Sandrail issues and upgrades

[Coletrain93]

First post so hopefully I'm putting this in the correct place. So last year I traded my motorcycle for a sandrail without knowing much about them and it was a blast. It has a 1300cc VW engine with a single weber 44idf carb.

I folded the stock VW trailing arm over doing donuts on a dirt road and replaced with +1inch mild steel trailing arms from mooreparts.com. along with bushings new bearings and new axles. I took it up to silver Lake sand dunes in Michigan 2 times this year and broke some parts but the main issue I've found was after hitting about 2 or 3 decent bumps in a row the rear end lifts off the ground and I lose my speed and it bottoms out pretty hard. I ended up breaking both old shocks and replaced them in the parking lot which made quite a difference but still does it occasionally and was quite annoying when I'm going up a big hill and the little bumps leading up to it rob me of the speed I need and climb it. I was hoping to maybe move the rear shocks to the front and put longer travel shocks on the rear without any other major upgrades but need some input on this Or any other way to get longer travel.

Also through 1st and 2nd gear it has plenty of power and then even with it running high rpms in 2nd when I hit 3rd it has no power and takes 2 minutes to pick up speed. The carb isn't tuned perfect but I wouldn't expect that large of a loss from just the carb but that's the only thing I can think of.

I was hoping to upgrade it to 1600cc or larger this winter with necessary supporting mods at the lowest cost possible. I've heard I can keep 1300cc heads which will raise compression but would I be able to do so and put dual carbs or should I even put dual carbs with only 1600cc size. Also can I go larger with the same block or is it only up to 1600cc.

[Axitech]

Holy crap, a DRIVER'S EDUCATION RAIL!!!!! Look at that, boys, you can drive it from the right seat and the left seat!!



Hahahhaaaaa Nice rail. Dump the dual exhaust and you'll pick up power. Good looking rail!

I just went back and looked again. Those are dual port heads so I'm not sure you have the correct info on engine size. One of the wizards will be along shortly and will have far more knowledge than me. Do yourself a favor while it's still light out. Get the engine number off the case just under the oil fill/generator stand. That will tell you a lot.
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[SamT]

Its a dual port motor so i doubt its smaller than a 1600. If it runs good just regear your trans. A 4.86 ring and pinion would be my recomendation. ($500 ish installed by a pro)

For the rear suspension there isnt much you can so cheap. Those rear shock are basically a pogo stick you will be happier if you go back to a non coil-over. Adjust your torsion bars to get ride heigth you want without using coils.

[SamT]

I forgot to mention switching to a bus trans may be your answer, it jas low gears and is stronger. You can switch to bus CV joints and clearance your springplates and get more travel. (Ive done 10" with 24 degree empi bus CV's and atock arms)
3 rib trans $300 cv's 59 each, adapter trans mount $65, bus to bug stub axles $125? Anyways take a pic of your trans so we can see what you have now.

[Sandjunky]

Putting longer shocks on isn't going to give you more travel unless your shocks are limiting your travel, which is a bad thing. You would know because your shocks wouldn't last long from the damage. Your travel is limited by your spring plates, your bump stops, and your CV joints. Getting more travel without upgrading your CV joints is a recipe for disaster.

If your rear shocks are warn out then they may be packing, which would cause your bounce issue after a second or third bump. When you hit the first bump your shock compresses, if it doesn't have enough rebound then it doesn't rebound fast enough to absorb the second bump, then by the third bump you may be fully compressed and bouncing off the tires and kicking your rear end up. Or it could just be that you are asking too much from your stock suspension.

Nice rail, BTW. Looks like fun.

[Coletrain93]

I'm not currently home but I'll post pics later today. Well the reason I wanted different shocks was because the shocks are what is bottoming out and that's how I broke the last ones but the local shop only had these as replacements. I think as far as the cv's go from what I can tell they barely make horizontal maybe just past before shocks bottom out so I figure a little more travel should be fine with these axles. As far as it being a 1300cc that's just what I was told by previous owner and just went off that I haven't looked into it any further. Is there a way to find any VW experts near me. I live near grand Rapids Michigan.

[Coletrain93]

Also what is a driver education rail I didn't get what you meant by that?

[Axitech]

[Coletrain93]

Haha ok I get it. Thanks for clearing that up for me

[Axitech]

Looking at the two shock pictures you posted, it would appear your shocks failed on the compression stroke, and not on the extension stroke. If that's the case, you don't need more travel, you need shorter shocks, or move the upper mounts farther away from the lower mounts.
_________________
He said to them, “But now if you have a purse, take it, and also a bag; and if you don’t have a sword, sell your cloak and buy one. Luke 22:36


The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.-Thomas Jefferson

[Coletrain93]

Well I figured the suspension has more travel left but the shock couldn't compress any further and took the brunt of the blow and eventually failed. I already had to move the upper mount up so when the suspension is fully extended the shock is almost completely extended.

[Sandjunky]

[Coletrain93]

Ok that makes more sense. How do you adjust the torsion bars on it? I've done it on a pickup but I assume this is different. And would you get full compression with torsion still applied by hooking frame to floor jack and jacking on trailing arm or did I just make that more complicated than it should be?
Engine code is b and this is what I got. Seems very underpowered for a 1600 any ideas as to why it's so underpowered compared to other 1600s
B 1600 F4 47hp Type 1, 2

[DWP]

To adjust the rear check this thread. Halfway down is a photo of a jack and chain. VERY important.
Measure the angle of the spring plate when it just comes off the lower stop as a reference.
http://www.thesamba.com/vw/forum/viewtopic.php?t=612119&highlight=torsion+bar+remove


dwp

[Coletrain93]

Here is the transmission, she's still pretty dirty from the trails the other day

[cbeck]

what size are the rear tires? done a compression test? done a tune up/adjust valves?

[Coletrain93]

I'll have to get back on the tires but I've done compression test, valve adjustment, plugs, tested wires, fuel filter and pump, carb rebuild, new idle jets air filter and put the jet doctor kit on because I was getting sand in my idle jets every 5 minutes at the dunes. It still does weird things like it will idle fine no miss all warmed up let it idle for 2 minutes after a good run around the trails the sometimes it just starts missing after sitting for a second and I thought maybe it was loading up on fuel but even after revving and trying to clear it up it still does it. And I've checked 2 times for intake leaks both with water and with eather but nothing just could find.

[SamT]

[Coletrain93]

Yes still running points. Any suggestions on a cheap replacement?

[dustymojave]

The 'B' engine case is a 69 1500 single port, single relief valve case.

http://www.thesamba.com/vw/archives/info/bugchassisdating.php

It's been upgraded to dual pot heads. Like most VW engines 46 years old, it has been rebuilt with parts other than what it was delivered from the factory with. 1600 cylinders and pistons are a direct fit with no machining required and 1600 cylinders are easier to get than 1500s. It never was a 1300. I expect the engine is at least a 1600 now. It may be larger.

The trans is 69-72 Type 1 Bug or Type 3. Same trans for both models. the ring and pinion ratio in that trans is 4.12:1. Should work fine.

If it lacks power, are you maybe expecting more power than it really has? It's no drag racer the way it is. And sand dunes need lots of power. But you should be able to have a lot of fun the way it is, especially on other surfaces like forest trails, unless something is wrong with the engine somewhere.
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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
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