Goal: modest power gains without loss of mileage or reliability. Recommendation?
Goal: modest power gains without loss of mileage or reliability. Recommendation?
Superturbodiesel.. what a great name. I'm looking for the expert opinion on ideas for making modest power increases with no sacrifices in MPG or reliability. This car is my daily commuter (70 mile/day, all freeway), so I'd like to keep it as reliable and efficient as it was.
Here's the current state of my 1983 617/W126, at 350k miles
The bottom end is still good, and I have a new head that's going on this weekend. I spend the last week getting everything hot tanked, blasted, and repainted. New seals all around, etc. Still need to rebuild the Turbo (yes, it needs it)
On order is a VDO pyrometer and boost gauge. I'm going to fit the pyrometer in this weekend after the head gets back on, and I'm machining the EGR blockoff plates after hours at work.
So.. what would you do?
Read the adjustment thread in the top section. Adjusting the pump doesn't affect cruising mpg.
Make sure the turbo is balanced after the rebuild! Adjust the ALDA and a few pump tweaks if you are up to it an Inter cooler is a good idea!
Seeing that you have a 300SD, the best cheap/easy modest improvement is to hack off the stock muffler and put a cherry bomb in its place. You'll end up getting boost a little sooner and a tad more boost everywhere else. It will also up your mileage just a tad. Just make sure you get an angled exhaust tip that prevents the exhaust from hitting the bumper or it will cause the plastic coating to warp.
Good tips.. the Inj. pump adjustment thread was a good read. I'll definitely do that.
For those who run an intercooler, what effect does it have on smoke, mileage, and power when running the stock pump elements?
And yeah.. I hacked out the muffler years ago.
I would avoid the intercooler unless you are pushing more turbo pressure. A vnt would do most of what you are asking with the least amount of risk (if psi is properly regulated). More anything else and you start looking at reliability.
(11-16-2010, 11:39 AM)ConnClark the best cheap/easy modest improvement is to hack off the stock muffler and put a cherry bomb in its place.That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
Quote:For those who run an intercooler, what effect does it have on smoke, mileage, and power when running the stock pump elements?None. An intercooler only allows higher power to be applied for longer by reducing combustion temperatures. It has no effect on power on its own.
(11-16-2010, 11:39 AM)ConnClark the best cheap/easy modest improvement is to hack off the stock muffler and put a cherry bomb in its place.That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
Quote:For those who run an intercooler, what effect does it have on smoke, mileage, and power when running the stock pump elements?None. An intercooler only allows higher power to be applied for longer by reducing combustion temperatures. It has no effect on power on its own.
(11-17-2010, 12:34 AM)ForcedInduction That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
(11-17-2010, 12:34 AM)ForcedInduction That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
I can't confirm the W124's muffler, but the OxCat adds significant restriction.
Besides, if most people's mufflers/resonators are like mine they're probably mostly plugged up into a straightpipe anyways.
(11-17-2010, 12:34 AM)ForcedInductionOn a 300SD the pipe is not straight through.(11-16-2010, 11:39 AM)ConnClark the best cheap/easy modest improvement is to hack off the stock muffler and put a cherry bomb in its place.That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
Quote:False statement.Quote:For those who run an intercooler, what effect does it have on smoke, mileage, and power when running the stock pump elements?None. An intercooler only allows higher power to be applied for longer by reducing combustion temperatures. It has no effect on power on its own.
(11-17-2010, 12:34 AM)ForcedInductionOn a 300SD the pipe is not straight through.(11-16-2010, 11:39 AM)ConnClark the best cheap/easy modest improvement is to hack off the stock muffler and put a cherry bomb in its place.That won't change power. They are both a free flowing straight through designs, the muffler works on expansion and the cherry bomb works on absorption.
Quote:False statement.Quote:For those who run an intercooler, what effect does it have on smoke, mileage, and power when running the stock pump elements?None. An intercooler only allows higher power to be applied for longer by reducing combustion temperatures. It has no effect on power on its own.
(11-17-2010, 03:32 PM)ConnClark False statement.Thats exactly what you have produced.
(11-17-2010, 03:32 PM)ConnClark False statement.Thats exactly what you have produced.
Part of the performance boost I got from hacking out the twin center resonators was that the car was now 40lbs lighter. Those things are huge.
No intercooler for me. If the inj pump adjustment doesn't produce considerable smoke without an intercooler, I'm not going to see a power gain from an intercooler as long as I'm in the stock pump.
But I will paint the parts red before reassembly. Because red adds 10 hp.
(11-17-2010, 06:37 PM)ForcedInductionEngine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.(11-17-2010, 03:32 PM)ConnClark False statement.Thats exactly what you have produced.
The difference before and after intercooler is so small as to be within the margin of error for any dyno and not felt on any Butt Dyno®.
Quote:G@s engines see an automatic increase in power due to the denser A/F ratio. These engines don't give a rats butt about anything but throttle position and boost pressure.Go Re-read the diesel Necronomicon and pay attention to section 2.5.2 and figure 2.43 . Note more power is made with a cooler intake manifold air temp with a lower manifold pressure than with a higher intake manifold pressure and higher intake manifold temp with the exact same fueling.
Quote:And if you follow that logic you'll see a reduction in power since the wastegate will still open at the same pressure but the ALDA will see less pressure due to the denser air and pressure drop across the IC core.
(11-17-2010, 06:37 PM)ForcedInductionEngine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.(11-17-2010, 03:32 PM)ConnClark False statement.Thats exactly what you have produced.
The difference before and after intercooler is so small as to be within the margin of error for any dyno and not felt on any Butt Dyno®.
Quote:G@s engines see an automatic increase in power due to the denser A/F ratio. These engines don't give a rats butt about anything but throttle position and boost pressure.Go Re-read the diesel Necronomicon and pay attention to section 2.5.2 and figure 2.43 . Note more power is made with a cooler intake manifold air temp with a lower manifold pressure than with a higher intake manifold pressure and higher intake manifold temp with the exact same fueling.
Quote:And if you follow that logic you'll see a reduction in power since the wastegate will still open at the same pressure but the ALDA will see less pressure due to the denser air and pressure drop across the IC core.
So, Whats the puropse of the Turbo...?
Its a way of getting More Oxygen into the cylinder during induction.
Now, it works by Compressing the air.--No secret there!
Compressing air makes it Hotter (The basic principle on which the diesel works, Again No Secret!)
Hot Air is Less Dense as its Hotter, and therefore expands, Therefore Per Cubic Foot will contain Less Oxygen than the Same Pressure air at a Lower Temperature. (Boyle's Law)
More Oxygen = Better Combustion, Or the possibility to make More power before hitting excess Smoke.
The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...
IF an Intercooler wasn't needed, You can be SURE Motor Manufacturers would NOT fit them to current Turbodiesel vehicles,--Cost would be a waste and therefore, Less Profit-- (I cannot think of ANY New Euro Turbodiesel Vehicles that have NOT got an Intercooler....)
--Things may be different in the States, where much larger engine capacities are the norm so have torque to spare anyway, but when you are looking at a Smaller Engines normally found in your average Eurocrapbox, an Intercooler allows a little More power to be obtained from the smaller engine, while allowing it to Pass the Current Stricter Emission Regulations...
A Charge Air Cooler, (Commonly called, Intercooler) also has the advantage to reduce Thermal Loadings on the engine...
A popular subject preached by many is monitoring the EGT's and keeping them below a prescribed limit--Well, Correct implementation of a Charge-Air Cooler will Lower EGT's....
QED.
oh thermodynamics! How about some water injection.
* cools intake air
* takes up space in the cylinder with liquid that can't be compressed thereby increasing compression ratio
* add meth and now you're adding more fuel too.
(11-17-2010, 07:14 PM)mcneil Part of the performance boost I got from hacking out the twin center resonators was that the car was now 40lbs lighter. Those things are huge.
(11-17-2010, 07:45 PM)ConnClark Engine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.Thanks for proving my point that the difference is too small to be measured on a large scale.
Quote:Assuming your up on the wastegate what you said will only apply if you take the pressure to control the wastegate after the turbo instead of at the intake manifold like your supposed too.Incorrect, the wastegate is never hosed to the manifold.
Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
(11-17-2010, 07:14 PM)mcneil Part of the performance boost I got from hacking out the twin center resonators was that the car was now 40lbs lighter. Those things are huge.
(11-17-2010, 07:45 PM)ConnClark Engine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.Thanks for proving my point that the difference is too small to be measured on a large scale.
Quote:Assuming your up on the wastegate what you said will only apply if you take the pressure to control the wastegate after the turbo instead of at the intake manifold like your supposed too.Incorrect, the wastegate is never hosed to the manifold.
Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
I live in the foot hills of the mountains and travel through the mountains quite frequently, so I will be installing an intercooler when the time comes.Some of our roads are 6% to 11% grades.How are they out west?I thought you guys had enough room to build long less winding roads with less steep grades?We got nothing but switch backs out here.One being Green River Cove Road.I actually get car sick at 5mph.LOL
(11-18-2010, 09:29 AM)ForcedInduction(11-17-2010, 07:45 PM)ConnClark Engine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.Thanks for proving my point that the difference is too small to be measured on a large scale.
Quote:Quote:Assuming your up on the wastegate what you said will only apply if you take the pressure to control the wastegate after the turbo instead of at the intake manifold like your supposed too.Incorrect, the wastegate is never hosed to the manifold.
Quote:Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
(11-18-2010, 09:29 AM)ForcedInduction(11-17-2010, 07:45 PM)ConnClark Engine dynos are far more accurate than a chassis dyno and show an improvement in power and fuel efficiency with a decrease in manifold temp.Thanks for proving my point that the difference is too small to be measured on a large scale.
Quote:Quote:Assuming your up on the wastegate what you said will only apply if you take the pressure to control the wastegate after the turbo instead of at the intake manifold like your supposed too.Incorrect, the wastegate is never hosed to the manifold.
Quote:Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
(11-18-2010, 11:58 AM)ConnClarkLets see.... I make 7 psi boost at 70mph. The temp gain would be about 50 degrees C. Plenty of heat there to dump.Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
(11-18-2010, 11:58 AM)ConnClarkLets see.... I make 7 psi boost at 70mph. The temp gain would be about 50 degrees C. Plenty of heat there to dump.Quote:The Intercooler was developed to allow a Higher Charge Air Density (And therefore More Oxygen) as the air is cooled Before its driven into the cylinder by the extra pressure derived by the Turbo...An intercooler has minimal to no effect on cruising economy, the boost is so low there is little heat to remove.
(11-18-2010, 11:58 AM)ConnClark Gains of 5% are not insignificant.5% would show up clearly and consistently on a chassis dyno.
Quote:OMG!!! You better go tell the the finns they did the green wagon all wrong.Um, they did do it wrong, thats why the blew up the engine.
Quote:While your at it you can tell several car manufacturers that they need to move their MAP sensors right after the turbo on all their digitally controlled wastegate models.Very different system.
Quote:Lets see.... I make 7 psi boost at 70mph.You have something dragging. Boost should be around 4-5psi at that speed on flat ground.
Quote:The temp gain would be about 50 degrees C. Plenty of heat there to dump.122*f with an optimistically efficient intercooler of 70% would only reduce that 85*, again, both are insignificant compared to combustion temperature.
Quote:IF an Intercooler wasn't needed, You can be SURE Motor Manufacturers would NOT fit them to current Turbodiesel vehiclesIntercoolers are needed on current models to safely produce the power density demanded by customers, as well as needed to meet emissions by reducing NOx.
Quote:Presumably if you had a VNT you wouldn't be making 7psi at 70.A VNT will make any pressure its set for. There is no "normal" pressure for them.
(11-18-2010, 11:58 AM)ConnClark Gains of 5% are not insignificant.5% would show up clearly and consistently on a chassis dyno.
Quote:OMG!!! You better go tell the the finns they did the green wagon all wrong.Um, they did do it wrong, thats why the blew up the engine.
Quote:While your at it you can tell several car manufacturers that they need to move their MAP sensors right after the turbo on all their digitally controlled wastegate models.Very different system.
Quote:Lets see.... I make 7 psi boost at 70mph.You have something dragging. Boost should be around 4-5psi at that speed on flat ground.
Quote:The temp gain would be about 50 degrees C. Plenty of heat there to dump.122*f with an optimistically efficient intercooler of 70% would only reduce that 85*, again, both are insignificant compared to combustion temperature.
Quote:IF an Intercooler wasn't needed, You can be SURE Motor Manufacturers would NOT fit them to current Turbodiesel vehiclesIntercoolers are needed on current models to safely produce the power density demanded by customers, as well as needed to meet emissions by reducing NOx.
Quote:Presumably if you had a VNT you wouldn't be making 7psi at 70.A VNT will make any pressure its set for. There is no "normal" pressure for them.
(11-19-2010, 09:22 AM)ForcedInduction If intercoolers are so important, why did Mercedes use non-intercooled diesels well into 90's when low-end car manufacturers (Ford, toyota, mazda, etc) were using intercoolers since the early 80's? Since MB is about the "high performance luxury" market, wouldn't it make sense for them to add $500 to the build cost to incorporate one (especially the W140 given that it was designed to accommodate an intercooler)? Wouldn't it make sense for them to have used one instead of screwing around with the expensive TrapOx and OxCat?
(11-19-2010, 09:22 AM)ForcedInduction If intercoolers are so important, why did Mercedes use non-intercooled diesels well into 90's when low-end car manufacturers (Ford, toyota, mazda, etc) were using intercoolers since the early 80's? Since MB is about the "high performance luxury" market, wouldn't it make sense for them to add $500 to the build cost to incorporate one (especially the W140 given that it was designed to accommodate an intercooler)? Wouldn't it make sense for them to have used one instead of screwing around with the expensive TrapOx and OxCat?
(11-19-2010, 04:22 PM)Alastair E the Makes you quoted generally had Sub 2.0L engines, so need every bit of help they can get.Incorrect. GM had a 3.8L and 4.3L turbocharged engines, Ford's were 2.2-2.5L, among others.
Quote:Mercedes generally used Larger engines that had more torque generally so didn't need (Yet) to resort to Charge-Air-Cooling.You have yet to suggest why they didn't use an intercooler, especially in meeting emissions requirements without expensive exhaust aftertreatment.
(11-19-2010, 04:22 PM)Alastair E the Makes you quoted generally had Sub 2.0L engines, so need every bit of help they can get.Incorrect. GM had a 3.8L and 4.3L turbocharged engines, Ford's were 2.2-2.5L, among others.
Quote:Mercedes generally used Larger engines that had more torque generally so didn't need (Yet) to resort to Charge-Air-Cooling.You have yet to suggest why they didn't use an intercooler, especially in meeting emissions requirements without expensive exhaust aftertreatment.