The Holset he341 3.0L

[Shadow]

Any reason you wouldn't just vent to air, like almost all the hi hp cars are doing? Was one of the most beneficial changes I made, when I got rid of the hose going to my exhaust!

[Sundance 6g72]

whats wrong with a catch can? seems simple enough, especially if you use the oem pcv as vacume source while out of boost BUT pair it with the check valve the dsm guys use (put it inline with pcv valve)

[Ondonti]

Any reason you wouldn't just vent to air, like almost all the hi hp cars are doing? Was one of the most beneficial changes I made, when I got rid of the hose going to my exhaust!

I have found that my vents work amazing under boost, enough that my oil passages were not enough to return the oil to the crankcase. I had 1 vent to each valve cover. I had to route both valve covers into 1 valve, drill the heck out of the passages in the head, and then add a fitting on the top of the oil pan for my other valve. Then I had to make a big oil air seperator for that. It was a fun project. Never put mileage on it to really care about the down side that the one way valves don't actually work. While I have not bothered to prove it I feel like I have less crankcase pressure under boost then an open vent setup would provide. Even if I ran open vents I could have the problem of oil not draining from the heads so I will always drill out the returns in the head.

This is not a high power vehicle/project. I would probably be better served running standard setup with a catch can on the rear cover like I did when it had an ebay turbo in 2005 but I would like to work the bugs out to see if I would bother going with exhaust evac again. The downpipe that was originally made for my Dodge Spirit has the valves welded in and I put the downpipe back in this car. Might as well work out the bugs before giving up.

I looked at smog pumps but ended up giving up since I was never sure what to look for in the junkyard.

I am kinda excited to see what the low rpms are like with the stock cams. Wondering if that will give me the grunt I want for towing in 5th gear up hills. Speed limit is lower in Washington so I can't speed up (increase cruising rpms) to make more power.

[Sundance 6g72]

lol, what is with you and wanting to tow in 5th gear :P

[paduster]

Because he can lol

[Ondonti]

imaginary fuel savings. I was getting about 17mpg towing but WOT up mountain passes in 4th gear (CASCADES, Blue mountains, north Utah, south Washington). The Blue mountains in Oregon would be the #7 toughest tow in the United States according to Diesel Power. I actually finished off the 5 years bad headgasket on my 2nd tow trip ON Emmigrant/Deadman's Pass (Blue Mountains). Doh. Drove 170 more miles stopping every 10 to refill water. I busted a coolant pipe (pinhole) which was the actual cause of the headgasket giving up the ghost. Still, I was beating on the motor mercilessly. Its actually very fun to tow up hill! Especially passing semi's. overladen-ed pickups, etc etc.

I don't plan on making that kind of trip again though! 2nd time was to pick up my free Starlet. Luckily that car was lighter then the Duster or I might not have gotten close enough to home to AAA tow.

My view is that a couple pounds of boost will be enough to make 5th gear almost always usable on the freeway when towing. The scary thing about low rpms and boost is that its the knockiest part of your rev range. Megasquirt would help :P
My biggest problem towing was audible knocking so I would have to dial back the timing and also run higher grade fuel. I was running the timing very advanced at high altitude (17-18 base). You have a lot more power when you are not pinging away :P

[Force Fed Mopar]

5th gear towing is hard on tranny bearings...

[Sundance 6g72]

5th gear towing is dumb :P

your crazy!

anyways, do you still have plans for the 3.3/3.8 awd?

[Ondonti]

5th gear towing is hard on tranny bearings...

How hard? I guess driving in 4th gear seemed like beating on the motor (plus super noisy) and less efficient for mileage. Now, if you would say that the bearings would quickly be damaged, then 4th gear doesn't sound as bad. I don't think the motor actually cares one bit about being 3000+ for long periods. It does kill mileage and sound like I am racing constantly :P

[Reaper1]

Well, consider that you are putting a fairly large torque load all the way through the shafts to an overhanging 5th that is only supported on one side...yeah, I could see that being hard on the transmission.

You might actually realize a gain in economy by downshifting. You would be in a more optimal part of the torque curve, less load, more efficient. Of course this all depends on the engine and the tuning.

[RoadWarrior222]

Yeah, totally depends where on the BSFC map you end up, but it can potentially happen.

[Force Fed Mopar]

I would much rather turn 3k than lug 5th. I doubt you'll see much change in mileage either way, it'll take less throttle input to hold speed uphill in 4th. I have driven w/ a scanner hooked up and watched injector pulsewidth, and there was like .2 difference between 4th and 5th at the same steady speed.

[Ondonti]

My experience with 3.0's is that once you go into the 2700 rpms (and that is super approximate) range economy takes a large dive. I know Adam drives way up there in the RPM's and experiences poor mileage himself. I would rather cruise in the 2000-2400 range. Injector pulsewidth might be similar but when you turn 40% more revolutions its going to add up to poor mileage.

I don't think there is much actual power available in 5th gear at 2000 rpms to do anything worse then someone doing 5th gear pulls. A couple pounds of boost would increase the "hurt" being put on the trans. I never do 5th gear anything fast or know anyone who does on a regular basis. This would mean 5th gear pulls are a bad idea, but obviously that load doesn't last as long as a tow uphill. I really never needed much throttle on flat ground. Flat ground doesn't need power and I was already shifting to 4th for painful hills, once even 3rd. That was really beating on the motor

I wanted to get a fresh transmission eventually to put in the Spirit and I don't want to kill it.

[Force Fed Mopar]

On flat ground I wouldn't worry, or anytime that the engine isn't really working hard. If you have to go to half-throttle or more just to maintain speed, I would drop a gear.

[RoadWarrior222]

Me three, I drop gears early going up steep hills well loaded, the water pump runs faster, the motor runs cooler.

[Sundance 6g72]

Only time i give 5th hell is highway speeds and im passing someone.. otherwise i dont give it much of anything. Downshifting is cool when you have a 3inch monster exhaust

[Vigo]

I know Adam drives way up there in the RPM's and experiences poor mileage himself.

That's the truth. I'm expecting my minivan to get better mileage in spite of being bigger, heavier, and having bigger and heavier wheels and tires. The 3.0 doesnt need NEARLY as much rpm as it runs in 5th gear at 70-80 with my trans and tire height.

[Ondonti]

Me three, I drop gears early going up steep hills well loaded, the water pump runs faster, the motor runs cooler.

Well at least cooling has never been an issue. Only time cooling is a problem is stop and go. The fan gets behind and has to catch up. Always scares me. Never gets warm on the highway. 3.0's do have nice big radiators. Maybe if I make more power at the same RPM I will find out that I outrun my cooling capacity at that rpm.

With more power its going to be hard to judge half throttle. When I was at 4400 feet in 5th gear I was probably half throttle a LOT but that was with no boost and thin air. Down here it should be very different, but nothing is flat here

[Ondonti]

Installed new VSS a few days ago. Have not gone about finishing up the rocker and cam swap.
Turned out that installing the springs with that wrench was much easier then removing. I was planning on modifying the wrench but things went too well on my practice attempt.

[RoadWarrior222]

Well at least cooling has never been an issue. Only time cooling is a problem is stop and go. The fan gets behind and has to catch up. Always scares me. Never gets warm on the highway. 3.0's do have nice big radiators. Maybe if I make more power at the same RPM I will find out that I outrun my cooling capacity at that rpm.

BTW, anyone else notice that when you're sitting in traffic, idling, and running hot, after a few minutes, it seems like the computer cuts fuel or something... might only be after the fan has kicked in a couple of times... then the idle will change a tad and it can seem to hold it at about half gauge (Well at least on a moderately warm day) .... dunno if that was deliberate or only seemed like that because my IAC might have been a tad sticky and freed up with heat or something.... but it's done the same time 2 or 3 times when I've actually been paying attention.