Rotary Baja Beetle conversion with VSB14?

8 posts · joined Jun 2013 · 19 Jun 2013, 7:32 pm

#960329

Hi,

Been lurking around here as guest for a few weeks getting as much info as i can but I've a few questions. Read all the older posts on rotary conversions.

I'm planning to take a beetle modify it for off road a little (Baja it) and fit a rotary engine. To be used in fundraising car rally.

So I need to find a beetle heavy enough to legally have a rotary but without the mcpherson front end for ease of off road conversion?

For those who have street legal beetle rotary conversions what models are they in? What weight did the engineers use on certification?

Using the VSB14 LA engine section and the RVD (RVD database link) it looks like the only model that doesnt have mcpherson strut front end and heavy enough it can have a rotary fitted is a 1970?

Those who have Baja'd there beetle did the rego paper retain the same weight once the upgrades were done?

Am i close or way off the mark? Appreciate everyones advice

bugzla Custom Title Time!

1,164 posts · joined Jun 2007 · 19 Jun 2013, 8:59 pm

#960346

where are you located

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 19 Jun 2013, 9:35 pm

#960350

Mid North Coast NSW.

Been working on NSW RMS model weights from that link in my first post

bugzla Custom Title Time!

1,164 posts · joined Jun 2007 · 19 Jun 2013, 10:13 pm

#960354

I have one that is engineered in qld and nsw 12a rotary if that's of any interest

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 21 Jun 2013, 1:07 pm

#960537

I might be.

What condition is it in?

barls Administrator Causer of Chaos and Mayhem

9,473 posts · joined Jun 2004 · 21 Jun 2013, 5:55 pm

#960555

start speaking to your local rms approved engineer and see what he says mate.

“We all pay for life with death, so everything in between should be free.” Bill Hicks
the chaos project - click me

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 21 Jun 2013, 6:53 pm

#960568

I fully intend too. Just like to have as much info first to help in asking right questions.

Eg from my understanding easiest beetle to off road is the non McPherson strut models which info is best from enthusiasts that know ins and out.

Smiley Veteran Volks Folk

2,125 posts · joined Oct 2008 · 22 Jun 2013, 9:34 am

#960624

You are correct, the best offroad VWs are either king and link or Ball joint front with IRS (semi trailing rear arm style) for the rear.

Have a bit of a read of this and it might be some good info for you.

http://forums.aussieveedubbers.com/viewtopic.php?tid=89893&page=1

Also. I'm not sure how you intend to use the car offroad, but I'm not sure that a Wankel engine will have the torque to take on any serious obstacles. It should be find for dirt roads and some beach work. But if you want to do some serious bush tracks you might have to gear the transaxle down a lot (fit a 1600 "3-rib" Kombi box). I'm not having a go at your choice of engine, I'm just suggesting this notion in case you haven't thought of it. The last thing you want to do it get to a hill and not be able to drive up it, not have to drive up it at 30km/h cause that's where your torque is.

If you have any more questions fire away! I don't know much about engine conversions, but general Baja questions I know a little.

Smiley 🙂

If you said I was a Volkswagen man, you'd be right.

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 22 Jun 2013, 11:48 am

#960639

Thanks smiley.

I had thought about the lack of bottom end but main use will be off road rallying kinda. Plan is to use it for camp quality escarpade and then some beach driving.
However would the fitting of kombi box effect highway speeds? I presume it would mean revving quite hard in 4th gear. Or is final ratio similar just lower first gear?

The idea of rotary was to give it longer legs on fast dirt tracks. The last 13b bridegy I built happily went to 12000rpm after that the extended Webber fuel bowl wouldn't fill fast enough! Hahahah

Smiley Veteran Volks Folk

2,125 posts · joined Oct 2008 · 22 Jun 2013, 12:58 pm

#960648

If you look at that link I sent you there is a bit of info on gear ratios. There are 3 different IRS Kombi gearboxes all with different ratios.

First thing you want to know is what RPM the Mazda engine happily cruises at on the highway. Whatever it revs at in the standard vehicle will be a good starting point. Next thing you want to do is work out what size rear tyres you want. In a full bodied baja with standard rear inner guards, suspension and bodywork you are limited to a max of 31" rear tyres. Any larger than this and the tyre will hit the suspension and not fit on there. It can also depend on the brand of tyre, as I have seen some people unable to fit 31s from certain tyre manufacturers.
There are mods you can do it fit larger tyres but we'll keep this simple for now. Besides, 31s are common, cheap and plentiful.

Once you work those 2 things out you can chose the gearbox that best suits your needs.
I think a 3-rib Kombi box would probably suit you best. It has the lowest ratios but the revvy engine won't mind that. It'll sit on about 3000rpm at 100km/h with 31" tall rear tyres.
That being said you might want to go with a higher ratio box and smaller tyres like 28-29" Won't put as much strain on the drivetrain and you won't need as much low down grunt to get it moving.

Smiley 🙂

If you said I was a Volkswagen man, you'd be right.

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 22 Jun 2013, 5:37 pm

#960672

Smiley that link answers just about all my questions on bajas. Your a wealth of knowledge!
Also checked out your build, bout page 14 of 35 so getting there. :-) how did you go when you got it certified? Any problems?

Edit: also just bought
Baja Bugs and Buggies: How to prepare VW-based cars for off-road fun and racing

Smiley Veteran Volks Folk

2,125 posts · joined Oct 2008 · 26 Jun 2013, 7:55 pm

#961148

RonanTheBarbarian wrote:Also checked out your build, bout page 14 of 35 so getting there. :-) how did you go when you got it certified? Any problems?

Certified for what?

I have a few blue plates now for different things 🤘

Smiley 🙂

If you said I was a Volkswagen man, you'd be right.

RonanTheBarbarian Learner Dubber

8 posts · joined Jun 2013 · 27 Jun 2013, 7:11 pm

#961260

Smiley wrote:
RonanTheBarbarian wrote:Also checked out your build, bout page 14 of 35 so getting there. :-) how did you go when you got it certified? Any problems?
Certified for what?

I have a few blue plates now for different things 🤘

Smiley 🙂

Now I've seen all 35 pages of build I realize Alyce has been to the engineers a few times. 😂

Actually after reading the baja link you sent I'm actually looking at green 76 bug this weekend, supposedly its ball joint front end and IRS rear(after explaining to the guy on phone what to actually look for so skeptical) and 810kg tare according to RMS specs so heavy enough for 12A rotary! 🤘
I'll probably have more questions after or even a very light wallet!

Smiley Veteran Volks Folk

2,125 posts · joined Oct 2008 · 27 Jun 2013, 7:28 pm

#961263

I have a few more pages to add to the build now as I have recently rolled the car and wrecked the body. I'm in the process of fitting a new body now. sigh, the work never seems to end.

Thanks for you kind words.

A 76 bug will be a good buy. As you say it should have IRS and B/joint suspension. And the late bodies look good as Bajas too.

Smiley 🙂

If you said I was a Volkswagen man, you'd be right.