Well, after far too many hours of internet research into the Briggsbuilt cars and finding only scraps of info.. I'd like to create a thread for others interested in building a chassis.

There are the lucky few that own one of the gen IV cars that might help out with real life measurements or some guys that know someone with a gen IV that can actually use a tape measure (definitly not K-fab) to post some major dimensions.

Why the gen IV.. to re-create the best developed chassis that the genius Briggs designed but gen III measurements are also welcome.

I'm working on a drawing from just a few good printed photos, side view and front/rear views, I'd like to thank the guys that have posted info and pics on this forum... its all some people have to go on now, reading forum posts from 10+ yrs ago with comments about why there wasn't more cars to race.. I've got quite good old school drafting skills but actual dimensions are rather useful when your trying to design something in 3d on flat sheets of paper.

And the dig at k-fab.. no offence but a 53 page blog on what he can afford to do to the briggs cars copy'd from his website and more than a few requests for some dimensions he gave up OAL 96" (2438.4mm) OAW 66" (1676.4mm) wheelbase 65" (1651mm) and.. width 28" (711.2mm) very back of the frame where mid-tube and rollcage meet.

That's a start but we could use more info when he posts... what more do you need.

The gen IV stadium cars were 700lb wet and 64" (1625.4mm) wide and up to 72" (1828.8mm) wheelbase, the SODA long wheelbase cars were +6.5" between the suspension points and +4.5" wider.
The +6.5" added was +2" forward of the B pillar and 4.5" behind it for a longer Engine compartment to fit the Polaris 440cc Engine, more elbow room for the driver too so width could of been added to the chassis mid-tube. There is an article in Dirt Wheels magazine July 1995 about the Briggsbuilt SODA cars.

The RPM billet transmissions that were used for the SODA cars used no less than 9:1 ratio gear sets and the stadium cars used 7:1 ratio, VW type 4 CV's were used and with an OD of 100mm I think I've worked out the bearings used for the rear bearing carriers are 100x150x24mm 6020-2RS. The rear stud pattern is 6x 5" pcd I'm not sure of the front pcd and the wheel hubs are machined from 7075 T6 aluminum.

Rear tires BFG radial T/A's 205/60-R13 21.75" dia 7" wide, front tires BFG trail masters 175/80-R13 23.5" dia 7" wide, the rear bearing carriers can fit 12" rims over them too. Knowing the tire or rim diameter is useful for scaling off a side view photo.

Steel tubing used for the chassis was 1.25" chromoly and what looks like 0.75" dia tubing for the cross brace and strut brace tube between the front shock mounts. Front spindles used 3/4" uniball size I'm not sure what size the heims are just that they were aluminum and the solid aluminum suspension links would be 7075 T6 with the steel tubing links being 1" dia and 4130 grade.

The widths of the chassis at various tube intersections would be helpful, also lengths of suspension links and chassis mounting layout for the heims. I have a side profile drawing of the briggs chassis mostly figured out it's the width's I'm having issues with then the challenge of the suspension next.

If others have any info to add or spot a mistake please contribute to the thread, cheers

I have Rennie Awanas old Gen 3 Briggs. The Gen 4 parked next to it in these photos I know the owner. He isn’t on fb but is on Instagram, Rustys_garage777 can’t guarantee he will pass on any info though. He has Shannon Millens Natures recipe buggy and it’s complete like the day raced. Awanas buggy I have came without an Engine or fuel tank. Rusty built a tank and dropped a rotax 583 in it for me. His Gen 4 actually comes with a RPM trans with a quick change rear end.

https://www.facebook.com/bob.pettit.104 ... 9574919680
See if this link will work for you. It’s a video I took of the buggy when Rusty picked it up. I stored it for almost 2 years for another guy. Never even started it. LoL.

Hey Rppjr, great pics on the difference between the gen III and gen IV chassis, that's ok if he doesn't want to share info on his car.. one thought when I was asking for dimensions is the guys that own them usually race em so how the car is tuned and setup is hard earned info not to be shared.

I read that Rennie Awana also built a long wheelbase gen III

This is a photo of the gen IV rear bearing carrier printed pic how I worked out the bearing size from the stud pattern, measured it in milimetres and scaled it using the known dimension.

I had one of those carriers and a Cover, it came With a parts lot of Gen 3 parts. Didn’t know what it was until someone saw a pic on fb. They wanted it bad. To the tune of 800$ bad. Send rusty a message on Instagram, it may take him a moment but he is pretty good at returning messages. I know his day job right now has him swamped, that would be the reason for not getting back to you. This is/was the last buggy Awana built. It was stretched somewhere between 7-12” I believe. Ran a Raptor 700 Engine, RPM trans etc.

Picture of the rear carriers

If you get on Facebook, Dan Roberto (RPM Trans) responds to pics on the buggy sights. One is a vintage racing page of these buggies. I can send you the name if you are interested.
Bob

Ah so that is the long wheelbase car cool, that pic of the rear carriers is useful I wondered if their was a bearing spacer used and the spacing is machined into the housing ring, I've looked at quite a few buggy designs and the hubs on the Briggsbuilt are unlike any others combine wheel centre and disc mount.. wheel hub and cv joint all together to save weight and increase suspension arm length for max wheel travel within the rules given.

I'm not on facebook, sometimes useful if I was with some of the groups on there.

This is a photo of tying to work out the suspension geometry, even knowing the length of the alloy upper link would be helpful.. horizontal dimensions don't distort as much as the vertical ones when looking at photos. Steering links look like 3/4" dia solid bar stock.

I’ll take a screen shot of this and send to him and see what he says . The stretched Briggs isn’t mine. I joined a fb group, the guy saw I had Awanas old buggy and messaged me. He knew Rory Holliday and was looking for a part for a fl250. Rory gave him Bud Orrs (spelling?) info. Bud Orr had Rory’s old car as well as the Shannon Millen buggy as well as a butt load of spare parts. The guy messaged me with pics of the body panels. Asked me if I could help him with all the parts he had just bought. Obviously I said yeas and asked rusty to come along. The Rory Briggs went to Australia and the Millen car stayed in California. I purchased more spare parts and he asked me if I was interested in the blue buggy. I declined and told some other people about it. They scooped it up and then sold it to a guy also in California called Rod Emery. He is known for rebuilding old Porsche’s. Anyways long drawn out story to I didn’t buy it. I do have the one Briggs as well as a few EEE buggies.
Bob

I sent the pic, he responded with he will measure the whole car if you want. He may reply to this thread or send you a PM.
Bob

Long story but interesting story, was trying to figure out through the forum threads where/who the gen IV's went to and so their was a briggs that flew to aussie.

I'm futher away in New Zealand, it's a shame what happened to this class of racing and we have a short course stadium track built here and someone promoting the old Mickey Thompson series as "Polaris" so sidexside racing now. I don't have the deep pockets needed for racing but have the skills to weld up a chassis that might surprise the motorsport guys here.

We have Kartcross buggies marketed here as "affordable" motorsport option at $40K each or $5K leased for the weekend rally event. Same old story as most countries, the price of racing is getting too expensive.. will see what a guy in a shed can come up with (one rather fast old indian for instance lol)

Any measurements would be appricated, was trying to get within an inch scaling off printed photo's but I have to use several of them so dimensions are a little off. Wanted it to fit on a 5x8 trailer so I might make the width 1500mm or two sets of suspenion arms, my frame drawing is 2250mm tube centres between the front horizontal tube and the rear most horizontal tube. Scaled the frame as 2260mm (89") length overall tube to tube.

Be using 25" ATV tires with 12" DWT red label alloy wheels.

Hopefully these are what you are looking for
Bob

That's a good way to document the suspension dimensions, I can see that links mounting bolt is about 2" from the uniball centre with a ruler on the photo.. there's not much info online about the suspension other than it has quite abit of ackerman designed into it, I found camber -2deg and caster of 4deg from a forum post but each car wouldn't be setup the same, somewhere to start from at least.

Could you ask him for pics of the other suspension links when he's got time too, the distance between centres of the 3/4" uniballs on the front spindle would be helpful and the length of the steering pivot arm off the spindle.

These are the best photo's I've found of the front spindles, the tapered cone part is hollow and the hi-miss for the uniball is machined into it.

Thanks to the forum member that scaned in his old photo's to this section years ago.

Ha just checked those last two threads in the Briggsbuilt section, thanks hoser!! Those pic's did inspire a build project.

Started drawing the rear hub from the measured photo I posted, kinda found out why 13" wheels were used.. put a 150mm radius arc on my drawing for approx. 12" dia wheel and the top right heim joint would hit the wheel. The stud pattern drawn is 4x137mm but I could go with 4x156mm Polaris and Yamaha pcd for more wheel choices since finding 12x8 DWT alloy wheels ain't easy where I live as I found out this week with two companies just stocking 10" atv wheels.

13” wheels were used because in the MTEG series you were required to run one of the tire sponsors (Yokohama,Bridgestone,Goodyear). Since 13” tires were the smallest any manufacturer made that’s what was used. 175/70/13-185/70/13-225/50/13 were the most common sizes run on the lites. I have used the Polaris wheels on a EEE with wheel adapters. If I did it again I would use Can-Am wheels as the bolt pattern is closer together and the price is less for the wheel adapters. Rusty is at Dand Hollow in Utah for the UTV Takeover event. Hopefully When he gets back he will send more measurements for you.
Bob

That makes sence they would run the sponsored 13" tires, was hoping to use 12" wheels so will have to make bearing hubs to fit when I source a wheel to measure. I'm wondering about the strength difference between 4x137 and 4x156 pcd, the cost between 6061 t6 alloy and 7075 here is about double that of 6061 pricing up 7" and 8" round billets.

All good, when Rusty has the spare time to get the tape measure out is sweet, the inside widths of the chassis tubes is the next to scale off photo's.. looks like the floor cross tube behind the seat is about 29" between the lower main tubes.

Well, far too many months later an update on this project.. kinda need more dimensions from an actual Briggsbuilt chassis I think, I have a side profile drawing of the 1.25" tube layout for the chassis but I got abit stuck on the widths of the horizontal tubes going across the frame.

Rear hub drawing showed the briggs hub wont fit 12" atv wheels I wanted to use that I have to import a set into NZ, looked at type 2 VW axles and their axle/bearing costs... without alot of dimensions from someone with a Briggsbuilt it's kinda hard to make a replica so started looking at Yamaha YXZ 1000r rear CV axles with a 756mm compressed length and RZR 1000 rear CV axles with about 730mm compressed length. The inner CV joints could have flanges welded to them and drilled to mount to a 60t sprocket chain diff, its the inner splines that strip out on the SXS/ATV diffs anyway so would cut them off after machining the flanges true to centre on a lathe.

I scaled my drawing down slightly to suit 12" rims and tires, its at 1600mm wheelbase and 2275mm total length now.. I could post a pic of the rough drawing if a few guys were interested in the info for their own builds. The angles and proportions are as accurate as I could do with the limited info online about the chassis. Should just build a simpler buggy but its been alot of hrs of research just to get this far on the project.

When Renni (Flyin Hawaiian) and Bob Briggs raced in MI against Bob's SODA Series cars Bob built Renni was smoking them all until he started to run out of gas. The next weekend race (they Renni stayed all week for the next race) when Bob returned he brought Renni a smaller diameter driven and new belt. Renni smoked them all, he was running a claimed 467cc hand build looking thing, had 20 feet of aluminum weld on the Engine looked mostly hand built off a FL350 bottom end, sounded like it was turning at least 9000 RPM. It even smoked Bob's CR500 top end Pilot Engine. The 440 twin sled engines in Bob's SODA Series cars did not stand a chance. IMO they were under powered by at least 35%.

A friend of mine drove Renni's backup car the 2nd weekend had the adjust the jetting from the drivers seat by turning a knob carb on it, like a Dial-A-Jet but I think it was home made never seen anything like it before it was trick. He had to lean it out for the corners then fatten it up for the straights. Rennies backup was fast but nothing like his personal car. I should have pics of those 2 weekends of racing some place here on the site.

Renni had 3-4 spare hand built engines in his trailer, unsure if he swapped engines between weekends or if it was all in the higher gearing.

While talking to Renni I asked if his car would last in a desert race like the Parker 400 he said NO and it was built to light was designed for short course racing only. So any of you running WOT (Wide Open Throttle) in the desert beware and inspect the frame often.