75 Performance.

[Duk]

Still some very slow progress with next to no updates  .

Something that I am keen to change about the car, is the location of the charcoal canister.
A significant part of the changes I have made, has been removal of weight forward of the front axle line. The fitting of a non impact absorbing bumper bar and the battery getting moved under the boot floor (1 day  ), will make significant changes (on top of the other changes) to how the car attacks corners. These will be offset somewhat by the bigger radiator, the supercharger and the water to air intercooler's radiator and circulation pump.

So, can anyone name a reason or 2 why I can't move the charcoal canister (for the evaporative emission system) into the boot?
The Adaptonic computer has a dedicated control system to drive a solenoid valve that regulates the purging of the charcoal canister. And with suitable vacuum plumbing, is there any reason why I can't mount the charcoal canister in the boot, near the fuel tank?

Despite the slow progress, on the whole I am really happy with how the car is coming together. My philosophy is to create a car that works well in as many situations as possible. It needs to be reasonably compliant to help it negotiate my favorite piece of treacherous, bumpy, winding back road. And at the same time do all of the normal, boring shit really well (big radiator for the 45* SA summers and 120 amp alternator with some upgraded wiring to help make sure the electrical system works perfectly and reliably over a long period)!

[MD]

Sometimes one can get so engrossed in the project upgrades that some really important stuff gets overlooked. No one should ever lose sight of compliance issues. Whatever changes are made need to be legal ones if the car is to be on the road.
Non-compliant vehicles are deemed to be unroadworthy and worse still unisurable. So if such a vehicle was previously registered for road use and its use is recommenced in its altered state without such changes being formerly approved, the use of such vehicle can land the user in knee deep doodoo.

If the vehicle is involved in an accident or causes third party damage,the driver/owner wears all the expenses-at fault or not.

Always a good idea to consult the eventual blue plate certifier AHEAD of time with the intended modifications to be sure that all your work will get the nod.

Now I just know you have planned well..

[Duk]

Sometimes one can get so engrossed in the project upgrades that some really important stuff gets overlooked. No one should ever lose sight of compliance issues. Whatever changes are made need to be legal ones if the car is to be on the road.
Non-compliant vehicles are deemed to be unroadworthy and worse still unisurable. So if such a vehicle was previously registered for road use and its use is recommenced in its altered state without such changes being formerly approved, the use of such vehicle can land the user in knee deep doodoo.

If the vehicle is involved in an accident or causes third party damage,the driver/owner wears all the expenses-at fault or not.

Always a good idea to consult the eventual blue plate certifier AHEAD of time with the intended modifications to be sure that all your work will get the nod.

Now I just know you have planned well..

In reference too???

[MD]

General advice to anyone modifying their vehicle and to those following your thread.

[Southern75]

How do you get to the dipstick ... is there room?

[Duk]

How do you get to the dipstick ... is there room?

Just.
If need be, I'll extend the handle so it's easier to get.

[Duk]

Some progress photos.

[Duk]

Have been moving about as fast as road kill lately, when it comes to this thing.
But here is some feedback on the bump steer issues that the Pace Engineering Long Shank Top Ball Joints (LSTBJ) cause.
The obvious behavior of having the LSTBJs was a dramatic increase in toe in with bump travel. Now interwebs research showed that the answer to toe in with bump travel is to lower the outer rod end or raise the inner (raise the steering rack)...................
So I initially bent the passenger side arm to lower the outer rod end, but I started with WAAAAY to much adjustment. Long story short, I bought another upright. 
I knew that the R32 Skylines used the same M14 thread for their tie rod ends but the tapered stud is too big. So I bought a good quality, adjustable  bump steer correction kit for the R32 Skyline and machined down the taper so it fits the Alfa's steering arm.

Now, at this point I will mention that I am a huge fan of having plenty of positive caster in my wheel alignment. So using my digital inclinometer I wound 7.5* of caster into it.................

With the new correction kit fitted solidly but in a temporary state (the top nut uses a rather aggressive locking mechanism that I didn't want to have to unwind unless absolutely necessary), I mounted the outer rod end as high as I could, using the kits usual layout and worked the suspension thru some of its travel.
End result, toe in with bump travel.
So I lowered the rod end again.
Still toe in with bump travel.
Lowered it more (by this time I was concerned with the rod end running out of articulation near full droop).
Still toe in with bump travel...................... 
In fact, the more I lowered the outer rod end, the more toe in with bump she appeared (at this stage I was just watching the wheel hub move about) to gain.

So I removed the top spacer and put the 2 thinner bottom spacers at the top. Hmmmmmmmmmmm, less apparent bad behavior. And this time I had stuck my little laser pointer to the brake rotor, but wasn't bouncing it off a mirror yet, just watching it wander across the shed wall.

Long story short, after going back over just about every conceivable set up and bouncing the laser off a mirror and back onto a vertical surface I bolted to a wheel stud, I had to reduce my caster angle to 5.5* (only 1 more than standard) and have the thinnest bottom spacer at the top, to get an acceptable (read: really friggin low) level of bump steer.
A quick comparison with an old factory tie rod end shows the new rod ends pivot point is actually higher than where the factory rod end's pivot point would be......... 

[MD]

   

Now, at this point I will mention that I am a huge fan of having plenty of positive caster in my wheel alignment.

Hi Dukster,

Just want to say that I used to think that too. However in reality, the 116 transaxles do not need more than 3.5* of caster to work well. I cannot imagine the 75 is any different in this regard.

I am saying this if it helps you solve your set up.

[Duk]

Standard caster angle is 4.5* for the 75 (though for some reason I had thought it was 3*).
Caster is a definite helper in trying to keep the outside front wheel perpendicular with the road to help maintain good tread contact patch, during cornering.
The higher roll centre height and the more aggressive camber curve from the LSTBJs, the higher spring rates and eventually chunkier anti-roll bar all help to keep the tyre contact patch much closer to ideal than standard, but I wanted to apply all of the techniques to do the job.
Oh well, I'll have to see how effective the end results are with the set up I have. I'm sure those changes along with the non impact absorbing bumper bar, the battery in the boot and the wider track width will make big changes to the cars ability to turn into corners and should massively reduce the understeery nature of the car.
Tho even when it had 'only' the LSTBJ, 105 lb/in additional coil springs and 4.5* positive caster, it was much improved over standard (well, lower, Koni's and heavy, shite 17x7 rims with a poxy +40 offset).

[Duk]

Thought I'd post a photo of my incomplete fabricated front 'bar.
Based on some 1.25" diameter x 0.120" wall thickness 4130 (Chromoly) tube/pipe and uses 40x40x3 RHS arms, it weighs noticeably less than the original 24mm solid bar and calculations show that it should be about 60% stiffer too. Or about the same stiffness as a solid 27mm bar.

[Colin Edwards]

Further to the performance of the 3.0 12V fitted to the 75, exhaust system work for the old girl needs serious consideration.  Specifically from the heads - but not including the rear muffler section.

Two design philosophies appear popular with regard to the headers:
* A virtual copy of the cast headers - fabricated three into one, featuring primaries around 500mm long
* Fabricated headers - two piece / joined primaries about 1200mm < 1500mm long - three into one collector located somewhere under the hand brake

Given the second arrangement would be near three times the weight of the first arrangement, would the extra mass be offset by any "PROVEN" engine output increase of the more complex solution?  Not looking for much performance increase.  Just don't see the point in adding mass for very little (if any!) gain.

Engine is as per factory apart from SZ cams and re-profiled / lightened inlet valves.

Colin

[Duk]

Making sure the pipe lengths are as close to equal as possible is very important.
A tubular version of the original manifold is basically pointless. When decent factory exhaust manifolds started to apear on equally decent engined cars, less than honest manufacturers would simply build a tubular version of those manifolds and claim improvement over the original manifold.
But unless the diameter and/or lengths are changed, how can there be any change in exhaust chacteristics???
Basically there can't be any changes if things are ultimately very, very similar.

1 good thing about the shorter primary pipe extractors is that it can be worthwhile to play with secondary pipe lengths and diameters to further chase power or a broader torque curve.

Personally I'd use 500mm primaries, 1 5/8", equal length pipes, with proper merge collectors and look at secondary pipes at least 700mm long, 2" diameter into a 2 1/2" collector before the cat.
Whether you could buy those extractors off the shelf or not, is anyone's guess.

[Storm_X]

So how's the car going now, has much happened in the 6 years from the last update ¿