Seicento Monster Cento/ECU Master Thread

[blu73]

sye, the drive looks pretty awesome at the moment

 

[Honeymonster]

There are 3 Seis, 2 Cinqs and an original 500 Abarth (in a garage) parked outside my house at the moment. Alas only one of them is mine lol. My next door neighbour is well into his Fiats but not a computery chap.

Still, five Cento's in my family alone.

Your drive lacks a Topolino, but still a most awesome collection.

 

[Honeymonster]

Well I spent the whole of yesterday working on a Cento...

Unfortunately it wasn't mine. :bang:

Considering its now covered a staggering 24,000 miles I was simply shocked by how much work the old dears Cento Sporting needed.

New rear cylinders/shoes/arms, rocker cover gasket, plug leads, vac pipes, cv joint, rear wheel bearing, starter motor (kept jamming), cam belt, check strap, lower engine mount (the metal bit!), alt belt, thermostat, and the list went on...

And after all that it still has a strange misfire at tickover (fine when revved, not the timing has been like this for ages) so most likely needs a crank sensor, tried coils no difference. It also has a nasty hiss coming from the brake servo. The brakes seem dire compared to any of the Seis, and the revs don't drop fully until the ICV compensates so I'm guessing the servo diaphragm is fubbared. It also needs a rad cap, radiator is looking ropey and the sunroof doesn't clamp down properly.

Just goes to show mileage is meaningless!

Anyway after giving it a thorough test drive once the work was complete, I'll stick with the Sei thanks. How do you boys put up with that steering which feels like it has about 300 turns from lock to lock.

As for Monster he's still waiting for bits to get powdercoated and some lines and there's a bit of welding on the intercooler left to do. But I can't rush the chaps it's not like I'm paying, most people are enjoying the sun that has finally turned up.

 

[fingers99]

Hissing servo may have something to do with strange idle.

Sei steering is useful for delivering Pizzas. Otherwise, it maketh no real difference. But as PAS systems go, it is one of the better ones (until it fails).

 

[Honeymonster]

Hissing servo may have something to do with strange idle.

Sei steering is useful for delivering Pizzas. Otherwise, it maketh no real difference. But as PAS systems go, it is one of the better ones (until it fails).

It's not just a strange idle, it pops and bangs like a rally car so gotta be ignition related.

Never had a Sei system fail, and our place is made of corners so less turns at higher speed is where it's at.

A quick rack would be nice and very Alfary but with a such a short car would probably be suicidal on the straight at high speeds...

Ah for variable ratio speed refferenced steering... maybe one day.
Would take some getting used to though, no doubt.

 

[fingers99]

Never had a Sei system fail, and our place is made of corners so less turns at higher speed is where it's at.

I have. I pretty much by passed it and fitted Cinq top mounts.

I'd not be 100% that it's ignition. Vacuum guage might throw up something interesting.

 

[Honeymonster]

I have. I pretty much by passed it and fitted Cinq top mounts.

Sounds like a good compromise for speed and feel but I thought the angled top mounts actually improved turn in?

I'd not be 100% that it's ignition. Vacuum guage might throw up something interesting.

I guess the leak could be screwing withe map sensor (I tried one of these too). I 'll fix the Servo first anyhow and see how it runs. I'm going to tag a few TDC sensors on my next Unto order anyhow seems like you can never have enough of these things.

Might have to do a head gasket change on Mrs. H's Sei too, seems the overheat light came on in traffic the other day because it was low and water but she forgot to mention it.

Been losing a very small amount of water for a while, she was supposed to keep an eye on it... (seems OK since she topped it up though, might have got away with it).

I'd like to get back to working on my own car at some point.

 

[blu73]

could you not just pull the pipe to the servo off the inlet and block it temporarily and see how it runs, clearly not to drive it around just to see if it makes any difference.

 

[Honeymonster]

could you not just pull the pipe to the servo off the inlet and block it temporarily and see how it runs, clearly not to drive it around just to see if it makes any difference.

Good call, indeed I could.

However since I need to change the servo anyway and the pipes are a &^&* to get off I guess it can wait till I change it.

 

[blu73]

ah yes, i forgot how much of a hassle that pipe is to get off

 

[fingers99]

Sounds like a good compromise for speed and feel but I thought the angled top mounts actually improved turn in?

The Jury is still out on that one!

On bikes a it does quite the opposite (compare an ancient Ducati V twin with a modern one) -- gives exceptional stability at the expense of low speed turn in (indeed, the old V twins are actually said to understeer and were pretty horrible at anything less than 40 mph -- and anything that needed to be taken at less than 40mph!) , while Noble have a steep head angle on their cars and recon this (while requiring PAS) actually helps (but helps exactly what no-one is telling). Lotus came to a similar conclusion with the FWD Elan.

In comparison. the Cinq is more like a modern front endy bike, the Sei more like the old Ducati.

Unfortunately Staniforth is mute on the subject, and will remain so forever unless we can come up with a turbocharged ouija board.

 

[Honeymonster]

Taken from the Holy Grail here:

http://www.autospeed.com/cms/A_111688/article.html

http://www.autospeed.com/cms/A_111691/article.html

Positive castor increases the amount of negative camber that occurs during cornering, which means that the outside tyre ends up being closer to vertical than it otherwise would have been. This means better cornering grip. However, unlike simply dialing-in negative camber, positive castor brings no problems in relation to longitudinal grip, tramlining or tyre wear. The only ill-effect is slightly increased steering effort - and this shouldn't be a problem on cars with power steering.
Changing castor invariably requires modification to the suspension – for example, commonly the tension rod is swapped for an adjustable design that allows the wheel to be pulled further forward. Another approach is to use an eccentric or firmer bush.

I'm assuming the strut top increases the castor? Therfore the above would suggest an improvement in conrnering. I trust this Julian Edgar's judgement, has always seemed a complete genius to me.

 

[Honeymonster]

Hmm actually I'm not entirely sure if moving the strut back can be classed as a change of castor? Does it actually set the wheel further in front or behind the steering point , however the description in the article would certainly make sense regarding a need for power steering in its application.

Edit:

DAMN check out him slamming camber bolts in the warning at the end of part 2! Won't be fitting those blighters then...

 

[fingers99]

DAMN check out him slamming camber bolts in the warning at the end of part 2! Won't be fitting those blighters then...

Of the two sets I have (neither fitted yet) the Monroe ones look substantially tougher than the Eibach ones.

Might look at some un-machined Rallysport top mounts, though!

The articles make sense, but I'd really like to see the effects in real time, on the real thing, if you see what I mean.

 

[Honeymonster]

The articles make sense, but I'd really like to see the effects in real time, on the real thing, if you see what I mean.

Wouldn't we all, he makes a clear point about how there are so many variables that can effect handling at the start of the second article (everything effects everything). How a single aftermarket part can throw everything out of kilter. He then goes on to point out it's also driver dependant.


However, what I'd like to know is why Fiat did it. There must be a good reason for their efforts and I (personally) find the standard Sei sporting steering feels more responsive than the standard Cinq sporting.

I'm sure it would feel exactly the same when fitted to a Cinq too...


Car companies are generally a lot wiser than us...

However clearly making this all adjustable is the ultimate answer, then tuning it to your personal driving preference which I guess is why you want blank top mounts...

 

[blu73]

see i much prefer the feel of the cinq steering, now i got the cinq back again i've started plotting swapping its all over and sticking the PAS in the cinq and the cinq stuff on the seiT.

I guess alot is down to personal preference though; so long as its not dangerous lol.

 

[Honeymonster]

see i much prefer the feel of the cinq steering, I guess alot is down to personal preference though; so long as its not dangerous lol.

At the speeds you drive I would have though power asistance would be essential, especially with the arms of a little old lady and one of them weilding a rolling pin?

:devil:

 

[blu73]

hey, appearances can be deceiving.

 

[fingers99]

However, what I'd like to know is why Fiat did it.

I think because they had to, to "keep up" with the competition. Same reason as they introduced canbus and ESP. Over 30 I don't find the steering of the Sei any lighter than the Cinq but I prefer the Cinq feel. And then, in moments of poverty I've delivered Pizzas in both (and the Cinq had slightly wider tyres).

 

[Honeymonster]

:yum: More powdercoated bits:





Notice the mat coating is supposedly 800 degree Celcius on the exhaust manifold, downpipe, drain, actuator bracket etc. The other stuff is is just the standard spec. Obviously the motorbike caliper and antique iron are not for the Cento.

Hope the weather is nice tommorow, look forward to sticking these bits on permanently at last.