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Has anyone gotten a Beetle beam engineered before?
psimitar - December 18th, 2019 at 06:09 PM

Hello all,

I am wondering if anyone has managed to get a lowered Beetle beam engineered before? Too offset the disc brake kit widening the track then the beam would be narrowed as well.

I'd like to have my Bug completely legal but also modified the way I'd like.

This beam subject seems to be quite teh sticking point with our boilermaker ADR rules.

Cheers :)

hulbyw - December 18th, 2019 at 07:56 PM

Give Bill at Talk Torque Automotive a call. He is a VASS engineer who knows VW's inside out. As far as I remember, Avis style adjusters are ok as you don't have to cut right through the beam but you would need to check with Bill.
Cheers.........Wayne

psimitar - December 20th, 2019 at 10:06 PM

Quote:
Originally posted by hulbyw
Give Bill at Talk Torque Automotive a call. He is a VASS engineer who knows VW's inside out. As far as I remember, Avis style adjusters are ok as you don't have to cut right through the beam but you would need to check with Bill.
Cheers.........Wayne


Thanks Wayne. I spoke to Bill earlier in the year and also had a consult with another engineer earlier this week.

I forgot to put in my original post about the beam being narrowed to offset the track widening of a wide 5 brake disc kit.

Avis/puma style adjusters can be engineered on a standard width beam but it's the custom beam that's the issue. It can be engineered but is a lot more involved and the new engineers receptionist is a bit bad at getting back with what legal document outlines the specs and testing that need to be adhered to.

I was hoping someone on Australias main VW forum would have come across this in the past although I know that the majority of narrowed beam Bugs are running around with an illegal modification as it is a PITA to make such a mod legal.

vwo60 - December 23rd, 2019 at 08:25 AM

It is very hard in Queensland to narrow the track as any narrowing is illegal, By fitting the incorrect wheels to return the track to the factory specs still has a very bad impact on the suspension, , as the 25 MM allowable track increase is about scrub radius and the extras loading on the inner trailing arm bearings, king and link pins and spindles, so doing this is the same as going over the track increase that is allowable as it has the same impact. My engineer refuses to accept any form a narrowing of the track and when I removed the narrowed beam from my Ghia that was used to fit Fuchs with the incorrect offset, It was 100% improvement in handling and drivability. I think you will have issues getting an engineer to approve the narrowed beam as he has to carry the responsibility for it's approval as it lacks sound engineering .

psimitar - December 28th, 2019 at 12:14 PM

Quote:
Originally posted by vwo60
It is very hard in Queensland to narrow the track as any narrowing is illegal, By fitting the incorrect wheels to return the track to the factory specs still has a very bad impact on the suspension, , as the 25 MM allowable track increase is about scrub radius and the extras loading on the inner trailing arm bearings, king and link pins and spindles, so doing this is the same as going over the track increase that is allowable as it has the same impact. My engineer refuses to accept any form a narrowing of the track and when I removed the narrowed beam from my Ghia that was used to fit Fuchs with the incorrect offset, It was 100% improvement in handling and drivability. I think you will have issues getting an engineer to approve the narrowed beam as he has to carry the responsibility for it's approval as it lacks sound engineering .


There is a major lack of common sense when it comes to getting something engineered. Due to the track increase from the brake disc kit then my engineer is OK with the narrowed beam as overall the track remains the same.
As the LP disc kit increases the track then it will of course increase loading on the small bearing but there is no getting away from this.
However, by being able to keep the wheel mounting plane at roughly the same spot then the offset of the wider wheel will be better. The more positive the wheel offset the more strain you put on the outer bearing, IIRC from researching this years ago. By having less positive offset it helps the load of the wheel be spread more evenly to the inner and outer bearings.
As for sound engineering, well so long as the beam is made properly and passes certain tests then it will be absolutely fine. Yes there will be some extra loading and the weight of the steering will be heavier but for the good old wide 5 front end upi don't have too much option once you get away from the drum set up.

Sure I could buy a fat girl to make a Subaru drivetrain easier but personally I don't like the look of them and much prefer the earlier styling. Even if I built a large CC VW engine I'd still have the same suspension issues up front if I want the thing to slow down properly.

vwo60 - December 29th, 2019 at 08:34 AM

The unsound engineering I refer to is the scrub radius changes that have some very bad effects on the handling of the car, the same track means nothing, , my engineer has currently asked me about the bump steer and scrub radius on the double wish bone suspension that I am currently installing in my car as these are the two things that have the most effect of the drivability, if you narrow the bean to install brakes that increase the track or wheels with the wrong offset it is exactly the same as going over track irrelevant of were the wheels end up, your engineer is wrong, draw a line though the king pin or the ball joints and were it meets the road at the tyres is your scrub radius, any change from this in the positive increase bump steer, tram lining , increased wear in the inner trailing arm bearing , king pins, link pins and wheel bearing while loading up the suspension with loads that it was never designed to handle, and going all over the road under hard braking. It has nothing to do with narrowing the beam, I asked my engineer and he said it is the relationship to the scub radius that is the issue. The solution is simple , don't narrow the beam buy wheels that have the correct offset to maintain the scrub radius. the front wheels are 6 x 17 with an ET of 60, fitted to as standard width beam, with disc brake conversion and dropped spindles all approved.

Bizarre - December 29th, 2019 at 09:45 AM

What wheels are those?

psimitar - December 29th, 2019 at 12:03 PM

Quote:
Originally posted by vwo60
The unsound engineering I refer to is the scrub radius changes that have some very bad effects on the handling of the car, the same track means nothing, , my engineer has currently asked me about the bump steer and scrub radius on the double wish bone suspension that I am currently installing in my car as these are the two things that have the most effect of the drivability, if you narrow the bean to install brakes that increase the track or wheels with the wrong offset it is exactly the same as going over track irrelevant of were the wheels end up, your engineer is wrong, draw a line though the king pin or the ball joints and were it meets the road at the tyres is your scrub radius, any change from this in the positive increase bump steer, tram lining , increased wear in the inner trailing arm bearing , king pins, link pins and wheel bearing while loading up the suspension with loads that it was never designed to handle, and going all over the road under hard braking. It has nothing to do with narrowing the beam, I asked my engineer and he said it is the relationship to the scub radius that is the issue. The solution is simple , don't narrow the beam buy wheels that have the correct offset to maintain the scrub radius. the front wheels are 6 x 17 with an ET of 60, fitted to as standard width beam, with disc brake conversion and dropped spindles all approved.


I get what you're saying but the scrub radius line through the king pin should intersect with the centre line of the tyres tread in the same point as factory. Hence isn't it possible to change the beam width and with custom offset wheels have this intersecting point in the same place?

I mean with a brake kit pushing the wheel further out you have to use custom offset wheels to kick the intersecting point back inboard so hence I don't see the difference.

I did refresh my memory last night with some light reading before bed :) but having another person who understands this is helpful in figuring it out :)

vwo60 - December 29th, 2019 at 10:39 PM

Quote:
Originally posted by Bizarre
What wheels are those?


Image wheels number Billet 91. https://www.imagewheels.co.uk/billet-91-alloy-wheel/ 

vwo60 - December 29th, 2019 at 10:48 PM

Quote:
Originally posted by psimitar
Quote:
Originally posted by vwo60
The unsound engineering I refer to is the scrub radius changes that have some very bad effects on the handling of the car, the same track means nothing, , my engineer has currently asked me about the bump steer and scrub radius on the double wish bone suspension that I am currently installing in my car as these are the two things that have the most effect of the drivability, if you narrow the bean to install brakes that increase the track or wheels with the wrong offset it is exactly the same as going over track irrelevant of were the wheels end up, your engineer is wrong, draw a line though the king pin or the ball joints and were it meets the road at the tyres is your scrub radius, any change from this in the positive increase bump steer, tram lining , increased wear in the inner trailing arm bearing , king pins, link pins and wheel bearing while loading up the suspension with loads that it was never designed to handle, and going all over the road under hard braking. It has nothing to do with narrowing the beam, I asked my engineer and he said it is the relationship to the scub radius that is the issue. The solution is simple , don't narrow the beam buy wheels that have the correct offset to maintain the scrub radius. the front wheels are 6 x 17 with an ET of 60, fitted to as standard width beam, with disc brake conversion and dropped spindles all approved.


I get what you're saying but the scrub radius line through the king pin should intersect with the centre line of the tyres tread in the same point as factory. Hence isn't it possible to change the beam width and with custom offset wheels have this intersecting point in the same place?

I mean with a brake kit pushing the wheel further out you have to use custom offset wheels to kick the intersecting point back inboard so hence I don't see the difference.

I did refresh my memory last night with some light reading before bed :) but having another person who understands this is helpful in figuring it out :)


You are quite correct , if you narrow the beam and fit disc brakes that widen the track, then fit wheels with a custom offset to retain the stock scrub radius, the only problem is, the track is now narrower by the amount you narrowed the beam, even my engineer will not a approve it as a reduction in track is illegal.
Why not do it correctly by not narrowing the beam and apply the above. just as I have on the Ghia, the best thing I ever did was remove the narrowed beam in my Ghia..

psimitar - December 30th, 2019 at 10:02 AM

Quote:
Originally posted by vwo60

You are quite correct , if you narrow the beam and fit disc brakes that widen the track, then fit wheels with a custom offset to retain the stock scrub radius, the only problem is, the track is now narrower by the amount you narrowed the beam, even my engineer will not a approve it as a reduction in track is illegal.
Why not do it correctly by not narrowing the beam and apply the above. just as I have on the Ghia, the best thing I ever did was remove the narrowed beam in my Ghia..


As the track is to the mounting face for the roadwheel then my engineer could see the logic in the overall setup with a narrowed beam to offset the widening the disc kit gives. I mean technically the brake disc kit is illegal as it would take the overall track beyond the 25mm increase allowed but there you go.

After more thought I may actually leave the beam as is, just with puma style adjusters fitted. I'll have to check where the stock scrub radius lays and then take it from there to figure out how it will all fit under the stadanrd arches :)

vwo60 - December 30th, 2019 at 12:48 PM

I do not understand how your engineer thinks it is ok to narrow the beam to accommodate the disc brake set up if it is the same as being over the 25mm allowance, change your engineer. what about the disc brake conversion that vintage Veedub had that actually narrowed the track slightly, if you can maintain as close to the stock scrub radius you will be rewarded with a better handling and braking car, the front end has many issues and if you change the scrub radius it makes the car a dog. if you use the over track disc brake kit it will require a custom wheel offset to cover the brake conversion, My ghia and green beetle have been built using composite wheels but has the desired effect with every person who has been in the cars telling me the handling is amazing. Attached is a VW technical drawing showing were the scrub radius is.