CDTi Remap questions...

[MSS]

I would go with mcaffee's post #10. The standard 131 tune is perfectly adequate for the 75/ZT and provides quite spirited performance. For anyone desiring a bit more of of spirited performance, or have exceptional needs such as towing, then the 160 remap (treat the 160 as a name rather than statement of the exact power output) will provide that. The rest is all irrelevant IMHO.

If you want real spirited performance, forget the 75/ZT and buy a XF 3.0D or a Mercedes CLS 3.0D. Both these cars have abundance of character similar to the 75/ZT but with performance at an entirely different level. Our XF-S only produces 275BHP but the 600Nm of torque gives it exceptional perfomance plus sound that resembles a petrol engine when accelarating.

The 75 is the wrong type of car with which to have aspirations of burning rubber or discuss BHP numbers. It's more approriate to discuss the colour of ones Chinos and quality leather driving shoes.

[LowFlyingBus]

Originally Posted by MSS

I would go with mcaffee's post #10. The standard 131 tune is perfectly adequate for the 75/ZT and provides quite spirited performance. For anyone desiring a bit more of of spirited performance, or have exceptional needs such as towing, then the 160 remap (treat the 160 as a name rather than statement of the exact power output) will provide that. The rest is all irrelevant IMHO.

If you want real spirited performance, forget the 75/ZT and buy a XF 3.0D or a Mercedes CLS 3.0D. Both these cars have abundance of character similar to the 75/ZT but with performance at an entirely different level. Our XF-S only produces 275BHP but the 600Nm of torque gives it exceptional perfomance plus sound that resembles a petrol engine when accelarating.

The 75 is the wrong type of car with which to have aspirations of burning rubber or discuss BHP numbers. It's more approriate to discuss the colour of ones Chinos and quality leather driving shoes.

Ha! Thanks... useful input. Not jumping ship at the minute. Yes, the standard 131 tune ain't half bad really.

Don't tell anyone, but I spent a day or two running without the rear muffler - just dumping under the car. (after checking it wasn't going to melt anything).
It's not that loud as the cat and turbo are still in there, but pleasantly growly with a heavy right foot. Almost feels faster, but I think it's only psychological ( louder = faster ). And annoyingly agricultural sounding when just pootling.

I was considering getting someone to make up a muffler-less rear section, but decided hard against it - as you say, the 75 is no boy racer, it doesn't suit it, and that wasn't why I bought it.

Muffler carefully reinstalled. Ah... much better!

[CivilSteve]

So a few bits to clarify on all of this.

Typical results of the various tunes on these cars is below (some variation between cars)
115 ~ 100hp
135 ~ 120hp
t4 '160' ~ 130hp
generic tuner ~ 135-140hp
decent tuner ~140-145hp
TD04 upgrade ~ 175-180hp

The stock turbo does not make more than this. It's just too small. You might find the odd car that squeezes a little more here or there but the majority of the cars will max out at 145hp or so.

If you want more than you need a bigger turbo. TD04 will make 180hp without becoming a smoke machine. Over 200hp is possible but needs injectors & VNT turbo

Cars can produce the same power MAFless or not. It doesn't matter how the car is controlling the amount of fuel injected (provided it's done right)

Source: Specialist tuner for MGRovers who has seen it all in person. Not just based on internet info.

Originally Posted by Jamiewelch

It isn't (compared to a stock 131ps)Also, just so people know with regards to MPG, once remapped you can never trust the MPG readout on the car, it uses the stock injector timings and duration to calculate the MPG, once these have been altered on the ECU the IPK isn't aware and miscalculates.

This is only true if the remap has messed with the injector calibration info. The basic t4 doesn't do this. I don't do this. The only reasons to do this are being too lazy or unable to find the fuel limiters in the tune so you bend the calibrations to make it act like a tuning box.
If you do it properly, you get the power and keep the dash screen readings accurate.

[LowFlyingBus]

Originally Posted by CivilSteve

So a few bits to clarify on all of this.

Typical results of the various tunes on these cars is below (some variation between cars)
115 ~ 100hp
135 ~ 120hp
t4 '160' ~ 130hp
generic tuner ~ 135-140hp
decent tuner ~140-145hp
TD04 upgrade ~ 175-180hp

The stock turbo does not make more than this. It's just too small. You might find the odd car that squeezes a little more here or there but the majority of the cars will max out at 145hp or so.

If you want more than you need a bigger turbo. TD04 will make 180hp without becoming a smoke machine. Over 200hp is possible but needs injectors & VNT turbo

Cars can produce the same power MAFless or not. It doesn't matter how the car is controlling the amount of fuel injected (provided it's done right)

Source: Specialist tuner for MGRovers who has seen it all in person. Not just based on internet info.



This is only true if the remap has messed with the injector calibration info. The basic t4 doesn't do this. I don't do this. The only reasons to do this are being too lazy or unable to find the fuel limiters in the tune so you bend the calibrations to make it act like a tuning box.
If you do it properly, you get the power and keep the dash screen readings accurate.

Thanks Steve, that clears up a few bits I'd vaguely wondering about. Interesting stuff.

[LowFlyingBus]

Originally Posted by CivilSteve

So a few bits to clarify on all of this.


generic tuner ~ 135-140hp

Is this like a RonBox or whatever they're known as, or a remap? I'm generally wary of 'add on' stuff but do you have an opinion on those tuning boxes?

[Ray L]

Originally Posted by Jamiewelch

Going on a drive isn’t scientific. Engine temperature, gear changes, external temperature, fuel, fuel temperature, air quality, air temperature at intake, throttle usage, engine adaptations will have been reset during map, injectors could decide to perform better one day, higher voltage could result in higher fuel pressure etc. There is all sorts that effects mpg. Do the same trip multiple times and you’ll get different readings.

Re: my 20 thread. I calculate always on the annual mileage divided by the annual fuel consumed. This then covers all driving usage and conditions throughout the particular year.

I think this trumps any other calculations, if i'm wrong tell me a more accurate way.

[CivilSteve]

Originally Posted by LowFlyingBus

Is this like a RonBox or whatever they're known as, or a remap? I'm generally wary of 'add on' stuff but do you have an opinion on those tuning boxes?

Ronbox is probably one of the better boxes (as it actually does something) but is probably closer to the t4 tune in terms of results.

The issue with those boxes is they work by ramping up the rail pressure. Which is a problem if your high pressure pump was already a bit tired and the seals start to leak.

Generic tuner is more the "jack of all trades, master of none" types. they might do an alright job, but chances are they haven't spent any time actually developing and testing the results on a 75/ZT

[daveconnolly]

I had the 160 upgrade on my 03 75.had it done maybe 6 years ago by Brian up here in the northeast. It is a lot more enjoyable to drive .I do pull a trailer tent. Often down to dawlish and on things like long motorway hills you don't know it's on.but on normal driving around town and on a roads its like a different car .also sure its getting more mpgi would recommend it .but try to use one of the experts on here .

[BigRuss]

Originally Posted by MSS

I would go with mcaffee's post #10. The standard 131 tune is perfectly adequate for the 75/ZT and provides quite spirited performance. For anyone desiring a bit more of of spirited performance, or have exceptional needs such as towing, then the 160 remap (treat the 160 as a name rather than statement of the exact power output) will provide that. The rest is all irrelevant IMHO.

If you want real spirited performance, forget the 75/ZT and buy a XF 3.0D or a Mercedes CLS 3.0D. Both these cars have abundance of character similar to the 75/ZT but with performance at an entirely different level. Our XF-S only produces 275BHP but the 600Nm of torque gives it exceptional perfomance plus sound that resembles a petrol engine when accelarating.

The 75 is the wrong type of car with which to have aspirations of burning rubber or discuss BHP numbers. It's more approriate to discuss the colour of ones Chinos and quality leather driving shoes.

I totally concur with the above.

I've always said this, if you want a performance car go and buy one there's plenty about that won't break the bank in purchase nor running costs.

I've got a similar car to your XF with both very similar torque and power output.
Effortless performance and that very nice sound track when you push it just a little bit.

Yes there's plenty of pub talk about maps, mine's better than yours etc but the truth of the matter is any map that overall improves the driveability of the car without issue can be considered a good map.

It's not me saying that, it's the Dyno manufacturers themselves

I see the usual suspects are out and about on this thread, I'll say no more as it's all been gone through many times before

Russ

[macafee2]

Just a bit of deviation but connected to speed and torque
My son in law was let lose with his mates a Porsche Taycan.
His conclusion, the police will need better cars if they ever come up against one of these.

macafee2