Author Topic: How I built the "Flying Brick"  (Read 60631 times)

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MD

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Re: How I built the "Flying Brick"
« Reply #15 on: September 01, 2011, 08:52:17 PM »
Hey pep! You and me must have gone to the same reform school. I get my Penthouse mags in BRAILLE just like you.  ;D ;D

Yeah Ads, I will try to keep it going..Here's some more for ya.

..and so we come to the brakes. Probably my favourite subject on cars funny enough. At this stage I was still interested in keeping the inboard rotors but determined to make them more effective. Initially it all seemed straightforward.

I dispensed with the booster transfer bar and booster assembly. This saved around 14kg. The original pedal box was altered to accommodate a 4 bolt 25mm Toyota tandem master cylinder. The brake foot lever was reworked to provide a 6.5 lever ratio as there was no boost.

Conversion plates were designed and made to fit a complete Nissan GTR twin turbo set of alloy callipers and original rotors. The front rotors are 296 x32mm and the rear rotors are 300x16mm ventilated of course. Whilst the front rotors are not as big as is currently fashionable, I can tell you at 920kg, I cannot recollect any other Alfa out braking the Brick.

An in-line bias adjuster was installed but found to be completely unnecessary even though it might seem odd as the rear rotors are in fact larger than the fronts. However, bear in mind that the available friction area of the rear pads is considerably smaller and therefore the balance is restored.

It is common knowledge that transaxles generally have inferior brakes compared with say the 105 in their original make up. I know this for a fact as I have owned both. However, potentially they should have better braking owing to their better weight distribution and this set up takes full advantage of that.

The rear rotors are so big that I had to cut service panels in the boot floor to change pads !! The original Nissan rotor centres were machined out and grafted onto the ATE previous centres

The entire braking system is provided with new tubing, stainless steel braided flexible lines and the hard lines are routed well away from the drive tunnel to prevent breakage if the prop shaft gets loose and cuts the brake line during the process. The original location is actually in the tunnel and this was a foolish move from Alfa.

To reduce weight, the handbrake was dispensed with. After all, it’s a racecar.

The actual brake pedal had some perforated mesh welded to it to provide additional grip and the configuration was set up for best heel-and-toe I could come up with.

As I said, it all seemed straight forward until I installed the engine and started to configure the induction side of things. What a nightmare!

The engine mounts were already custom made to level the engine in the hope that the ram tubes would not go through the bonnet as it would be a bad move to put a bend in them but that wasn’t the only problem. The plenum was going to interfere with the master cylinder and so a solution was needed to that would satisfy both the induction and the placement of the master brake cylinder on the induction side. Another month of delays and $600 later, I had a solution. A master cylinder that was activated by a 90* plunger mechanism. This was designed by a good friend of mine who shall remain anonymous to protect his virginity. ;D
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MD

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Re: How I built the "Flying Brick"
« Reply #16 on: September 01, 2011, 08:54:08 PM »
more of the brakes..
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MD

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Re: How I built the "Flying Brick"
« Reply #17 on: September 01, 2011, 08:59:05 PM »
Still rolling..
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MD

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Re: How I built the "Flying Brick"
« Reply #18 on: September 01, 2011, 09:01:03 PM »
Putting the anchors on with this lot..

Transmission soon...
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Sheldon McIntosh

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Re: How I built the "Flying Brick"
« Reply #19 on: September 01, 2011, 11:24:18 PM »
This is great stuff MD, thanks for sharing.  It's funny how, after about twice on the track, brakes become a very important topic to you all of a sudden....  I'm constantly looking enviously behind the wheels of 911s and and EVOs and so on these days.

BradGTV

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Re: How I built the "Flying Brick"
« Reply #20 on: September 01, 2011, 11:57:42 PM »
thaks for sharing mike, great infomation!
79 gtv sr20, 83 gtv, 83 gtv6 3.0, 75 ts x 3, 85 gtv, 76 gt, 91 164, Subey L Series, S13 silvia, Bmw e30 318i, VT SS 6spd

MD

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Re: How I built the "Flying Brick"
« Reply #21 on: September 02, 2011, 09:51:11 AM »
The transmission of the Alfa transaxles is the Achilles Heel of these models. This is because: -

1.   It effectively has three flywheels
·   The engine flywheel
·   The prop shaft
·   The clutch flywheel
2.   The prop shaft is an extension of the crankshaft and the balance issues are critical
3.   The gear selection is woeful with a long throw and large selection gate. Yes there are lots of different attempts to fix this and different owners claim that their shift is great. That is until they shift a Mazda MX5 or a competition Escort. (you get the idea)
4.   The need for a two-piece shaft because of where the gear selector is placed in the tunnel.

So if you had budget like the Super Cars do, this can all be fixed even without a torque tube like the Porsche 924 has.

Here’s what you would do to minimise the problem: -
1.   Install a flex plate at the back of the crankshaft with ring gear on it.
2.   Fit a one-piece carbon fibre prop shaft with a BMW front coupling and a universal joint at the rear. (CV’s are better for balance but push and pull the crap out of the rubber coupling during acceleration and deceleration)
3.   Make a custom shifter mechanism inboard to accommodate the one-piece shaft and fix the general selection issues at the same time.
4.   Install a custom clutch flywheel of about 125mm diameter with a multiplate miniature pressure plate ( like motor cycles)
5.   Selection refinements inside the gearbox itself.

This will get the power robbing spinning mass down to zip and get the gear selection to equal any “stick-in-the-box” set up.

So does the Brick have that? Well in a sense it has about 50% of that which is mostly due to budget constraints. It does have revised flywheels, custom shafts and couplings, competition clutch and inboard gear selection. One of the biggest problems I have had in designing and making custom prop shafts in Brisbane is a lack of machine shops that have the necessary skills and equipment to correctly balance them once they are made up. A huge frustration.

I am not going to dwell on gear ratios and the lightening of gear sets as these have already been discussed elsewhere on this Forum.

If any of these modifications are of interest to you and you want to adopt them, please bear in mind that to make the components and or adaptations involves some serious bucks if you cannot do it your self. What you are seeing in this topic of modifications has in effect cost many thousands of dollars to finally implement satisfactorily. It seems like machine shops have their own financial language and their prices are usually quoted in telephone numbers.
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MD

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Re: How I built the "Flying Brick"
« Reply #22 on: September 02, 2011, 09:57:07 AM »
..more
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MD

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Re: How I built the "Flying Brick"
« Reply #23 on: September 02, 2011, 09:58:14 AM »
.and some more
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MD

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Re: How I built the "Flying Brick"
« Reply #24 on: September 02, 2011, 09:59:01 AM »
continued..
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MD

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Re: How I built the "Flying Brick"
« Reply #25 on: September 02, 2011, 10:00:44 AM »
This thread is longer than pep's wish list  :)
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MD

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Re: How I built the "Flying Brick"
« Reply #26 on: September 02, 2011, 10:02:06 AM »
and to conclude the transmission stuff.
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alfagtv58

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Re: How I built the "Flying Brick"
« Reply #27 on: September 02, 2011, 10:04:52 AM »
Really enjoying this thread, thanks MD.

Quick question, you mentioned in your initial post you were building this to go and play with the AROCA boys.  Did you also have in mind an existing CAMS/AASA category?  i.e. were you just building it to go as quick as possible or building it with racing in improved production/2L Sports sedans or similar in mind also?
1967 Giulia Sprint GT Veloce - (WIP) Strada
1977 Alfetta GTV Group S - Corsa - For Sale (http://www.alfaclubvic.org.au/forum/index.php/topic,9600.0.html)
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aggie57

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Re: How I built the "Flying Brick"
« Reply #28 on: September 02, 2011, 10:22:23 AM »
MD - great thread. Keep it up.

Not sure I agree with your comment that the transaxle is the designs achilles heel though.  The front suspension geometry would have to run that close......
Alister
14 Alfa's since 1977. 
Currently 1973 GTV 2000, a couple of Mercs,  a '14 Beetle (yes, seriously......), 2020 911 C2S (manual!)
Gone......far to many to list

Neil Choi

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Re: How I built the "Flying Brick"
« Reply #29 on: September 02, 2011, 10:31:13 AM »
I am envious on the build, keep it coming and I am learning something all the time from this.

Cheers
Neil