[AusSTi]

Has anybody had turbo lag on their STi's? How can you fix this problem, would it be better to get a whole new turbo?

[elucas730]

Are you talking about a USDM STi? Just wondering if your name, AusSTi, means you are in Australia. Anyways, the USDM is not laggy at all. The larger 2.5L engine means more power down low than the 2.0L engine. A smaller turbo will almost always spool faster, but you don't want to do that. Maybe you could look into engine management?

[abdi]

Welcome to the forum. I'm not sure how anyone can address your questions. It is critical that you become familiar with some basic engine concepts.
http://auto.howstuffworks.com/turbo.htm
Abdi

[AusSTi]

Yes i'm talking about a 2.0 litre australian version. Thanks abdi, i understand that there has to be a certain speed to allow enough airflow to get it spinning, just that when i was at low revs it felt dead, and then it suddenly kicks in.

[JJSupah]

I remember reading a review for an Aussie Sti. In the review they said that the car had HORRIBLE turbo lag and basically said the car kinda sucked because of this. It was a vicious review. I guess its the smaller engine that causes the lag? But...Isnt the Jap Sti 2.0L? Does it have the same problem? As for mods to limit the turbo lag, You've come to the right place cuz there are alot of smart people on this site that can help you out.

[staticx313]

Originally Posted by AusSTi

Has anybody had turbo lag on their STi's? How can you fix this problem, would it be better to get a whole new turbo?

Turbo lag is just something that is apart of owning a turbo. Mainly to fix this you can do numerous things:

Boost controller - A boost controller shuts the wastegate until a given point , making MUCH faster spool up and more psi (if desired). Electronic works the best, but mechanical boost controllers are ok too.

Downpipes - Removing the cats and free up a LOT of pressure will make the turbo spool faster and this will also rise psi a little and will cause faster spool.

Catback exhausts - A free flow exhaust will allow for more exaust to flow allowing for a faster spool up.

3/16" mod - Replacing the restrictor in the hose going to the actuator (or compressor.. i forgot which) with a 3/16" connector rather then the stock, this will allow for a slightly faster spool.

There are plenty of mods you can do to increase spool. Replacing the turbo is a BAD idea. Unless you have a form of tuning or know that the turbo you're replacing the stock with is ok on the stock setup (fuel wise and ecu wise). Also.. you'd have to change to a SMALLER turbo to get quicker spool up... this means faster spool yes, but less hp and less capable boost. Give APS a call since you're in aussi land and see what they can do to help you with your lag problems!

Robert~

[abdi]

AusSTi,
I wasn't sure what experience or knowledge you might posses. I was trying to keep things simple for you. Those are some big questions. One that is hotly debated in car forums everywhere. :wink: Many guys here a very much willing to help you out. Naturally all of our stock Sti's (U.S, OZ, JP, UK etc..) suffer some form of turbo lag. There are many ways to go about it. I was just reading on of my favorite magazines, Speed from Australia. I'm not sure if you are familiar with it. The Aug-Sept issue had a great article on a MY 03 STi tuned by Croydon Racing Developtment in AU.
They used an SR40 turbo and Top Mount intercooler from APS, with full exhaust system, and some other goodies with a dyno tune. They were able to attain a very responsive and driveable 298Kw STi. I am a big fan of some of the Australian tuning houses. Like Robert said above, you can call some places like APS and AVO and have access to some of the most capable tuning in the world. Obviously, it takes money to achive many of the goals or fixes we are looking for. There are many affordable ways to approach this as well. I hope that we at the forum can be of help to you.
Here are some links near you that have STi specific technical details that might be of interest.
http://www.croydonautosports.com.au/customercars.htm
http://www.airpowersystems.com.au/
http://210.15.220.239/homepage.html
Abdi