MG ZS td fusion performance remap figures

[p_b82]

i know i am playing slightly late catch-up each time - but i am yet to ever see a single L-series in any guise get beyond 300K. whether it was designed for that is irrelevant - the early 'bomb proof' engines have bodywork rust in the (s)DI.

the vag units that melt pistons are all badly tuned. i know of many that are 200bhp+ that are running, and melted pitons are not a chancer trying his luck, they are some-one who has been told by a tuner that it can cope and it not being the case - eg bad mapping.

I was told that my turbo was good for the engine and was safe and reliable - i know differently.

I know I might sound harsh, but you have said some fairly 'strong' things here and yet you do not seem to have any evidence to back up your theory other than what you say. i have seen a lot of L-series both VP-30 and vp37 (and older mechanical pumps) in various levels of tune generate power in excess of what you say is the max the engine can deliver.

reliabilty is all relative once you start to exceed the desgined limis by more that 20% - teh 'safe' tune is significantly more than this with SDI injectors and a mild remap... which really takes a huge amount of stress out the pump itself....

timins solenoid failure is not linked to actual tuning - i am ware of a lot of 'OE spec' cars that have failed - in fact it is Dr Dave's biggest and most vociferous argument against a vp30 pumped car; and he knows his stuff!

[zsserbia]

I'm not saying you're not right, any derv out there can be tuned in variety of specs and provide a lot of joy on the road... My point is that driving habits should be a bit different once they are tuned in order to keep them safe from any malfunction - If oe spec engine fails when revved to high than why shouldn't a tuned one do so? Or if tuned engine delivers more power and torque at 3000 rpm then it used to deliver at over 4000 before it was tuned, then why not just utilizing this and not revving it's guts through the tailpipe? The main reliability issue of modern diesels is that they rev to high and still aren't up to the task except for some modern tdi's which are actually built for racing... Good thing they deliver so much power but they can't be bulletproof past the revs they were designed for decades ago. It's nice though that they can now provide satisfaction of overtaking some of the petrolheads on the motorway, but that's just about it. Those who punish them on the track, may be punished more severely on their way home. That's why no one can tune someone's derv and guarantee there won't be any side effects. Tuners are in many cases not to be blamed...

[p_b82]

That is a very fair point and i agree with you on that one....

I am in the position i am as the tuner that sold me a part did not do his sums correctly and a a result i have blown the HG twice.

the limiter on an OE car is or should be set to 4200 - that is the engine max load rating; mine however came out the factory with a much higher limiter than that - before i fiddle with it.

However with all that said i have toned the fuelling down from above 4200 rpm as i just dont need to use those revs.

It would be rare that a derv would deliver more torque at 3000 than it did at 4000, just due to the way we usually have little turbo's - but again i agree with the sentiments disels are just not designed for reving - unless you drop the compression ratio to counter the increased cylinder pressures that the lower time for the various cycles then require.

but as soon as you do that you loose the efficiency and make cold starting harder etc..

hoo hum.. tuning something on a low budget compared to what the motor manufacturers spent millions on is never going to be an exact science, nor an easy process

[zsserbia]

Glad you agree on my point and not glad about your hgf's. It seems that tuning a derv to it's optimum performance sometimes takes few bitter steps before you actually get there...

I wouldn't start a new thread on my derv but here's a couple of lines if you care to read as you may find out sometimes ignorance is blessed:

I purchased my zed based on thorough mechanical check, diagnostics test and a fair test drive down some curvy roads. Didn't know anything about it's history as original service book doesn't say anything past 30k miles (it was around 65 on the clock, but seemed original mileage)

Immediately it went for a full service including all belts because I didn't know if they' we been done already. Also put a new top ic hose. Specialist said the belts were changed some miles ago but cambelt was one tooth advanced and pump was advanced a couple as well. He suggested new ones should be fitted to factory setting as the engine seems to be in a great shape. So it was done.

Immediately I noticed a positive change in throttle response 3-4k rpm but negative change 1-2k which was annoying to me. Also the rev limit was 4200. Thought it may had a remap and now it's messed up with timing belts returned to oe specs.

Anyway thought I could give it a go with maf sensor cleaning and tightening the tps cable which had some free play.

When I removed the maf I noticed there was a lot of oil and dirt residue, obviously done by an to oily aftermarket air filter. I gave it a thorough clean and adjusted the tps cable.

I went for a ride slowly at first through a couple of traffic lights until i noticed the thing started idling so smooth it was almost unrealistic. After 20 miles or so i thought I'd push the throttle a bit. Found out it would take just a tiny touch at the pedal to get it going comparing to what it was before. Thought ok, it was just the tps cable so maybe I really try it out right now. Boy was I surprised! It pulled so smoothly through the entire rev band and sounded so beautiful and it was now reaching 5300k, maybe not usual for an oe spec. Also a showe in the back felt like a lot more than standard and not usual for a standard one. It was even accelerating better than some bmw 320d which really left the guy in shock but dunno if something was wrong with his car...

So, right now I drive it normally with just slight touch of the pedal and rarely revving it over 3k because I usually don't need to in everyday driving... How much horses are under the bonnet? I really don't care. Was it remapped? Couldn't care less... What do bmw derv owners think of it? I care even less than that. I know I love it and It makes me happy and I really think this is what matters in the end... Don't you think?

[peterzs]

Love my derv to bits, goes fast enough for me.

Have some SDi injectors sitting in a box, but all this talk of the fuel pump giving up, if too much power put through it, has put me off fitting them.

Have to wait and see if I get the "need for speed".

[p_b82]

teh SDI's will actually take slight amount of stress off the pump - if you ran it to the same power and torque levels as it was before... if you leave the mapping to suit the old ones and get the extra torque then there is no additional difference.

Maybe a little more heat in the pup mechanism - but nothing i would constitute as a risk....

it is amazing how getting a car to run 'right' is so much better than covering up past issues. i just have a slight MAF issue i think; bought a new one and it is a lttle flat sub 200k still - and the timing may have to be slightly adjusted again - it was off when the fuel pump timing solenoid was failing; and as a result was tweaked slightly: could be linked to the sub 2k hesitation.

[zsserbia]

Some say it really is important ''getting it to run right'' as a starting point before doing any mods, especially paying attention to maf sensor and get it sorted by either cleaning or fitting a new one or give it a try with mafam or combining it with a pierburg maf.

When you get satisfactory results and your derv shows some real muscle immediately from 1k then you should proceed with the planned mods and eventually a remap. Otherwise you may learn the hard way a properly running oe spec car is accelerating better than a 150+ bhp tuned one...

No matter how many horses are there if they are tripping each other on the way