Could a swb beach buggy ever handle really well?

[maxyray]

Hi all,
My name is Max and I live in the UK. I've not posted under this part of the forum before. But have a on going build thread for my 1776 EFI turbo engine here...
http://www.shoptalkforums.com/viewtopic ... 3&t=138344

After finishing my new engine I came up with the idea of taking it to track days which started me thinking of all the mods i could do to make it into a little road/ track racer and below is my current plan.





First up...
Move battery and try to get some weight to the front.
Cup torque bar.
IRS rear conversion.
16x7 front and 16x9 rear Fuchs reps with toyo r888 tires.

Later down the line I was thinking...
11" vented discs all round with Wilwood dynalite calipers.
Red9design front wishbone and rear uni ball with coilovers.
Hd freeway flyer gearbox.
Intercooler.

Eventually my goal is to build up a Porsche 356 coupe replica out of the buggy so I would like all mods to be transferable.

The buggy currently has a few good points, that it's very light, has a great power to weight ratio. I guess the current engine has around 150hp at 14psi of boost but I will be pushing to 200hp soon. It has an 8 point cage that ties to the front beam and the rear. It also has 4 point harnesses, bucket seats and the fuel tank is over the front beam.

My question is this, I've been told that a short wheel based car with rear engine and drive will never handle well. Is this true and would I just be wasting my time and money chasing an dream that will never work?

[ps2375]

http://www.aircooled.net/vw-handling-suspension-tuning/

[PhillipM]

My question is this, I've been told that a short wheel based car with rear engine and drive will never handle well.

It might not have the finesse of a MR car, but there's no reason you can't make it handle well.

[maxyray]

http://www.aircooled.net/vw-handling-suspension-tuning/

Thanks for the link. Some good reading there. I think using coilovers is the way to go to dial in the handling rather than swoping sway bars.

[maxyray]

My question is this, I've been told that a short wheel based car with rear engine and drive will never handle well.

It might not have the finesse of a MR car, but there's no reason you can't make it handle well.

Good to hear. What mod would you recommend? At the moment the rear feels very unstable on the roads. Will have to take it to a track to see how it really handles.

I currently have soft dampers on the rear with 3mm toe in. Maybe I'm running to much rear camber!

[Dale M.]

Auto crossed a 69 pan with FG body.... It was IRS and BJ front beam.....Ran 3/4 sway bars front and rear... Type 3 brakes on rear (disk are to big for 1360 lb car) with stock drums on front... Disks will take you from free wheeling to lockup to fast in light car....... For tires and wheels I ran 5.5 x 13 wide fives and Formula Ford cantilever Goodyears (we were running a MOD class and not "street" class)... Has caster shims in front beams and some extra shims for more caster...

As for handling all the pros will tell you how to drive buggy as if it were a front engine car.... Does not work that way, ingress to corners is totally different as you need to setup car for the turn sooner than with front engine car and once you reach apex of turn you can add power.... Get a little to power happy to soon going into turn, and you will loop it and your are along for the ride toll car give control back to you....

It can be fun, local buggy held top time of the day for a long time before Subaru's (with $10,000 in "extras") came along.... Corvette's and Porsche's hate buggys...

Only thing I really learned was I was not a "driver", buddy of mine who was usually tops in class was faster in my car than in his.... With him driving my car he was 4-5 second faster in my car than me.... Yes in auto cross 4-5 seconds can be a lifetime, can be difference from being at top of class to bottom of class...



Car was sold about three years ago when I retired from auto-x...

Dale

[Ol'fogasaurus]

Max, if your intent is to have fun and you are having fun it is not a waste of money! There is an old engine builders saying: "Just how fast do you want to go... show me your wallet". Before I forget, you have built a very nice, clean buggy (it depends on where you live as to the term a glass bodied car like yours gets used when talking about it.

I followed Dale's build until he got frustrated and that is not uncommon. I used to belong to a car club where most of the members did Auto-X, some just more competively than others. Frustration came after you moved pass just having fun and testing yourself.

One thing about the front suspension you might consider is removing the leaf stack from the top tube and replacing it with a "through rod". That should take some of the stiffeness out of the front end. Some people nick some of the leaves which allows the stack to be reinstalled as a whole but then the nicked leaves will break and the suspension is softened... maybe. Some remove a leaf or two but I am not sure that is a good idea. I am seriously thinking about building another beam w/o adjusters and doing that very thing (I off-road but the problem is still the same).

I would not go with the off-the-shelf type of coil over shock (I am talking about the EMPI and others style of shock here) for several reasons. Your term of "dampener" is probably a more accurate term and the coil overs usually don't have the valving you are going to want and the coils off-set your leaf stacks and can make the ride even stiffer than it is. Soften it up a bit as you want the tires to remain in good contact with the surface you are drivin on and get a good quality of dampener.

If you can find Dales build string there is a lot of good stuff in there as how he approached his build.

Going to IRS is a good thing but I would also check your local rules. My glass buggy would have been classed to race against VW powered "Pony" cars because it was modded.

With the shortened wheel base, as you alluded to the weight of the car moves to the rear and you sit farther to the rear. The term used where I am for the shortened wheel base is the car become more "twitchy" or the turning gets quicker because of the shory wheel base (redundant statement but I think you know what I mean. Kind of comparing a Go cart to an 18 wheeler as to the turning radius).

Your cage sound like a good one as it is what replaces the job the roof of the donor car did. I also stiffened up the side of my buggies where the body mounts to. If you do that you should be surprised at the difference in feel the first time you get back in it when it is done.

Are the seates mounted low to help lower the CG?

Anyway, some thoughts: good, bad or indifferent.

Lee

My opinion is worth something less than you paid for it.

Edit. If you don't already have one, a Kaffer/Truss/traction bar for the transaxle frame horns are a must. Piledriver has a URL for the ones he did (I upgrated to Win 10 and lost a lot of stuff, mostly in my favorites list) that is simple to do and looks like it should work very well. This setup keeps the engine and transaxle mounting forks (aka "pickle fork") from jumping up and down and swaying from side to side.

Also there are some short bars you can buy that bolt in from the front beam to the slots were there were the "up bolts" that connected the body to the pan. They are outboard of the frame head and give the beam some additional support where you might need it. This is dependant on how and where your cage hooks to the beam.

[maxyray]

Auto crossed a 69 pan with FG body.... It was IRS and BJ front beam.....Ran 3/4 sway bars front and rear... Type 3 brakes on rear (disk are to big for 1360 lb car) with stock drums on front... Disks will take you from free wheeling to lockup to fast in light car....... For tires and wheels I ran 5.5 x 13 wide fives and Formula Ford cantilever Goodyears (we were running a MOD class and not "street" class)... Has caster shims in front beams and some extra shims for more caster...

As for handling all the pros will tell you how to drive buggy as if it were a front engine car.... Does not work that way, ingress to corners is totally different as you need to setup car for the turn sooner than with front engine car and once you reach apex of turn you can add power.... Get a little to power happy to soon going into turn, and you will loop it and your are along for the ride toll car give control back to you....

It can be fun, local buggy held top time of the day for a long time before Subaru's (with $10,000 in "extras") came along.... Corvette's and Porsche's hate buggys...

Only thing I really learned was I was not a "driver", buddy of mine who was usually tops in class was faster in my car than in his.... With him driving my car he was 4-5 second faster in my car than me.... Yes in auto cross 4-5 seconds can be a lifetime, can be difference from being at top of class to bottom of class...



Car was sold about three years ago when I retired from auto-x...

Dale

That's very interesting Dale about the brakes you're running as I've heard a few people saying that it's good idea to run the same or even bigger brakes on the rear as most of the weight is back. I was thinking of running 4 pots front and rear with a pedal box with two master cylinders so I can tune the bias. 

I would only favour vented discs as I will be on a track for say an hour of hard driving with top speeds of 90mph and don't want brake fade due to heat. 

Autox isn't big in the UK from what I've seen. Think there are a few hill climbs about though. 

Love the way your buggy looks. Real mean! 

Do you have a link to your build? 

[maxyray]

Max, if your intent is to have fun and you are having fun it is not a waste of money! There is an old engine builders saying: "Just how fast do you want to go... show me your wallet". Before I forget, you have built a very nice, clean buggy (it depends on where you live as to the term a glass bodied car like yours gets used when talking about it.

I followed Dale's build until he got frustrated and that is not uncommon. I used to belong to a car club where most of the members did Auto-X, some just more competively than others. Frustration came after you moved pass just having fun and testing yourself.

One thing about the front suspension you might consider is removing the leaf stack from the top tube and replacing it with a "through rod". That should take some of the stiffeness out of the front end. Some people nick some of the leaves which allows the stack to be reinstalled as a whole but then the nicked leaves will break and the suspension is softened... maybe. Some remove a leaf or two but I am not sure that is a good idea. I am seriously thinking about building another beam w/o adjusters and doing that very thing (I off-road but the problem is still the same).

I would not go with the off-the-shelf type of coil over shock (I am talking about the EMPI and others style of shock here) for several reasons. Your term of "dampener" is probably a more accurate term and the coil overs usually don't have the valving you are going to want and the coils off-set your leaf stacks and can make the ride even stiffer than it is. Soften it up a bit as you want the tires to remain in good contact with the surface you are drivin on and get a good quality of dampener.

If you can find Dales build string there is a lot of good stuff in there as how he approached his build.

Going to IRS is a good thing but I would also check your local rules. My glass buggy would have been classed to race against VW powered "Pony" cars because it was modded.

With the shortened wheel base, as you alluded to the weight of the car moves to the rear and you sit farther to the rear. The term used where I am for the shortened wheel base is the car become more "twitchy" or the turning gets quicker because of the shory wheel base (redundant statement but I think you know what I mean. Kind of comparing a Go cart to an 18 wheeler as to the turning radius).

Your cage sound like a good one as it is what replaces the job the roof of the donor car did. I also stiffened up the side of my buggies where the body mounts to. If you do that you should be surprised at the difference in feel the first time you get back in it when it is done.

Are the seates mounted low to help lower the CG?

Anyway, some thoughts: good, bad or indifferent.

Lee

My opinion is worth something less than you paid for it.

Edit. If you don't already have one, a Kaffer/Truss/traction bar for the transaxle frame horns are a must. Piledriver has a URL for the ones he did (I upgrated to Win 10 and lost a lot of stuff, mostly in my favorites list) that is simple to do and looks like it should work very well. This setup keeps the engine and transaxle mounting forks (aka "pickle fork") from jumping up and down and swaying from side to side.

Also there are some short bars you can buy that bolt in from the front beam to the slots were there were the "up bolts" that connected the body to the pan. They are outboard of the frame head and give the beam some additional support where you might need it. This is dependant on how and where your cage hooks to the beam.

I would 100% just be building this for fun. I enjoy building it as much if not more than I do driving it. The track days are non competitive just something I would like to get into. 

As far as the front and rear suspension goes here is what I'm thinking... 

Front Wishbone kit or the Ez rider coilovers and the uni ball irs set up for the rear. http://red9design.co.uk/type1.htm

I've called them and they can add a softer springs for the buggies weight. What do you think? 

Here is a pic of the cage (sorry for the poor quality)



I still need to find a better way to connecting the rear of the cage to the rear suspension. And I will add a cup brace. 

The seats are on custom mounts I made  they sit probably 2" off the pan. I may be able to lower them a bit. I will look into that. 

Cheers for the ideas. 

[Ol'fogasaurus]

Your cage is somewhat similar to mine with the exception of you using the "T-top" style of center bars which, in ways, is much better than my "3-bar" style for getting in and out. On my 3-bar style I have a center bar (bent slightly) and two outer bars also bent slightly (I can't post pictures right now. I don't know what the problem is) at the bends of the two hoops; you have to fold like a jackknife to get in or out. For off-roading like I do, the outer bars are for protection in case you slide or tip into a tree or something like that. One good thing about both is the bars in the center are good place for mounting a GoPro style of camera.

IFS is nice to have and somewhat more tunable but I think they have the possibility of being a bit more in weight. You most likely be using a properlly designed coil/dampener setup rather than the torsion bars and coils which can be over-kill.

Brakes are another thing. Dale is correct about being able to over brake with the shortened pan and type three (the backing plates are hard to find here now) can be a good choice. There are also adjustable proportioning valve available to fine tune things... if you need it.

Your support of the front end is good. I haven't done the upper tube yet mainly because I am not sure on how I want to do it. My cage is mounted similar to yours with the lower part of the cage sitting on the body mount tunnel so it is removble without removing the body also. Mine, because I ride in the sand sits on a 1 1/2" X 3" X .095 wall rectangular tube with stiffens thing up a bit.

My upper tube mount, I think, I want to be removable at the same time and I don't want to have to cut holes in the body. I notive you have a separate firewall which is something I don't remember seeing before. Good job!

The cup bar, does it have the same job as the bars I mentioned, that is keeping the pickle fork steady?

Old buggys here (we refer to the fiber glass buggys as Manxes [a general catch-all term like Jello or Kleenex) which is a actual body name] or dune buggy or something just as simple as a "glass buggy". Moving off the left coast to the center of the "states", the word tub buggy is often used and as you move towards the right coast and a lot of places overseas it is a "Beach Buggy") often just have a tube going across the rear of the buggy under/to support the package tray/rear seat is which the down bars of the cage is usually attached. Your "package tray" design has to be a lot stronger than the tube or piece of "U-channel" like mine came with. Again, I like your idea better.

I would prefer a straight not bent bars in the back but what you have should be more than OK.

We have quite a few guys here who road race Bugs and Ghias and maybe even some type 3's. I am hoping they will jump in and put their "two-bits" (a slang term meaning 25 cents or giving their opinions and expertise) wotth in.

Lee

[maxyray]

Your cage is somewhat similar to mine with the exception of you using the "T-top" style of center bars which, in ways, is much better than my "3-bar" style for getting in and out. On my 3-bar style I have a center bar (bent slightly) and two outer bars also bent slightly (I can't post pictures right now. I don't know what the problem is) at the bends of the two hoops; you have to fold like a jackknife to get in or out. For off-roading like I do, the outer bars are for protection in case you slide or tip into a tree or something like that. One good thing about both is the bars in the center are good place for mounting a GoPro style of camera.

IFS is nice to have and somewhat more tunable but I think they have the possibility of being a bit more in weight. You most likely be using a properlly designed coil/dampener setup rather than the torsion bars and coils which can be over-kill.

Brakes are another thing. Dale is correct about being able to over brake with the shortened pan and type three (the backing plates are hard to find here now) can be a good choice. There are also adjustable proportioning valve available to fine tune things... if you need it.

Your support of the front end is good. I haven't done the upper tube yet mainly because I am not sure on how I want to do it. My cage is mounted similar to yours with the lower part of the cage sitting on the body mount tunnel so it is removble without removing the body also. Mine, because I ride in the sand sits on a 1 1/2" X 3" X .095 wall rectangular tube with stiffens thing up a bit.

My upper tube mount, I think, I want to be removable at the same time and I don't want to have to cut holes in the body. I notive you have a separate firewall which is something I don't remember seeing before. Good job!

The cup bar, does it have the same job as the bars I mentioned, that is keeping the pickle fork steady?

Old buggys here (we refer to the fiber glass buggys as Manxes [a general catch-all term like Jello or Kleenex) which is a actual body name] or dune buggy or something just as simple as a "glass buggy". Moving off the left coast to the center of the "states", the word tub buggy is often used and as you move towards the right coast and a lot of places overseas it is a "Beach Buggy") often just have a tube going across the rear of the buggy under/to support the package tray/rear seat is which the down bars of the cage is usually attached. Your "package tray" design has to be a lot stronger than the tube or piece of "U-channel" like mine came with. Again, I like your idea better.

I would prefer a straight not bent bars in the back but what you have should be more than OK.

We have quite a few guys here who road race Bugs and Ghias and maybe even some type 3's. I am hoping they will jump in and put their "two-bits" (a slang term meaning 25 cents or giving their opinions and expertise) wotth in.

Lee

Thanks Lee good to hear my cage is up to standards. I made it myself with a hydraulic pipe bender and a load of scrap tubing. 

If I was to build it again I would probably make the two rear bars cross over the back bench to add more strength and support. 

Here is a pic that shows the cage from the top. 



I really would like to make a custom 5 bar cup brace, then tie in the two rear bent bars. 

Have you ever seen a battery mounted right behind the front beam on the passengers side? I think there may be room for it there and would offset some of the divers weight and help to keep the nose on the ground! 

[Ol'fogasaurus]

A battery behind the front beam, no. Riding in the sand like I do we keep as much weight off the front as we can so I'm not much help there. I'll try to post something up but I do have two builds going on. They probably won't be of much help though as they are more directed towards off-road. A lot of similar problems but a lot of differences too.

Lee

[Dale M.]

As for build thread... NO I never documented the build very well, have some pic buried deep in my computer (someplace).... A couple of other things.... Full wish bone ("a" arm) front end is not really going to help handling much for auto x but gives you cool bragging rights on street.... The are primarily for looks and probably not well engineered for race application...

As for front suspension, add adjusters if you do not have them and getting correct number of "working" leaves in front suspension is paramount... I cheated, I removed all the half leaves in from stacks and just used all the main leaves, on my red street buggy and blue track car...

Another issue with shortened pan is "Ackerman" steering... I actually ran as much negative camber I could in front as I could dial in with ball joint eccentric for best tire patch and ran with a slight bit of toe OUT... To compensate for loss of Ackerman steering.... Also for brakes a skid test at 40 mph (65 kph) show equal brake lock up with standard type 1 brakes on front and type 3 brakes on rear with SINGLE PISTON master cylinder....

As some point you will have a transition from a "street" buggy to a "race car" a single buggy can not be both... Build it as a street car the occasional get a little workout in auto-x and enjoy your buggy, or build it a race car, forget street driving and get a whole bottle of tranquilizers to ease the frustration...

What kill the racing thing for me as I had car at max tune and I was just a slow driver realizing the only time I moved up in standing is other faster driver failed to show up at event.... ALSO I was towing car for about 6 hour round trip (156 miles one way (251 km)) for about 4 minutes of track time and the incidents on public roads was sort of unnerving... Twice in one day about 25 mile apart there was full blow panic stops where pickup was in full anti-lock mode and trailer tires where howling when car entered from side road (ran stop sign) and at 55 mph there was not more then 2-3 inches between my front bumper and his rear bumper as he was trying to get up to speed and I was trying to slow down... And then up the road a bit was going to pass two big diesel rigs (18 wheelers) going about 10 mph (uphill) when rear truck decides to pass slower truck in front and came over into my lane, again same scenario, missed putting grill of my truck all over rear if his trailer by inches.... Gave him the royal middle finger salute as I finally got by...

Just build street car you can be proud of and occasional take it to a track event and have fun...

Dale

[Ol'fogasaurus]

Nice honest post Dale, good job!

Max, I've been been thinking about the battery up front by the beam and I can think of more reasons not to than any advantages of doing so.

Even though I am being silly on this I don't like the battery and fuel tank in close proximity in case of a spark or fuel leak (vapor). I know cars now days do it but we are dealing with tired metal here too.

(silly again. Remember I think off-road at times) If you were running one of the new style of dry batteries then the potential bouncing/shaking around of the battery fluids and sulfated droppings in the bottom of the wet battery may or may not affect it as much but the main reason I wouldn't do it is the distance it would be from the the electronics that count; the generating system.

Voltage drop (look it up and there is discussion and charts on the subject) is one thing and grounding is another related problem. Old metal doesn't transmit electricity (in this case the ground side where all the work is done) as well as new metal. Other than your cage you don't know who has been welding on the pan and if they were clean/good welds, etc.. Even in todays cars a lot of problems can still be traced to grounding.

Just some thoughts because you asked.

Lee

[PhillipM]

I'd probably put at least one diagonal in the side 'door' bars just to let your cage stiffen the floorpan up around the torsion arm mountings (Doesn't matter how good your dampers and springing is if your chassis is flexing instead) - then, I 'd get it on track, give it some welly and get some idea of where the car is letting you down, starting from scratch like this, well, you can pretty much just throw your wallet at it and still not have everything you think you might need.
Take it out and see what issues come up and take it from there, there's nothing particularly bad with the beam front suspension that can't be fixed with some alterations for example, rather than paying out for a wishbone kit straight out of the door - I'd sort the rear first personally.Definately ditch those heavy wheels for your lighter options though, the unsprung weight ratio on a buggy is poor to start with, without making it worse.

The dynalites might be a little lacking in beam stiffness, especially on the rear, depends on the weight and wheel/tyre sizes but the Midilite might be a better bet. Discs are more linear in response than drums generally though so even though you may not need any extra braking power, the extra finesse may be handy on track.

Can't give you much advice on bolt-ons, as I generally just pick up a welder and make what I want