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Old 05-19-2008, 06:44 PM   #31 (permalink)
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Quote:
Originally Posted by JoJotheTireMan View Post
I am running 195/60R14s and the other size recomended for my car is 185/60R14. Not sure what the R&P ratio is off the top of my head, but I do know that there are not too many R&Ps out there any taller than what I have as a starting point.
It depends on what your trans code is but if you have a 3.67 R&P you're about as low as you can go stock. IMO your best bet for gearing experiments is to get a couple significantly taller tires on steelies from the j-yard with a scanguage or open equivalent (*plugs the instrumentation forum*) and do a few runs at 55mph over the same route switching tires between each to see if taller gearing will help you out much.

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Old 05-20-2008, 02:22 AM   #32 (permalink)
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JoJo, I found it!

The link to the company that is already working on this same engine concept.

http://www.scuderigroup.com/

This looks to be more work than I would tackle. However, this company seems to think the idea has merit so perhaps you're onto something
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Old 05-20-2008, 08:07 AM   #33 (permalink)
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Quote:
Originally Posted by roflwaffle View Post
It depends on what your trans code is but if you have a 3.67 R&P you're about as low as you can go stock. IMO your best bet for gearing experiments is to get a couple significantly taller tires on steelies from the j-yard with a scanguage or open equivalent (*plugs the instrumentation forum*) and do a few runs at 55mph over the same route switching tires between each to see if taller gearing will help you out much.
Yes, 3.67 R&P sounds right, just do not have the book with me, but I do know it's what they put in almost all of the A3 cars, in other words I do not have the shorter geared GTI gearbox or anything. Indeed, I could try a little taller tire, but wheel well clearance will limit me from going much taller than stock. Due to my typical commute being mostly highway, I think I have exhausted my gearing options with the .715:1 TDI 5th gear, should do the trick, now if I can find the time this weekend to get the gearset swapped I'll be in better shape soon. JoJo
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Old 05-20-2008, 08:08 AM   #34 (permalink)
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Quote:
Originally Posted by JerkOfAllTrades View Post
The link to the company that is already working on this same engine concept.

http://www.scuderigroup.com/

This looks to be more work than I would tackle. However, this company seems to think the idea has merit so perhaps you're onto something
Thanks for the link, I will look it over. ^5 JoJo
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Old 05-20-2008, 12:13 PM   #35 (permalink)
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OK, so their idea is similar yet different. I still may explore my idea further, and their site gave me some good input to this type of process. Very cool design on their part too.

See, I was after modest boost, they went all the way to 50 bar!
I am looking for less net HP, they (in theory) will achieve a net increase of HP, and a more efficient internal combustion engine than ever before. Very cool stuff indeed!

Anyone want to say it couldn't work now?

Granted my design is much simpler, but very similar and I had never heard of this until today, so much for my "original" idea, but hey at least it means that great minds think alike.
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Old 05-21-2008, 05:11 PM   #36 (permalink)
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Quote:
Originally Posted by Joseph Davis View Post
That being said it's going to be much easier to make your 2 liter fuel efficient than any FI car that will require boost to pull the vehicle up even mild hills. There is a lot to be said for the KISS principle. I take on a lot of odd projects, but I wouldn't even attempt yours for practical reasons. Better to spend your money de-stroking your engine or the like, would result in a more reliable and less expensive solution.
Being a huge VW nut I have to agree, destroking it would likely be a much cheaper option.

My great idea is to get a 1.8 crank in my 2.0 (thus lowering compression ratio and decreasing to a 1.9L), give it the mildest turbocharger (A turbocharger accomplishes what you were thinking of in the original post, except all of the cylinders are going to be pumping for you), and then put it into a VW Scirocco 2 (lowest drag, ~1800Lbs, dirt cheap when thrashed) with 175mm wide tires (or narrower, if available). Possibly adding a Diesel transmission to the setup.

That rig was really a hot-rod Idea from me, the lower compression is just to add turbo boost, and the de-stroking would just result in a better revving engine.

Better to get a 1.7L motor and just use that with Diesel trans, they have 3.4 final drive (IIRC, not 3.89/3.94 like all the rest), if you want to be insane, the TDI 6-speed trans from a euro model is said to make for insanely low revs (~1500 @ 65), for a 4-cyl. But the cost: xxx-x,xxx

Check out a "truck cam" grind http://www.techtonicstuning.com/show...artnum=109.07K (only for solid lifter motors?), this is said to deliver all the power from idle to 4,000. Pair that with a 1.7-1.8 motor and the Diesel trans and you would see a big deal.

Maybe a 1.6 crank is available for an ABA from a european car? You might need the pistons and rods though.

(I put a 2.0L 3A engine from an Audi 80 into my Rabbit Gti, it would roast the tires into 3rd gear, and still get 25mpg, while blowing the doors off of v8's )

I would investigate a torque tuned exhaust, a little smaller to get more torque.
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Old 05-22-2008, 10:16 AM   #37 (permalink)
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Gearing Summary

Go here for the gearing specs of just about every VW tranny out there:
http://www.techtonicstuning.com/trannyratios.asp

Summary:
I have a 3.67 R&P now.
There are a few with 3.65 R&P, not worth the effort or cost involved for such a small drop, not to mention the vehicle speed sensor issue if you switch R&P ratios.
The VW motorsport 3.32 R&P would be nice, but good luck finding one of those, never mind the $$$$, and VSS issue.

As far as 5th gears go, the .71:1 is the lowest I can find for my 020, and I had to have it machined to even fit the retaining mechanism that my trans uses.
Even the 1.9L TDI uses the same R&P (3.67) with a .75:1 5th gear. I will be geared slightly taller than that in 5th.

I would love to combine that with the TDI 4th gear also as mine has a .97:1 4th where the TDI has a .91:1 4th.

Now, a 5th gear swap can be done in the car without removing the trans, but a 4th gear swap would be a whole lot more work, and not worth it as I spend most of my miles in 5th at highway speeds anyways.

I did the math, and if I average a 500RPM reduction in 5th gear at the same vehicle speeds, then I will spin my motor a quarter of a million times less per week! That just has to save some gas, no?

I fear if I go any taller in gearing without adding more HP/TQ, then I will be forced to downshift to 4th more often which will negate any 5th gear swap gains.

The bang for the buck factor really is why I am doing it this way. $100 and a few hours, hopefully this weekend, and I'm done with gearing. Any other option to go taller or mess with anything but 5th gear will require trans removal, tear down, and rebuild. There goes any potential fuel savings dollars as I would have to recoup the original cost of the rebuild, never mind the extra labor and down time.

I know anything is possible, some things just are not practical. Like the cost to import a euro 6 speed, although I would love a 6 speed, but that is not going to happen unless someone wants to mail me one for free, which I doubt will happen either.

Can anyone see any gearing options that I may be missing? I am not sure of compatibility between different types of trannies either, I am just comparing 020s.

I mean I could just go buy a prius, right? How long will it take me to save 20Gs on fuel? I doubt the prius would last that long, seeing I have 2 good A3 Jettas, and 1 for parts, and I paid 1G for all of them combined. Yes, I would spend less for gas per week with a prius, but I have no car payments and never will, worth more to me than the potential to save a whole gallon or two max per week.

Fuel costs are still only 20-30% of the total cost to own/operate a newish vehicle these days.

I try to look more at dollars per mile than miles per gallon.
I bought my current beater for $400, have about a grand into it total with repairs and what not. I have averaged 30+ mpg for just over 20K miles in 1 year. So, 20K miles for a grand, and I'm getting 30+mpg, how can I beat that?
Total cost of ownership/use is what our cars really cost us, not just what we pay at the pumps.

Now, that being said, not everyone wants an oldish beater with all the problems they typically come with, but I am lucky as I do all my own repairs/maintenance, so that keeps the costs down significantly. When most people think a car is worth next to nothing anymore due to age/mileage, that is when I will snag them on the super cheap and run them utill they are really done.

My wifes subaru has given us 70K+ miles for a total cost of maybe $1200 plus fuel. 200K+ on the clock now and she still runs great. We got it for next to nothing as it had a blown HG, their loss is my gain I guess.

I just don't see the point in buying a 20K+ car when I can get a $500 beater to get me to the same point a and b as the new car will. Don't need extra insurance as the car costs as much as the deductible anyways, crash it, recycle it, repeat. Cheaper excise taxes, cheaper parts, etc, etc, etc. If I didn't fix them myself, then maybe I would see things differently.
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Old 05-22-2008, 10:52 AM   #38 (permalink)
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Quote:
Originally Posted by nubie View Post
Being a huge VW nut I have to agree, destroking it would likely be a much cheaper option.

My great idea is to get a 1.8 crank in my 2.0 (thus lowering compression ratio and decreasing to a 1.9L), give it the mildest turbocharger (A turbocharger accomplishes what you were thinking of in the original post, except all of the cylinders are going to be pumping for you), and then put it into a VW Scirocco 2 (lowest drag, ~1800Lbs, dirt cheap when thrashed) with 175mm wide tires (or narrower, if available). Possibly adding a Diesel transmission to the setup.

That rig was really a hot-rod Idea from me, the lower compression is just to add turbo boost, and the de-stroking would just result in a better revving engine.

Better to get a 1.7L motor and just use that with Diesel trans, they have 3.4 final drive (IIRC, not 3.89/3.94 like all the rest), if you want to be insane, the TDI 6-speed trans from a euro model is said to make for insanely low revs (~1500 @ 65), for a 4-cyl. But the cost: xxx-x,xxx

Check out a "truck cam" grind http://www.techtonicstuning.com/show...artnum=109.07K (only for solid lifter motors?), this is said to deliver all the power from idle to 4,000. Pair that with a 1.7-1.8 motor and the Diesel trans and you would see a big deal.

Maybe a 1.6 crank is available for an ABA from a european car? You might need the pistons and rods though.

(I put a 2.0L 3A engine from an Audi 80 into my Rabbit Gti, it would roast the tires into 3rd gear, and still get 25mpg, while blowing the doors off of v8's )

I would investigate a torque tuned exhaust, a little smaller to get more torque.
Much cheaper way to lower the CR on one of these VW motors is just to get a thicker HG, can make a drop of 10:1 down to 9:1 which would be more ideal for a boosted motor.

I can't see adding a turbo to even a smaller 1.8L saving any fuel compared to the 2.0L NA. That is why I was looking at supercharging (more low end HP/TQ gain than a turbo) a 1L as my alternative to save some fuel by displacement reduction. Never mind adding any kind of forced induction to an already decent powered 4 banger is just going to increase fuel usage, well for me at least because the temptation of using that extra power will get the best of me from time to time.

I do still have an 81 rabbit hiding out in my barn with 77K original miles on her, I have a 1.7L, and a 1.8L CIS motors, I have a 3 speed auto and the GTI 5 speed also. So I do have the ingrediants for a very light economy hatch, just need to find more time for that project.

The A3s have much better creature comforts though, like say something simple like a cupholder. The old rabbits are pretty much just a tin can with wheels, and that is what it sounds like when you hit a bump in one too.

Exhaust, I agree and when I find an OBX tri-y header on the cheap then I will snag one, as the tri-y design is much better at building low end and mid range. I believe they were initailly designed for motorhomes and whatnot.

I think I am on the right road for improvements to my current 2.0L NA, the EPA rating is 21/29 and my last tank I got 38 mpg, and I still need to swap the 5th gear in :-)

My other idea was more of a long term thing, would not cost all that much as I have the spare parts to begin with. It was just something I had to get out of my head and see what others think about it. I also think about how to run the cam at the same pace as the crank so my pumps run as 2 strokes and so would the charged 2, but need to sit down and figure out if the cam could handle this job if designed right. I'm still into it for a custom cam, and some ECU tuning at most as the rest is just stuff in comparison.

Thanks for the input, any and all ideas are appreciated.

Anyone else have any other ideas for my ride, well other than driving habits and aero mods as I do my best with driving technique and aero mods will be phase 2 of my plans.

Thanks again....JoJo
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Old 05-22-2008, 12:10 PM   #39 (permalink)
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Like I said, VW nut:

83 Rabbit (junked and gone ) Free
84 Gti (no funds to get registered, smogged ) $300 initially (idiot I bought from put $1200 into a head job, the bottom end was completely trashed)
85 Jetta 3sp Auto $400
95 Jetta (daily driver)$500
96 Jetta (mom uses)$200

For sure go to VW vortex forums to see if anyone is doing this sort of thing , here are some off-the-top of my head ideas that cost under $100

Transmission:
Go to a pull-it-yourself junkyard, they should have a manual 5sp Diesel :

AGS (86-90 1.6 Diesel) 3.94 3.45 1.94 1.29 0.91 0.75

While you are there, snag some output shafts (those cups that the axles connect to) from a 100mm axle car (or the inner CV joints from a 90mm car), and the .71 5th speed from another trans (no need to remove the trans, just pull it in the car!), and a decent looking clutch disk from a 1.8L 8v (smaller splined shaft on cars that aren't 2.0 ABA or 16v, 1.8L have the same size clutch disk otherwise)

According to some quick calcs that will net you ~300rpm drop or more just for that, and they should charge you around $100 for the whole mess. (we have a Pick n Pull brand store around, and all of the ones in CA do 25% off Wednesdays, and 50% off on holidays, like the upcoming memorial weekend).

I wouldn't do any custom machining for something as trivial as a 5th gear swap. You can get $400-700 for the used transmission from your Jetta (1994-1999 right?), maybe more if you know how to wheel and deal, or know a VW nut who needs it for a 1.8t swap into an A1/A2 chassis.

the Gti 5speed is not good for economy, it is a close ratio box, 5th is like 4th in the Jetta box, imagine that on the highway. I did a 5th swap into a close ratio box, it sucked to have such a huge jump in RPMs between 4th-5th.

I have swapped a close ratio with the smaller splines into my moms 96 with a stock 1.8L clutch disk (but it was the 100mm output shafts), and I have run my 84 GTi on a 100mm output flange tranny using Scirocco 16v or Late A1(89-92) Cabriolet axles. Neither of these is exactly what you are looking for though.

Header:
Don't bother with a header, the VW A3 (1994-1999.5) header is a 4-2-1 header already and is a damn good performer, you can't do better for less than $500, and since you want better torque and mileage, you would want one tuned for economy, which they don't make (afaik), it would be a bigger and tuned for higher RPMs, reduced low-end torque, increased high-end HP.

Crank/pistons/short block:
I would seriously keep an eye out for a complete set of 1.6 block stuff for an ABA (Euro/Mexico/Brazil/Canada??), that would really increase the fuel mileage. Double check to see if you are running 185 or 195 tires, if possible investigate 175 tires, that will help with the frictional losses.

The key to all of this is finding a pull-it-yourself yard, they have the best prices. I don't know about swapping parts down to a 1.6/1.7L for an ABA, but the whole short block is typically under $100.


Phenolic Spacer:
A phenolic gasket/spacer for your intake manifold, this prevents the heat from the engine warming up the intake and heating the incoming air, they claim better MPG for this. (I don't know if it is worth it though).


Camshaft/Adjust the timing:
I don't know about a better performing camshaft, but you could pull a late-model cam gear (skinny spokes) from a junk yard and have a machinist cut a couple new keyways in it to retard/advance the cam, giving you a more efficient engine with more torque down low. This shouldn't cost more than $30-50 total.


Bypass AC / Underdrive / Alternator bypass:
Edit, almost forgot, you can get a Vr6 water pump pulley and "A/C bypass kit" belts for $30 from a few places ($27??), when you don't need your AC you can swap it out in about 15mins and reduce the drag on your engine. Smaller alternater, I don't know if there is one, but the VW has a truck-sized battery, I can run mine for 3 days or more with no alternator, even coming back in the dark (no AC running). So if you top charge it at home and use an alternator disconnect switch while doing errands in town you can save some MPG and enjoy increased low-end torque (on the 3sp Jetta I could really feel the power it freed up!). You can always switch it back on if it needs to be on, a Voltmeter is $2-4 at Harbor Freight tool stores, mine works great (I have checked it against the Fluke meters where I used to work), so you could add it to the dash and keep an eye on the volts. A big solar panel on your rear-window deck lid can help keep it topped up (they aren't really worth much, but every little bit helps)

An Aluminum reduction pulley may not be worth it, but it could seriously reduce the drag on the engine from all the accessories. (keeping an eye on the temps and the battery is a good idea if you aren't racing with a reduction pulley). But if you top off the battery at home then it shouldn't be an issue. Why spend gas to charge a battery when the electrical grid is much more efficient and cheaper?

If you want to exercise your arms a little you could ditch the P/S (I wouldn't on the Jetta unless I used 175 tires pulled the AC out and moved the battery to the trunk.)

Daytime Lamps:
You could turn off one of your daytime running lights (they are always on), just like a late-model chevy, or add a daytime Running light and switch off the daytime lights altogether (I think vwvortex may have info on that), or if you live in a bright area (not the mountains), the lights may not even be visible. I think I heard a guy say it is removing one pin will disable them.

Engine Rocking/Wasted motion:
On the subject of wasted energy/motion, I am looking into putting a hockey puck in my front engine mount to reduce the engine rocking. It looks like removing the bottom of the front engine mount from underneath and swapping the rubber puck there with a stiffer/larger spacer will compress the top mount insert a little(soft rubber with lots of holes), reducing the rocking without removing the entire front engine mount. I typically slow down a quarter to a whole block ahead of time and shift into 2nd to slow my car to a near stop, then apply my brake, the reduction in engine rocking should make a huge difference. Too bad I forgot to look for a regulation puck last time I was in town.

Edit 3 (too much already?):

Aero Mods: Mirrors/Antenna:
Remove the passenger side mirror and swap the drivers to a more aerodynamic unit, make up for it by fitting a "rally" style mirror that goes across the entire car in the cab, you will be able to see nearly as easily (perhaps better in the usual VW blind spots ), and the law only requires 2 mirrors, one must be the inside mirror OR the Drivers side mirror. That is CA, I would check your laws.

I think you can cut a piece of plastic to cover that corner where you remove the mirror and use some 3M trim tape to attach it. I have found a very nice black plastic folder at Staples that I used to make a blanking plate for my mom's car because she doesn't have a radio.

I don't know about removing the antenna, but it couldn't hurt, you could swap to an inside one on the dash or rear parcel tray. (Being cheap and strange I might even hook up to the defrost grid during summer :P )

Last edited by nubie; 05-22-2008 at 12:59 PM.. Reason: more info
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Old 05-22-2008, 01:13 PM   #40 (permalink)
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2 Cylinder mod:
I keep coming back to your 2 cylinder mod idea, I like the idea of a 1L in fact. I just wish that a 1L would actually do a good job of moving a Jetta (I know even my 1.7L Rabbit felt all too peppy, a 1L would do it good I think). I would like to remove 2 rods and pistons and grind off the cam on those two cylinders to keep the valves shut, but I don't know how you could balance the Crank at that point. You would need to fake out the engine management, unplug the injectors and ground out those two spark plugs, but it could be done I think.

If you were headed that route already, it is possible a short crank and a 1.8L block could get you in the 1.2-1.4L range. I would love to see that actually, but in reality I wish I could source the stuff from Euro OEM, I am sure they have smaller engines in their line-up over there. In fact I wish the Polo would come out already over here.

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