What mods for road going 75 V6???

Started by Duk, September 07, 2010, 06:52:14 PM

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Duk

My 75 has bean out of action for to long and I'm wanting to get some enthusiasm for completing the work that I've planned. So I thought I'd ask, and this is potentially 'dangerous', but what modifications have other people done or would like to do for their road going 75 V6???
Any suggestions should be based around improvements for handling, performance and/or drivability or improved reliability.

Current mods that are completed but not necessarily tested/used(*) are:

Chassis and Front Suspension/Brakes:
Vin's long shank top balljoints, Koni Yellows, *225lb/in additional coil springs, *inner guard chassis bracing, *some seam welding, polyurethane bushes, Volvo 4 piston calipers and slotted 164 rotors.

Rear Suspension:
Koni Yellows, Polyurethane Watt's linkage bushes, *spherical bearing DeDion pivot, *175lb/in springs with adjustable seats (hardly completed, but nothing major to get done).

Modifications In Motion:
Battery to the boot, a K shaped upper chassis brace (remote mounted reservoirs for master cylinders), bump steer correction, dual plenum chamber longer primary inlet manifold(started, but....), extractors (made by me), Nissan/VL Commodore engine management system, Rear Brakes - Wilwood rotor and and series 4 Mazda RX7 Turbo rear calipers.

Other Thought of Modifications/Changes:
Lightened flywheels, maybe even an aluminium engine flywheel, light weight clutch disc, lower chassis rail brace, raised pivot point/modified floor short shifter or cable type shifter mechanism, ported heads, bigger radiator, light weight front and rear bumper bars (Veloce or Evolution type).

scott.venables

This is what I've done:

-Flywheels. I think these should be a priority.  I wouldn't bother with aluminium, for a road car you can turn/mill enough off the engine flywheel to make it uncomfortable before you need to go aluminium. That's all subjective of course and this is only my opinion.  Also, considering the different thermal expansion rates and the fact that you need enough ring gear-flywheel interference at 10 degrees to be able to start the motor, I'd worry about bursting the ring gear when the motor's warmed up.

-Steering wheel spacer, seat rail extensions and re-bent accelerator pedal

-105 type castor bar ball joints (not bushes)

-AC and PS removal and lightweight crank pulley if you're keen! (I haven't quite finished the pulley)

Also, considering you've got knuckle risers, probably drop spindles too (I haven't got either)

Cheers, Scott

Duk

#2
Quote from: scott.venables on September 07, 2010, 07:55:23 PM
-Flywheels. I think these should be a priority.  I wouldn't bother with aluminium, for a road car you can turn/mill enough off the engine flywheel to make it uncomfortable before you need to go aluminium.
Cheers for that 1! I saw your flywheel balancing technique for the engine FW, and I'll use that.
http://www.alfabb.com/bb/forums/milano-75-1987-1989/38390-lightening-rear-flywheel.html
http://www.alfabb.com/bb/forums/milano-75-1987-1989/46463-flywheel-balancing-jig.html

Quote from: scott.venables on September 07, 2010, 07:55:23 PM-Steering wheel spacer, seat rail extensions and re-bent accelerator pedal
Nice ideas!!! ;D Did you do anything with the throttle ratios to make sure you still got full throttle? Cruise control is on the maybe list for boring highway work, so that kinda/maybe does away with bent accelerator pedal.
I might use a deep dish Nardi steering wheel instead of the spacer. The Isotta wheel on the car never really did it for me  ::).

Quote from: scott.venables on September 07, 2010, 07:55:23 PM-105 type castor bar ball joints (not bushes)
I have the polyurethane bushes, do you think it's worth while still, to go to 105 ball joints?

Quote from: scott.venables on September 07, 2010, 07:55:23 PM-AC and PS removal and lightweight crank pulley if you're keen! (I haven't quite finished the pulley)
AC (unless I can't get it to work) and power steer stay (5.5-6* positive caster and hopefully some wider wheels and tyre down the track). 8) But I would like to cross drill some of the pulleys.

Quote from: scott.venables on September 07, 2010, 07:55:23 PMAlso, considering you've got knuckle risers, probably drop spindles too (I haven't got either)
I have toyed with the idea of upside down lower ball joints, but I am reluctant due to legal issues. But I suppose it's no more an issue than a welded suspension component  :-\. Having said that, my ride height wasn't that low, so I recon the roll center height was quite reasonable and the camber curve a lot more effective than standard. I do highly recommend geometry changes to the front end  ;D  8) :D

Cheers.

tony8028



Quote from: scott.venables on September 07, 2010, 07:55:23 PM-AC and PS removal and lightweight crank pulley if you're keen! (I haven't quite finished the pulley) AC (unless I can't get it to work)

So you'll be removing the a/c then ? :)

Have never known a/c to work in either 75s or 33s....not on a hot day anyway!
(past cars)
1988 Alfa 33 ti
1990 Alfa 33 ie
1992 Alfa 75 TS
1988 Alfa 75 TS
1990 Alfa 164
Currently driving 2004 147 Manual

scott.venables

The standard throttle ratio remains. The pedal is just bent slightly towards the brake pedal and down a little if I remember correctly. Makes heel-toeing easy.  Depending on how tall you are, you might like both a deep steering wheel and a spacer. 

I didn't really drive my car with the rubber/poly castor arm bushes in so I can't say how much difference there is. But considering how the joint moves, the rubber/poly washer idea is nasty.

The crank pulley is hard work to lighten.  I've machined mine back so there's only the back 2 grooves left and to do that I've had to machine the ID, the back and drill quite a few holes to retain the static counter balance.  It gets complicated because even if you've ended up with the same static counterbalance, you've moved the counterbalance rearwards which probably affects the dynamic balance of the pulley, crank and flywheel assembly. So I got to balancing and stopped. :) ???

Did you realise the knuckle risers lower the front roll centre?

Cheers

Duk

Quote from: scott.venables on September 09, 2010, 10:32:45 PM
Did you realise the knuckle risers lower the front roll centre?

That all depends on the ride height. With the lower arms set basically parallel with the ground the roll centre height in moved up, but I'm only going by a picturing of the virtual swing arm pivot point.
The biggest advantage is the gain in negative camber with bump. Most people don't realize this, but the standard Alfa virtual swing arm pivot point is towards the outside of the car, so the left hand wheels VSA pivot point is even further left (out in space) of the car. So as the suspension moves into bump the wheel goes into positive camber. Chuck in the excessive body roll that also adds positive camber........
Any way, the long shank top ball joints and a reasonable ride height equals WIN  ;D But I did look at getting a set of Richard Jemmison's drop spindles, it just got real expensive.....