"Boosting fuel rail delivery"
Discussion
iAlex said:
Someone has just told me they have something fitted to their X5 which boosts the fuel rail delivery to 35000 bar and thus giving no turbo lag at low end. Makes the throttle much more active?
This sounds to me like throwing a load of different words together to make a sentence!?
That would be someone not knowing or understanding what turbo lag is.This sounds to me like throwing a load of different words together to make a sentence!?
Try Googling the difference between boost threshold and turbo lag for more info.
iAlex said:
Someone has just told me they have something fitted to their X5 which boosts the fuel rail delivery to 35000 bar and thus giving no turbo lag at low end. Makes the throttle much more active?
This sounds to me like throwing a load of different words together to make a sentence!?
Your friend has just bought a 10p resistor from ebay for 20 or 30 quid, and will soon be spending several hundred pounds on one or more of the following itemsThis sounds to me like throwing a load of different words together to make a sentence!?
1. Catalytic Converter
2. Injectors
3. Turbo
4. EGR
5. etc.
mini me said:
Most I have worked with on our modern production diesels so far had been 1700 bar so sounds like your friend Is a little confused.
That's still c. 25000 psi - do these systems really run at those sort of pressures? I used to work with 200 bar/3000 psi air pressure and that was scary stuff!C8PPO said:
mini me said:
Most I have worked with on our modern production diesels so far had been 1700 bar so sounds like your friend Is a little confused.
That's still c. 25000 psi - do these systems really run at those sort of pressures? I used to work with 200 bar/3000 psi air pressure and that was scary stuff!C8PPO said:
mini me said:
Most I have worked with on our modern production diesels so far had been 1700 bar so sounds like your friend Is a little confused.
That's still c. 25000 psi - do these systems really run at those sort of pressures? I used to work with 200 bar/3000 psi air pressure and that was scary stuff!
C8PPO said:
mini me said:
Most I have worked with on our modern production diesels so far had been 1700 bar so sounds like your friend Is a little confused.
That's still c. 25000 psi - do these systems really run at those sort of pressures? I used to work with 200 bar/3000 psi air pressure and that was scary stuff!I suspect he means something like a DPT chip. http://www.dieselpowertuning.co.uk/
I have the economy one fitted to my X-Trail and they do work - very well. They're basically an engine map that is closer to optimum than OE, as they are designed with UK fuels in mind, whereas OE has to cope with the crap you get in the 3rd world.
I have the economy one fitted to my X-Trail and they do work - very well. They're basically an engine map that is closer to optimum than OE, as they are designed with UK fuels in mind, whereas OE has to cope with the crap you get in the 3rd world.
rhinochopig said:
I suspect he means something like a DPT chip. http://www.dieselpowertuning.co.uk/
I have the economy one fitted to my X-Trail and they do work - very well. They're basically an engine map that is closer to optimum than OE, as they are designed with UK fuels in mind, whereas OE has to cope with the crap you get in the 3rd world.
Had a look through that site and I can't quite work out what the system is. If I've missed the point and it's a fully mapped device (it's certainly priced accordingly) that alters the ECU I/O's and is specifically calibrated to each model then fair enough, but it looks like a semi-universal or simple modifier, and for some systems it looks like a basic fuel pressure or boost increase, either of which in isolation I would strongly advise against. I have the economy one fitted to my X-Trail and they do work - very well. They're basically an engine map that is closer to optimum than OE, as they are designed with UK fuels in mind, whereas OE has to cope with the crap you get in the 3rd world.
It would likely have a positive performance benefit, but I would not be confident of the longevity of some of the engine's components.
If you're going to do it, then a full remap is the only way IMHO
Edited by The Wookie on Monday 6th December 16:44
A common rail diesel engine's minimum AFR (and hence it's maximum torque output) is limited by 3 major controlling items:
1) the "smoke limit" (visable tailpipe black smoke)
2) non visable tailpipe particulates (max set by EU emissions limts)
3) Maximum peak cylinder pressure
What the "bodgers" do is to fool the ecu into thinking the fuel rail pressure is below the target (by sticking a resistive divider into the analogue signal line to the ecu), hence the ecu increases the fuel pumps delivery volume, and rail pressure increases. Now, for a given injection pulse duration, more fuel is delivered from each injection event.
This WILL make more torque but saying it is more "optimum" than the OEM's calibration is a bit silly!
If the OEM used this rich an AFR they wouldnt be able to sell the car at all (fail emissions test) and the increased cylinder pressures might cause durability issues, and they would get a poor reputation (already happened for some) for making "smokey" diesels!!
If you car has a DPF, the tailpipe black smoke issue is likely to be reduced, but i would like to bet that the DPF regeneration thresholds are now so wrong that you may even get a thermal runaway on the next regen event leading to the whole car catching fire...........
Basically, if going about 3% faster is everything to you, go ahead and F**K your car up a treat, for everyone else, i suggest just leaving it as std!! (or at the least get a proper remap!)
(it is also the case than on the latest engines, the closed loop combustion noise detection, that "listens" to the firing event to optimise fuel mass and timing, may just "optimise out" your new extra fuelling leaving you with no extra performance at all!!)
1) the "smoke limit" (visable tailpipe black smoke)
2) non visable tailpipe particulates (max set by EU emissions limts)
3) Maximum peak cylinder pressure
What the "bodgers" do is to fool the ecu into thinking the fuel rail pressure is below the target (by sticking a resistive divider into the analogue signal line to the ecu), hence the ecu increases the fuel pumps delivery volume, and rail pressure increases. Now, for a given injection pulse duration, more fuel is delivered from each injection event.
This WILL make more torque but saying it is more "optimum" than the OEM's calibration is a bit silly!
If the OEM used this rich an AFR they wouldnt be able to sell the car at all (fail emissions test) and the increased cylinder pressures might cause durability issues, and they would get a poor reputation (already happened for some) for making "smokey" diesels!!
If you car has a DPF, the tailpipe black smoke issue is likely to be reduced, but i would like to bet that the DPF regeneration thresholds are now so wrong that you may even get a thermal runaway on the next regen event leading to the whole car catching fire...........
Basically, if going about 3% faster is everything to you, go ahead and F**K your car up a treat, for everyone else, i suggest just leaving it as std!! (or at the least get a proper remap!)
(it is also the case than on the latest engines, the closed loop combustion noise detection, that "listens" to the firing event to optimise fuel mass and timing, may just "optimise out" your new extra fuelling leaving you with no extra performance at all!!)
iAlex said:
Apparently it boosts tickover pressure and reduces as turbo kicks in but 'can get a bit mad if set too high, so i just keep it at a comfort level'
Be sure to get back to us and let us know your "comfort level" when BMW hand you the bill for a new DPF/Turbo/HP pump/Injector set/ entire car....... ;-)Gassing Station | General Gassing [Archive] | Top of Page | What's New | My Stuff