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Kev says you have to go silly or don't bother - challenge accepted - weekend car....

  406 V6, Race Buggy
This is what we play with when we manage to get 5 minutes where we're not fabricating/prototyping go-faster bits for racers and track cars, it's pretty much in a constant state of rebuild, it's on it's 3rd engine swap now (and it's 5th engine), 3rd gearbox, front suspension, rear suspension, 4th set of brakes....basically, the only part of it actually left from the original car (it was a VW Beetle, believe it or not) is about 6 inches of tube in the middle of the car:
Baden Hall Day 2.jpg
New Suspension Trail Run 1.jpg
Waterbeach Bridge, Cambridge.jpg

We like silly, silly is good
  406 V6, Race Buggy
It's loads of fun until you get up on the Monday after a race weekend, when your spine screams 'Please, No!'

It had one of those spinning dorito's in the back in those photo's - was just shy of 270bhp, and ~800kg depending on the time/parts it was running, so pretty nippy.
It started off at just over 700kg with 100bhp and a 2.1 litre VW flat 4 originally, and we've just finished a conversion ditching the rotary engine (they kept turning from rotary engines into stationary ones), so now it has an F20C in the back with a supercharger from a 5.0 Jag V8 bolted to the side, around 370bhp on low boost, and ~830kg


ClioSport Club Member
That is obscene!

What's the balance like with (I assume) a lot of the weight at the rear? I imagine it can be a bit of a handful, but in a good way.
  406 V6, Race Buggy
Yes, RWD, open diff (at the moment, I'm trying to build/adapt my own out of off-the-shelf clutch packs - because the we can turn the boost up, as she should do 550bhp on full beans, but it's no faster than 370 with the current traction available).
All the weight over the rear is for traction - and some events you still end up just creeping at walking speed through some slushy stuff in the bottom of a Welsh wood, it gets a bit wet sometimes:

Waterbeach, Cambridge.jpg

Although when it does get some grip or a bit of help from a wee bump it will lift the front 2nd gear and hold it for a while (1st is only for putting it on the trailer):


Because it's quite rear biased it's a bit of a handful - think old Widowmaker 911, but with the weight hung further back and on knobbly mud tyres....
So all the suspension geo. has been completely reworked to help it out a little, and the new F20C engine is mounted quite a lot further forward with the gearbox shortened too. We end up with a similar weight balance from moving other parts to the rear for traction, but much less of it is hung out back like a pendulum.
We also have brakes that can work on either side of the car independently, so if the front goes light you can brake the inside rear wheel slightly to bring it around.
  406 V6, Race Buggy
Here's what she looked like originally, a fair few years ago after just being built, nothing fancy really bar the actual rollcage (all T45 tube), it had a 2130cc Volkswagen flat 4 in - basically a bored out, hopped up aircooled Beetle engine, with the heady heights of 4.5krpm and 100bhp, a VW Bus gearbox, and some off-the shelf front and rear trailing arms/hubs/brakes that are commonly sold in the 'states for sand/baja cars - acquired by buying a knackered car someone had imported and cutting anything half decent off it.
No doors/windows, etc, just basically for a bit of fun up and down the tracks and competing with production class Landrovers, etc, in Safaris. Mega low budget, as you can see by trailer lights, lorry mudguards, chickenwire, and that we made our own wheels :D

TL:DR - decent frame, load of half knackered scrapyard bits welded on.

5 speed 091 transaxle (we did fit a short ratio kit at some point)
~8 inches of travel up front, trailing arms, standard beetle torsion leaves, pair of used cheap yellow bilstein dampers.
-12 inches of travel at the rear, torsion bar (twin bars, setup to bring another in as a bumpstop), 4 x cheap yellow Billies.
- 2 pot front brake calipers, transit rear calipers, terrible Greenstuff pads (regulated at the time as sponsor of the races), independent brakes so left/right of car can be brake seperately.

But it went kind of okay, surprisingly on our early events it outpaced a lot of the production 4wd stuff and also a few of the regular 2wd even managed to airborne a few times:

We got a bit of development work going, started repairing/upgrading some of the worn used parts we had, upgraded the front end to Fox coilovers, etc.
Then the engine blew up:

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  406 V6, Race Buggy
Anyway, initial thought was to sort the engine out, we managed to jerry rig it a bit whilst we ordered more bits, but whilst out on a test run it lunched the gearbox too. Just as an extra kick in the nuts.

So, now we need a gearbox and more engine, if you've got to throw a bit of money at it, and the car is faster than you expected even with old knackered bits....why not spend a little more and update it to a more modern motor?

Queue rotary engine swap, the Renesis unit from an RX-8, attached to big beefy transaxle out of an old Renault van (see, we got some Renault relevance in there eventually!), so, one engine:

And our patented '9 Inch Angle Grinder Diet Plan" -

Right. Now, how the hell do you get a Mazda rotary on an old Renault Van gearbox when all you have is some spare VW flywheel and clutch bits and the old Renault plate that was on the box?

Mr. Angle Grinder had the solution again, one adapter plate made, then a bit of machining to fit the little 200mm VW flywheel (lightweight chromoly forged unit from the old engine) fit the rotary, then a cheap VW paddle plate with the centre knocked out and the Renault centre welded in...

Et viola:

Also, you many notice a set of Fox coilovers accidentally fell on the back to replace one pair of the tired Billies - the car has shedloads of updates between these main ones but I'm just keeping it a short synopsis.

Then it was old enging cage off, down to the workshop and it had an exhaust manifold an hour later:

And then over the next week or so started to mock up plumbing for radiators/oil coolers and new rear cage/panels:

Realised we couldn't feed the radiator with the side scoops as originally planned and stuck on a quick and dirty roof scoop:

And about 6-7 weeks later:

  406 V6, Race Buggy
Brakes were struggling a bit even on just the drift day there, so went up to 8mm discs instead of 6mm, and bumped the diameter by about 10mm, the most we could easily get, I machined 'em out of a bit of SG Iron plate, we started getting a bit fancier...



May notice it's also sporting doors/windows now too - made it a much nicer place to be in the mud!

Although, the first event with the new engine, we had a few heat problems, both engine air intake temps too high, and we melted the alternator:



So, we altered some of the radiator shrouding to help it out, and upgraded from the old 12" fans to some 16's, and directed a little more air through the side scoops - it finished the next event:




And the event after we fixed the very high intake temperatures by feeding the airbox from the roof scoop and the nice high pressure air in front of the radiators:



That took her up from 240+ to over 260bhp, perked things up a little.
  406 V6, Race Buggy
Pretty much, if you look the rearmost silencer was a cheap ebay universal bike can that was floating around, but we didn't have anything suitable for the bigger side box, so that was welded up out of some scrap ally tube and sheet and packed with some ceramic kiln blanket I'd been using to lag a forge with :D

Wheels are old Peugeot rims with the centres chopped out and the spokes cut out of flat sheet and shaped in the press then welded in, etc.
  406 V6, Race Buggy
Anyway, it had plenty of niggles and issues sorted out, heat problems, fuel boiling in the rail so we had to move the tank to the front, coils dying, etc, etc.

So, come winter it got pulled apart to sort a lot of it out:

This was 3 weeks before the start of the season - quite a lot left to do!
We upgraded the rear calipers to some 2nd hand Hi-Spec 4 pots, and put Carbotech pads in all around as we were cooking pads even the grease in the CV's was melting at some events.

We'd also been chewing chunks out of the rear tyres so we made some wider rear wheels to go up to 235's on the rear:

Also fitted a new alternator as again we cooked another (quite a lot of current draw + mud coating = not good), this time geared down a little to reduce the heat levels, made another clutch plate (we got through 2 a season, loads of other TLC/worn parts replacements, and, most important, got rid of that terrible looking numberboard:

Then went flying again:

Threw a bit of mud around:

Won the 2wd championship, etc, etc. ;)
  406 V6, Race Buggy
It's pretty fun. Shedloads of work though. I've skipped over most of the fabrication/repair stories just to things up to date more quickly. I'll flesh it out when I get to the latest engine upgrade
  406 V6, Race Buggy
Took it to Curborough the next year early on just to bed bits in:

Anyway, now were were getting it a bit faster the other set of Bilstiens on the rear really weren't keeping up and kept overheating, so they also got swapped out for another set of Fox Coilovers with remotes, and now we had two coilover units, we ditched the rear torsion bar system along with the bushes in the outer arm that gave a lot of toe change (although, given they were originally designed for 36bhp....they didn't do too badly) - fabricated a rose jointed arm, and stuck a pair of springs on the coilovers instead. We kept the secondary torsion bars though.

And a bit of hack-and-slash further down the arm to be able to run springs on both rear dampers:

Ta da - the linkage is the secondary spring/torsion bar setup, allows us to set it as either rising rate helper spring or high rate bumpstop.

I also modified the front Fox emulsion dampers - I ripped the remote canisters off the old knackered Bilstiens, rebuilt the best pair, and made new hoses and bolted them to the Fox units, that gave much more consistant damping with less fade, you can just see them on the front here:

Did a bit of flying to check the damper modifications out thoroughly:




Went to a 2 day event with a couple of clubs combined at Baden, Saturday was dry and lovely:


Sunday started raining heavy:


1 lap later:


I think we won two trophys for 1st in class there from 2 clubs (one ran a different day), and by the end of it we were actually 3rd overall in the entire championship mid-way through the season (bearing in mind that's against mostly 4wd cars, modded Landies, Bowlers, and dedicated spaceframe, kevlar clothed £100k racers like you can see in the background on a couple of the earlier pics)

Djw John

Scotland - South
ClioSport Area Rep
I'm amazed you've worn out any tyres, you never seem to be on the ground long enough.

Awesome project, really like the drive it, fix it, rag it, fix it again approach.
  406 V6, Race Buggy
Oh I've plenty more pictures of it in the air, I think most of them are bar the ones where it was stationary
  406 V6, Race Buggy
Right, onto the fun bits, we'd been eating coils pretty often, and leads, I put Magnecors on for Baden which solved the lead issue but we still ended up chasing a coil misfire on Saturday and overnight, so to solve it once and for all, stuck some D585 coils on designed for running an American V8 in a truck instead:

I also rebuilt/revalved all the dampers as the new suspension had so much less friction the low speed damping was way off, made a couple of replacement skid pans under the gearbox and engine as they'd got pretty battered by now and one had a hole in it, same for the mudguards, as the front right had an arguement with a pair of concrete fence posts and some chainlink fencing, and the rear had a hole in it from the tyre firing a rock through it.
So off we went to another event at Ross, where it was flying.....for the first run...after that, misfire is back.

Hmm, checked all the coils, leads, plugs, everything fine, took it back out - it wouldn't start without a lot of cranking - wouldn't rev over 7krpm, lost about 100bhp...oh oh.
We managed to limp it around and finish the event, and still managed to just win the 2wd class trophy by a few seconds. But when we got it back it wouldn't even start with a tow - curse of the rotary engine!
Lost compression, it was kaput, death of engine number 2...

Even more annoying, when we got the results through that night, we'd moved up to 2nd overall in the championship and were just 3 points behind first - bearing in mind a 2wd car hasn't won for decades! Bugger.
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  406 V6, Race Buggy
Now, we missed a couple of events due to the car being parked up, work, etc - which put us out of the championship overall, but we'd still won the 2wd championship as nobody could catch us even if we didn't turn up :D (most of them had retired in a few events already through crashes or issues, and were finishing way behind us when they didn't) - but we eventually managed to drop on a bare Renesis block at a salvage yard but which had no manifolds, ancillaries, etc - no problem for us so we got it cheap enough to drop another in, spent a few late nights getting the car back together, and off we went to another event at Sevenoaks, everything went okay apart from again a misfire stopping the engine revving past 7krpm and being about 50bhp down all day as a result - we pulled in on one stage to try to fix it, but I wish we hadn't when we saw the timesheets as we were still pretty quick even so - we would have had 4th place overall if not for pulling in, and easily on the podium without the misfire, doh.

Anyway, we eventually traced that down to a bit of dodgy wiring in the adaptor loom that came with the coils when we actually got it home, so with that sorted, we loaded up and went to Minehead:

....where it promptly spat a few teeth off the diff:

It actually kept going until we parked up.
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  406 V6, Race Buggy
Anyway, a bit of post-race analysis suggested either an oil film failure from overheating (we were using the turning brakes as a diff on some slippy side slopes for quite a long time) as the oil was fairly cooked and the centre gearset had been pretty damned hot and had gone blue - or possibly just a coincidental fault/failure with the oil contributing - as the rest of the teeth on the crownwheel looked great.
Fortunately we had a spare gearbox so that got put in (along with another new clutch plate welded up and fitted, as it had started to rip the splines out) - and we ran some Millers NT 75w-90 in the gearbox instead of the usual Total 75w-80, just to give a bit more heat resistance and EP protection. (transaxles are a tricky balancing act for oils).

We got it together Friday afternoon ready to set off that night for the next event....and couldn't get it out of reverse once we'd backed it out for a test run. b****cks.

2 hours of lots of blue air later, we had the engine back out, 'box out, stripped it, and found that the issue was just a burr on the selector for 5th gear and reverse from wear over the years, there was no way to clean it up properly without affecting other tolerances or a complete rebuild - so, for a quick fix, 5th gear came out and went on the shelf, and I knocked off as much as I could of the burr and chamfered it, just in case.
Can't snag on 5th gear if it's not in the casing!
And it made the car lighter, so I'm calling that a net performance gain.

So, 30 minutes later gearbox back together, engine and box back in, radiators and exhaust back on, fluids refilled and bled, test driven, works beautifully, load her up!

This was the last event of the season at Kirton - a very rough event at a quarry with 2-3 foot high steps cut into a lot of the track, even picking lines and being careful to keep the car together (people going flat chat were ripping balljoints, wishbones, whole corners off cars), we still punched a hole in the floor landing on a rock, cracked a skidpan, battered the one under the engine to the point it bent the sump, and cracked the windscreen on a hard landing when it hit the frame on the floor.
The cheap replacement engine was again feeling decidedly unhappy towards the end of the event - another intermittent misfire that came and went, and hot starting issues (sound familiar?).

Despite being careful with the car, we picked up 4th place overall here, our best so far, we also won the 2wd class but that was because nobody else would take their 2wd there for fear of breaking it, so we kinda got it by default :D



Car needed some major repair work afterwards but it was bloody fun!
  406 V6, Race Buggy
Some more from Kirton:

Right, since the front arms were pretty knackered by now and Kirton had put a fair few grooves in them after pounding the bushes out, and the car was struggling for front end grip, winter upgrades consisted of mocking up new arms:

A little wider for more grip, and with much more castor and camber (quite tricky to add on a trailing arm setup, we had to make offset kingpin bushes):

And longer to give more front travel:

Now, unfortunately the winter upgrade budget didn't stretch to some new, longer dampers and we couldn't find any takers for our old 8" Fox units to do a swap, so we ended up shifting the mounting points, which meant moving the damper tower, changing installation angles and required better mounts to keep the installation stiffness up, so, actual new arms made up in T45 tube, EN14 end fittings, new damper mounts on the top arm:

New, stiffer upper towers:

Et Voila:

....and slight technical hiccup with the bonnet. Remember Mr 9" Angle Grinder? He fixed it. Good man:

Much better:

We did plenty of other bits and pieces and also added some prefilters in the rear bonnet for the airbox intake - we kept blocking the cotton cone on there and having to swap it every stage, so these took the bulk out early and left the cotton just to catch anything in case the paper filters got wet.

And it was off to try the new suspension at Walters Arena shortly after....

...didn't have enough travel, apparently.
  406 V6, Race Buggy
Okay, all went fairly well there with the new suspension, bar the bit where one of the original VW parts salvaged from the other arm (a hardened washer that stops the bolts pulling through the kingpin) cracked and....well, pulled through the kingpin.

That resulted in the upright getting ripped away from the arms and dangling by the track rod and the brake line - with predicatable results to the brake line...
Fortunately, it still managed to limp around the rest of the stage at a respectable pace, and the arms and uprights were made strong enough that there was no real damage. So, two new washers, rebuilt everything, blocked off the end of the knackered brake line and finished the day with 3 brakes.

Suspension worked beautifully - if anything it was starting to show up the rear end now as the front had oodles of grip.

The engine pulled well too - this was the 4th engine by now - yes, I've skipped quite a lot and just tried to put in a few updates to show what we were doing - stuff like the above arms, etc, we were doing every weekend for years, this car has had more updates than Windows XP.
Anyway, we put the revised R3 Mazda motor in a while back (which wasn't simple, as the oil system, sump, electrics, starter, etc, are all different, so we had to make the mounts, hoses and loom adaptable so it could take both engines) - that one started to loose compression after a year, so we had it professionally rebuild whilst we were doing the arms, etc, and a bit of porting work, it pegged 268bhp on the dyno even on a running in map that was a bit rich.

Anyway, the next event was Waterbeach airfield again, so a thorough rebuild of the arms (with some thicker, beefier EN24 washers made up on the lathe), and repair/bleed to the brakes, and it was nearly ready.

Oh, but in the meantime, we'd had 3 weeks to plan more shiny parts:

Straight cut, short ratio 3rd and 4th gears at 9krpm+ ?
Quick, book a hearing test! :D

Oh, and I rebuilt the dampers as I didn't have chance over winter and they needed some retuning to work with the new arms anyway...the old shock oil doesn't look too bad for 2 years of abuse, sure, it's a little dark, but it's clear, not cloudy and no real debris in there either, gotta be good, right?

Oh, wait, yes, it's supposed to be this colour, nevermind, slightly cooked then :D

Anyway, off to the event, and that's where this photo originally came from :D

It was very, very wet, to the point where one car sunk in mud up to the door handles after landing a jump and they had to leave it there until the week after and go dig it out :D

We were so slow crawling sideways and scrabbling for grip through the same section that two people walked past us :D
  406 V6, Race Buggy
A few more from Waterbeach - I said it was wet....




We were going relatively well there, until the last lap, when the spline ripped out of the centre of the clutch plate on the very last stage at the startline 😬
The car didn't even jolt, or move, or anything, just sat there on the startline not moving :D
Bugger, so a new Renault centre acquired, welded into the VW plate.

We were also having hot starting issues again, which was pretty weird with such low milage on shiny, freshly rebuilt engine, quick convo suggested maybe the starter was tired after all these engines, so we swapped in a 3kw Mitsubishi unit with 15 teeth instead of the OE 13t, and it seemed to be back to firing up okay again.

After fabbing up the new mountings for that, refitting the clutch, box, engine, shafts, etc, we fired it up to run it down the lane before setting off for the next event drive.
Turns out this time the plate was fine but the pressure plate diagphragm spring had got jammed with some debris/gravel and cracked the spring - so back in the shed it went, and we missed that event completely whilst awaiting a new one.

We did get it to the next event though:






As you might be able to tell, there were quite a few photographers standing there after our first go around :D
  406 V6, Race Buggy
Okay, the downside of all that fun was....the engine wouldn't start again once it cooled down and we got back, even with the new starter.

Hmm. It'd only done a few hundred miles. A compression check revealed the same issue, way down and knackered, and a bit of investigative work showed the side plates were scarred and worn to hell. Bugger.
They build tried to wipe his hands of it so we ended up messing around getting other opinions and side housings micro-hardness tested, turns out he hadn't realised that the later RX8 engines have a much thinner, harder nitride layer than the earlier RX7 motors, and he gone through it when he lapped the plates.

Argueing that back and forth took the best part of a year, and rather depressed with things, we just shut in in the shed and didn't even open the door for 12 months. :( - and started putting it up for sale in various places, as we'd rather fallen out with it by then.
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  406 V6, Race Buggy
So, what do you do when you open the door 12 months later, find the car buried in 5ft of weeds that grew through the gravel, when you're sick of opening up dead rotary engines?

Remember Mister 9" ?
angle grinder for the dirty minded...

Rip the bloody lot out and chop the back off:

  406 V6, Race Buggy
We decided to do the clutch a little better this time to save having to keep welding new plates up, so, flywheel off the new engine was skimmed down to give a bigger biting surface:

And a 230mm cover and plate from a 200SX were fitted, with a Renault splined centre just rivetted in for easy replacement - the spline is also about 8mm longer than the previous setup, so there should be less stress on it anyway:

Mister Angle Grinder also chopped out all the middle of the beam tube which was no longer required because of the switch to springs from torsion bars, so we pushed the transaxle right forward and put it on poly mounts rather than the old solid ones - they'll barely flex in use but will take out shock loadings from the frame flexing, etc:

And then we made another adaptor plate with the old angle grinder and a pillar drill, and in the new lump went:

Well.....if you had 9krpm+ want the same again so the gearing works - F20C from an S2000, similar power at 240bhp too. Unfortunately it's a lot taller and a bit longer, but pushing the transaxle forward put the end of it almost exactly where the rotary was:

I'm sure there were some important structural tubing here before....oh well:

  406 V6, Race Buggy
Everything seemed to fit okay, so out came the grinder and we made the hole for the clutch and flywheel, bolted it all together so we could check the pedal travel - we ended up with a good 30mm or so of space behind the release bearing, so we just double stacked them for the minute to check the operation:

Plans to go a little wider on the rear tyres as they were still getting chewed up ran into a slight problem....not much clearance left there:

Also, a supercharger fell off a passing 5.0L V8 Jaguar, and just happened to land here, it's fate, you can't say no to fate:

Now, whilst looking at the clutch to make a spacer to take up the 30mm of space - we started getting more serious ideas, I mean, 30mm is a fair distance when you're talking about the weight/momentum of the engine hanging out back there - so, a new disc on the angle grinder, some aluminium welding rods and some serious gearbox surgery resulted in it suddenly being 30mm shorter and the engine even further forwards:

We need to shorten the input shaft now but that's not too difficult on these as they're a split shaft.

Of course, if the engine is further forward, you then need to redo your engine and gearbox mounts, again:

And as you can see, I might have convinced the idiot with the angle grinder that a bit of reinforcement back in the centre tubes might be a good idea...

And in comparison to where the engine now is compared to the rotary, this is the old rear engine/crash cage:

And then it was onto Tronbone Time:

  406 V6, Race Buggy
Glad you're all enjoying it, or at least having a laugh at my expense :D

I'll pop another update up later tonight.
  406 V6, Race Buggy
That exhaust manifold took quite a lot of nights of swearing to fit it in, the rotary one we did in about an hour, this one was about 2 weeks, with an hour or two every evening, and it's still mighty tight:




I know, the welds aren't quite as nice as the ally TIG, but like I said before, we built this thing out of scrap parts - all that tube was secondhand stuff chopped out of a dairy farm up the road!


...yes, definately a bit tight.

The reason for the huge manifold is because with the gearing on the Renault 'box still being fairly wide we basically only use 3 gears for the most part, so the manifold is made to bolster the 5krpm area rather than the top end - I don't really need more power than it'll have on low boost atm - we can't put it to the floor, but a wide spread of it is beneficial everywhere.
I've also gone for a more powerful harmonic than is usually tuned for in road cars so I should get a wave even lower than that to fill the bottom end in even more for slow second gear stuff.



Anyway, that should be more than enough exhaust pictures for now.

Next job, not a scrapyard part this time, but actually spent some money, although it's where it needed it - the rotary has a tiny, flat sump with good oil control and great ground clearance.
The F20C has a sump taller than Kryton's forehead, so.....



We bought a dry sump kit, it had a lot of issues, I'd never buy from the guy again - first pump was siezed, second had a noisy bearing, and as you can see there the belt didn't fit properly, the spacers were the wrong length, etc, etc - this is what you get when you take shortcuts instead of making it yourself!
I fixed it all later, you'll see, for now, shiny, tiny dry sump, loads of ground clearance.

Much better. Also, a radiator fell in.


And a new rear engine cage was made up to suit everything now that the sump was sorted:

  406 V6, Race Buggy
Next step, we need a pulley for that bloody big chunk of ally later:



I did some quick line/beermat sketches of the old rear end and some quick ones of what we could do over the new engine:





But...well, it's a racecar right?
Every 10 year old knows a racecar needs big wings...