Yes all sounds normal. It is extremely common for the boost level to drop with age.

Original pressure will be 17psi on the 25/45/zr/zs.

 

And that pressure drop is something related with the turbo "internals" or the "adjuster" that becomes loose?

I tested today with an Ibiza Tdi 90 stock for reference and it was almost side by side until 100mph or even a slightly slower. I think the 25 should be a little faster, no?

 

It is the actuator that degrades with age. Simply adjusting it back to standard may help. Most people will fit larger injectors and turn the boost to 19psi for a whole lot more power than standard.

Standard power is 103bhp on the 25 diesel.

 

I think for now, i prefer to restore his stock power instead of increasing it.

So, it should be an easy task to adjust the actuator? Maybe i´ll go to a car repair shop to correct that.

The fear i have, is they give so much pressure. Whats the best way to test the pressure then? Can be in neutral gear?

 

Car must be under load to get an accurate boost level. Typically at full throttle above 2500rpm in 3rd gear or higher.

To adjust you simply loosen the locknut on the actuator arm, and turn the knurled adjuster to shorten the rod slightly. Say 1/2 a turn at a time. Then go for a test drive to see what it is at. Then repeat until the desired boost level is achieved (careful it'll be very hot!).

 

Thanks, i´ll try that.

One more question, if not asking too much.

I have non oem turbo hoses.

The hoses were made on a workshop and i really didn´t like the job. Some "curves" aren´t "curves", are "angles".

I think i´ve seen those 17psi even after i fit these hoses but in the case of these hoses being the culprit to the lower boost, increasing the turbo to the stock 17psi, would put more effort on it than at 17psi but on stock hoses?

I mean, oem hoses = 17psi, non-oem hoses = 15psi (have to increase boost to 17psi). Even both cases the turbo being at 17psi, the turbo will be under more stress under the second option or it´s the same?

Sorry about my english, i hope you understand what i mean.

 

Boost pipe failures are common, but usually give much lower boost levels (if any boost at all!). Non standard boost pipes may be ok, but without seeing it is difficult to tell. If they are the standard size then it would be unusual to cause a problem.

Air pressure is measured at the turbo outlet (not at the engine), so as long as the pipes aren't leaking they are unlikely to give a performance problem.

Silicone versions of the pipes are available but not cheap.

 

Tomorrow i´ll post some pics of the hoses.

I doubt they are the culprit bue since they make some "agressive" angles, they could be limiting the air flow. But like i said, i think i´ve seen 17psi after that.

I´ll try to recovery that 1.5psi lost and i´m in hope those 1.5psi could make a nice difference

 

OP

to measure boost i recently bought this http://www.ebay.co.uk/itm/Torque-An...th-Interface-/380375128264?pt=UK_Diagnostic_Tools_Equipment&hash=item58901fd8c8

works with torque app on my android phone.

 

I have a scangauge that can read the boost too.. That device can search and delete error codes on yours?

Today i went to a car repair shop and they gave an adjustment. Two full turns gave about 0.7 to 1psi boost. Now i´ve seen 16.8psi one time. However it´s difficult to see on the scangauge probably because it won´t update the value very often. Sometimes it shows 15.x, other times to 16.x.. on peak. I´ve tested on 2nd, 3rd and 4th gear and the higher value was on 4th.

However i´m getting the feeling the car wakes up a little later and its a bit slugish until 3000rpm and then is better than before. This make any sense? Or maybe it´s because the car is now faster after 3000rpm, that gives me the sensation of being slower until that?

 

If you are getting full boost close to 2000rpm, and it holds all the way to 4000rpm above then the boost system is probably okay, with no boost leaks.

You could try unplugging the MAF sensor to see if that is causing low down power loss - if it is a pre 2004 car it won't turn the engine management light on. If it is 2004 or later with the later ECU mapping you would need a cheap OBD scanner to turn the light off.

With such a close call in the 'race', I wouldn't be too worried. The TDI might have been running a few bhp more than it is rated to, 90bhp is a marketing term close to the real number, or might have been a very good engine by luck, giving a few bhp more than most, the Ibizas might also be a bit lighter?

The 25TD (101PS / ZR TD 100)) is only rated as giving 99bhp on paper, so not a massive difference. VW TDIs of that age were also quite often more torquey low down in the rev range than the Rover L series, often with some smoke to go with it, I don't know if the TDI90 is like this though, but I went in a standard Ibiza TDI110 (about a 2004 model) and that felt very much quicker than a ZR TD101 low down in the rev range, more than the 10bhp peak power difference would suggest.

 

Yeah i got "constant" boost between 2000-4000rpm, so it shouldn´t be a leak problem.

However i´m surprised even with two full turns on the actuator i can´t get 17psi on peak. Its seems it has only increased about 0.5psi. Maybe it needs even more turns, don´t know.

Today i measured the car performance´s with an Android app and got this numbers on two different rounds:

0-60mph: 10.84 / 10.44
1/4 mile: 18.27 / 18.05

Official 0-60mph number is 9.9s (or it´s 10.5? I´ve seen this two number), so it seems a little worse it if´s 9.9s. Car hasn´t catalytic converter, it´s lowered and has 205/45R16 (stock had 175/65R14). Maybe the tires won´t help too, but MG ZR has stock 205 and official number is 9.9 too.

 

I only managed to get 0-60 in 8.6 seconds (GPS speed), with about 135bhp in my ZS (TD115 map + SDI injectors), the book time for the car as standard with 111bhp is 9.5 seconds. The 8.6 seconds was after many goes at getting a good 0-60 time, and I found that a 2nd gear start was the way to get the best time, hard on the clutch though. With the engine left as stock I very much doubt I would be able to get the book 0-60 time on mine.

If yours has the 9.9 seconds quoted 0-60 time, you're only half a second off. Depending on the manufacturer, the test drivers who set the quoted 0-60 times can be very abusive to the car to achieve those numbers.

I would unplug the MAF sensor to see if that gives more power low down, it has a big effect on power below 2500rpm, so a poor MAF won't effect the 0-60 much as you're revving it very high, but in normal driving the MAF will have an effect. The car won't rev above about 4000rpm with then MAF unplugged though, but at least you can see whether you get any more low down grunt with it unplugged. If this helps, then it's probably time to get a MAFAM, mine is on the original MAF + MAFAM, is 11 years old now and has 130,000 miles on it, runs with good power where it should do in the rev range. A clean of the MAF with brake cleaner has helped as well, I do thi9s about once every 6 months - spray only, don't touch the MAF with any brushes or cloths etc.

If yours is a MKII model then unplugging the MAF will put the EML light on, what year is yours? Certain very late MKI models will also throw the light on with the MAF unplugged I think, some of the cars made in 2004.

 

Mine is 2001 so no light

I´ve tried it before and it seems to rev a litter better on low rev but nothing special.

I´ve tried the clip mod too and this will increase low revs power, indeed, but above 2500/3000rpm it doesn´t seem to help so much.

I think my MAF is ok. I have other MAF, tried to change them and no notorious difference. On Scangauge, the MAF values seem´s ok too.

Another thing i´ve remember. I have a subwoofer + amp which weight about 20kg. According to my calculations, these few 20kg puts about 0.2s more at 0-60mph on a car with 100hp.

However, it´s weird the scangauge won´t show the 17psi.. The max i´ve seen was 16.8 once and on 4th. I´m afraid to give more turns to the actuator.. It´s "normal" two full turns only give about 0.5psi?

 

I've found the actuator to not be linear when adjusting it, so a couple of turns can make little difference, and then within one turn the boost changes a lot. If you had a good sized boost leak in any of the hoses I imagine you would not get over 10psi.

As far as I know, it is safe to screw the actuator in fully, you can't do any harm whenyou can measure the boost too to make sure it is not going too high.

Scangauges are nice aren't they

 

In that case i think i´ll will play a little more with the actuator

About the Scangauge, yes they are

They are great toy. However it´s a shame they can´t read and erase error codes at least on 25 Diesel MK1

 

Yes they are a great toy! I found a product on the Chinese trade site Ali express that will do the fault code reading and clearing, for £35 delivered to the UK. It needs a PC to display the data though and a bit of time to set up. It is a nice piece of kit.

 

Can you you give me the link please? It works on yours? Which year is yours?

 

Mine's a 2003 model, so most readers won't work. It should have the same compatibility issues as yours.

Here's a link to a thread where I talked about it: http://forums.mg-rover.org/showthread.php?p=6737625

It looks like the product is found at this link now: http://www.aliexpress.com/item/NEW-2013-2-R2-version-grey-TCS-SCANNER-freeshipping/708480079.html

 

Thanks for the link.

It seems the exact model a friend of mine has bought for 150€ here in Portugal

 

No problem, hope it works out. The Ali express site offers free shipping to the UK (government subsidy), I hope it is the same to Portugal too!

 

The 113hp ZR has the same turbo boost?

Today i drove a 113hp ZR and i saw 17.x on Scangauge. I have seen once 18.x and another time 19.x psi but that time it was with the paper clip mode, i don´t know if that mod increases the boost. Those 18 and 19 are weird. I though they have the same 17psi boost as the 100hp version.

It have a noticeable performance difference in low revs too.. I´ve heard about this difference in low revs between 100 and 113hp versions but i don´t know if its "normal" all this difference or not.

 

One more thing that sticks on my mind are the boost hoses..

I really didn´t like the job done and if it´s done know, i´ve had refused it. Here in the picture you can see why.. Whats your opinion. Can these "curves" limit a lot the air flow?

 

A considerable amount. Find some standard pipes, and throw those monstrosities in the bin!

 

What i suspected

Sometime ago, one of the OEM hoses splitted, then i order a custom hoses and they did this beautifull job.