1972 Hillman Imp "FAF"- Pedal Box

[skamanfrank]

Hi all,

I've never been particularly good at maintaining build threads, but guess I'll give it a go again.
I imagine/hope some of you will remember the car and know of it all ready, but for those of you who don't, allow me to offer a brief summary of the car's history...

Bought when I was 18 (about 8 years ago now) with my first student loan payment, a beauty of a 22'000 mile minter



Then only a couple on months into ownership, this happened (driver error):


With no broken glass and just a big dent on the roof, it got fixed (to a point) and put straight back into daily service:


It went through a few sets of wheels:






Got used in all weathers (it was the daily after all)!:


This happened:


And this happened:


This also happened alot:


And as a result this happened alot:


Which also caused this to happen alot:


It even won "Used and Abused" at National one year... an appropriate and fitting award!


And then it gradually got into a worse and worse state. I got fed up of doing the minimum required to keep it going and on the road, rust started to set in, etc etc. So, I finally moved into a house with a garage and eventually decided that it was time to give FAF the restoration it deserves!



So, that brings us up to the present day pretty much! The car is currently in the garage mostly stripped and awaiting some much needed TLC.
The plan is full blown restoration and a vast array of modifications as well.

The "todo" list is as follows:

> Caribbean blue paint as per the original.
> All the original chrome trim replaced including the bumpers
> Substantially lowered, but keeping (as close to as possible) full suspension travel via remodeled front suspension geometry.
> Fuel injected motor with closed loop lambda control, AMR500 supercharger tuned for a flat torque curve throughout the rev range, limiting power to around 80HP (to avoid expensive clutches and broken gearboxes)
> Special 7J wheels... not being disclosed until they have arrived... not getting ahead of myself and tempting fate!
> Fully bespoke/modern wiring loom, made up as main harness/dash harness/engine harness to facilitate future additions/modifications
> Custom Xenon projector headlights
> Custom (discreet) LCD dash hooked up to ECU via serial connection
> Electric windows and remote central locking







Baaaaasically the intention is to turn it into Project "Turd Polishing". I just want lots of more of the modern comforts in the coolness of a Hillman Imp that will look relatively standard, but go well and handle like a demon. Even more than they already do!
A lot of effort that will never be worth it in money or time to anyone but me. I figure I have no kids and as of yet, no mortgage... so now is the time to do it huh?


Updates to come... Thus far a majority of the work has been on the suspension, so I guess they'll be the first updates to come!

[georgeb]

I think I'll just bookmark this one. Sounds like a good plan.

[tomcatcars]

Be good to hear how things go stage by stage.

[94bruce]

Looking forward to seeing this

[Seth]

Great to see you back Frank, and that FAF still lives.

[dikkehemaworst]

Oh yes it's the time to do it.
never had the money so started working , met my wife , got 2 beautiful daughters and a mortgage. Now i got 3 cars , but still no money and even less time.
please finish your project before it's to late !!!

Bookmarked!

I just realised all my cars have the engine in the back , so i love the imp....

[skamanfrank]

So, suspension mods you say?

We all know imps look cool, but lets be honest.... we all know they look cooler, lower.







So, just lower it yeah? Well FAF has been on lowered or chopped springs most of it's life but I've decided to take it up (down) a level.

Rob's imp (singer?) is a fantastic example of what you can do with air (and there's a bright orange stiletto on air I think too?).....



....which I did consider, along with hydraulic suspension but I've decided that I'd like to stick with the concept of a shock and a spring.

Having had it on coil overs and short springs in the past, the handling is good, but the ride quality does suffer a tad. I want to go much much lower than is usual (Ash's imp aside) with just springs whilst maintaining original ride quality and improving the handling even further.

The aims are:
> Get it really low
> Maintain the original amount of suspension bump at the lowest desired ride height, whilst allowing for the car to run at a slightly elevated height if need be.
> Keep as many of the bolt on bits as original as possible, such that replacements in the future (if needed) are easier to procure. Do this by modifying the chassis over bolt on parts where possible.




Now, the imp front suspension is not particularly common.
It consists of a swing/A arm with a coil over shock set up, and kingpin/stub axle arrangement on the end:



This is generally a good package, but the two issues I'll facing by going lower are:
1) The camber is fixed and not particularly adjustable- The lower you go the more negative camber you get.
2) The lower you go, the lower the inboard swing arm mounting points get, increasing the angle of the swing arm relative to the floor because the height at the outboard point is fixed by rolling radius.

#1 can be fixed relatively simply, #2 is more of a problem.
As the car is lowered, the swingarm angle increases and as the wheel experiences bump, the arc of motion of the wheel causes more lateral movement and change in camber angle, decreasing the tyre contact patch with the floor.

Hopefully these give you a brief idea:




Ideally, through bump, the wheel should move in a vertical motion with the least camber change and lateral movement possible.
So, if lowering the car, the only way to fix this is to raise the inboard suspension mounts to level out the wishbone with the floor at the desired ride height....

....HOWEVER. There's a floor in the way.




So what's the fix....? Raise the front floor, at the same time, raising the suspension hard points of course!!

[skamanfrank]

One of the first things required to get me down nice and low is to raise the shock mount on the inner wings.
For a given length/rate spring.

The car is lowered by almost as much as you raise the shock mount (not quite because the shock/wheel travel ratio isn't 1:1), but in this case I'm going get the mount as high as possible. Assuming it all works out... this will allow me to run a longer spring and potentially a helper spring (or something else that I have in mind for the future).

Thankfully I was able to buy two replacement mount plates, which meant less fabrication was required and the final product could look a bit more "factory"
Car went off to Carl in Hillmorton, who's normal bag is air cooled VWs, but he did a cracking job:

Carl added a bit of sheet to each plate so that they could be blended nicely into the wing






The bolts holes were originally for bolting the mount into the wing. As they have now been welded in the bolt holes aren't needed but have stayed in case they can be used for anything else (like mounts etc).
With a bit of primer chucked on for protection, the finished article:

[skamanfrank]

No love for my sexy new shock mounts then?

Not much of an update... but I'm quite excited that my sexy sexy new wheels are currently in the care of DHL and on their way to me. Not disclosing what they are till they arrive.... but I'm sooooo excited!

[Deleted]

awesome little car, always wanted an imp. Keepin an eye on this

[qwerty]

Excellent project! I really like the concept and look forward to watching it develop.

[skamanfrank]

Cheers gents!


Exciting news.... just been informed that my new wheels are at home waiting for me. Last chance to guess what they are before the big reveal later on

Also got a PIC development board in the post today, which will form the basis of my digi dash driver, and I managed to source the donors for my Xenon projector headlights!

[remmoc]

watching with interest

[skamanfrank]

Happy chappy right now!

[remmoc]

What are , look really nice

[mk2polobloke]

I love Imps, great looking little cars.
'Really pleased to hear you're gonna restore and repaint this to look original. I also like your ideas for the modern upgrades. I hope you will be keeping the original dash layout when you install your new 'discreet LCD unit'?
That is a very tidy piece of fabrication on the strut top mounts, it will look factory like you said. Keep the updates coming on the rest of the suspension work.
Unlike the majority on here I'm not really interested in fancy wheels but those new ones are particularly nice and will look great.
Keep up the good work mate,
Cheers, Richard.

[RetroMat]

Watching with interest, i'm looking forward to seeing this project evolve. Inspired choice on the wheels!

[projectquartz]

Love Imps and your plans! The finish on your turrets are amazing did he lead load over the joints or something? Shame the holes got added! Keep the updates coming!

Charlie.

[code109]

looking forward to this build! looks promising already

[RA40tony]

Hayashi Street Fins!!!!! Woohoo!! NIce work, its going to look great!!