Crank up the boost 1.9TD ?

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
benj
Posts: 154
Joined: 14 Jul 2003, 19:30
Location: United Kingdom
My Cars:
Contact:

Post by benj »

ok fair enough
Paul Thomas
Posts: 80
Joined: 13 Aug 2002, 19:44
Location: United Kingdom
My Cars:

Post by Paul Thomas »

Ok, it's been a while now - how are you guys getting on with the tweaked pump ?
I'm considering doing mine in a few weeks once time/money allows, any advice ?
rossd
Posts: 420
Joined: 16 Mar 2001, 20:18
Location: United Kingdom
My Cars:

Post by rossd »

Mine is still fine, flying along like usual [:D]
One aspect that all the tuning guides seem not to cover is the MOT. If you follow any of the guides on the net you will find you will have one very smokey engine. They advise you to turn the screw on the top of the pump (if Bosch pump) clockwise. This is not actually correct.
If you take the top off the boost compensator and rotate the diaphragm, you will have to turn the adjustment on the top of the pump anti-clockwise to see less smoke. Thinking about it, it's actually logical as to why[:D]
Brian Oblivion
Posts: 98
Joined: 19 Jan 2004, 14:48
Location: United Kingdom
My Cars:

Post by Brian Oblivion »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by rossd</i>

Thats fine IN A PETROL ENGINE!!!
Diesels do not work as a petrol engine does.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
If I remember my college lectures on Thermodynamics I thought the old diesel engines worked differently to petrol engines but that modern diesels work to the same principle as petrol, apart from the fuel type/ignition method/compression ratio...
I'm not sure about this so will have to check to see if they do work differently.
Interesting Mr Bond
BatteryMan
Posts: 11
Joined: 23 Feb 2004, 15:36
Location: United Kingdom
My Cars:

Post by BatteryMan »

Hi Kev,
I am thinking of going along to Allard for a tweak. What power and torque increase did this give, and how is the performance effected. Any significant change in the economy ?
Thanks,
Bob
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by KevMayer</i>

Hi Mark,
I just had it done to my Xantia 1.9 Turbo D.
Allard Diesel Sport did it. The boost pressure was increased from 0.8 bar to 1.15 bar. Fuelling was then increased to match the increased airflow.
The increase was done by adjusting the waste gate spring tension on my KKK turbocharger. If you increase the boost, you also need to increase the fuelling otherwise you may be running with a lean mixture, which, I believe causes your engine to run hotter.
I once increased the waste gate spring tension on my old Audi 80 1.6 Turbo D with a Garret T2 turbo. It increased the boost pressure from 0.6 bar to 0.8 bar (I measured it) but I didn't adjust the fuelling. I think it ran lean, because the temperature gauge was always a lot higher after this tweak. In the summer, on a fast run, I had to open all the windows and turn the heater on just to keep the engine temp down.
So, boost increase alone is not good. Don't forget the fuelling.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
ohms69
Posts: 136
Joined: 14 Oct 2003, 01:39
Location:
My Cars:

Post by ohms69 »

How much extra power can you get from this tweak? Is 115bhp the limit and if so why?
Which is the better turbo KKK or garret? My new BX quick, but nowhere near as quick as the old one...Why is this?[:)]
neilsxm
Posts: 54
Joined: 05 Jan 2004, 05:19
Location:
My Cars:

Post by neilsxm »

hi all
(ohms 69)you can get pretty much what power you want out of anything if you are prepared to put the money in but on a standard engine,standard intercooler,injectors thats about as far as you'd want to go with out harming fuel consumtion,relialibity,etc
just are word of reallty to you all when you increase boost you seriously increase cylinder pressures so it's better to get the performance you want without drasticaly inceasing boost pressures
http://www.rbracing-rsr.com/compression.htm
if you don't believe me just fill in the above calculator and see for yourself
----hth-----
--neil--
ohms69
Posts: 136
Joined: 14 Oct 2003, 01:39
Location:
My Cars:

Post by ohms69 »

I visited the derv doctor today for a performance tweak. What a difference![8D]
The BX officially flies!! But god, my Turbo is noisy now it sounds like a blasted kettle!!
I would thoroughly recomend the tweak toanyone, especially TD BX owners. the combination of this new found torque and the positive effect of lightweight is enough to see off just about anything.[;)]
You should have seen the look of shock on the face of the BMW 325i driver when he got BX'ed!!
Pure class!! God I love this car[8D]
KevMayer
Posts: 1051
Joined: 12 Sep 2003, 22:01
Location: Staffordshire, United Kingdom
My Cars:
x 2

Post by KevMayer »

ohms69.. What power do you think your BX has now ?
It sounds a lot of fun. What model is it..TZD ? How old is it ?
I ran a K reg BX TZD TurboD for a while. The turbo whistle sounded like there was a police siren in the distance. My two little girls used to ask me if the police were coming. It was metallic silver with a rear spoiler. A wonderful car. I kick myself when I think that I got rid of it. It was very quick as standard. With a tweak as you now have it would have been dramatically fast.
I just might get myself another one... one day... and take good care of it.
sooty
Posts: 464
Joined: 31 Jul 2002, 00:34
Location: United Kingdom
My Cars:

Post by sooty »

I done mine some time ago. I increased the max. fuel settings, then adjusted the boost fuel back (weaker) from the standard settings because of excess black smoke on boost.
The boost pressure at 80/90mph is no higher than standard on a level motorway, unless you climb.
I reach standard boost at 2400 and 1.25bar at 4250 and it will see off any HDI pug or cit, or even a yuppie/rep 115 A4.
KevMayer
Posts: 1051
Joined: 12 Sep 2003, 22:01
Location: Staffordshire, United Kingdom
My Cars:
x 2

Post by KevMayer »

BatteryMan..
I was pleased with Allard. The chap that did the work was Mr Allard himself. He is a real gentleman.
He doesn't use a rolling road, neither does Dr diesel I believe, but, from experience he recons that he can increase the power from 92 to 110 Bhp. The torque goes from 148 up to around 175 Lbft.
My Xantia drives nicely. Its no rocket ship, but it goes well and it really moves if I need it to.
The fuel economy is approximately the same as before the tweak..or maybe slightly better (1 mpg). I do keep an eye on the fuel consumption. I drive the car hard... always accelerating too fast. I only got around 36 mpg before the tweak. I recon I get around 36 to 38 after. So nothing to shout about, but at least it didn't become worse. I have got well over 40 mpg by taking it steady, but I become drousy and tend to nod off.
Allard charged me 80 quid for the tune up. I had almost done enough to set it up myself before I went so he went easy on me. I paid 10 quid for a ZX1 equivalent engine treatment, 34 quid for a K&N air filter and 16 quid for a copy of his tuning manual (which wasn't much use to be honest. It doesn't give much away).
So, good luck.
Just thought.. If its a sunny day you can drop your car off at Allard's and walk into Monmouth town. Go to Peacocks and buy 3 pairs of socks for 2 quid like I did. 2 hrs later the car will be done.
ohms69
Posts: 136
Joined: 14 Oct 2003, 01:39
Location:
My Cars:

Post by ohms69 »

Hi Kev,
The BX is an absolute animal now. No idea what the power output is, but who cares! Torque is the key and trust me, this BX goes like the absolute clappers. Words cannot describe how much fun I've been having in the BX!
If you own a BX then you already know that generally every other motorist on the roads have a tendency to look down there noses at you... There is no better enjoyment than out accelerating just about every other car on the roads in a car that most people laugh at...Who's having the last laugh now old buddy old chum?[8D]
the only other car I can refernce my BX with is my Renault 5 GT Turbo, and although the GT Turbo would be faster over a timed sprint I swear the BX would keep up with it in gear 50-70 and 70-90...No joke!
Since having the work carried out I've been making pointless drives to absolutely nowhere, simply because I enjoy driving the car that much!![:D]
Put it this way, a brand new BMW 528I was literally going nowhere, although a new M3 managed to pull a gap.
Having seen exactly what's involved I feel I may have a play myself. It's currently running 20psi, with not a hint of soot out of the exhaust, which means fuelling is just about spot on. How much more fuel and boost can be run before pistons start melting...Time will tell!![;)]
Pass me the formula for the homemade WI kit!![}:)]
ActivaV6uk
Posts: 650
Joined: 20 Nov 2003, 16:51
Location: United Kingdom
My Cars: C5 X7 2.7 hdi

Past cars
Activa, silver MK1 (221bhp stock) stripped out with twin sparcos Evo seats. 95
Activa, light met red MK1 98
Activa, dark met red MK1 98
Activa, dark met blue MK1 (202bhp stock) 96
Xantia exclusive V6 auto 3l 98
Xantia 2l 8v auto
BX 4x4 GTi dark met silver
BX 4x4 GTi white
BX GTi 16v white fibre bumpers
BX GTi 16v black fibre bumpers
BX GTi 16v hurricane (doa)
BX DTR estate

Post by ActivaV6uk »

Ross I’m a bit worried you have your facts wrong. You can run a TD lean and they do get hot because of it, that is why people have noticed there engines get hotter. A turbo increases the length of the explosion not the severity of it if you have more oxygen than fuel in the explosion as with all things (welders too) you get a much hotter burn. Also diesels don’t suffer with pre ignition because they fuel is not added with the air, it’s added under pressure at the start of the downwards stroke and then they ignite because the air and engine is so hot.
There are things you can get away with on TD's like having valve over lap on the exhaust/intake stroke which are risky on a petrol but people should always adjust fuel and boost at the same time other wise problems can arise.
Andy
rossd
Posts: 420
Joined: 16 Mar 2001, 20:18
Location: United Kingdom
My Cars:

Post by rossd »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"> You can run a TD lean and they do get hot because of it<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Could you explain how they get hot? Diesels work by changing the amount of fuel injected to control engine speed. At tickover, just enough fuel is added to make the engine turn over at that speed, so you could say its lean at tickover. Surely, if what you say is true, diesels would overheat when they ticked over.
Running a diesel engine rich dramatically increases combustion temps, you should see how the EGT increases when you increase the fuelling. Running them 'lean' does NOT increase temps. (See edit below)
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Also diesels don’t suffer with pre ignition because they fuel is not added with the air, it’s added under pressure at the start of the downwards stroke and then they ignite because the air and engine is so hot<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
The fuel is added just before TDC, as there is an ignition delay. The timing itself is also altered by the pump according to engine speed vs load.
Edit: Sorry, just re-read your post and saw what you were getting at, with your welders torch analogy. True, the more oxygen you add the hotter the torch gets, but in a diesel engine you cant simply turn up the oxygen. True the turbo adds more when its working, but more fuel is added by the injection pump to create more thermal expansion to spin the turbos impeller, thus it creates boost. This is why you dont see boost when the engine is simply revved in neutral. The injection pump needs to sense the load (eg accelerator down, engine speed low, fuelling goes to max) to add more fuel to get the turbo to spin.
Sorry if I havent explained that clearly, but I'm just off to a lecture!
Guru Meditation
Posts: 259
Joined: 18 Dec 2002, 02:30
Location:
My Cars:
Contact:

Post by Guru Meditation »

So Ohms, you are running your BX at 20psi-that's quite a bit higher than stock.
I am thinking about tuning my ZX Aura TD-possibly by first checking stock boost, then increasing boost but leaving fuelling alone, then by increasing on-boost fuelling.
Question is-Just what is the Maximum amount of Boost you can safely run on these engines? Obviously more torque=less tyre life, less clutch life but I thought that under mild tuning engine internal components are not too adversely affected. What is the limit if say for example I want my current 111K mile engine to see 180k mile+?
Post Reply