V6, raising the fuel pressure

Chris570 · Post by **Chris570** » 03 Nov 2010, 12:47

i have a 4bar FPR here from my AX days, it is compatiable with the V6 engine.

Question is, will it make much difference fitting it, is it worth it...

Post by **CitroJim** » 03 Nov 2010, 13:14

Wouldn't have thought so and no, I I don't reckon it is...

They're good if you've remapped and the injectors are struggling to flow enough at peak power...

You can then use it to up the fuel pressure and get a comcomitant increase in injector flow rate...

Persponally, I'd leave the engine as it is. Not enough power for you then?

Chris570 · Post by **Chris570** » 03 Nov 2010, 13:18

CitroJim wrote:
Persponally, I'd leave the engine as it is. Not enough power for you then?

well more power is always better. Its not something i'm going to chase. t was just a passing thought i had considering i had an FPR lying around

addo · Post by **addo** » 03 Nov 2010, 20:41

I can't see it doing much - the ECU will just reduce injector dwell quick smart.

Do anyone like Cat offer lumpier cams? That plus a remap, might be worth pursuing.

Stempy · Post by **Stempy** » 04 Nov 2010, 07:13

I put 3.5 bar regulator in mine when I had the injectors off to clean them. I put it in because I spent some time improving the airflow on the intake side and have fitted a K&N panel filter. This was something I'd picked up from my biking days and could make a noticeable improvement.

You need to take the fuel rails off to get to it so it's not a quick job and probably not worth the effort unless you are making other modifications also. Bear in mind that it will also make the fuel pump work harder.

I can't say that I've noticed any major power hike on mine but then again economy hasn't suffered either. I guess a before and after dyno run would be the only way to tell for sure, as any improvement would be fairly minor. As Jim says, it's only at flat out speeds that you would get any usable gain and it's not often you get to go flat out in a V6. I tried it once and scared myself silly

I just like tinkering with engines

f00lzz · Post by **f00lzz** » 05 Nov 2010, 06:20

Only my opinion! But the Xantia V6 is very much a 'wolf in sheeps clothing' the 3.0 V6 delivers more power than the drivetrain can sensibly handle anyway.. a sudden takeoff can easily leave you you frantically fighting the torque steer and if you happen to be turning right or left at the time it almost feels uncontrollable. Perhaps TC may have helped, but regardless you already need to 'moderate' the amount of power you release to prevent wheelspin so why bother to increase the power output?

Stempy · Post by **Stempy** » 05 Nov 2010, 06:45

Well I suppose you can make most cars wheelspin if you give them a bit of welly

. I agree that the V6 isn't what you would call under powered, but then again it's no supercar either. If you look at a contemporary equivalent then you are looking at 220bhp+ power outputs. I believe the ES9J4 engine has been tuned up to 800bhp so it has plenty of potential if you want to spend the time and money. I've often thought about fitting a nitrous kit, then you really would have a wolf in sheeps clothing

But that's probably being a bit cruel to the poor old girl. I'd be better off spending my cash on a 350Z

Post by **CitroJim** » 05 Nov 2010, 06:52

Stempy,

I agree with every word there

Including the 350Z bit...

[confession]

It's a bit of a secret but I'm a big Z car fan. Not the 60s TV show but the Nissan version...

I saw a 300ZX the other day and fair fell in love....

[/confession]

f00lzz · Post by **f00lzz** » 05 Nov 2010, 06:58

My lad would love to get his hands on my V6 and is always banging on about getting it 'chipped' and from a technical viewpoint I can understand being able to getting the maximum power from an engine or to 'maximise' it's potential... but realistically, on a car to be driven on UK roads... what for? You can't really (legally) use what it's got now! And, like I said, tune the engine all you like but you won't be able to use it because of the limits of the drivetrain! Now! If you want to have a track car!!!

Chris570 · Post by **Chris570** » 05 Nov 2010, 07:23

i'm pretty sure that if someone tracked a Xantia V6 Andre Citroen would not only spin in his grave but also get out of it and beat the cr*p out of who did it!

In my experience of the V6 so far it has a fair bit of power but there could be more, the engine feels restrained. Mine hasn't felt like it has too much power in any of the scenarios its been in as yet. I think the golden rule here though is just because an engine might have 500bhp doesnt mean all of it has to be used exiting a corner (take note BMW Drivers

)

Post by **CitroJim** » 05 Nov 2010, 07:38

Chris570 wrote:i'm pretty sure that if someone tracked a Xantia V6 Andre Citroën would not only spin in his grave but also get out of it and beat the cr*p out of who did it!

Nah, he'd shake them warmly by the hand and then go for a long drive in it!!!

The V6 was designed as a long-distance, refined and effortless cruiser. This it achieves in spades.

Yes, I'm sure the ES9 has lots left to offer but any exploration of this might take the edge off the refinement and thus nullifying the original design.

It was never intended to be a supercar in the accepted sense of the word.

As F00lzz says, it has far more than can be usefully employed on UK roads for most of the time...

What it does well, it does well but a sports car it isn't and never pretends to be...

Relax and enjoy the refinement

citrov6 · Post by **citrov6** » 05 Nov 2010, 14:39

FPR is a bit rubbish, it gives more of an illusion of making the car go quicker, more noticeable is fuel consumption particularly at idle, if your using it in traffic also it will hit your fuel costs quite a lot. The computer adapts as much as it can. It has a motronic on there that should give the right of fuel for the air that is available, it is also quite good at optimising ignition timing. Cams would be a good bet, but I think these also need heads, seems restrictive around 5500rpm even with standard cams. i was going to try some heads form a 230 clio but i think they are VVT