| |||||||
| Register | BHP Garage | Classifieds | Team-BHP FAQ | Members List | Calendar | Search | Today's Posts | Mark Forums Read |
| Modifications & Accessories Engine swaps, forced induction, tyre upgrades, free flowing exhausts....its all in here! |
![]() |
| | Thread Tools |
| | #46 (permalink) |
| Distinguished - BHPian ![]() | I understood the point of preignition where the first time the injector is fired after BDC to reduce the diesel knock and make the engine run smoother but at the same time have also read that the injectors are fired upto 5 times per cycle depending on the fuelling requirements. This would mean that the pulse duration into the number of times the injectors are fired would be the total pulse duration on each cycle. This would limit the rpms achievable by the engine.Which is what brought me to the conclusion of using larger injectors with the correct ecu could help solve the problem of additional boost and rpms. This would logically be easier to do on a traditional turbo diesel where one could increase fuelling referenced to boost on the mechanical pump. Karthik it is about time you came on to this thread and tried to clear up any wrong info put up including by me so that we do not go off on a wrong tangent. Direct injection is a completely new thing for us to understand so easily, please help.
__________________ [FONT=Arial]I'm busy, and I stay busy, but I want to remain in control of things where I can stay in the city and go home at night to my kids.[/FONT] Last edited by Psycho : 24th April 2008 at 09:50. Reason: I hate opera mini as it trims my posts down and I need to rewrite them again. |
| | |
| | #47 (permalink) |
| BHPian Join Date: Mar 2006 Location: goa
Posts: 398
| That to is made for reduction of noise as just one perinjection did not get the noise down enough to compete with the petrols, the side effect of that is it looks like a big pulse width,the 5 preinjections are hardwared in the latest systems these do not vary according to the fuel requirement only the final injection pulse varies,that is if a system is designed with 3 preinjection pulses than it will give 3 pre injections from lowest to the highest rpm [through out the rev range] same is the case with 5 preinjection [the only excemption can be that if the engine temperature is high enough the preinjection can be reduced, but I am not sure about this].5 pre injectionssystems are seen only in really expansive cars [read merc,beemeers,etc] not the cheap common rails, swift,dicors,etc.these make do with put 3 injections. Also higher number of preinjections means that the cylinder remains hot for longer duration, this help the diesel burn more efficiently.As these are used when the piston is moving towards the TDC, and not at the TDC. |
| | |
| | #48 (permalink) |
| Senior - BHPian | ![]() I know you didnt mean it that way and it was just a comparative term but in no way was the DDiS cheap. Cost us all of 6 Lakhs !! Lol.
__________________ "I’m in no condition to drive…wait! I shouldn’t listen to myself, I’m drunk!" - Homer J. Simpson |
| | |
| | #49 (permalink) |
| BHPian Join Date: Mar 2006 Location: goa
Posts: 398
| The systems in these cars are a generation older than the once on the imports, the cars are not cheap in any sense and on even down on quality.Only thing is the ECMs and the injectors are cheaper than those on the cars with 5 preinjection Thats all, the systems on these cars are better than the one on the Laura [Pump Duse] VW is using the new common rails on their new models. |
| | |
| | #50 (permalink) |
| Distinguished - BHPian ![]() | Hey Dinar that's some good info there. Have you been working with CRDIs and if so would love hear more on this topic. It makes more sense now about the last pulse being the main pulse for the required fuelling. It gives us more opportunities on understanding on how to work around the ecus much better. Ps: so this does mean gradually increasing the fuel pressure on the rail while referencing it to boost would definitely help in incresing fuel flow and more power from the engine.
__________________ [FONT=Arial]I'm busy, and I stay busy, but I want to remain in control of things where I can stay in the city and go home at night to my kids.[/FONT] |
| | |
| | #52 (permalink) |
| BHPian Join Date: Mar 2006 Location: goa
Posts: 398
| Increasing the pressure on the rail helps in such a way that higher pressure, of diesel is injection atomizes the fuel better , and also the simple rule that higher pressure means more quantity of fuel [this is very small increase]. Diesels usually work well with higher pressure ,higher fuel pressure mean finer atomization [simple comparison between DI and IDI systems]and hence efficient burning. In common rail thou the pressure is constant through out the range, increasing the pressure by even few bars in the system will give big benefits. case with swift diesel with peggy back, only care has to be taken while doing this is the pressure should be kept in check, since the pumps in mechanical there is a chance of over pressure which can harm the pump,rail,injector and other plumbing. In mechanical systems one can increase the pressure but the benefits are not that much in small engine. In larger engine like the cummins with mechanical pump one can increase the bhp torque and also peak rpm of the engine by changing couple of spring on the pump. |
| | |
| | #53 (permalink) |
| BHPian Join Date: Sep 2005 Location: bangalore
Posts: 166
| Keshav - Preinjection is primarily a refinement factor and most lower end CRDI cars do away with 2 to 3 preinjections, completed in 8-12 deg of crank rotations at idle and merges into 1 or 2 injections as the revs go high. We are testing max flow capabilities of OE injectors so you can expect that data soon. Increasing fuel pressure to increase fuelling with ability to adjust with respect to boost, driving style, etc should be fun !! And dude, guys like you should be busy tuning and not worry about lower level details like these ![]() |
| | |
| | #54 (permalink) | |
| Distinguished - BHPian ![]() | Quote:
How do you expect someone to tune without knowing the basics of how an engine operates and what are the limits to where one can push it. I would at no point want to go beyond recommended capabilities of an engine. Simple things like max flow data is a boon in cases where we do not have data even available online. Look forward to more info on this .
__________________ [FONT=Arial]I'm busy, and I stay busy, but I want to remain in control of things where I can stay in the city and go home at night to my kids.[/FONT] | |
| | |
| | #55 (permalink) | |
| BHPian Join Date: Aug 2007 Location: New Delhi
Posts: 291
| Quote:
__________________ ABHIK <<<If everything seems under control, you're just not going fast enough>>> | |
| | |
| | #56 (permalink) |
| BHPian Join Date: Aug 2007 Location: New Delhi
Posts: 291
| So comming back to the topic ![]() Pete's 2nd and 3rd stage can be activated with the car still stock or the stages are in accordance with the state of mods on the car? In short is it driver prefference to activate these stages or state of mods on the car?
__________________ ABHIK <<<If everything seems under control, you're just not going fast enough>>> |
| | |
| | #57 (permalink) | |
| BHPian | Quote:
actually abhik- the topic is souping up the DDiS, not pete's box for the DDiS, but hey! its your thread ![]()
__________________ All's well that ends well- MONSOON D R I V E 08 (but why did it have to end?) | |
| | |
| | #59 (permalink) |
| BHPian Join Date: Mar 2006 Location: goa
Posts: 398
| The stage 2 will work fine with stock filters and every thing, but stage 3 requires universal filter as the system runs rich at top end, the car smoke due to this. there will be carbon deposits if it smokes too much... |
| | |
| | #60 (permalink) | |
| BHPian Join Date: Aug 2007 Location: New Delhi
Posts: 291
| Quote:
Sorry bro but was a little confused about the box and its requirements and was related to the topic so i thought i could push in a Pete's query aswell![]()
__________________ ABHIK <<<If everything seems under control, you're just not going fast enough>>> Last edited by abhik : 26th April 2008 at 22:49. | |
| | |
![]() |
| Thread Tools | |
Similar Threads | ||||
| Thread | Thread Starter | Forum | Replies | Last Post |
| Another Swift DDIS Recall | BUSA | The Indian Car Scene!! | 28 | 27th August 2007 17:31 |
| Why Swift DDiS and NOT Indigo DICOR ??? | abhibh | The Indian Car Scene!! | 30 | 23rd June 2007 22:07 |
| Tata Indica Turbo DLX vs. Maruti Swift DDiS LDi | rkirana | Hatchbacks | 8 | 17th February 2007 11:04 |
All times are GMT +5.5. The time now is 06:48.









.
Sorry bro but was a little confused about the box and its requirements and was related to the topic so i thought i could push in a Pete's query aswell
