B3.3T Jeep YJ
10-06-2006, 11:04 AM
#46
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Thanks for the kind words.
That project is really coming along for you--you've got a great product to show for all your hard work
That intercooler looks like it grew there, too. JMO, but you'd be miles ahead with a front mount intercooler, though I'm not sure what your space constraints are. I see you're quickly learning how addictive the power and economy of a diesel is. Even with the pump fully maxed, my mileage has stayed the same or gotten better, overall. Please keep us updated on your progress--this is a fascinating project!
That intercooler looks like it grew there, too. JMO, but you'd be miles ahead with a front mount intercooler, though I'm not sure what your space constraints are. I see you're quickly learning how addictive the power and economy of a diesel is. Even with the pump fully maxed, my mileage has stayed the same or gotten better, overall. Please keep us updated on your progress--this is a fascinating project!
10-16-2006, 08:37 AM
#48
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Update.
I've tinkered with the max rpm governor screw and turned the fueling screw another 1/4 turn. Max EGT's are still below 1100 F and exhaust is clear (except during shifts when my friend reports the engine releases a puff of smoke -- much like my VW does). The engine originally started cutting off fuel at 2600 rpm but it's now been raised to ~2900 rpm. This should still be quite safe as the spec sheet shows the destructive harmonics starting at 3250 rpm. This little bit of extra rpm makes the jeep more driveable in certain situations (like merging onto the interstate).
It's been really cold and windy here as of late. Morning commutes have often been below freezing and the engine takes awhile to warm up. Think I'll have to rig up some type of front cover. Last fill up only averaged 28 mpg. Thinking this is due to the cold/wind and possibly changing mix of diesel fuel.
Other things I've done in the past couple months to "dieselize" the jeep are: replaced steel fuel tank with a plastic one to minimize condensation. Added a Stanadyne Fuel Manager with 100W fuel heater and 5um fuel filter/H2O seperator elements inline with the factor fuel filter/H2O seperator. Added an electric lift pump and an inline mechanical pressure gauge. Replaced the trouble prone vacuum actuated front axle engagement motor with a mechanical Posi-Lok system.
This will probably be the last update for awhile as I'm about done tinkering. I appreciate all the kind words and helpful suggestions offered through this thread. Peace.
I've tinkered with the max rpm governor screw and turned the fueling screw another 1/4 turn. Max EGT's are still below 1100 F and exhaust is clear (except during shifts when my friend reports the engine releases a puff of smoke -- much like my VW does). The engine originally started cutting off fuel at 2600 rpm but it's now been raised to ~2900 rpm. This should still be quite safe as the spec sheet shows the destructive harmonics starting at 3250 rpm. This little bit of extra rpm makes the jeep more driveable in certain situations (like merging onto the interstate).
It's been really cold and windy here as of late. Morning commutes have often been below freezing and the engine takes awhile to warm up. Think I'll have to rig up some type of front cover. Last fill up only averaged 28 mpg. Thinking this is due to the cold/wind and possibly changing mix of diesel fuel.
Other things I've done in the past couple months to "dieselize" the jeep are: replaced steel fuel tank with a plastic one to minimize condensation. Added a Stanadyne Fuel Manager with 100W fuel heater and 5um fuel filter/H2O seperator elements inline with the factor fuel filter/H2O seperator. Added an electric lift pump and an inline mechanical pressure gauge. Replaced the trouble prone vacuum actuated front axle engagement motor with a mechanical Posi-Lok system.
This will probably be the last update for awhile as I'm about done tinkering. I appreciate all the kind words and helpful suggestions offered through this thread. Peace.
10-23-2006, 09:10 AM
#49
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Update.
Was looking at ways to try to estimate what the hp/torque of the B3.3T is doing in the jeep. Was looking into G-Tech type devices that measure acceleration and how that data can be used to estimate hp/torque. Turns out my boss has an older 3 axis accelerometer (Valentine g-analyst) from his days of racing and he was kind enough to let me borrow it. I spent some time this weekend measuring the straight line acceleration of the jeep. I've averaged multiple runs over the same stretch of road (going both ways to account for any elevation change) and did some number crunching.
Measurements were made at 45 F and 850 ft elevation in 2nd gear (2.33 gear ratio). My axle ratio is 3.07, my wheels are 30x9.50, but when I measure the radius from the ground to center of the axle the radius is 14.7. Assuming under load the tire might squat a bit more I'm using 14.5 inch for the tire radius. For total weight I'm using 3500 pounds. I've measured the jeep at the scales at the dump and they claim the weight without me in the jeep is 3500. I think that's too high. From what I've gathered a 4 cyl manual tran jeep YJ with a soft top is 2940 lbs. I'm assuming the diesel engine, with a hard top, 5 bigger tires, steel rims, and from spring helpers, and my 190 pounds puts me about 3500-3600 lbs. I'm using 3500 to be conservative. Using a drivetrain efficiency of 85% (seems typical for rear wheel drive vehicles).
From the acceleration numbers you can calculate force if you know the mass (my assumption of 3500 lbs). From this you can back calculate all the way to the flywheel. Also from the acceleration numbers you can calculate velocity (if you know the initial velocity of the run, which I did from my speedometer). If you know velocity and your gear/axle ratio and tire radius you can calculate rpm. If you know rpm you can calculate horsepower from the flywheel torque data. As a check on the accelerometer data I used this to calculate velocity and compared it to the speedometers readings and it matches my observed speedometer readings. This gives credibility to the accuracy of the meter. I have not corrected for temp, elevation, or wind resistance.
I've added a picture of the calculated, estimated horsepower and torque numbers. Looks like I'm in the neighborhood of 340 ft-lbs and 139 hp at the flywheel!
I've also noticed from the last couple fueling adjustments that the waste gate is becoming over powered. When I was below a 1/2 turn on the fuel screw the max boost was ~12.5. Now that I'm at a full turn the boost goes as high as 14 psi. This higher boost may be why my max EGT's haven't really increased over the last 1/4 turn adjustments?
Was looking at ways to try to estimate what the hp/torque of the B3.3T is doing in the jeep. Was looking into G-Tech type devices that measure acceleration and how that data can be used to estimate hp/torque. Turns out my boss has an older 3 axis accelerometer (Valentine g-analyst) from his days of racing and he was kind enough to let me borrow it. I spent some time this weekend measuring the straight line acceleration of the jeep. I've averaged multiple runs over the same stretch of road (going both ways to account for any elevation change) and did some number crunching.
Measurements were made at 45 F and 850 ft elevation in 2nd gear (2.33 gear ratio). My axle ratio is 3.07, my wheels are 30x9.50, but when I measure the radius from the ground to center of the axle the radius is 14.7. Assuming under load the tire might squat a bit more I'm using 14.5 inch for the tire radius. For total weight I'm using 3500 pounds. I've measured the jeep at the scales at the dump and they claim the weight without me in the jeep is 3500. I think that's too high. From what I've gathered a 4 cyl manual tran jeep YJ with a soft top is 2940 lbs. I'm assuming the diesel engine, with a hard top, 5 bigger tires, steel rims, and from spring helpers, and my 190 pounds puts me about 3500-3600 lbs. I'm using 3500 to be conservative. Using a drivetrain efficiency of 85% (seems typical for rear wheel drive vehicles).
From the acceleration numbers you can calculate force if you know the mass (my assumption of 3500 lbs). From this you can back calculate all the way to the flywheel. Also from the acceleration numbers you can calculate velocity (if you know the initial velocity of the run, which I did from my speedometer). If you know velocity and your gear/axle ratio and tire radius you can calculate rpm. If you know rpm you can calculate horsepower from the flywheel torque data. As a check on the accelerometer data I used this to calculate velocity and compared it to the speedometers readings and it matches my observed speedometer readings. This gives credibility to the accuracy of the meter. I have not corrected for temp, elevation, or wind resistance.
I've added a picture of the calculated, estimated horsepower and torque numbers. Looks like I'm in the neighborhood of 340 ft-lbs and 139 hp at the flywheel!
I've also noticed from the last couple fueling adjustments that the waste gate is becoming over powered. When I was below a 1/2 turn on the fuel screw the max boost was ~12.5. Now that I'm at a full turn the boost goes as high as 14 psi. This higher boost may be why my max EGT's haven't really increased over the last 1/4 turn adjustments?
10-23-2006, 09:42 AM
#50
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Do you know what psi your wastegate is set to open at?
Just because you only see 14psi doesn't mean that the wastegate is being overpowered. Before you probably only had enough fuel for 12psi and now you have enough for 14psi, but the wastegate may not open untill 16psi. You can only make so much boost for the given amount of fuel.
Just because you only see 14psi doesn't mean that the wastegate is being overpowered. Before you probably only had enough fuel for 12psi and now you have enough for 14psi, but the wastegate may not open untill 16psi. You can only make so much boost for the given amount of fuel.
10-23-2006, 09:59 AM
#51
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Do you know what psi your wastegate is set to open at?
Just because you only see 14psi doesn't mean that the wastegate is being overpowered. Before you probably only had enough fuel for 12psi and now you have enough for 14psi, but the wastegate may not open untill 16psi. You can only make so much boost for the given amount of fuel.
Just because you only see 14psi doesn't mean that the wastegate is being overpowered. Before you probably only had enough fuel for 12psi and now you have enough for 14psi, but the wastegate may not open untill 16psi. You can only make so much boost for the given amount of fuel.
I'm assuming since my EGT's are still really good (~1100 F max) that the turbo is still operating in an efficient manner at 14 psi. Is this a correct assumption?
10-23-2006, 10:58 AM
#52
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I would have to agree with that assumption. I would say that at 1100 (pre turbo?) your probably getting pretty close to the max the turbo can produce. And those are really some impressive numbers!!
10-23-2006, 11:09 AM
#53
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Pre turbo numbers (there's a pic in the yahoo link that shows the probe location).
10-30-2006, 02:10 PM
#54
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On the plus side, using the correct unit conversions puts my friends WRX STI calculated hp/tq from the accelerometer at 300 ft-lbs (one data point peaks at 305) and 314 hp (he has a cat back exhaust which is supposed to gain ~5 hp). This was using 15% drivetrain loss. These numbers are very accurate compared to actual dyno runs.
Using the corrected spreadsheet and actual measured weights for my jeep (from the gravel pit ~ 3850 lbs with me in the jeep and 3/4 tank of fuel) and 20% drivetrain loss (with bigger/wider, lugged, mud tires from what I've read 20% is closer than the 15% estimate I was using) puts me at 273 ft-lbs and 117 hp.
Sorry for the mistake in the original calculations.
10-30-2006, 03:19 PM
#56
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Thread Starter
At idle it's a bit rough and is at an oscillation frequency with something in the jeep when it's cold which causes a rattle that I don't like, but if I move the rpm's above 1000 it smooths out. I've fiddled with my homemade motor mounts several times and made small, incremental improvements in the vibration at idle, but it's never going to be as smooth as my VW or my inline 6 Cummins.
Now that temps are getting colder (well, today it's 70 but it's been in the 30's and 40's most of the last month) I can say that the grid heater is a good option to have. Starting the jeep after sitting outside all day at temps below 40 results in a 5-10 second black exhaust show. Using the grid heater results in brief puff of smoke. Will be interesting to see how it does with real cold weather that will soon be upon us.
With the cold temps and co-introduction of winter/ULSD fuel blended with my normal biodiesel concentrations (40-60% at these temps) has caused my fuel mileage to drop to ~27.5 mpg for back and forth to work trips (last three tanks 27.5, 27.5, 27.6 mpg).
12-01-2006, 09:14 AM
#57
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Update.
Motor mounts:
Switched my home made rubber isolator between the engine and frame mount to one of these Dodge V8 isolators (http://www.motormountz.com/motor-mou...&submit=Search)
This type happens to fit nicely with what I was already doing, was dirt cheap, and was designed to handle similar engine weights. Significant improvement in vibration at idle and is extremely smooth above 1700 rpm.
Fueling screw:
Turned the fueling screw up some more. Went another 1/2 turn but had to bring it back 1/4 due to the engine rpm's "hanging". When I would accelerate and push the clutch in to shift the engine's rpm's would "float" and take too long to drift back down for the next shift point. Backing it off eliminated the problem.
Cold starts:
Yesterday was the coldest day of the year so far. The jeep sat outside at work all day. The morning temps were ~13 F and only warmed to about 20 F by mid afternoon when I left. Ran the grid heater for about 5-6 seconds then started the jeep. Lots of white/gray smoke for about 5-6 seconds. Think I'll increase the grid heater cycle to about 10 seconds and see how that works. Right now I'm triggering the relay for the grid heater with a simple "push button" switch in the cab. This seems to be working well. I'm using a single battery at the moment that is the same one I use in my wife's VW Jetta TDI. It seems to be doing well with running the grid heater and turning over the engine.
Fuel Mileage:
The station where I'm fueling has had a 70/30 blend for the past month. Back and forth to work (~16 mls one way, mostly county rds and freeway) fuel economy is staying ~ 27-28 mpg.
Motor mounts:
Switched my home made rubber isolator between the engine and frame mount to one of these Dodge V8 isolators (http://www.motormountz.com/motor-mou...&submit=Search)
This type happens to fit nicely with what I was already doing, was dirt cheap, and was designed to handle similar engine weights. Significant improvement in vibration at idle and is extremely smooth above 1700 rpm.
Fueling screw:
Turned the fueling screw up some more. Went another 1/2 turn but had to bring it back 1/4 due to the engine rpm's "hanging". When I would accelerate and push the clutch in to shift the engine's rpm's would "float" and take too long to drift back down for the next shift point. Backing it off eliminated the problem.
Cold starts:
Yesterday was the coldest day of the year so far. The jeep sat outside at work all day. The morning temps were ~13 F and only warmed to about 20 F by mid afternoon when I left. Ran the grid heater for about 5-6 seconds then started the jeep. Lots of white/gray smoke for about 5-6 seconds. Think I'll increase the grid heater cycle to about 10 seconds and see how that works. Right now I'm triggering the relay for the grid heater with a simple "push button" switch in the cab. This seems to be working well. I'm using a single battery at the moment that is the same one I use in my wife's VW Jetta TDI. It seems to be doing well with running the grid heater and turning over the engine.
Fuel Mileage:
The station where I'm fueling has had a 70/30 blend for the past month. Back and forth to work (~16 mls one way, mostly county rds and freeway) fuel economy is staying ~ 27-28 mpg.
12-01-2006, 10:37 AM
#58
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ive actually been inspired by your post (long ago) and ive been in the process of putting a b3.3T i ordered into a 1991 Cherokee...
i will post pics...
i will post pics...
12-01-2006, 10:57 AM
#59
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Excellent! Looking forward to the pictures.
I almost went that route due to the difficulty in finding a descent YJ at a non outrageous price. The XJ's are more affordable and would produce a more practicle conversion. Also with their better aerodynamics you should get better fuel economy.
So how far along are you? What are you using for adapters? Do you have the AX-15 tranny? Are you doing a body lift for the hood clearance or doing a scoop?
I almost went that route due to the difficulty in finding a descent YJ at a non outrageous price. The XJ's are more affordable and would produce a more practicle conversion. Also with their better aerodynamics you should get better fuel economy.
So how far along are you? What are you using for adapters? Do you have the AX-15 tranny? Are you doing a body lift for the hood clearance or doing a scoop?
12-01-2006, 11:39 AM
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Excellent! Looking forward to the pictures.
I almost went that route due to the difficulty in finding a descent YJ at a non outrageous price. The XJ's are more affordable and would produce a more practicle conversion. Also with their better aerodynamics you should get better fuel economy.
So how far along are you? What are you using for adapters? Do you have the AX-15 tranny? Are you doing a body lift for the hood clearance or doing a scoop?
I almost went that route due to the difficulty in finding a descent YJ at a non outrageous price. The XJ's are more affordable and would produce a more practicle conversion. Also with their better aerodynamics you should get better fuel economy.
So how far along are you? What are you using for adapters? Do you have the AX-15 tranny? Are you doing a body lift for the hood clearance or doing a scoop?
You can't do a body lift on a cherokee as its a unibody. So I guess you'd have to do a scoop.
I've got a cherokee that needs a new engine so keep us informed as to how it fits!!
Thanks, Aaron