speed gearbox paired with us turbo cars does feel like the gears are very tall.

I went from a 97 Outback with a 2.5 NA to an 02 WRX. My little 2.0 turbo makes me very happy. Even below 2k rpm the WRX motor moves along better than the DOHC 2.5. (Now it does have a Cobb AP V1 on it).

ransom
ransom GRM+ Memberand SuperDork
10/10/12 11:39 p.m.

There's certainly some adaptation to be done on my part.

Once I'm up at higher speeds it's easy to be in the right gear more readily.

The most common place it feels "soft" is in second gear, down in that lower 2.5-3k revs... (most of my driving is around town) I'm surprized that in such a low gear it's not almost violent.

It feels odd to say, but if I can ever get the damn thing to an autocross, I expect to need first gear quite a bit

sachilles
sachilles SuperDork
10/11/12 5:37 a.m.

I believe the stock tunes restricts boost in first and second gear.

Ojala
Ojala GRM+ Memberand Reader
10/11/12 9:07 a.m.

In reply to sachilles:

Yup, it's one of the benefits of the newer ecu versus the older denso and JEC.

ransom
ransom GRM+ Memberand SuperDork
10/11/12 9:23 a.m.

Well, that's certainly going to effect a feeling of softness... You can wait a looooong time for boost the ECU says you can't have...

GTwannaB
GTwannaB GRM+ Memberand Reader
10/11/12 3:11 p.m.
ValuePack wrote:
sachilles wrote: drive by wire throttle It can be edited out.
+1. A friend edited the lag via OpenSource in his'07 2.5i, you'd never know there wasn't a cable there.

Any more details on this. I would love to do the same to my 05 2.5i Subaru.

Nitroracer
Nitroracer SuperDork
10/11/12 9:33 p.m.
GTwannaB wrote:
ValuePack wrote:
sachilles wrote: drive by wire throttle It can be edited out.
+1. A friend edited the lag via OpenSource in his'07 2.5i, you'd never know there wasn't a cable there.
Any more details on this. I would love to do the same to my 05 2.5i Subaru.

I'm interested in this too, for a 2.5i 05 Legacy.

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