VWDiesel.net The IDI, TDI, and mTDI source.
Engine Specific Info and Questions => IDI Engine => Topic started by: zyewdall on December 20, 2005, 01:00:46 pm
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Wow! What a difference replacing the intake snorkel makes. We did that on the '81 rabbit, and ran 3" aluminum dryer vent hose from the aircleaner box up to a hole in the blank section between the radiator and the starboard headlight. Noticeable difference. Still not like the Jetta TDI :lol: But it'll climb one hill on the highway at 55 now, instead of 45 before.
Has anyone else done this with a 1.6NA? Did you notice similar results? Thanks to Northboundtrain for suggesting this.
I'll get photos and post them this weekend.
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yeah but mine got smashed in the crash, and i havent had time to make a new one, i think i remember noticing like a 2 mpg difference for the better as well
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I made a SWEET design with mine, i took off all the tubing all together except the little like 1" diameter tube and drilled MANY 1/2" holes all through out the front half of the air box. Made a HUGE diffrence and sounded SO sweet!
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i would post pics of my old setup if i knew how, it was a rain gutter adapter that i cut out a hole big enough for and then used 3 inch PVC to go to the grill for a cold/ram air intake
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If you want to send me the picture I'll post it.
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Yes, pics please - I'd like to do something like this to my 1.5 -
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Here is mine :
(http://i17.photobucket.com/albums/b64/Mathdiesel/Clarence052.jpg)
(http://i17.photobucket.com/albums/b64/Mathdiesel/Clarence053.jpg)
Made from 3" PVC and about 4" PVC for the log part
The log bolts to the manifold with a steel flange. Steel tube goes from the flange trough the manifold.
I need to built some kind of heat-shield for it, but i got the whole winter to think about it since its off for the season.
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Here's the assembly on the '81 rabbit.
(http://images5.theimagehosting.com/SnorkelWillsRabbit.jpg) (http://www.theimagehosting.com)
I'll post one of the '90 GTI too when I get it done. I just started the engine for the first time since buying it 9 months ago today. Runs good. :D Now I just have to wire stuff to the actual ignition switch instead of hotwiring everything. :?
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In my experience, the aluminum dryer duct won't stand the vibration.
Andrew
Yeah, for long term I suspect you are right. Making one out of PVC or ABS drainpipe would probably be more durable.
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If you say that the car runs better with that air intake, i'll do that in my Rabbit 1.6D 81'.
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zyewdall's intake can be duplicated with PVC I sent vwmike my pics to post, all you have to do is get the rain gutter adapter to 3 inch PVC and cut out the square into the plastic air cover and JB weld it, then sand it smooth, use some body filler if necessary and then paint it black and it looks like it is supposed to be there. then plumb the spay painted pvc from there to the front grill
if you want to make a funnel for it then use some floor vent things that are a rectangle and have a 3 inch inside diameter hole to give you a nice ram air colector in the grill
and yes it makes a difference, as far as power goes I really couldnt feel a difference, but i noticed it with milage gain
later
Justin
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I sent you the links back to the pictures the other day. Here they are resized though:
(http://www.tdtuning.com/pictures/S4200015-1.JPG)
(http://www.tdtuning.com/pictures/S4200017-1.JPG)
(http://www.tdtuning.com/pictures/S4200019-1.JPG)
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ages ago, I rigged up a spare interior fan (rabbit type) to blow into the n/a diesel air filter box at full throttle. Noticeable difference, and didn't need ram air to be effective. It was good from the get-go. I guess when you're only making 52, a couple extra here and there really are noticeable.
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ages ago, I rigged up a spare interior fan (rabbit type) to blow into the n/a diesel air filter box at full throttle. Noticeable difference, and didn't need ram air to be effective. It was good from the get-go. I guess when you're only making 52, a couple extra here and there really are noticeable.
A supercharger you mean... Sounds intriging.
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A supercharger you mean... Sounds intriging.
I wonder if a small motorcycle supercharger would work. You don't want too much boost unless your engine was designed as a TD from the get-go. Special metal for the exhaust valves, oil jets for the pistons, oil cooler, etc. But small amounts of boost on a NA would be cool.
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the oil on a supercharged engine would not get as hot because it is not using exhaust heat to be spooled.
i dont think the high tech exhaust valves are generally needed either.
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the oil on a supercharged engine would not get as hot because it is not using exhaust heat to be spooled.
i dont think the high tech exhaust valves are generally needed either.
Good points, I hadn't considered those. Well we just need someone to try it now!
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the oil on a supercharged engine would not get as hot because it is not using exhaust heat to be spooled.
i dont think the high tech exhaust valves are generally needed either.
Good points, I hadn't considered those. Well we just need someone to try it now!
I'm game. I'd like to see how 5 or 10psi feels on the rabbit.
But I'm also broke right now, so I can't really afford a supercharger just yet....
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an electric one, of sorts. I can't imagine it made even a single psi, but perhaps it was enough to negate the restriction of the airfilter or something.
Probably one of those cheesey ebay electric superchargers would be more effective. or Nitrous and a Giles pump.
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here are some Pictures of my intake that i had set up before that dumb lady pulled out in front of me and smashed up the caddy
vwmike was kind enough to host these pictures for me
www.tdtuning.com/pictures/S4200015.JPG
www.tdtuning.com/pictures/S4200017.JPG
www.tdtuning.com/pictures/S4200019.JPG
I should let be able to let you know how a rabbit with 15-20 pounds of boost feels by the end of the weekend if all goes well
later
Justin
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Dr. Diesel
Electric superchargers can work especially on small displacement engines. What you have to know is the CFM at a gtiven RPM of the engine and get an electric fan that can handle more than that to get positive boost. I'll have to do some checking and calculating but it should be possible to 5 - 10 psi.
Bernie
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its impossible to get 5-10psi from an electric supercharger for more than 30 seconds at a time on an automobile. we are talking about hundreds of amps here, dedicated banks of batteries in the trunk, and huge thick copper wiring. the reason its impossible is because you dont have enough space in the car for all the batterys needed. not to mention the heavy 100lb motor needed to drive a supercharger like that.
i have seen the kit which does this, and its goot for 10 seconds of electric boost. real legit electric kits. they have a baknn of golf cart batterys in the trunk, some kind of large a/c motor in the trunk as well, and ducting going to the front of the car to provide a path of air flow from the supercharger in the trunk to the intake under the hood.
all those ebay kits are is just ventilation fans from the bilges of power boats, some are just computer fans in a plastic duct. those things cause more of a restriction than anything. they actually rob you of power.
its very easy to make boost with a small blower. its also very easy to make cfm with a small blower. the problem, and this is where most prople fail, is making high boost and high airflow together. think about this. a 12v cigarette lighter compressor can put out 160lbs of boost, but unless youre engine has air airflow requirements of a weed wacker, that thing is useless.
a gas powered lawn blower can make lost of cfm, hundreds of it actually. but gas powered leaf blowers dont even make 1 psi of boost. actually, all of the ones i have tested make less than 1/2 psi of boost.
so the problem, is getting boost pressure AND high airflow. you cant even get 1/10th of a psi of boost out of those ebay electric motor fans.
an easier way to think about it is to look at the power requirements of electric motors. a conventional belt driven supercharger can take anywhere from 25,000 watts to 300,000 watts to drive them. a turbo is more efficent but still relies on power from the exhaust gas to drive, say anywhere from 15,000 watts to 250,000 watts to drive, (this is all depending on the application and stupid details which dont actually matter in the aspect of this discussion.
look at the alternator of a vw, lets say you upgrade to one of those 90 amp jetta units. at full power the 90 amp jetta alternator puts out 1296 watts of power. yup, thats less than most toaster ovens, or electric hair dryers.
so we have 1300 watts to play with. now take away some power for the injection pump solenoid, some relays, maybe a headlight or 2 :P and perhaps a cabin fan. say we have 1000 watts left. thats roughly 1 horsepower wirth of power you have to play with. you think a electric supercharger can be driven off 1000 watts? thats not even enough to turn the starter on a car, much less the powerfull motor it would require for a real electric supercharger to actually do anything.
this post isnt ment to offend anyone here and i apologise if i have. i understand the novel idea of an electric supercharger. it seems like a good idea untill you actually gety into the mechanics of it. i looked into it myself. it just isnt practical from any stand point.
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its impossible to get 5-10psi from an electric supercharger for more than 30 seconds at a time on an automobile. we are talking about hundreds of amps here,
I certainly agree that high-powered engines need a lot of air and pressure to be supercharged, but our little diesels don't need nearly as much. We also have anectodal evidence that a heater blower is beneficial. Granted, it's not scientific, so I take it with a grain of salt.
Anyway I agree that computer fans and marine bilge pumps are not the way to go. I would much rather have a belt-driven supercharger. More efficient and probably lighter too.
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i understand the novel idea of an electric supercharger. it seems like a good idea untill you actually gety into the mechanics of it. i looked into it myself. it just isnt practical from any stand point.
He's right. In a high boost turbocharger installation the shaft horsepower developed within the turbocharger can often be as high as the engines horsepower at the crankshaft. Supercharging is no better, an eaton supercharger will draw some 38hp from the crank to make 15psi of boost, you better hope you can make that back...
There ain't no free lunch. Electrics are being experimented with as an anti lag system to supplement the turbo, but cannot be used continously, there is simply not enough battery capacity...
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i understand the novel idea of an electric supercharger. it seems like a good idea untill you actually gety into the mechanics of it. i looked into it myself. it just isnt practical from any stand point.
He's right. In a high boost turbocharger installation the shaft horsepower developed within the turbocharger can often be as high as the engines horsepower at the crankshaft. Supercharging is no better, an eaton supercharger will draw some 38hp from the crank to make 15psi of boost, you better hope you can make that back...
There ain't no free lunch. Electrics are being experimented with as an anti lag system to supplement the turbo, but cannot be used continously, there is simply not enough battery capacity...
Something to think about with turbos vs. superchargers is that something like 80% of what drives a turbocharger is heat expansion in the exhaust. Exhaust gas velocity accounts for very little. Typically, (in a gas engine anyways) the power seen at the crankshaft is actually only about 1/3rd of the total energy created. The other 2/3rds is lost in the form of heat through the exhaust and cooling system (though I suspect that this is more efficient in a diesel as less heat energy is created). So, a turbocharger is mostly drawing it's energy from a previously wasted source. That's not to say it is without it's faults as the increased backpressure is detremental to power production.
Superchargers on the other hand take their energy from the crankshaft which is the one source of energy you really care about. If you want a lot of low speed response and good power up to a point then a supercharger might be for you. But, if you're interested in efficiency and upgradeability you'll find much more potential in turbochargers (no supercharger can touch the efficiency of a turbo).
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whether or not superchargers are as efficient as turbos, you can't deny the fact that they work. Last spring, I finished off an A1 jetta G60 for a guy. It had a stage 4 kit on it, and I've never driven anything as crazy as that before. (including some hotrod v8 cars at a couple speed shops I've worked for) It was absolutely insane. 1st and 2nd gear were absolutely useless, and in 3rd, punching it anywhere over 1700 rpm would result in almost immediate wheelspin. Maybe the same engine and same boost from a turbo would make more hp, but I wouldn't trade it for the immediate, RIGHT NOW power made by the supercharger.
quite a bit better than my interior fan'ed n/a.
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G60 engines can be fast....when they run. They're nice and torquey but I've seen far too many G-laders with holes blown in the case for me to ever think that was really a good idea. Then theres the management which really isn't that great either and the engine is worn out after about 120k miles. I'm just going to stay away. My turbo gas Rabbit hasn't made the most power it could for a variety of reasons and with the large turbine on it I consider it to be a form of traction control. I used to have an old Arkay turbo kit on my Rabbit. It had a ported and polished Eurorace head with oversized valves and such. That thing made 90% of it's torque below 3000 rpm and went through clutches like underwear. There was also the broken CV joints and the broken transmissions..... 020 transmissions just weren't designed to take that.
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too many G-laders with holes blown in the case
hehehe... works amazing. wouldn't want it though. I'm glad I'm the fixer and not the owner. Taking that general idea but substituting a lysholm compressor, NOW you're talking!!... about stuff that doesn't belong on this forum.
EJECT!! :arrow: :lol:
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In my experience, the aluminum dryer duct won't stand the vibration.
Andrew
Yup..... It's cracked off now :D
I think I'm going to put a 4" PVC one on there. Perhaps put it up to a small hood scoop instead of down to the bumper? What do you think? Is a NA diesel with a hood scoop false advertising...
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http://www.vwdiesel.net/phpBB/viewtopic.php?p=13966&highlight=#13966
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What do you think? Is a NA diesel with a hood scoop false advertising...
No way Zeke. Do the hood scoop. And then you'll have to get one of these too: http://www.jcwhitney.com/autoparts/Product/tf-Browse/s-10101/Pr-p_Product.CATENTRY_ID:2001905/showCustom-0/p-2001905/N-111+10201+600001926/c-10101
Or maybe just come by one evening and we'll fab one up for you out of some scrap angle iron and metal roofing 8)
Seriously though, the pipe is a lot quicker and easier to run than making a hood scoop. I prefer to use 4" galvanized ducting. Mine works really well.