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Discussion Starter #1
I'm in the process of rebuilding a 1.7 16V to stuff into my Series 1 berlina Sud and I now have to make a critical decision: Carbs or go with the stock Bosch fuel injection. I've read on the bb that the Bosch FI has an annoying problem of stumbling at low speed. I've also read that Alfa did a pretty good job of engineering the FI in the first place.

My goal is to build a car that is fast as hell, fun to drive and as reliable as possible. What do you guys recommend? And if it's carbs, which ones should I use for this motor and does anyone have the jetting specs?
 

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Firstly, there are no carbs that will just "bolt on" to the 16v heads - you will need to manufacture (or have manufactured) a pair of intake manifolds to match the carbs you wish to fit. Also, the stock camshafts are probably innappropriate for use with carburetors, they won't have enough lift to allow you to obtain maximum power. The higher the lift, the higher up the rpm scale it is before you start seeing more power (ie 4000rpm+).

By the time you've bought a pair of Weber IDF 44's or even IDA's, manufactured the intake manifold, had custom cams made, dyno'd the engine and jetted the carbs etc you'll have spent an absolute fortune and lost some reliability!

The Motronic system is actually pretty well designed, although a bit primitive by modern standards. There are "holes" in the rpm range, where it just feels like it be programmed smoother - but thats the 100rpm increments at which it is programmed. the 16v throttle bodies are a work of art - they are matched to the engine, the throttle linkage is all there - adding a new ECU and spending an hour on the dyno would be much better money spent.

At the end of the day, depends on what you want - "everyday drivability, carbs, and lots of power" is a bit of an oxymoron!

~Benjamin
 

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Discussion Starter #3
Thanks for the info. You can actually buy brand new manifold adapters designed to match webers to the 16V, but I agree about all of the extra work to jet it right. However, I am still going to deal with the nightmare of splicing the 16V harness into my older Alfasud, which will probably be more total hours of trouble. As for a new ECU, wouldn't that be a lot of work as well? And what brand of ECU would be worth adding to my car in order to improve on the stock Bosch system?

I've heard that www.squadra-tuning.com sells a reprogrammed chip for the 16V, although I'm not sure if they can improve the low speed stumbling issue. What do you think?
 

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I'm not experienced with programming with the Motronic at all, and I am a bit sceptical about dropping in a new chip - you have no idea how the rpm/torque curve has been modified.

I would suggest a Motec system, but any major brand that is readily programmable is probably fine. The megasquirt electronic kit is also pretty good if your competent with a soldering iron (so I've heard anyway).

Guessing you wouldn't get any change out of $3k-$4k Aus, for upgrading to a decent ECU, including dyno time assuming you do most of the installation yourself.

Who offers the 16v carb manifolds?

~Benjamin
 

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i agree - i would just upgrade the fuel injection system - more power, better reliability and prob less money.. carbs sound good but at the end of the day theyre old technology
 

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I'm a carb user. Reason being it's cheap and easy to tune. With a few grand, a good after market ECU and good tune(incl ignition mapping) on dyno would probably get you more power and efficiency. Bear in mind of course the ignition module differs. This will cost a lot more than whatever you have to do to get carbs in. But I kindda think carbs are really cool. A mechanical unit that can perform such feats. I'm always proud of my carbs.
 

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However, I am still going to deal with the nightmare of splicing the 16V harness into my older Alfasud, which will probably be more total hours of trouble.
Thats not so hard, its actualy quite easy.I installed a Marelli-weber IAW into a Sud some month ago.I can help if you like, only the 2 electric diagrams are needed. The 16v is probably on my 33 site :rolleyes: :D, if you have the Haynes manual tell me which diagram refers to your car exactly! Pm me or something... :) But if I were you I wouldn't use the wires from the car if its form 76.. theyr crap, too thin and probably shot at many places. On the sud I wrote about we used the harness from a 83 year car, much better.. and I recrimped and soldiered on additionaly all terminals, relayed the lights everywhere too etc. Blade fuse conversion is not a bad idea too...:rolleyes: :cool:
 

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Discussion Starter #8
Thanks for the info! What would be the advantage of removing the Bosch FI and going to the Marelli system? How much would it cost and will I get any better performance (and where do I buy it)?

As for the wiring, the stock harness is in excellent condition. I have the wiring loom that comes out of the computer from the Alfa 33 16V. I was just planning on adding the 16V harness to the existing car.
 

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Go down this path if your serious, individual throttle bodies. Where are you located? Here in Oz we have a huge market of EM systems, you should be able to find a suitable one for < AU$1500.00 no need for splashing into motec but that would be nice.

http://www.alfasprint16v.fws1.com/index.html
 

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Thanks for the info! What would be the advantage of removing the Bosch FI and going to the Marelli system? How much would it cost and will I get any better performance (and where do I buy it)?

As for the wiring, the stock harness is in excellent condition. I have the wiring loom that comes out of the computer from the Alfa 33 16V. I was just planning on adding the 16V harness to the existing car.
There is no advantage, I just wrote that connecting the IAW to the cars loom was totaly easy, and the 16v injection harness would be no problem too... ;)
If your harness is excellent than your lucky, but never theless I would ad at least relays for the lights, if for not any other reason than to protect the column switch from melting one day...The suds and sprints electric system is from factory a totaly bad design with totlay underscaled wires diamaters and missing relays....
So tell me wich diagram refers to your car, and I tell you what to connect where from the injection harness to work if you like...;)
 

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The injection harness is completely stand alone except for like 2 wires, the tacho and the power.

I can't see why anybody would think that the standard harness was too hard to fit.

Also, if your sud was running the single carb 1.5 before, any offsets in power for FI vs carbs wouldn't make a difference unless you had to compare the two.

The standard FI with a bigger exhaust and a chip is plenty of power for such a light car and is enough for streeting.

Not that you guys are probably into the traffic light wars, but a 16v with the standard 16v exhaust that shrinks down at the back, and no chip makes a sud more or less untouchable at lights.

But maybe it's different in your country.

lenus.
 

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Not that you guys are probably into the traffic light wars, but a 16v with the standard 16v exhaust that shrinks down at the back, and no chip makes a sud more or less untouchable at lights.

But maybe it's different in your country.

lenus.
The word "restrained" comes to mind! My 16v is getting the exhaust mods shortly :)

~Benjamin
 

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Discussion Starter #13
What kind of exhaust mods are you talking about? I guess this opens up another thread, but I am considering the crossover exhaust that Ansa originally offered. I have pics and specs on it. My local exhaust guy can build the headers and the Ansa warehouse guy in Southern California said he can match the muffler and resonator to current Ansa catalog parts (the original crossover system is long out of production).

I've heard all sorts of claims about the crossover. Some say it reduces torque and increases HP. Some say it improves everything. Any ideas?
 

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Personally I would stick with the original headers, for the 16V they are already substantially larger than the 8V models and breathe really well. They are also a type of extractor, really well designed and are the best option for a street car IMO. By opening up the rear portion of the exhaust ( and removing the cat) to allow the exhaust out faster, things will improve significantly, even that low down stutter, not to mention sounding better too...
 

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Discussion Starter #15
The 16V headers were not included with the 16V engine I brought in from Germany. Besides, I'm stuffing it into a Series 1 'Sud berlina and keeping the inboard front disc brakes, so I'll have to build custom headers regardless. I figure that if I'm already making headers, I might as well build the best kind. Apparently, Ansa and Supersprint both built crossover exhausts for the 16V, so there is supposed to be a significant performance advantage to the system. I wonder if anyone else has any before/after stories about going crossover with a 16V?
 

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I'm going to be putting an exhaust on my 16v sud soon, and I've been looking at different options.

What I am leaning towards is the crossover interference design found on the permanent 4's. They are drastically different to the standard headers and also the crossover design too.

I'm not sure as to what sort of characteristics they have or anything like that, but what I do know, is that on my brothers P4, with this exhaust and a 2 1/4" pipe to the back with a squadra tuning chip, it manages to put it 130kw ATFW estimated, when measured at all 4 wheels.

I'll try to get pictures of the headers. They are unlike anything I've seen posted before on the forums.

Also make sure that if you're going to get a copy ansa manifold made up, that they have bigger pipes all around. As mentioned previously the 16v exhaust is already bigger. An 8v exhaust won't bolt up at all, the flanges on the 8v exhaust are too small!

And by ansa, I'm really assuming that your talking about ansa sud manifold, not one for a 16v.

lenus.
 

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Turbocharge!

Tuning a naturally aspirated engine will cost you $$$$$$ and you will just be moving the peak torque higher and higher. Carbs or EFI, to get any decent power increase on a 16v you are going to need to improve the induction, port / polish the heads, larger valves?, skim the heads, deck the block, new cams (there are 4 of them! $$$), perhaps larger injectors??, new exhaust, oh and remap the ecu (or buy a completely new one?!), if you are running carbs you will have to tune them on a dyno. Actually, you will need to do that with a new ECU anyway. So the advantage of carbs is?????. Carbs start to make less sense on the 16v when you consider they are not even a simple bolt on. You will need to make the linkages, and have the inlet manifolds custom welded.

What else? Oh, because your peak power is now at 7500+ rpm you may want to strenghten the internals. Perhaps new custom made pistons? $ Or new forged con rods $$, Shot peen the crank$, blueprinting $.

The 16v is already highly tuned out of the box. Alfa did a very good job. 99kW from a 1.7 naturally aspirated engine? That is very impressive, especially considering it was made in 1990.

I am not saying you can't tune a 16v for more power. You can! But you are embarking down the path of diminishing returns for your $$. You will be building a cranky, temperamental, high rpm screamer that will refuse to idle properly, with exactly zero mid range torque. The torque on the standard 16v is bad enough! Awesome for a track car, not so good for a road car.

130kW ATF from an exhaust and chip? Lenus I'm sorry but that is fantasy. Dyno reports often greatly exaggerate the flywheel outputs because they bluff the results in 'shootout mode'. Even the best exhaust on 16v will net you about 10% extra power max. This has been confirmed time and again on naturally aspirated engines from just about every manufacturer in the world. Especially highly tuned 16v motors. And a chip? They just advance the timing 1 or 2 degrees in a few spots, and marginally enrichen the mixture here and there. Basically they take away the manufacturers 'safety margin' to account for all loads and temperatures, low octane fuels etc to prevent pinging. A chip will net you 3% extra power, being optimistic. Only if the motor was originally tuned by a dunce will a chip help. I have never thought of Alfa engineers as dunces.

So why am I a fan of turbocharging? Now I am not foolish enough to believe that installing a turbo is easy, it will also cost you money, but I believe the end result is better value.

A well selected, mildly boosted (8psi) turbo will increase your peak torque by
around 20% throughout most of your rev range. Of course a 20% power increase follows. So basically a turbo will emulate having installed a motor of 20% more capacity in your sud. So whats that? A 2 litre! nice.

Modern turbos have almost no lag, if they are well selected. If you want more peak power, select a peakier turbo. Your peak power may reliably climb by 30% or more.

A well set up turbo can maintain driveability, fuel economy, and make a car much more tractable. A small, low lag turbo with torque everywhere will make your car a blast on the road, allowing you to accelerate hard out of corners, even if your revs have dropped below 4000rpm.

The good news is that with perhaps a larger fuel pump and injectors, the stock Fuel injection system fitted to a 16v should be able to cope with a low boost turbo just fine. If you need to slightly modify the mixtures and ignition mapping, you can install an interceptor chip. If all else fails, you can install an aftermarket ECU. I doubt it would be needed. An on-boost ignition retard and adjustable fuel regulator might be all the $ you will need to spend.

As Carroll Shelby said: "Horsepower sells cars, but torque wins races"
 

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Discussion Starter #20
I agree with you that it's too much trouble to heavily modify the injected 16V and still keep the car streetable and relatively easy to drive. However, adding a turbo is another major project and there is limited room inside the Sud engine bay. Besides, with a good performance exhaust and some slight massaging during the engine rebuild (balancing, gasket matching and some basic headwork and manifold flowing), I should be in the 140 to 150 hp range. From what I hear, that is already plenty of power for a car that barely weighs more than 1900 pounds. I'm adding a Quaife limited slip diff to help put down the power and I've been told that any more hp would overwhelm the front wheel drive and upset the car's handling.

I've also heard that a K&N filter is a noticeable improvement over the stock filter box, yielding better throttle response a few more hp.
 
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