Underpowered with big tires

[bikesndbugs]

Ive got a pretty worn out 1600 dp and a stock 78 swing axle. I wanna run 31s in the rear. 4.12 r and p. Ive got power through all the gears but 4th is useless on everything but flat. I'd like to be able to actually use 4th and improve milage as it takes a lot of gas to get off the line.

What is the most cost effective way to help this? Besides tires as it did the same with 235s I hope 31s will help with 5th gear top end making it more usable at freeway speeds. Granny regear, motor rebuild, single port for more low end, bigger motor?

[Multi69s]

Your expectations of engine versus tire size is way off. n Even a strong 1600 won't pull 31" tires worth a darn. Why are you stuck on such large tires. If you have to run tires that big, you need to do two things. Go to a lower R&P like 4:86 and go to a larger engine: 1776 minimum.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[race-desert]

4.37 ring out older swing helps mucho. close 3 and 4 next.

[rockerarm]

Hi. Why not consider the bus 002 with the original 5.37 ring and pinion?
Your gallery pics indicate you have some fab skills to easily convert to the IRS.
Many have stated the bus 002 is stronger than some built type 1 trans'.
Understand that all a trans is is a torque multiplier. It does the same as the sprockets on one's 10-15 speed bike. Get yourself some simple graph paper, calculator, the formula, gear ratios, tire dia's, favorite beverage and plot out different combo's. VW engines are somewhat small in displacement and need this torque multiplier (ie: trans) to be able to function.
Hope this helps, Bill.

[I Ride Sand]

swap in a swingaxle bus trans with reduction gear boxes. that causes other issues, but would work. or swap in a 002 or 091 bus box. needs to be converted to IRS but is the best option. or build a big engine. but that will break your stock trans, and 4th will still be unuseable as it will drop your RPM too much on the freeway. a vw needs to spin at about 3400 rpm to cruise at 75. anything less and they get pretty hot.

and the last, easiest, cheapest option that makes the most sense:




























































































swap to 235's and freshen the motor! mine ran awesome with an 1835 engine, mild cam and 235's.
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Just a dirty coyote playing in the desert.
now where'd that dirty badger run off to?

[Multi69s]

[dustymojave]

Poll Response: Item 4 - None of teh above.

OH, and BTW...

That is a '68 trans ... not a '78.

I've had a couple of pretty stock 1600s in my Baja with 4.12 gears same as your '68, with 30 x 9.50 tires. It looks fine and runs 70mph on the freeway. I hope you've downloaded all my pics since Photobucket is being so stupid. 1776 or 1835 is better, and even bigger is even better. But more power breaks more gearboxes.

The only place I feel a turbo in a Baja makes sense is for climbing big sand dunes, sand drags, or mud bog drags.

If your pals are telling you that you need more power, tell them to quit waving that thing around and put it away, and be careful they don't catch it in the zipper. Folks like to spend other people's money.

I've listened to Class 5 Open Baja racers whine for decades about how they "need" more power. So $20K Type 4s that make 275hp and break unloading off the trailer, and even with full tube frames, all fiberglass bodies that are all but unrecognizable as Bugs, +14 beams and +4 front arms and +10" wheelbase, and 7x12 rear arms and $25K gearboxes and Ecotecs that make 250hp on the $10K computer... And an AGS 5-1600 Bug with the full stock pan and steel body, 85hp and drum brakes and stock size front arms and beam and 0 x 1 rear arms and a $4k gearbox wins a MORE 5-Open Championship. Then another enters both classes and wins 5-16 and takes 2nd 5 Open and closing on the win.

It's a Baja Bug. Leave it a Baja and have all the fun the law allows.
_________________
Richard
Offroading VW based cars since 1965
Tech Inspection 1963 - 2012 SCCA/SCORE/HDRA/MORE/MDR +
Retired from building Bajas, Fiberglass Buggies and Rails in the Mojave Desert. Also Sprints & Midgets, Dry Lakes, Road Race cars. All types New and Vintage
SoCalBajas Member
Kicked Cancer's A$$...1st and 2nd round...Fight ain't over yet.

[oldschool5er]

THIS ^^^^

[bikesndbugs]

[Multi69s]

Since money is a major factor for you, do a full rebuild on the engine first. Then you will know where you really stand. It also looks like a new trans will be needed down the road. Finding a good trans guy and custom work is very expensive. Depending on your fab skills a bus trans may be a cheaper way to go. However that is AFTER the engine is at it's best.
_________________
69 road Bug 2110
73 Squareback - 2L, T4, Automatic W/ AC
Gone, but many fond memories 69 Baja Bug 2010 - 5 Rib Bus Transaxle
Gone but not forgotten 72 Baja Bug 2010
My builds
T4 into Squareback http://www.thesamba.com/vw/forum/viewtopic.php?t=458944&highlight=
Auto Trans Rebuild http://www.thesamba.com/vw/forum/viewtopic.php?t=516066&highlight=
AC in Squareback https://www.thesamba.com/vw/forum/viewtopic.php?t=...highlight=

[Bad_chopper]

People may get sick of my 2 cents. Bit I had just as much into building a 1776 as I do swapping in a 2.2 Subaru. If you are good with electrical and pretty mechanical it's a semi difficult swap bit doable. I have been using. It's an option just not a plug and play option.
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my build page http://www.thesamba.com/vw/forum/viewtopic.php?t=536267

[bikesndbugs]

[Mal evolent]

[Bad_chopper]

If it's an all original 1600, its probably due for a full rebuild. If you do an upper end rebuild with a turbo, that may constitute a cam change, definitely need lower compression. Down side of a turbo is you'll still have the low end torque of a 1600.

A 002 transmission will have low gearing, fairly inexpensive. Get a set of jugs and piston, rebuild or buy new heads,go with whatever carb(s) you want. Easy to do, decent power, and cheap way of gearing.

A couple ways to determine if you need a complete rebuild are. Where is it leaking from, what is your oil pressure, look into an oil analysis, end play in crank. And other reason would be put a good low end torque cam in.
_________________
my build page http://www.thesamba.com/vw/forum/viewtopic.php?t=536267

[Mal evolent]

mandatory link to a must read page: http://www.aircooled.net/vw-performance-engines/
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73 Beetle Baja, Ghia front brakes, Type 3 rear brakes, 2220 ( 94 X 80 ), Weber Progressive, Bosch SVDA, '97 Mustang seats

Baja Bugs for Volkswagen Virgins: Index

[Bad_chopper]

[bikesndbugs]

Motor isnt original as its a 1600dp and og would be 1500 sp. It doesn't leak oil. Well a very very small amount out of One of those crappy spring pushed tubes
I don't want high hp I just want enough to get around. I think a 1600 with a little bit better heads nice carbs and a little bit a valve mods (solid shafts and ratio rockers would keep it nice and simple.
I had planned on going 002 and irs but not yet so ill do motor now and start setting up for the swap

[veeweeman]

The best option in my opinion is swapping out the tranny...I have a 002 and run 33s...65mph is around 3500 rpm...first gear is a little tall to start but once you get rolling the gearing is perfect around town...the 002 is a very tough trans...just stay away from the 091, the difference between the 2 are cost! ...the 002 takes all type 1 tranny components while the 091 is all new design and parts, expensive parts! ...the 002 is basically a beefed up overbuilt type 1 tranny...I promise you that the 002 with 31in tires and a stock 1600dp will be a match made in heaven.

Good luck with your decision

[bikesndbugs]

An 002 plan was in the works anyways I'm a bit worried about freeway cruising with 31s on it. A friend said he's give me one but third is blown so for now ill do motor and start collecting irs parts.

[earthquake]

I was looking at some of you pictures and your cage look good, How big is the exhaust on your motor? If its bigger then 1 3/8" on a stock 1600 its probably hurting your bottom end some.

Casey
_________________
74 CLASS 11 LOOK-A-LIKE
69 DUNE BUGGY
79 INTERNATIONAL SCOUT II
05 SCION XB SERIES RELEASE 2[#437]
95 Chevy C3500 dually
98 Ford E150
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