Hello,
I've done some tinkering on the VTS and lost cruise control in fifth gear.
I've put a bit longer fifth gear to keep RPM's lower(~700), but now the BSI calculations are wrong so it won't engage cruise control in fifth(will in fourth).
Can gear ratio for fifth gear be changed using Diagbox?
Changing gear ratio
Moderator: RichardW
- GiveMeABreak
- Forum Admin Team
- Posts: 36996
- Joined: 15 Sep 2015, 19:38
- Location: West Wales
- My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow - x 5645
Re: Changing gear ratio
I don't think so - the BSI and the Engine ECU have independent control over the cruise and speed limiter functions - but work together to exchange info.
It's active from 40 kmh and 4th gear on a manual - and takes data from the ESP system too - so I think the parameters are programmed in and are pretty much set up as defaults and can't be changed for safety reasons.
It's active from 40 kmh and 4th gear on a manual - and takes data from the ESP system too - so I think the parameters are programmed in and are pretty much set up as defaults and can't be changed for safety reasons.
Please Don't PM Me For Technical Help
Marc
Marc
- xantia_v6
- Forum Admin Team
- Posts: 9052
- Joined: 09 Nov 2005, 22:03
- Location: France or NewZealand
- Lexia Available: Yes
- My Cars: -
1997 Citroen Xantia V6 (France)
1999 Citroen XM V6 ES9 (France)
2011 Peugeot 308 CC THP 155 (NZ)
1975 Jaguar XJ-S pre-HE (NZ) - x 825
Re: Changing gear ratio
I did wonder if changing the gear ratio would kill the cruise operation, now we know.
The relevant constant is probably programmed into the engine ECU, maybe an ECU repair or chip-tuning company could adjust it, but it probably wouldn't be cheap.
The relevant constant is probably programmed into the engine ECU, maybe an ECU repair or chip-tuning company could adjust it, but it probably wouldn't be cheap.
-
OnlinePaul-R
- Donor 2023
- Posts: 6916
- Joined: 07 May 2009, 16:24
- Location: Wirral, NW England; Vaucluse 84, France
- Lexia Available: Yes
- My Cars: 2015 1.6 Blue HDi 120 Peugeot 308 Active SW
2013 2.0 HDi 163 C5 Exclusive Tourer
2003 2.0 HDi 110 C5 Exclusive Estate (Gone)
2001 2.0 HDi 90 Xsara Estate (Gone) - x 1369
Re: Changing gear ratio
It may also be an engine speed thing. The engine ECU may not allow CC if the engine isn't going fast enough.
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
Inside every old person is a young person wondering what the hell happened.
"Trying is the first step towards failure" ~ Homer J Simpson
- Cutac
- Posts: 348
- Joined: 28 Aug 2016, 19:36
- Location: Croatia
- My Cars: 2011 B7 Citroen C4 1.4 VTi
2006 Citroen C4 2.0 VTS - x 20
Re: Changing gear ratio
According to this, it can be done. I'll try to find the option in the Diagbox and if there is none, I'll call a renowned Croatian chip tuner for help.
https://www.etuners.gr/peugeot-207-rcgt ... ion-guide/
Engine is spinning fast enough, 2500 at 100 kph, 5000 at 200 and so on until 226
https://www.etuners.gr/peugeot-207-rcgt ... ion-guide/
Engine is spinning fast enough, 2500 at 100 kph, 5000 at 200 and so on until 226
- GiveMeABreak
- Forum Admin Team
- Posts: 36996
- Joined: 15 Sep 2015, 19:38
- Location: West Wales
- My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow - x 5645
Re: Changing gear ratio
There you go then - you'll have to get a chip tuner to do it - as it won't be a Diagbox option. Seems easy enough to do though looking at those pics
Please Don't PM Me For Technical Help
Marc
Marc
- EDC5
- (Donor 2020)
- Posts: 1216
- Joined: 01 Jul 2017, 21:48
- Location: N. Wales
- My Cars: Citroen C5 RHR AM6
- x 120
Re: Changing gear ratio
That's a really nice mod to make to a car. I've always thought that most cars could do with a longer top gear!
- Cutac
- Posts: 348
- Joined: 28 Aug 2016, 19:36
- Location: Croatia
- My Cars: 2011 B7 Citroen C4 1.4 VTi
2006 Citroen C4 2.0 VTS - x 20
Re: Changing gear ratio
Yeah, seems like it's a few clicks and a few numbers.
Yup, and especially if you've done the calculations. Did some thorough calculating to find the best ratio, found it as 0.69 instead of factory 0.86, found the needed cogs in a HDi gearbox, swapped it and voila!
Top speed is barely impacted(weather has a greater impact), fifth gear acceleration is slower, but car is much quieter on the highway. In spirited driving I never, ever exceed fourth gear so fun factor is not hurt.
It's just that I've lost CC and between 60 and 80 kph there's a gap. 70 is a bit too high for fourth(around 2600 rpm), too low for fifth(around 2000 rpm), but I manage.
Yup, and especially if you've done the calculations. Did some thorough calculating to find the best ratio, found it as 0.69 instead of factory 0.86, found the needed cogs in a HDi gearbox, swapped it and voila!
Top speed is barely impacted(weather has a greater impact), fifth gear acceleration is slower, but car is much quieter on the highway. In spirited driving I never, ever exceed fourth gear so fun factor is not hurt.
It's just that I've lost CC and between 60 and 80 kph there's a gap. 70 is a bit too high for fourth(around 2600 rpm), too low for fifth(around 2000 rpm), but I manage.
- Cutac
- Posts: 348
- Joined: 28 Aug 2016, 19:36
- Location: Croatia
- My Cars: 2011 B7 Citroen C4 1.4 VTi
2006 Citroen C4 2.0 VTS - x 20
Re: Changing gear ratio
Dug through Dbox, didn't find anything. There is a menu inside ECU which says is for when fitting a new ECU. That I don't dare to open .
Anyone ever opened that?
Anyone ever opened that?
- GiveMeABreak
- Forum Admin Team
- Posts: 36996
- Joined: 15 Sep 2015, 19:38
- Location: West Wales
- My Cars: C3 Aircross SUV HDi Flair Peperoncino Red (The Chili Hornet)
C5 X7 2.0 HDi Exclusive Mativoire Beige (The Golden Hornet)
C3 1.6 HDi Exclusive Aluminium Grey (The Silver Hornet)
C5 MK II 2.0 HDi Exclusive Obsidian Black
C5 MK I 2.0 HDi SX Wicked Red
Xantia S2 2.0 HDi SX Hermes Red
C15 Romahome White
XM 2.0 Turbo Prestige Emerald Green Pearlescent
XM 2.0 Turbo Prestige Polar White
XM 2.0 SX Polar White
CX 20 Polar White
GS 1220 Geranium Red
CX 2.4 Prestige C-Matic Nevada Beige
GS 1000 Cedreat Yellow - x 5645
Re: Changing gear ratio
Wise move - that's for coding a new engine ECU to the BSI!
Please Don't PM Me For Technical Help
Marc
Marc