Our very own "barn find"...

[cjheath]

I thought yellows were harder "sports" and reds are standard, so yellows front - reds back would be a 105 thing? Or have i mixed up my colours 

No, you have it correct. Both yellows and reds have adjustable rebound damping, but fixed bump damping. The yellows differ from the reds in that the damping is about 30% harder.

Both are progressive in bump with two rates - some of the oil holes through which the oil must go get blocked by a thin metal valve, which gets pushed into action when the shock is pushed hard. FWIW, I believe that the Bilsteins have a different progression mechanism, which isn't a simple 2-level action - can anyone confirm this?

Harder damping is necessary if your springs are harder than normal. Hard springs normally also means higher tyre pressures and/or contact-patch size (tread width), which forms part of the spring rate. The tyre's spring rate is not linear like the springs themselves, but more exponential, so the net rate is complicated - but no part of the stroke can be harder than the spring itself.

Koni yellows are commonly thought to be too hard for standard 105 rear springs, and on the high side for the standard front springs (modulo what I said about tyres). Some people like yellows on the front only (that's my setup), but with standard springs they shouldn't be set too hard.

Too many folk fit very hard dampers in the hope they'll improve roadholding, without understanding the principles of critical damping. Over-adjusting dampers to a very hard setting reduces road-holding, as it prevents the spring from returning to its neutral location as quickly as it could, so the wheel jumps off bumps and doesn't get back on the road properly.  Under-damping causes oscillation past the return point, which reduces road-holding also, but that shouldn't be a problem with any Konis on standard springs, unless they're worn out.

[aggie57]

...   Reds at the front and yellows at the back makes some sense given the typical set up is stiffer at the front but then both can be rebuilt and revalved so what they are now may not be what they were when new.
....

I thought yellows were harder "sports" and reds are standard, so yellows front - reds back would be a 105 thing? Or have i mixed up my colours 

Oops - mea culpa!  Typed and pressed enter too quickly!

[aggie57]

I thought yellows were harder "sports" and reds are standard, so yellows front - reds back would be a 105 thing? Or have i mixed up my colours 

No, you have it correct. Both yellows and reds have adjustable rebound damping, but fixed bump damping. The yellows differ from the reds in that the damping is about 30% harder.

Both are progressive in bump with two rates - some of the oil holes through which the oil must go get blocked by a thin metal valve, which gets pushed into action when the shock is pushed hard. FWIW, I believe that the Bilsteins have a different progression mechanism, which isn't a simple 2-level action - can anyone confirm this?

Harder damping is necessary if your springs are harder than normal. Hard springs normally also means higher tyre pressures and/or contact-patch size (tread width), which forms part of the spring rate. The tyre's spring rate is not linear like the springs themselves, but more exponential, so the net rate is complicated - but no part of the stroke can be harder than the spring itself.

Koni yellows are commonly thought to be too hard for standard 105 rear springs, and on the high side for the standard front springs (modulo what I said about tyres). Some people like yellows on the front only (that's my setup), but with standard springs they shouldn't be set too hard.

Too many folk fit very hard dampers in the hope they'll improve roadholding, without understanding the principles of critical damping. Over-adjusting dampers to a very hard setting reduces road-holding, as it prevents the spring from returning to its neutral location as quickly as it could, so the wheel jumps off bumps and doesn't get back on the road properly.  Under-damping causes oscillation past the return point, which reduces road-holding also, but that shouldn't be a problem with any Konis on standard springs, unless they're worn out.

I remember way-back-when, we used to run yellows at the front with standard springs and at Winton we'd turn up the rebound which had the effect of unloading the inside front wheel on turn in, thereby increasing the load on the outside front which in turn reduced understeer and improved turn in.  Could all have been in the mind of course but then he who thinks he can go faster generally does!

My very first 105 GTV, back in Kiwi Land in the early 80's, had been set up for production racing (the B&H 500 Evan - you'll know of that) and had Koni reds at the front and Gabriel Ryders (Riders?) at the back.  Seemed to work; the car came 3rd overall in an event limited to 2 litre cars, behind a couple of Golf GTI's. 

[Evan Bottcher]

the B&H 500 Evan - you'll know of that

I went to New Zealand once.  Very green.  Twisty roads.  Funny accents.

[Davidm1600]

I have had koni yellows in my '69 1750 GTV for probably 10-12 years, with standard springs, and simply rebuilt but standard suspension.  I also run the car on 14 x 6 BWA Alfa alloys, and I have to say I have never found the ride to be compromised or uncomfortable.  To me the setup gave me peace of mind, in comparison to what it was like when I bought the car. 

I used to have Koni yellows on the front, Koni reds on the same alloys, but with stiff and lowered springs on my 2L Berlina, and rebuilt but standard suspension and found it at times a little skitterish on the track.  The 1750 GTV in comparison feels totally controllable.  I also have Koni yellows on my Fiat AC 124 sport and love them.   

[Evan Bottcher]

A pair of NOS Carello taillight lenses.  The ones on the shelf off the car aren't too bad actually, but I couldn't resist the lure of ebay 'buy it now'.

[Evan Bottcher]

Well that's the last things I'll pull off the car before it goes to the panel shop.  Trunnion arm was a pain to pull out, but soaking the stud where it bolts onto the diff with WD40 and some persuasion from a shifter and a big lever got it off.  The car is sitting on wheels and ready to move.

It's taken four years to get to this stage.  I guess there's about 4-5 man-days of actual work in that four years stripping the car.  Things stalled mainly while I worked out someone to do the panel and paint work, but now things should move a bit more rapidly... (he says with optimism).

[pep105]

It's nice to see a series 1 1750 with the correct rear taillights. Thats a good find those lenses are rare
especially as it doesn't look like theres any reproduction ones around.  

I find the Koni yellows in the front and reds in the rear works well, especially once I rebuilt the suspension and
not set to the hardest setting.

Evan good thread you've made up a lot of distance in a short time, are you planning on removing the front & rear windscreens as well ?

[Evan Bottcher]

Yeah I forgot about the screens...  I'm scared of breaking them to be honest, particularly the back one which I understand is hard to replace.  Any tips?

[pep105]

I managed to get mine out, I also managed to break the front one..........

With the rear screen run your fingers under the seal on the outside and just check to make sure it hasn't been glued or sikaflexed in.
it shouldn't be but you never know.

Then get inside the car, if you've got no interior like I did grab the rear seat cushion and put it in there so you have something to place yourself on. Lying on your back with your arse on the seat stick both feet in the top corners of the rear glass. Then gently but firmly
put pressure on the corners of the rear glass. You should feel the glass start to move and eventually one corner should pop out. Make sure you have someone on the outside just in case the glass flys out. I didn't but you should   I found once the top of the rear screen was out completely about half way down, I was able to grab the glass from the outside and manouvre it out.

Process should be the same for the front however mine was glued in, so I spent a lot of time cutting the seal away with a razor blade
right around. After a bit of labour and a lot of swearing in 2 languages I thought I was in a position to get it out. This time a mate of mine was there to help and I was on a high after getting the rear out. With a bit of pressure the glass began to move however it was tight but it seemed like it was gonna come out, I then told him to put his hand where my foot was (probably a mistake) then crack. There may have been part of the seal still glued in which might have been the cause (or my technique   ) no drama I needed a new front screen anyway.............

Also make sure you take out the screens complete as a unit with the anodised trim. That trim is expensive to replace and is an expense you dont need.

If your local Id be happy to give you a hand

Hope this helps

Cheers
Pep


     

[aggie57]

Evan - who's doing your panel work and painting?  I have two projects to get done this year and Paul Rankins tells me he's too busy.

Alister

[alfagtv58]

I am at the stage of needing to remove the front and rear glass too.  I was really worried about damaging the chrome trim, the glass would be nice to keep as is, but the trim is what I was more concerned about!  So I asked around and the suggestion was leaving the removal and refit to the pros (like Windcreens Obrien/Natinal Windscreens/Novus etc.....while they cant guarantee removing without breakage, they are a better chance that you or I with a size 13 hoof in a strategic spot.

I guess it depends on the state of the glass in there at the moment....if its knackered, try it yourself, but be really careful of the rubber and trim.

[ItalCarGuy]

I didnt have that problem with my Super. Mine would have come out if I braked too hard!

[Evan Bottcher]

Hmm.  Front screen is pretty rough, it'll be replaced anyway.  The rear should be okay.  Might give it a go anyway.

What's the availability for rear glass these days?  Ten years ago they were not being manufactured anywhere, so you had to hunt.

[cjheath]

Hmm.  Front screen is pretty rough, it'll be replaced anyway.  The rear should be okay.  Might give it a go anyway.

What's the availability for rear glass these days?  Ten years ago they were not being manufactured anywhere, so you had to hunt.

I don't know but PGI supplied me with a front w/s recently - maybe give them a call.

Re removing and refitting glass, I've used the procedure recommended above several times. It really isn't scary or dangerous, just don't try to get one end out before the other - just get the whole top out evenly and all goes well.

The anodized trim in the rubber is actually easy to get in and out, you don't need a pro for that. Just make sure that you bend the rubber (pulling the slot open), not the trim! To get it in again, you need to clean the slot well - it'll be dusty/gritty - use a toothbrush, detergent and lots of water. Use some o-ring grease, and after fitting it, make sure to push it fully home all round - it has a barb that locks it in.