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KAM Racing - go silly or dont bother project build

#1
This is going to be a long one lol
We've been working on a car for a few months and as its now starting to take shape I'll start posting about it.

This is a story that started many years ago and the idea was what started the business off in the first place. Lets start a business to get money to build a racecar...

Back in 2004 I bought a Peugeot 205. Eventually it was specced up with an Mi16 engine on throttlebodies, 6 speed gearbox and a few other mods.
Entertainingly fast but stripped out was getting tedious as a daily. One day it was parked and everything that could sold off.
 

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#2
There was a championship called Eurosaloons. So I bought a few goodies and started getting work on the shell. The shell went on a diet and Satchell Engineering custom suspension was duely purchased. Full rollcage added.
s**t happened. Work was expanding and meant a full time job so we got so far and stopped as no toys could be financed..
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#9
Probably the end of last year we sat down with some strong coffee and started to brainstorm what we were going to do with it.
We've been sponsoring a few drivers in Time Attack so this seemed a great platform to build something cool

We threw some basics that had to be met.
a. It had to be light.
b. It has to handle like a Peugeot 205 XS - nimble and well balanced as a chassis - better than a GTI!
c. It has to be well north of 300bhp

We knew we had a good chassis to start with The Satchell Engineering suspension has reangled front wishbones, strengthened subframe and Peugeot 405 hubs. The rear was using a Mark Shilaber 309 rear beam with turreted dampers. The plan is to use a Maxi Motorsport wide arch kit with 120mm each side width increase at the front, 80mm per side at the rear and also move to something not done in Time Attack on smaller wheeled cars, use the Pirelli 225/50R15 tyre.
 
#10
Nice Brace work Matey, do you do the Fabrication yourself ?
I've had to back away from doing much physically so far. I'm not skilled enough nor do I really have time.
I can however pick a rule book apart and come up with some wild ideas to create an engineering knightmare.

So I did just that lol...

The cage came back to haunt us later but thats a few chapters away.
 
#11
To do the dirty work, and to bring my doodles, thoughts and concept to life it was time to bring in a proper engineer. Cameron from Saloonlibre was brought onboard and the shell taken to his workshop

The plan was to push the rules as far as we could. To correct the geometry for such a wide car. Acquire some Lotus Elise suspension parts as the hubs have a hole for a driveshaft, go double wishbone and get a good scrub radius and kingpin angle. For the engine we had a Mazda 13b rotary dummy engine and a Honda K20 gearbox as I'd seen someone do a not-so-great-job of putting the two together and staying FWD.

That was basically how we fell down the rabbit hole..

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PhillipM

ClioSport Club Member
#15
That's pretty good, friend of mine took his old Simca to be acid dipped before I welded all new parts in and the guy refused to lift it out of the tank because it was bending every time they tried there was so little left...
 
#16
First port of call is to get some measuring done and properly design the front suspension.
We have driveshaft clearance to overcome as a move to double wishbone would mean the coilovers will mount on the wishbone.
There are two options. Create a fork over the driveshaft to mount on the lower wishbone or mount to the upper wishbone.
The upper wishbone was the obvious first choice. We wanted to manage costs as best as possible
But then some measuring happened
the suspension loads would be primarily through the upper wishbone and there was simply not enough meat on the hubs. Lotus mount to the lower arms so they have a good sized damper motion.
A custom fork and lower suspension casing would be almost as much as a custom hub so we bit the bullet and got designing a hub...

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#19
So this is where things get interesting.
Cameron wanted to have trailing brakes. No real benefit other than it looks 'Racecar' so why not!
Unfortunately with a bit of maths it looked like the Ackerman angles would be rubbish due to the steering rack having to sit too far forward
Shame but we had to go with a more normal FWD setup.

Now for the geometry! Ideally we'd want a teeny bit of negative scrub for FWD but with the width of the calipers and the offsets available for wider wheels it was not going to be possible. We would have to go with a bit of positive scrub. Not ideal but better than crap loads of KPI

Because this car is going to be driven at speed and not to the shops a more parallel setup for Ackerman has been chosen to work the tyres better. Its all about the tyre slip angles, limiting them for maximum grip.

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#20
The simple steering route would be to have the rack in a similar position to standard but theres a few disadvantages to this. As you adjust camber you would have to recorrect the toe. We could switch the setup upsidedown but the lower ball joint has to cope with a lot of loads and we would potentially have issues with compliance steer.
This is where the wishbones and subframe flex under load. it steers the wheel more, rather than less, causing oversteer. We'd have to beef things up to cope and this would add weight.

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#24
Next up on the design list is to sort the engine and gearbox. I wanted to use a standard RX7 flywheel and a twin plate clutch (using the Honda Splines) but the gearbox choice eliminated any off the shelf solution. The RX7 uses a really large 320mm flywheel and the Honda EP3 a 300mm flywheel.
After measuring a few starter motors the RX8 one looked the most promising. Designs were sent to TTV and they made something shiny.
Its only 7.6kg total weight. Not the lightest - I could have gone for a 5.5" clutch I guess, but it will be relatively light on the pedal compared to a single and will cope with more torque than we will produce!
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#25
Guess what happens when you are feeling smug about your suspension design all being finalised...
There was a rumour circlating that the rules were going to change for 2018! Then the bombshell. Maximum width had been reduced. For all Club spec cars the maximum limit was 100mm from the waistline of the bodywork under the door mirror.
Now given the standard bodywork comes out about 40mm we were looking at 80mm too wide each side at the front! it was a real kick in the balls. The whole reason for all this effort was to not have horribly compromised suspension with a massive wide track width.
Do you cut your losses and the costs spent on design, reverting to a modified Mcpherson strut setup based on what we have, or keep spending for less of a gain?
 
#27
Well that was the decision at that point. The hubs and virtually all the parts had been designed. The benefits had been massively reduced but theres still an advantage. The shorter track width gave a number of notable issues. The tyres would be closer to the bodywork and the wishbones were at worse angles.
Problem A. The Wishbone was already close to the wheel rim

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#29
Problem C. The Time Attack rules state we are not allowed to change the original mounting suspension mounting point position or orientation. Also adjusting the upper wishbone mounting point upwards to improve wishbone angle would put it in a weaker chassis point. This is a problem for our damper mounting point as that was to use the upper wishbone.
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#30
First thing to now tackle was the tyres. I blagged a free 225/50R15 tyre from Pirelli and we put it on a spare 8" rim. Quite frankly it looked suited for a van! It was huge!
It still looked overtyred with a bulging tyrewall. We decided it would need an 8.5" rim to sit nicely but that rolling radius meant the chassis would sit 120mm off the ground. I've had my road 205 lower.

I stomped my foot and drew a line. It had to be under 100mm ground clearance or less.

So I blagged another tyre. The 205/50r15 tyre was significantly smaller in all proportions. Fitted on a 7.5" wheel this would look spot on. This allowed some tweaks to a nicer scrub radius. The arches were going to have to be tubbed, and the hub tweaked 20mm to sort the wishbone angles. Remember the discussion about a forked damper or a custom hub? We took a couple of steps back, I found a Nissan GTR forked damper, we got the drawings off the manufacturer and moved the damper mounting point to the lower wishbone. So we ended up with both in the end!. ££! This now took the suspension loads off the top wishbone and fixed that issue. I wonder if we could have used those Elise hubs in the end.
Ride height was looking a healthy 80mm off the ground - thats proper race car low

The drawings were send to the scrutineers and we got the final ok! Time to start cutting.
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#33
I guess at this point most people will be bored of CAD drawings and virtual issues. Luckily there was need of hard graft and the buzzing sound of an anglegrinder.
First however you need a laser!
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#39
It was time to do the rear tubs. This required cutting the rear of the cage out as we'd have to redo that.
This is what we needed to remove
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#40
Its not often you should be cutting the cage but it exposes the true quality of the workmanship. I'm not really one to get angry but this really did boil my piss. Actually I went mental. When you trust someone to fit a cage you expect them to do a proper job so the cage can save your life in an emergency. This would simply not hold out in a high speed accident.

The reason is bad interpretation of the rules. The MSA rules state the cage must be as close to the bodywork as possible. This had been done but at the detriment of being physically able to weld completely round the tubing.

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Once you've found this you have to start looking at the rest of the cage. It didnt fail to disappoint...
 

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