Xantia XUTD Tuning - Effects

rashmore · Post by **rashmore** » 09 May 2005, 19:27

Yes hes open saturdays. discount for two (cash), mate and i went over so got discount. time taken depends upon fuel pump fitted.
Make sure he's got plenty of circlips. Lol, when Derv doctor did mine he lost the circlip for the turbo - it popped off never to be seen again.
At first you'll think that not much difference - he'll take u onto the main road for a test - usually the dual carriage way and let u nail it up the hill, so best have a run up it under normal tune. Once you leave the main road with its 50 limit and safety cameras for the twisty country lanes, you'll have a big grin on your face

will pull much more strongly with the urge kicking in lower in the rev range - mine u can feel at 1800 (ish), then really takes off at 2k, no point revving it out as torque curve is flat by that point, so little in the way of speed increase.
have fun [:)]

Chrispy · Post by **Chrispy** » 09 May 2005, 21:48

Just spoken to Gav....(very helpful chap). He says that I may have a funny fuel pump on my car with anti-tamper plates? Err....

davek-uk · Post by **davek-uk** » 10 May 2005, 15:49

Yep that's right - same on mine. You can still play with the settings and get a much more responsive drive. These cars must be terrible de-tuned on purpose.

Chrispy · Post by **Chrispy** » 10 May 2005, 17:07

According to Gav (I sent him some photos of my fuel pump) it's much more of a difficult job to do as they have to angle grind off the anti tamper plate to adjust it up. That un-nerved me a bit, but I'm still going to get it done. He says it's a days job not just 3 hours too....

davek-uk · Post by **davek-uk** » 10 May 2005, 17:44

I haven't bothered trying to access my max fuel screw which will restrict overall performance. Taking the pump off and angle gringing the plate off sounded far too much trouble! Despite that you can still transform the performance by adjusting how the boost fueling is delivered. Additionally, I'm not sure how much control the ECU has over the workings of these later type pumps - would adjusting the max fuel screw actually make that much difference?

Kowalski · Post by **Kowalski** » 10 May 2005, 18:09

The ECU only controls the timing advance of the injection, it can't adjust injection pressures or lengths or anything like that, the pump is largely still a mechanical pump.

davek-uk · Post by **davek-uk** » 11 May 2005, 20:05

Ah, there would be quite a benefit to accessing that damn hidden max fuel screw then. I don't suppose there is an easy way on a armoured bosch pump?

Chrispy · Post by **Chrispy** » 12 May 2005, 03:02

Well angle grinding the thing off seems to be the way forward! He he...brutal but effective. Seems PSA cottoned on to people fiddling with the pumps to get more power. It probably jeapordised people's purchases of 2.1 TD's and HDi 110's as you can get the same grunt out of a 1.9 XUDT. 90 horse just isn't enough boys and girls....PSA know it hence the HDi 110 fitted to the 406's and Xantia's.

Kowalski · Post by **Kowalski** » 12 May 2005, 03:48

The anti tamper plate is to protect the imobiliser electrics on the pump so you can't simply bypass them and steal the car.

davek-uk · Post by **davek-uk** » 12 May 2005, 14:10

That's assuming they were once worth stealing!
Is the plate really tough? Is there any possibility of drilling a suitable hole to access the max fuel screw? Having just done the cambelt, I'd rather not go to the trouble of removing the pump...

wilkobob · Post by **wilkobob** » 12 May 2005, 14:22

Im thinking about getting my zx done, how much (if anyone knows) does it cost, I know its got the lucas CAV pump on it, but unsure which turbo is fitted (not actually looked). I would do it myself but am unsure about the process (have looked at guides). Am I correct thinking id need a boost guage? If so how much do these cost?

Chrispy · Post by **Chrispy** » 12 May 2005, 15:10

The Derv Doctor near Derby charges £120 plus vat for the 22-26 bhp upgrade. I'd rather take it in than do it myself to be honest. I'm not that handy when it comes to cherry poppers. Petrols? Fine...let me at em. But I'm still new to weasels. The guide off t'internet talks about spilling diesel everywhere and fitting a boost gauge and fiddling with screws and looking at smoke etc....scary!

capri_tzd · Post by **capri_tzd** » 12 May 2005, 15:37

Little help here... how much would a tune up/increase of boost cost on an XU7TE? What's involved in doing it myself? Also, would it cause the engine to be less reliable or increase the stress on the engine or turbo?

rossd · Post by **rossd** » 12 May 2005, 17:57

Tuning up an XUD7TE would be the same as the 1.9.

Chrispy · Post by **Chrispy** » 12 May 2005, 19:10

According to Gav @ The Derv Doctor it causes no extra stress on the engine....it simply takes up the slack in the manufacturers settings. As long as you take care of your engine (which should ideally be healthy to begin with) and don't drive like a t1t then you should be fine. Overboosting it past an extra 26 bhp will increase the risk of popping the head gasket though. It will probably also start to smoke like a swine too. Be reasonable about the gains and all will be well.
A mate of mine has chipped his Seat Toledo TDi and wound the boost right up on the black box. Now it does go well but it looks like the flaming bat-mobile as it goes down the road with plooms of smoke coming out.