Xantia V6 Activa --- Performance Engine Upgrades

[HansNOR]

I think it must be that the roads are so different that makes us disagree. Here we got a speed limit of 80 km/h , same as your 50 mph. But the roads invite for inspired driving. Hills and winding roads that urge you on to put some weight on the accelerator. And going up I would argue that there is a need for as much as you can get.






Bergsdalen (a friends 1300s beetle)


Lysebotn


Trollstigen

It's a lot of fun to go a little Colin McRae up those climbs

[CitroJim]

Yes, I think you are quite right Hans!

I'd love to ride those roads in your pictures on my bike and drive them in my Activa. Roads just made for an Activa!

[Stickyfinger]

Better brakes would make that a faster road more than an extra 20 or 200bhp would ever do. This would be true either up or down the road and by a VERY wide margin. There is no point in BHP if you cannot get rid of the speed.

[daviemck2006]

Better brakes would make that a faster road more than an extra 20 or 200bhp would ever do. This would be true either up or down the road and by a VERY wide margin. There is no point in BHP if you cannot get rid of the speed.

I agree, especially on a road like that. And I know I'm new to xantia ownership, but not citroen, and I'm afraid to say the brakes on my activa certainly do not inspire confidence. In fact I would go as far as saying they are the poorest brakes I have driven with for quite a while. Any car can get up to a speed that they may need to stop quickly, even my little 107, so every car needs to be able to stop. I just don't have the confidence that the activas brakes would stop me if they needed to, however I have never used them in anger yet.

[Stickyfinger]

Mine do stop me perfectly Ok on normal roads .....but for how long is another thing altogether as I think even the larger [standard] set up would soon fade with heat with harsh use on a long taxing road/track event.

Sadly I do not think the Pug fitted Brembo callipers fit with original wheels (?)

I have worked them hard across Salisbury plain a good few times in both dry and wet weathers, I feel very happy they will always stop me without unwanted ABS activation all the time. They are all new (disks & pads) and if I stamp on them with a lead foot at speed I can lock them/abs activate.

Update the Callipers from a post 2000 car and fit decent pads as job No1 if the early type are fitted.

I (may) consider grooved disks or some type of concealed ducting but it would have to be hidden...... however I do not often go down mountains so that can wait


FYI, a knackers/rust bucket 406.v6 coupé can be cheaper than a 2nd hand set of Brembo callipers (free engine and G'box as well)

[daviemck2006]

I think I need to give it some stick and use them more when I get a decent dry day here to give it some. I am intending giving the brakes the once over, and Chris did give me new discs and pads for the back. Maybe the calipers are sticky as the car wasn't used very often, and there is a broken handprake cable. I do have a set of 17" wolfrace alloys that will fit if I were to upgrade the brakes, but if the standard wheels did not fit it's not a road I would want to go down. A brake service is high on the list of things to do.

[Koukku]

I did a bit of engine and brake tuning on my previous V6 Activa which I drove on the track quite frequently, even took it to the Nordschleife once.

The mods were not that extensive, just a stainless 3" cat-back, Viper cold air induction kit, grooved rotors, brake cooling and better brake pads. And of course fat grippy tyres on lightweight 16" wheels.

Cat-back added about 8hp throughout the usable rev range (dyno tested before and after). Probably wouldn't do that mod again due to the noise... not for a daily driver anyway. ECU tuning was also done on the dyno but there were no gains to be had. The manifold is most likely holding the engine back, but having a proper one made would've cost over 1000€. Might be cheaper in the UK though. Then there is the Clio V6 which has an engine based on the ES9J4... might have some features that can be transferred over. There has been at least one engine swap from a 255hp Clio V6 Trophy to an Activa, but I'm not sure how that ended up. Then there are the Catcams' cams... anyone tried those?

There is one 406 V6 Coupe here in Finland with a Procharger and water/air intercooler running something like 500-600hp... it has had some extensive engine mods, but I think the stock parts are good for 300-400hp. Except maybe for the clutch.

Even with stock power and grippy track day tyres I had trouble putting the power down coming out of corners, so I'd probably start with an LSD and add power later.

Brakes were the biggest issue for me, as there were no performance pads available for the 288mm front brakes. After lots of trial and error I found Ferodo Premier pads to be the best solution; no fade, and reasonable pad life after adding some brake cooling... I used air scoops that were designed for Astra/Vectra and attach to the lower control arm. They fit the Xantia with minimal modifications. Not sure if they're available anymore though: http://www.migweb.co.uk/gallery/data/2/ ... Small_.JPG

I did buy the 406 Brembos but never got around to even test fitting them before selling the car. I do know that they would not fit under the stock wheel. And of course the Brembos don't have a handbrake on them... For the rear I was planning on installing Xantia estate rear brakes as they are slightly bigger.

I recently bought a V6 Activa again, but it'll need some work before I can even start thinkging about mods...

[DHallworth]

I used to think the smaller brakes on my Activa were border line dangerous when barreling up towards roundabouts on national speed limit dual carriageways.

I fitted the V6 brakes to mine a while before the V6 conversion was done and noticed a remarkable improvement... However, when Robert at BL Auto's drove it he commented that the brakes on it were s**t. I'd put genuine Citroen disks on it and Pagid pads as I couldn't get OE pads when I needed them. He also commented that they'd tried all sorts of aftermarket pads and had never managed to better the genuine Citroen pads.

After my engine swap was done and I was back at home I was walking through the workshop and I saw a package on the shelf I recognised... I'd bought 2 sets of Genuine pads on eBay for £23 and had forgotten I had them. After fitting these with the genuine disks I can confirm that the difference in braking is massively noticeable. I've not had any fade at all on them despite doing 90 miles in one go through the Yorkshire Dales last year with an advance driving instructor sitting beside me.

From now on I'm fitting genuine all the way

That's an interesting thought on the Brembo's... We've got 2 Brembo 4 pot calipers that we replaced on our 406 Coupe when they needed a refurb. It's an alloy caliper with a stainless plate that lives between the pad and the caliper body. The screws that hold the plates on cannot be removed and have to have the heads drilled off them, to refit they basically screw another self tapper into the body of the caliper.

Dad being a perfectionist didn't fancy this so bought two replacement calipers as with my trade discount at Peugeot there was no difference in price between replacing and refurb'ing the calipers. One thing you notice instantly when working with them is that there's a massive difference in weight between the alloy bodied Brembo 4 pots and the standard V6 calipers on the Xantia. When I get time I think I've got spare Activa hubs in the garage too so I'll see if the mounting holes line up, if the do, I'll offer up a standard wheel to it and see if it'll clear the caliper.

Standard V6 brakes are 288mm discs, the Brembo's are 305mm discs, so there would be a fairly big improvement in braking area if they would, however, the brakes fitted to my early 407 Coupe were 330mm discs, the later ones are 340mm discs. The discs fitted to the front of the 3.0 HDi C5 we've got are also 330mm discs which look huge but I very much doubt they'll fit as the discs on that are 12.9" so chances of getting them under a 15" wheel I'd imagine are next to non.

Hmm, I feel a day of experimenting coming on.

David.

[BenC5HDi]

How will you provide a handbrake if the Brembos do fit?

[DHallworth]

Actually, that's a good point, and something I'd forgotten about... The 406, 407 and C5 all have handbrakes on the rear...

I wonder if the handbrake mechanics from the 406 can be transferred to the Xantia going it shoes inside the discs on the rear? The rear discs on the 406 are also much bigger then the Xantia ones.

Either that or swap them back for an MOT and leave it in gear when parked

David.

[Koukku]

I investigated the 406 rear brake conversion, and there is no way to mount the 406 rear brakes... the rear suspension arms and hubs are totally different in design. C5 might be more viable route... but I always thought it had handbrake at the front?

The 406 Brembos are a bolt on for the Xantia front hub, that much I know. And they won't work with 15" wheels. But if you're after performance, you'll probably want to change the wheels anyway...

Another thing to consider is that the rubber seals in the caliper meant for dot4 brake fluid may not be compatible with LHM. Might be an urban legend, but that's what I've heard.

[DHallworth]

I've heard the same thing about the seals but have never looked into anything.

The C5 we've got is the X7 with the electronic handbrake which is at the back of the car. Thinking about it, the 407 and X7 C5 both have 5 stud wheels as well, not 4 stud wheels so the hubs would need changing too.

To be honest I'm not likely to actually change much on mine as I prefer it to look totally standard. However if someone could recreate the original Activa alloys in 17" form with the appropriate strengthening etc. built into them I'd probably be tempted as the choice of 15" tyres these days is poor.

David.

[Koukku]

leave it in gear when parked

You do know that brake pressure is lost after a while when the engine is off? Good luck when starting the car parked on a hill with no handbrake. I recall having a scary moment after buying my first Activa and not using the handbrake... almost hit a wall when depressing the clutch stepping on the brake to start the car.

[DHallworth]

Yea, it was meant in jest

[Koukku]

Here's some info from Finnish SportPug forum, written by the guy that had the 406 coupe ES9J4 with way over 500hp (he's currently building a mid-engined car out of it)...
- stock exhaust manifolds are good for at least 400hp (with a ProCharger)
- Catcams' cams alone added about 100hp to a supercharged ES9J4 (had not tested them naturally aspirated)
- ES9J4 heads flow 10% more than ES9J4S heads (I recall them being good for 400hp, but can't anymore find where I saw that info)