blip

Rather than bury this in my other PPP related thread I just wanted to get opinions on another 'characteristic' I have noticed.

I'm not saying this is a fault of the PPP or of the car, but as this is my first Impreza I have no reference point with these things and so can only ask other WRX owners on here. Please don't interpret this as a 'don't buy PPP' thread by any means as I actually think the car is awesome with it fitted. This may have nothing to do with the PPP at all.

Anyway, I get quite a severe 'lightswitch' effect with the power if I momentarily lift/feather/backoff the gas when accelerating hard. What I mean is the car decelerates abruptly for a moment making the whole car shudder or jerk as if all power has been shut down (rather than a more normal or progressive loss of speed) before getting back on the gas. It's like severe engine braking, but with no in-between stage (hence the lightswitch analogy), no progression in the loss of power, even though I am only feathering the throttle rather than completely lifting off.

It doesn't do it all the time but when it does, for example when I was overtaking a line of cars (so was accelerating hard, fairly high revs), and lifted slightly whilst deciding whether there was time to get past the next car, before I put my foot down again. At the point I lifted slightly it happened and the car jerked noticably and slowed more than I would have expected.

Anyone had this? It's a bit embarassing when it happens as it looks like I can't drive to other road users (waits for obvious barbed comments )

I'm wondering if it is related to the flatspot issue? Something to do with the ECU mapping at certain revs and certain throttle positions? Or just a turbo characteristic?

TimboMY03

Relax, To greater or lesser extent the symptoms described have (and do) effected all 3 of my Impreza Turbos including my MY03 too. Although, it's rare and usually due to hard acceleration followed by quick lift off due to gear change or driver hesitancy.

Tim

BlueSimon

Yep,i get it changing gear arround 4500-5500 rpm, no 3 on my 'pisses me off' list.

Simon

Blue

I get this too, as I did on my MY00. You're asking the car, when its on full boost for 265bhp/none/265. Its only doing what you're telling it to!

Regarding your other issue, I played about last night on my way home (78 miles!!) and had no hesitancy in 2nd, 3rd or 4th between 3-4k and 4-5k revs. It ran smoothly all the time. Itried it gently and hard and all was fine.

blip

I'm talking about a slight lift or feather as opposed to completely lifting off and then foot back down, so surely that isn't asking the car for 265bhp/none/265bhp. More like 265bhp/200bhp/265bhp or something similar.

BlueSimon

Blip,
Im talking the same thing really, cos it happens as soon as i start lifting so that i dont get the overrun inbetween gears.But instead get the 'im going to pull this transmision in two, effect' as you do.

Simon