ltalbott

Hi from Oz,

I have just had a free flowing exhaust and boost valve (now 1.0 psi/bar?) added to my Legacy GTB, plus airbox mod (too hot out here for a cone filter) but wondered what would be the best chip/ecu upgrade to sort out the fuelling??

Parts/accessories are very expensive here and I am wondering whether to go for a UK mod/chip and get that sent over and added.

Can anyone help??

Lee

GTB Limited

Lee,

2001MY onwards can be ECUtek'd, anything prior to that in twin turbo form, your out of luck.
The only other way is after market ECU or piggy back module.

Earlier single turbo models can be chipped.



Mark
UK Twin Turbo Legacy Register

ltalbott

Thanks for that Mark. Sadly it is a 1996 model so I guess that I am out of luck on the chip front!.

Do you have any suggestions on which after market ECU or piggy back models are the best. As previosuly mentioned I am looking for the cheapest possible option.

Also, is there antyhing else that you feel is worthwhile doing to the GTB mod wise. It is pretty stock at the moment apart from the pneumatic boost. I have also drilled some holes into the air box to get more air in but retaining most of the colder air.

One thing I have noticed is that it really bogs down at about 4000 rpm before taking off again. Any suggestions as to what could be causing this.

Lee,

2001MY onwards can be ECUtek'd, anything prior to that in twin turbo form, your out of luck.
The only other way is after market ECU or piggy back module.

Earlier single turbo models can be chipped.



Mark
UK Twin Turbo Legacy Register[/QUOTE]

GTB Limited

ltalbott,

Unichip, is popular.
legacyb4
loads of knowledge on here, and a good few TT owners in Oz, be worth asking questions.

Mods:
panel filter.
cat back exhaust, don't decat.
good aftermarket recirc dump valve.
brakes.

No bleed valves.

The bogging down is affectionatley known as the VOD (valley of death), you can't cure it, just hopefully minimise it.
You just have to learn to drive around it, the dip is cause by the lack of exhaust gas pressure as the second turbo comes in.


HTH

Mark

Kevin Groat

And here was me thinking that the chaps in Oz might have a simple solution to sorting the VoD - but the fact that they're asking us.....guess I'll live with it meantime

rich_russell

You do learn to live with it...

The trick is to get the engine operating on the 2nd turbo before you pull out to overtake - by changing down a gear for instance. You soon learn (from the engine note) which turbo you're running on. On the dragstrip, I've found it's possible to get onto that bigger turbo fairly quickly off the start, by pulsing the throttle before the lights change.

I've actually grown to like the VOD - very definately a 'beauty and the beast' kind of car. If you keep the revs down to below 4000, it behaves well, and has bags of torque, but doesn't use excessive fuel. But if you let it loose on the 2nd turbo, it's a serious Porsche overtaker that leaves you frantically grabbing the next gear...

Rich.

ltalbott

Mark,

Sorry for the slow response but that is great feed back. Thank you very much.

I was thinking that a recirculation dump valve would be a good addition as normal dump valves only attract cops here and are very frowned upon!!

The VOD is quite annoying, its funny if you stay in 3rd and gas it, it seems to pull fine, its when it kicks down from 4th to 3rd that it is a problem.

Why no bleed valve. This has made the first turbo spool up alot faster and apparently boosts the second trubo but I cannot see how it can and I have to say it doesn't seem to have helped much.

Appraenlty Unichip don't do one here for a car that old ie 1996 but may see if I can source a Jap chip.

Cheers for now.

AJbaseBloke

Which part of Oz?

In Melbourne you are lucky enough to have AVO turboworld. Terry has been tweaking them over in Japan, and can work some magic in Australia too. He has a sub-com that seems to do a rather good job.

HTH

GTB Limited

Italbott,

bleed valves leak the boost pressure acting on the wastegate, to increase the boost pressure.
They don't allow for atmospherics, so when it's hot things can get dangerous.

Not a true reading in various conditions.

The std D/V is a bit crap, a good aftermarket one would be fine.

HTH

Mark

AJbaseBloke

AVO does a full recirc that fits perfectly - the test one is on my car It is rather good too, very crisp, no fuddy-duddy waffle moments.

IMHO watch the bleed valves on the TTs - upping boost without supporting mods can lead to tears as boost control can get dodgy once near the capacity of the wastegate (which is tiny). Once past it, of course, the only solution is to lift before it goes bang Knocklink and good boost gauge would be a sound investment if you are going that way me thinks.

HTH

Cheers

CustomScoobyIOM

What ECU do you have out of interest? Code no?

Thanks,
Jon