Age: 38 Zodiac: Joined: 17 Jan 2010 Posts: 84 Location: Malaysia
Posted: Fri Mar 05, 2010 13:37 Post subject:
It tried another half turn and seems like the boost compensator don't like boost drop, no power gain but slightly more smoky, I does feel better cruising...
Custom a manifold and a good wastegate isn't cheap... My friend recommend me to change a turbo if want to custom a manifold.... now everything is money money money
Age: 34 Zodiac: Joined: 25 Dec 2007 Posts: 2234 Location: Malaysia,Kuala Lumpur
Posted: Sat Mar 06, 2010 11:56 Post subject:
You want the car to go fast,this ain't cheap i tell u
Banana manifold cost about 1K a piece ..... if can custom manifold then u should take the opportunities to replace that tiny turbo to a larger one like TD06,IHI-RHF7,.etc ..... But when replace to a TD06,the flange need a little mod to fit only.....but when u need a IHI or other manafacture like Garett,you need to replace the entire flange to fit it,but this is not a big job if the manifold involved in a customising
Anyway i think your engine is just not enough fuel or the compression is not in a good state.....on my MK1,whenever i turn up the fueling it can get smokey but more power i can gain.....while yours is pretty abnormal
Age: 34 Zodiac: Joined: 25 Dec 2007 Posts: 2234 Location: Malaysia,Kuala Lumpur
Posted: Mon Mar 08, 2010 15:00 Post subject:
Thats a good news....i never seen one like that before
If then u can just mount another bigger turbo and a external wastegate without the expensive custom made manifold....but anyway Banana Manifold will give the biggest blow to the turbo to make them spun fast then the stock one ~
Age: 102 Zodiac: Joined: 20 Feb 2008 Posts: 1355 Location: New Zealand
Posted: Mon Mar 08, 2010 18:36 Post subject:
As Austin7 eluded to you won't get boost without more fue lor if you do get a little more boost without altering the fuel chances are the vehicle will go worse as the combustion process is too cold and less than ideal.
The only way to safley tune a diesel engine is to use a Pyrometer Exhaust gas temperature probe. And don't compare tuning diesel engines to petrol, they behave totally different. The 4G93T you talked about dropping boost at high rpm is very common with std turbo engines and is computer controlled to prevent them detonating.
Age: 38 Zodiac: Joined: 17 Jan 2010 Posts: 84 Location: Malaysia
Posted: Tue Mar 09, 2010 1:40 Post subject:
For a small turbo like that installed on a 2.8L engine, I believe its not the fuel problem but is the wastegate problem. How do you explain problem like half throttle will able to keep boost at the max but full throttle unable to keep the boost?
Banana manifold will blow my pocket faster , maybe I'll discuss with my friend who do stainless steel welding, show him my technical drawing and ask him to fabricate for me . It won't be that difficult cause there are no precision involved. The laser cut thick stainless steel flange will be the expensive part if not wrong. I believe it can be done below RM500
I haven't found any expert tuning diesel engine around my hometown, I'll be the first one to do these mod , maybe I'll do the mod end of this year.
During the time, I'll need to do more research and collect $$ for the mod.
For a small turbo like that installed on a 2.8L engine, I believe its not the fuel problem but is the wastegate problem. How do you explain problem like half throttle will able to keep boost at the max but full throttle unable to keep the boost?
Banana manifold will blow my pocket faster , maybe I'll discuss with my friend who do stainless steel welding, show him my technical drawing and ask him to fabricate for me . It won't be that difficult cause there are no precision involved. The laser cut thick stainless steel flange will be the expensive part if not wrong. I believe it can be done below RM500
I haven't found any expert tuning diesel engine around my hometown, I'll be the first one to do these mod , maybe I'll do the mod end of this year.
During the time, I'll need to do more research and collect $$ for the mod.
the turbo on the 2.8 is fine for high boost, but as i have said several times you need to get more diesel in, if you get max boost at 1/2 throttle then it fades away as you increase the throttle the diesel pump is not giving you enough fuel.
Age: 34 Zodiac: Joined: 25 Dec 2007 Posts: 2234 Location: Malaysia,Kuala Lumpur
Posted: Tue Mar 09, 2010 19:57 Post subject:
Iain,if u have been carefully see his previous post,you will find out that he state when he increase the fueling via the Fuel-Metering Screw,only got black smoke appear on exhaust but no power increase and the boost level still like before the fueling was tweaked
Age: 38 Zodiac: Joined: 17 Jan 2010 Posts: 84 Location: Malaysia
Posted: Wed Mar 10, 2010 10:09 Post subject:
half throttle doesn't give much acceleration speed than full throttle but the boost stay 0.95bar, if i go from half to full throttle, the boost stay at max for few second and start dropping to 0.8bar. From full throttle slowly to half throttle, the boost won't increase back to 0.95bar until I fully release the pedal and put to half throttle again.
in a moment of silly ness i got 1.5 bar out of my old 2.8 with no problem buy increasing the fueling and boost
disconnect the presure hose to the wastegate and drop it, turn the star wheel under the diaphram 180degrees to lower the spring tension on the diaphram and ensure that their are no leake in the presure hoses from the pump to the diaphram.
are you taking your boost reading while driving on a hill or at home in the garage
Age: 38 Zodiac: Joined: 17 Jan 2010 Posts: 84 Location: Malaysia
Posted: Wed Mar 10, 2010 10:28 Post subject:
hey, I'm not that newbie ok, of course playing around on the street with dangerous moves, playing with top speed... (so far didn't get caught by police )
But what makes you think increase fueling will increase the exhaust gas flow rate that much? all I know is after combustion the exhaust gas flow rate increase due to air temp increase and the air expand, but the mass flow rate of the air is about the same.
That's mean I have the get the exhaust gas hot enough to push the turbine?
ok basics, the turbo spins due to the speed of the exhaust gas's leaving the engine
on a diesel you need more and more fuel to create more and more exhaust gas to get the turbo spinning faster.
if i take my 2.8 pajero 4m40 that has the wastegate spaced by 3mm and turn the fueling down i can get 0.6 bar max , as i increase the fueling ( namely the boost compensator) the boost presure increases proportionaly as i increase the fuel level.
ie boost is directly proportional to the fueling level.
I have been tuning diesels for 20years and writain many ecu map when i worked designing diagnosict gear for Bosch Gmbh, trust me to get mega boost levels you need lost of fuel.
if you look at the videos of the dodge ram and large cummins engines you will see so much smoke that it looks like it has blown.... that is the level of diesel fueling you need to get silly boost levels.
if you look at the ecentric code below the diaphram you will find a plastic ring, get someone to take 25% of the ring away with lathe ( or stick the pin in a drill and hold it carefully against a file) this will allow the pin to drop further under boost and give even more fuel..
I have been tuning diesels for 20years and writain many ecu map when i worked designing diagnosict gear for Bosch Gmbh, trust me to get mega boost levels you need LOTS of fuel.
Age: 34 Zodiac: Joined: 25 Dec 2007 Posts: 2234 Location: Malaysia,Kuala Lumpur
Posted: Wed Mar 10, 2010 16:17 Post subject:
Agree with Iain.....i now understand why those Diesel monster that will overtake and smoke a Supra that easy is because they use alot of fuel to generate a high flow exhaust gas to push the turbin to thier limit.....
For Diesel,if you want to get power,don't bother about smoke,they will smoke like a chimney
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum You cannot attach files in this forum You cannot download files in this forum