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2nd Gear Boost?

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Old 06 February 2001, 12:52 AM
  #1  
Lewegie
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Have read somewhere on here that the engine management system lowers the performance to protect the gearbox when in second gear.
I think it maybe when held above 3000 revs and then booted, the boost is lowered which may expalin your findings.
Old 06 February 2001, 09:52 AM
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ChrisG
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Question

Fitted a boost gauge over the weekend and I am getting the usual 16psi peak/15psi held in 3rd/4th/5th gears.
However in 2nd I get around 13-14psi peak gradually falling to about 10psi. Is this normal?
Car is MY00 UK spec with K&N panel, de-cat center and Magex back box and running super-unleaded.
Any advice appreciated.
Thanks,
Chris
( Edited due to poor spelling )

[This message has been edited by ChrisG (edited 06 February 2001).]
Old 07 February 2001, 06:58 PM
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RB5SCOTT
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I get the same thing and its really annoying i.e coming out of a roundabout where the throttle is held for a couple of seconds it just won't shoot out of the corner,then at about 5600rpm it finally comes on boost.

i have been told the same thing as LEWIGIE from Pete Croney

is there anyway of overcoming this

cheers, Scott
Old 07 February 2001, 08:18 PM
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PeterPerfect
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I get the same problem with my MY99 as well

Old 07 February 2001, 09:01 PM
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GTJ
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Chris,

See also the topic:
Old 08 February 2001, 12:46 PM
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Mac's Power
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Thsi is not a "problem" but a "feature" of the ECU. As GTJ says it is for passing tests.

P.
Old 08 February 2001, 09:01 PM
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Richard Gledhill
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Yep, it's for passing emissions tests. The cure is only to change down to 2nd when you need the acceleration, or dip the clutch for a second or so before then accelerating away. <B>Very</B> obvious what's going on when you have a boost gauge! 7psi, up until 5000rpm or so, then 13psi...

In terms of how much boost you get held in lower gears, the problem is that in lower gears the engine is speeding up (revs) much more quickly, and so the turbo can't keep up with providing the correct amount of boost - as soon as it's determined the pressure is right for the current revs, the revs have gone up, etc, so it's always playing catch-up. In 3rd, and particularly 4th and 5th, the turbo system can keep up and so that's why you get highest boost in 4th and 5th.

[Anorak off! ]

Richard
Old 09 February 2001, 02:59 PM
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ChrisG
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Thanks for the replies guys.
Aa long as there is nothing seriously wrong!
Chris
Old 09 February 2001, 10:47 PM
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GTJ
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Richard,

never heard of left foot breaking?

GTJ
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