MCRAE HATER 2

My GTB seems very slugish under 5000RPM until the second turbo kicks in, is there any mods to improve on this

pwebb

hmmm - popularly known as the Valley Of Death or VOD -
check out the archives on the legacyb4 mailing list at yahoo groups - endless reading on this subject.

Essentially caused by insufficient exhaust pressure when the second turbo is activated - not enough to keep the primary on song and spool up the secondary terribly quickly - thus there is a pause while the secondary turbo gets going. It doesn't help that the ecu momentarily actuates both wastegates when the throttle is floored - leading to even more pressure being wasted.

Summary of findings to date would be: most engine/exhaust mods will make this worse not better - I would advise learning to drive around it and avoid the revs dropping back under 5000 rpm when changing gear - technique will come with practice.

see you on the legacyb4 list ?

Paul W

Jonathan Witts

I had a similar issue with gutless low down performance. After changing the O2 sensor three times, with immediate, short lasted improvement it was tracked down to fault fuel pump.

Now that has been replaced I have the low down grunt of the first turbo, then the VOD, until I get a blast from the second turbo.

Or Like Paul said it may just be the "normal" power curve. Has it always been like it ???

Jon

[Edited by Jonathan Witts - 2/25/2002 8:28:16 PM]

MCRAE HATER 2

Ive just found a web page on about an engine earthing mod, do you think this may help ?

Jonathan Witts

I did my earthing mod when the car was brand new ~ so could not realy tell a before and after - all the guys in Japan swear by it, so I took their word. Its cheap and easy - couple of hours tinkering on a saturday is good relaxation !!!

Jon

Regacy

I found the same problem with mine. (98 GTB) Talked to a few people who explained the difference between the two turbos and how top get the optimum power out of them. The first needs to be 'helped' up to speed with a gentle feeding in of power whilst the second will work with a less subtle foot to the floor approach. Try it it's incredible, short shift into 2nd a gradually feed in the power through the first turbo until your foot is flat for the second. It takes a bit of practice but.... full boost on both turbos and no VOD. The difficult bit is the self-control to ease the power in when you need it quickly, but it works