Subaru wrx 01, lag?

star_equines, Nov 12, 9:09am
Hi, I have a 01 subaru wrx turbo, what could cause the car to be abit laggy between 3.5-4500 revs! Doesn't do it all the time and nothing coming up on scanner.

fiddle44, Nov 12, 9:22am
im no ace at this but have just noticed that the twin turbo models are renowned for it,also have been told they stopped making them as the cant find the cause,single turbo is fine.b t w what sort of k's are you getting per tankfull,son wants one,

star_equines, Nov 12, 9:41am
Mines only single turbo, so im not sure either. Depending on where most of my travel is done (town/highway) as to what I get but I have gone 550km full tank (mainly highway) and thats with current problem. I dont find it much more costly to run then my 2ltr toyota I also use.

I was told to leave twin turbos alone.dont last as long.

mechnificent, Nov 14, 10:26am
It's a well known problem with them. google up "subaru", and "valley of death", or "VOD". which is a description of the horsepower curve ongraph.

It's caused by the change from one turbo to the next, and nothing really seems to stop it completely. About all you can do is try to drive so it isn't too bad. ie, don't throttle partly off in the problem revs, try to keep it above or below the problem revs.

splinter67, Nov 14, 6:40pm
Has it had any modifications done to it like a big fridge on the front

intrade, Nov 14, 7:00pm
i had the same with my tdi vw i figured out soon what caused it on my one.
the intercooler is tini behind the wheel and when i boost it for longer it gets hot and insufficient in cooling the hot intake air= noticable powerloss . I fixed it by fitting a special gutter thing from a audi q7 in to the wheel arch.
I was thinking of getting a subaru water sprayer to cool the intercooler with water as some of the subaru have this .
You got a option to explore now on diesel power loss is more noticable with hot air even then petrol

star_equines, Nov 15, 11:20pm
Big fridge! Are you talking front mount intercooler! yes.

star_equines, Nov 15, 11:22pm
Im blonde(literally) I thort it only had one turbo!
When it starts to hesitate like if im in 4th I just put it straight into 5th gear, good or bad!

splinter67, Nov 15, 11:31pm
Ok what else has it got

itsbutters, Nov 15, 11:35pm
You don't have two turbos, so don't worry about the "VoD". You might however have a boost leak or something.

mechnificent, Nov 16, 1:23am
Ha, my mistake. I didn't go off and check the specs, I just took Fiddles word that it was a twin turbo model.

mechnificent, Nov 16, 1:32am
Hard to say when they have been modified Star. they have long manifolds standard and because of that the computers make calculations about what mixture to pump into them anticipating that there will be a lag between the throttle opening and the air actually speeding up. putting a longer pipe on there throws things out even more.

How long has it been doing it!
Are you sure there are no leaks anywhere on the intercooler piping when it gets under pressure! hard to check that.
Have you had a tune up and changed the fuel filter!
Have you checked the fuel flow and pressure!
Has it got any other modifications, like a blow-off valve, or different computer. haha, getting really tricky then.

Tell you the truth. I generally refuse to work on modified cars because most of the modifications have been poorly thought through and done.

Trying to figure out what is wrong with it without seeing it is going to come down to lucky guesses probably.

mechnificent, Nov 16, 1:36am
If you go to clubsub.co.nz. it's an online forum, there might be someone near you that will look at the car and the modifications and check they are all well done, they might have a few spare parts, like an airflow meter they could fit to see if it helps.

hijacka, Nov 16, 8:34am
I am, They stopped making the twin turbo because it couldn't comply with the changing emission laws, VOD (valley of death) is the switch over point where the secondary turbo kicks in. Its normal for sequential twin turbos

intrade, Nov 16, 8:40am
i flixk my tdi from 3th gear in to 6th and floor it and poof i am gone .

hijacka, Nov 16, 8:40am
I would say its the front cat in the uppipe that the bugeyes have thats causing this problem. You will be reaching full boost by 3500rpm and the turbo actuator opens to let out the exhaust gases in attempt to control boost pressure, but the front cat slows down the exhaust gasing to much at this lower end of the rpm range which slows turbo spool hence the slight loss of power at this point. Get a after market uppipe without the cat.Perrin do a nice one. Come on over here anyway and introduce yourself.http://www.clubsub.org.nz/forum/ See sponsor fortyone for what you need cheers