Stu, what sort of mpg are you getting from that tuned diesel? Used while having fun, I mean?

Given that diesel is 6-8p a litre dearer than petrol, it still needs to have a much better mpg, or we are in the realms of silliness: a car that's NOT as fast as it's petrol equivalent and ends up costing as much, or more, to run, and cost more to buy in the first place?

Given that modern diesels are so good, how come we aren't seeing them on rallys or f1?

Just seen the post above, pretty much answers my first question.

What about the second?

 

i get 47 mpg on a motorway run and about 25-30 when i play with these

 

See earlier images.

Used as hard as average closed test track conditions at night allow, she tends to return about 26mpg ish. That includes top speed runs too.



It certainly does have much better MPG in all conditions than petrol and given its torque curve, what are you going to pit against it as an "Equivalent car"?

 

There one thing a diesel can't deliver no matter how much Torques or BHPs it has and thats the sound..... all part of the experience of owning a performance car imho.

ps I'm no Diesel hater btw, we run 3 diesels in our household as well as my Scoob!

One diesel engine that did surprise me by being remakably nippy (not a performance car by any stretch of the imagination) is the 1.4 and 1.6 psa units as found in small Peugeots/Citroens and Fords.

Stu - When you've mapped a big diesel like the 325 do you still get that sudden drop of power at the top end or do you get it to tail off much like a petrol car does??

 

thats one of the main things you miss from a petrol car,,,,they sound crap



see the vid i posted on the prev page,they do drop off slightly but not too bad to be fair

 

Agreed. Thats why I still have my 7200rpm V8 as well.


The tail off you feel is literally the RPM transition from peak torque to less torque and because some diesels have huge torque spikes it feels like you hit a wall when you approach the upper ranges of the turbochargers compressor and its mapping. That is one of the reasons for the new twin and triple turbo versions, to maintain that torque curve for as long as possible... basically two engines in one. A small turbo for low end grunt and a large turbo for high end grunt... plumbed in the best way possible, compound charged.
Without said technology, there is no getting away from the fact you make a jump from say 375ft to 175ftlb in around 700rpm.

Thankfully, petrol engines dont work the same which is one of the reasons they are such a joy to push hard. I doubt diesels will ever catch up with that due to their inherent burn speed limitation.

You can see the curves on mine here... (and in the chaps video on last page)




its as linear as pretty much any petrol engine, if not more-so, but these twin turbos are unique in that aspect currently. (The triples are even better of course...)
Sadly, the single turbo systems will always be a compromise if you want to still enjoy the low down grunt they are famous for.

 

Thats what irritates me about diesels hence my reference to running out of keys on a keyboard - as you put it hitting a wall.
We have an Audi A3 2.0TDi 170. Off the mark its like a scolded cat but you have to change gear quite quickly to keep up the momentum, which, imo, makes it a little dull to drive and always wanting more (if you get my drift) What I do like though is the acceleration from 40/50 to 70 when on a run, it flies then oh and the 50-60mpg

Sounds like hitting the wall can be reduced but not eliminated. You never know what technology is around the corner though........

Interesting how the compound turbos work though, something I didn't know

 

Yeah it didn't hang about Tickled me your mpg dropped of the scale though

Be interesting to see a similar vid but in 0-60 guise. As I said previous for doing what you did in the vid a diesel is great. Off the mark up to 60 they just frustrate me...... Are you auto or manual, could tell 100% on the vid. Assuming auto

 

If you look through my YouTube vids there is a 0-60 vid , the 335 d supposedly run 4.8 to 60mph with just a remap and quarter in 13 flat , never run the car up a strip or timed the 0-60 on mine

 

Could the future of petrol performance cars not be saved by having duel maps like ECUTEK racerom so you can have one mode for performance and one for mpg? It would seem to me that we can have it both ways it's just the focus is leaning towards diesels. I would rather have a performance petrol car than a equivalent diesel and if the costs could come down then all the better.

p.s diesels of old used to weigh a lot more, how do they compare these days?

 

Yeah, I know what you mean there. I guess its one of the reasons most the big power diesels are autos. LOL

The other thing that diesels dont quite have is that instant throttle responce that a petrol offers. Its certainly not far off now as they are improving the burn speed all the time with more and more injection pressure and a few map tweaks to the injection point can help no end (at the expense of trees and suchlike of course)

Ive ordered the VBox sport, so when it comes I will update this topic with some actual numbers.

 

I will see what I can do as im nipping to the nurburgring for an hour soon...

 

Chap on another forum I'm on did a run to 100 in his 335d, stupid fast.

 

Stu, I know diesels have come on in leaps and bounds over the last decade. Diesel car sales outstrip petrol ones and understandably there's more r and d in diesel over petrol. I like the elastic nature of a turbo diesel power delivery. I gain more satisfaction and make swifter progress by being in a higher gear and riding the torque curve. The economy is an added bonus.
The thing that concerns me is all the temperamental paraphernalia like the dpf, egr etc. things like high pressure pumps and injectors. If and when they go wrong they're an arm and a leg to replace. Any money saved via economy is wiped out in an instant.
The other thing that concerns me is that you have to at least one motorway journey a week to regenerate the dpf. Can this facet not be remedied? Other than removal.

 

My DPF died within 5k miles of me buying the car , now removed , makes a big difference

 

Just spotted this thread, so here's my daily runabout that gives the Scoob a rest during the week/rain.

Leon FR 2.0 TDi PD170
Full BTCC Bodykit
Stainless Twin-Exit ToyoSports Rear Box
BBS/RS4 Replica 8x19's
AMD DPF Delete
AMD Performance Remap !!!!

If anyone knows of a better remap solution, please let me know.
I'm thankful of the DPF delete as it stops all the annoying re-gen cycles, but I am not too happy with the Performance Remap for reasons below :

• It has deleted all but 2 OBDII sensor outputs (I think I am left with Calculated Load & Battery Voltage), therefore my Torque Pro App on the phone no longer works. AMD were not aware of this until I took it back for them to look at. They then confirmed this, and blamed it on the DPF delete changes.
• Throttle Response is ON/OFF when the turbo spools i.e very aggressive, so much so that due to it being only FWD (with quite crude traction control) you find yourself backing out of the throttle more often then not. However 2000rpm in 5th and just squeeze the throttle a touch and it flies...very impressive.
• Flat foot high rpm and then lift off the throttle, the engine runs on at full power for a few milliseconds more then you would like (can feel quite scary, most noticeable in 2nd).
• I have downloaded via MPPS the map, decoded with the help of PPDMAPS (some of the PPDMAPS map locations were wrong and/or with reversed parameters) and created a TunerPro XDF file to review the map. Although I am no expert in Diesel mapping I'm not 100% happy with what I've seen compared to the base map. Quite coarse changes and some strange goings on in the 'Driver Wish/Request' maps (probably accounts for the throttle response issues)
• The Map clearly has EGR deleted, although that wasn't requested. As I still have EGR fitted I'm not sure what the effect would be.

If anyone can help or know of a better alternative I would be interested to hear.

 

Sorry guys but what is DPF and what does it do?

 

Scott

I am told these guys offer great packages for Seat

http://www.revotechnik.com

 

Diesel Particulate Filter

It's purpose is to catch all the soot that on older diesels you see coming out of the back.
To prevent the Filter clogging up the car has to run a re-gen sequence every so often. This superheats the DPF to burn off the soot.

This to me has always seemed like a strange idea, as the soot still ends up in the environment you just can't see it.

Newer diesels (Peugeot I think) have some kind of chemical in a reservoir which is used to clean the DPF, although I am not 100% sure what it is or how it does it.

 

Diesel Particle filter ....pain in the **** if you just do short trips,it blocks,can cause all sorts of problems

 

They don't support the PD170 only the CR170.
From what I have learnt there were issues with the PD170 as the Siemens ECU can be quite temperamental. Also not every version was the same, so it may work on 1 car and then have trouble on another. Revo then pulled out of doing the PD170.

I think these issues are now cracked and understood, but only a few tuners offer PD170 options.

I'm hoping Stu will come along with a solution/answer

 

Diesel Pariculate Filter...it's a scam invented by governments....you don't see lorries and buses belching out black smoke I don't suppose?

Stu...same question: if diesels are so good, why are there no diesel rally cars and why don't F1 run diesels?

 

+1 and as I said before , if we was to start seeing duel maps on standard performance cars like ECUTEK racerom we could have one map for mpg and another for performance to flip the balance back to petrol turbos could we not.

 

Didn't Audi do very well in Le Mans with their diesel powered racer? I think slowly diesel is making it's way in to motor sport. However I doubt if it will oust petrol or other high octane fuels.
Apparently dpfs were implemented to improve air quality and to comply with EU requirements. I've heard even car manufacturers hate them as they're so problematic.

 

Yeah but Le Mans has a lot to do with fuel economy and the diesels probably stop less. Plus it will have a lot to do with marketing and not that a diesel car makes a good race car. It would have cost alot more to develop and been a ball ache for the engineers.

The guy's that run Mercedes f1 would probably like to have diesels engines in their cars for marketing reasons.

 

They also ran turbodiesels in the WTCC a few seasons back (did they ever have them in the BTCC; can't recall?) alongside the NA S2000 petrol engined cars...

...But now have switched to NGTC 1.6 turbo petrol, a la the BTCC.

As far as I'm aware, the NGTC petrol engine is now exclusively the only engine used in both series.

 

Smaller cc petrol turbo engines seem to be the new trend in performance cars. You just need to look at the m5/s4/a45 amg and so on.

 

Yes diesels were used in the BTCC, only one season iirc. Plato drove one of the two Seat Leons! I'm sure there was a privately run BMW at one point......

 

Aaah yes, I remember now.

Damn my aging 'memory'.

 

Indeed the emission control systems can be a pain if not looked after, and sometimes even that doesn't help. The systems, whilst under complex PID control, are actually quite simple. EGR, which is used to change the temperature of combustion can still be bypassed with no problem (when done properly, not just switched off in ecu) and so can DPF (used to remove exhaust soot) currently as the only MOT check is a "visual" so if dealt with carefully, it can be removed and we have done literally thousands through our network, if not into the tens of thousands. However, a little common sense will actually stop these systems failing. The DPF is of course the big one... It can be a headache, but 80% of problems are operator error. (But not usually operator fault, as the operator is not up to speed with what the vehicle needs) Indeed a DPF can easily last over 100'000 miles.

A brief rundown...

A DPF requires a regeneration event when back-pressure starts to get high. Because this superheated the exhaust system, there are safeguards built into the program to ensure this is done with plenty of cooling airflow around it and on a engine in good enough health to take it. The programming looks like this...

• Engine temps must be higher than 90c
• Engine must have been running for over 30 mins
• No faults must be present in the management system
• The vehicle must be doing a steady state of OVER 40mph
• The vehicle must have been in this state for a few minutes

If all the above conditions are met, it will initiate a DPF regeneration where injection events are added, and retarded, in order to superheat the exhaust system and catalyse the soot held within it. This process will continue until the back pressure sensor reports acceptable levels at which point the process ends and a timer is set to countdown to the next regeneration event.

Now, as any garage will tell you, the amount of vehicles that come into the workshop with ZERO management errors are very very few and far between. This means no regeneration will take place on said vehicles.

The most common one is glow plug errors, people assume because it starts ok they will ignore it, and ignorant garage staff back up this decision because they don't understand the complications this causes.

The next most common are thermostats leaking. It's VERY common on the BMW x30 and x35 motors. It only leaks off its seat slightly, but enough to drop coolant temps to around 86c. Again, ignorant garages, including main dealers, report this temperature as fine. It's not. Modern diesels almost exclusively run between 94 and 104 degrees and again, this small discrepancy stops regeneration events.

Another big one is oils... Did you know a DPF equipped car MUST run a special engine oil? Again, many bloody garages dont know (or care?) about this and continue to use the barrels they have in stock that give the most profit. Wrong oil clogs DPF's fast as they cant handle the soot that non DPF compatible oils cause!

Anyway, I'm waffling and I've a car to Dyno, but if anyone's interested to learn more, please just say so as I'm always happy to talk technical about cars, but fear it's boring you lot to tears so I will leave it right there for now.