Hey all,

Hopefuly someone out there might have a idea of whats happening to my MY99. Have searched and found ppl with similar issues but not quite.

Throughout all gears the boost comes on normaly and is pulling fine but after a few seconds you can hear the boost just dropping off. I drove around for awhile wondering what was going on, testing different things and its easiest to test in 5th gear sitting at 100, I'll put my foot down, boost will pick up, few seconds latter, dropp off and you can feel it not pulling as much, then a few seconds latter boost will come back on, repeat cycle all the way through the rev range, on, off, on, off.

Only recent mod is a 3" turbo back and a new air filter.

Anyone encountered this? Any ideas?

Clutch is possibly on the way out.

__________________
[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

car not tuned.... standard turbo with over 100,000ks with standards internals.... your not gonna hold boost....

saying that depends how much boost drop your gettin?

Clutch is only about 6 months old, heavy duty from MRT, so I sure hope not. Does feel like the clutch.

3" Turbo back can give you boost spikes. Best bet is to either get an EBC or an ECU and a tune.

With the extra flow of your 3" TBE your hitting your boost target early which isn't leaving your ecu enough time to control the boost smoothly which gives you an on and off effect.

So you think the ECU deteting to much boost and winding it back to normal levels?

I have been quoted for a full tune with a Autronic Plug and Play, BUT I still wanna do alot more research before I commit to a new chip.

Mr_Psi whats the reasoning behind this one? Just curious - I can't think of a reason to generalise the standard turbo in saying its stuffed that's all..

Yeah, my old car used to do the same thing untill I had the Link installed.

The ECU has a set target for at what rpm it should start controlling boost. With the new exhaust the boost level at that set rpm would be much higher so the ECU has to "rush" to control the boost.

Electronic Boost Controller, or New ECU and tune will fix your problem.

never said the turbo was on its last legs... i am saying the td04 doesnt old boost well because it is a small turbo.

also keep in mind the standard waste gate spring is .5bar therefore any more boost put into the turbo the spring/wastegate wont account for as it is already accounting for 6psi or so!

When you mentioned a standard turbo over 100kkm i assumed you were reffering to the condition of the turbo, otherwise milage wouldn't matter i'd have thought.

I think sleepy's on the right track but i've seen alot of stock wrx's with TBE exhausts + stock ecu with out a worry?