berkasal

i got one from HKS, but never installed it,
how do you install it
does anyone have the instructions, or how much would it cost to get it done, is it worth it??

I got an HKS turbo back 3''

Mister 2

iTrader: (14)

What is your current setup? Do you understand how a wastegate works? I just want to know where to start my explaination.

berkasal

well i have a full turbo back exhaust with 3'' piping all the way and the place i had it istalled told me they couldnt do the wastegate, they didnt give me any reason all the exhaust parts are HKS, muffler is hi-power

I think I know how it works but i wouldnt wanna depend on my knowledge on this so enlighten me

WRX-.-v

Can you explain? I am a n00b and I want to learn.
Please explain, the difference between internal and external, its function, pros and cons.
Thank you in advance!

Mister 2

iTrader: (14)

The stock turbo has an internal wastegate. The wastegate will by-pass exhaust gasses around the tubine and is used to control (limit) boost. Here's a little explaination: http://auto.howstuffworks.com/turbo4.htm

The internal wastegate is more than adequate on your stock turbo and is also used on most of the upgrades. An external wastegate is used on much larger turbos which do not have an internal wastegate built in or when the internal wastegate is not large enough to control boost.

In order to install an external wastegate you'll need to make substantial mods to fit it in there with no real performance gains. Here's a pic of what an external setup would look like: http://www.dnperformance.com/wrx2.html

Also if your turbo already has an internal gate (yours does) then to run the external, the internal gate has to be welded shut.

HTH,
Dean

Mister 2

iTrader: (14)

Also my previous car (MR-2) had a large turbo (TD-06 20g) and an external wastegate. IMO the external wastegate did help to limit lag. Because it is larger than an internal wastegate would be, it (external) stayed shut longer and allowed boost to build quicker. The smaller size of an internal wastegate would require it to start opening sooner in order to limit boost.

I also had my external wastegate dumping to atmosphere (instead of going thru the muffler) so when it opened it was loud .

On a WRX most of the work would have to be done custom unless you're prepared to drop $$$s on something like the link above or buy a premade kit like the GReddy T-67.

berkasal

well thats the most reason i want it, it sounds amazing, i just saw a wagon wrx the other day he had an external wastegate. i was jealous.

Mister 2

iTrader: (14)

Sounds wicked with the external 'gate dumping to atmosphere. I'm gonna try to get the same thing out of the stock turbo and internal wastegate.

I got a used HKS dp which as many know has a flat flange. I'm gonna drill the flat flange for a 1" wastegate dump to atmosphere and then have a divider made that will fit into the turbine housing to seperate the turbine exhaust and wastegate exhaust flow. This is the hard part because if the divider doesn't closely match the internal contours of the turbine housing then I'll have a full time exhaust leak.

My other option is to actually have a divider welded into the turbine housing itself and not be part of the dowpipe. I'll post up pics when its done.

berkasal

make me one also

it sounds like its gonna take a long time, good luck

mmboost

iTrader: (2)

External wastegate does make for better performance. In fact an external wastegate with a completely divorced exhaust is the best setup. This is the case because you don't have to reintroduce the wastegated exhaust back into the turbo's output. Being that they don't travel the same path with the same obstacles and pipe dimensions, they disturb eachothers flow if the wastegated exhaust is reintroduced. There are compromises for each style of setup, but that is the best one.

If you want to learn about custom turbo setups I suggest "Maximum Boost" by Corky Bell. You can get it on Amazon, etc. A teeny bit outdated,but still all very true and very helpful.

jason