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View Full Version : RICA Upgrade - power in 4th



mulletboy2
Tuesday 8th February 2005, 20:04
Is it normal for there to be an obvious reduction in power in 4th compared to 1st, 2nd and third? Given how smooth the power delivery is throughout the range, I would have thought it would atleast be a gradual decrease in power rather than you change into 4th and there's an obvious and immediate decrease in power?

Just wondering if something's amiss, or whether it's normal?

Cheers

Mark

mikey
Tuesday 8th February 2005, 20:27
have you got the 280bhp or the 304bhp version?

Justin
Tuesday 8th February 2005, 21:03
Mark if you change gear fast the boost drops for a second then climbs again, its always done it, i imagine thats what you mean

mulletboy2
Tuesday 8th February 2005, 22:13
Cheers guys :)

mikey - 304bhp I believe.

Justin - I'll go out and check that... to be honest, I didn't even look at the boost guage when doing it.

Cheers

Mark

mulletboy2
Tuesday 8th February 2005, 23:55
Justin - right you were mate :) It got up to full boost after a few seconds. Don't suppose you have any ideas on the cause, or what can be done about it?

Cheers

Mark

Justin
Wednesday 9th February 2005, 00:13
Nope ask Adam @ VT

mulletboy2
Wednesday 9th February 2005, 01:37
No worries mate, cheers :)

Cannondale99
Tuesday 15th February 2005, 01:32
Mark, I noticed no reduction in power on our little spin on the motorway.

However, I do drive a 2.0 Vectra :eek:

Bracer
Tuesday 15th February 2005, 09:55
I think you'll find is rev's related, i.e. when you go up into 4th the revs drop to the point that its not best to be boosting that high at that revs due to heat and load on the rods. Once the revs have risen a little more the ECU allows full boost again. The feeling of power loss is then made worse by the change in gear ratios.

mulletboy2
Tuesday 15th February 2005, 20:43
Cheers Bracer, I'll take a look and see if I can find any correlation, although nookie's due for a service within a week or so ... piling on a few miles on her :D

Chris - it is noticable, although it took me a little while to spot it.. I guess it's one of those things that once you know it there, it gets on your pecs a bit. Mind you, still lovely to drive.. I just don't want that little lag there :D

hamish
Tuesday 15th February 2005, 21:25
Mark,

What, exactly, are the revs, and what is the boost (in bar) when you feel this 'drop' in power ?
Please tell me that you are aware you have bought a Volvo T5 and not an inter Gallactic ground attack missile !
You do need to spool turbo's up in the previous gear to get them to boost in the next gear. i.e. If you want full boost straight away in 4th you will need to use the full rev range in 3rd.
As your engine is an older unit (and does not have vvt, and has hydraulic lifters) there isn't much point revving past 6000 rpm.
Please advise revs and boost.

Regards,
Hamish.

hamish
Tuesday 15th February 2005, 21:35
Mark,
Just reread your post.
I've sussed what the drop in power is....Justin is quite right... there is a deliberate drop in boost when you load the engine up in 4th.
This is quite deliberate in the mapping, it is there to save the con rods from bending !

Regards,
Hamish.

mulletboy2
Wednesday 16th February 2005, 01:16
Hamish - cheers for the replies. Oh well, I can live with it as long as it's not a problem with the car :)

I'll be giving you a bell over the next few days regarding a service for her.

Cheers

Mark