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Which one is the best

2K views 17 replies 5 participants last post by  AntMat 
#1 ·
Hye all... Which airfilter is the best for Alfa 146TI 2.0TS to gain good in Hp... K&N., PIPERCROSS or BMC CDA.... Pls advise. Thanks
 
#2 ·
you won't see any major gains from an air filter/induction kit...
At best you're probably talk 2 or 3 bhp, there's a good thread around here one of the lads started that explains induction fairly well.
I'll try find it and post a link :)
 
#3 · (Edited)
here's the link:

http://www.alfaowner.com/Forum/tuning-and-upgrades/116879-inductions-kits-what-you-need-to-know.html


and if you want to run a cold air feed as well, there's a little bit of info here (it's on a 147 though, so i don't know if it's too useful on a 156..):

http://www.alfaowner.com/Forum/tuning-and-upgrades/117332-intake-cold-air-feed-questions.html

**EDIT
This seems to be the best one for the 156..... the homemade GTA intake for the 156:

http://www.alfaowner.com/Forum/tuning-and-upgrades/117748-gta-intake-mod-on-ts-my-verdict.html
END EDIT**

good luck :)
 
#4 ·
The BMC CDA would be the best from the list as it would avoid heatsoak.

On that particular kit, you would be looking at a 5bhp increase, but a remap/chip would give you a bigger gain when combined with the CDA.
 
#5 ·
Look carefully at where you are going to draw your cold atmosphere from regardless of open or enclosed filter, lower front grills are normally best as they offer the best area for cool air and forward motion forces cool air into the cold air feed.

There are rumors that damp and water can travel up a cold air feed and work its way through the filter and into the engine causing alot of damage, but I think unless you drive through a deep puddle at high speeds its pretty slim myself.
 
#6 ·
I assume you are talking panel filters. Steer clear of K & N unless you plan doing the Paris - Dakar (then you'd need to change it every 1,000kms or so) or crossing the Nul Arbor Plain! The oil becomes stickier after a bit and this time of year, particularly with increased under bonnet temperatures due to global warning, the oil being volatile can migrate to the "throttle box" and upset the MAF sensor for starters.

Pipercross, Jetex or Ram Air should be a good bet. Your EMS should adjust for increased air flow and you won't get much from re-mapping - a complete waste of money with a n/a engine in my opinion and that of others who know what they are talking about.
 
#7 ·
The factory map should be able to keep up with a simple filter change and cat back exhaust but anything past that ie manifold, sports cats, dectas etc should really be looking at with the intent to have remapped.

I have been told even a standard engine can see gains from a map and gain a pony or two but more importantly smooth out the power curve and get rid of the falt spot below 3k/4k
 
#10 ·
you'd be looking to do all of the following and probably more to get 50bhp more:

-stainless steel manifold
-sports/racing catylitic convertor
-cat-back exhaust system
-improve induction & add cold air feed
-higher spec cams
-ECU remap

I'm not even sure all of that would get you the extra 50bhp, but it would be a start....

good luck
Phil
 
#13 ·
Agree a good list could be pushing maybe 40bhp maybe a tad under with the cams but to be honest Id settle for decent manifold, sports cat, cat back exhaust and airfilter upgrade and a remap - 15bhp - 20bhp depending on the parts used I recokon.

Then look to improve the handling and brakes, you get more enjoyment out of these mods than the extra pony's :thumbs:
 
#14 · (Edited)
The remap would be a waste of money. My 155TS produces a bit over 170bhp. The engine has B & C Stradale cams whose profiles are specifically designed for improved torque, Regazzon exhaust, matched combustion chambers and ports and hi-flo air intake. The addition of the remap, which costs an arm and a leg when compared to computer plug-ins, produced another 3bhp but allows for larger valves. The difference in torque figures, however is another matter and allows for much safer passing at lower rpms.

To achieve the sort of figures you're looking at, you'd need to get more fuel in and then out. This would mean sourcing a large valve head. Quite simply it would be cheaper to supercharge.

Later I shall attach various pieces by David Baker who really knows what he is talking about when it comes to normally aspirated twin cam 16 valvers. He must have learnt something at my knee:lol: !



PUMA RACE ENGINES - ENGINE CALIBRATION & CHIP TUNING

To operate properly an engine needs the correct amount of fuel at all times and the correct ignition timing. Getting these factors right is essential after any tuning modifications have been done and is called calibration.

Fuel Mixture

The power generated by any petrol engine comes from the fuel burned inside the cylinders. Any fuel needs oxygen to burn though and that comes from the air. We have seen in previous articles that an engine is really an air pump. The amount of power produced is directly related to the amount of air the engine can process per minute. Tuning modifications are designed to enable the engine to flow more air - just squirting in more fuel without improving the air flow does nothing for power. Every molecule of fuel needs to combine with exactly the right number of oxygen molecules if it is to burn completely and release its energy. For best power the ratio of the weight of air to fuel to achieve this is about 12.6 to one. So for every 12.6 lbs of air the engine processes we can burn 1 lb of petrol. We call that an air/fuel ratio of 12.6 to 1. For best economy the ratio is weaker - modern cars are set up to use an A/F ratio of about 15 to 1 at part throttle for good cruise economy. At full throttle the mixture is richened to maximize power output.

If the A/F ratio is weaker than 12.6 then power drops because the engine could be burning more fuel with that amount of air. If the ratio is richer than 12.6 then power also drops - the excess fuel can't burn because there is not enough oxygen present and just gets pumped out again along with the rest of the exhaust gases. Also this excess fuel displaces some of the air that the engine could otherwise have processed. Whether an engine has carbs or fuel injection the calibration must be correct at all rpms and throttle positions.

Copyright David Baker and Puma Race Engines


Carbs are calibrated by changing the size of the various fuel jets. Bigger jets let more fuel through for a given amount of air. The standard car will have been calibrated by the manufacturer but if the engine is modified in any way then the fuel mixture may no longer be correct. The solution is to take the car to a rolling road dyno where the A/F ratio can be measured and altered with different jets if necessary. In principle a fuel injected car is no different. The ECU stores on a chip a map of how much fuel the engine needs at different speeds and throttle positions to achieve the correct mixture. Signals from the crank sensor and throttle sensor tell the ECU what is happening. The ECU then looks up those positions in its internal map and triggers the injectors for exactly the right amount of time.

Ignition Timing ***

It takes one or two milliseconds from the time the spark occurs until all the fuel/air mixture in the cylinder is fully alight and expanding. The spark plugs therefore need to be fired a little while before the piston reaches Top Dead Centre so as to get the fuel mixture burning at the right time to push the piston down and generate power. When measured in crank degrees rather than seconds this time delay is called ignition advance. The perfect time to trigger the spark depends again on engine speed and throttle position. Cars used to use a mechanical distributor to set the spark timing. Nowadays it is normally done by the ECU in a similar way to how the fuel mixture is controlled. The ECU stores another map on its chip of how much ignition advance is required which operates just like the fueling map.

Copyright David Baker and Puma Race Engines


The amount of ignition advance required depends on the engine design. Average figures would be between about 10 crank degrees at idle to about 30 degrees at peak rpm. The required advance usually increases with rpm up to about 3,000 to 4,000 rpm and then stays fairly constant. It also needs to increase at low throttle openings and reduce again at full throttle. If the spark is fired too early (over advanced) then the mixture starts to burn too soon and tries to push the piston backwards down the way it came before it reaches TDC - very bad for power and a major cause of engine damage. If the spark is fired too late (retarded) the piston has already gone part of the way down the bore on the power stroke before the mixture is alight and much of the effectiveness of the energy released is lost.

If I had £1 for every person who thinks that more ignition advance is a good thing in its own right, I'd be a rich man. Like most other things, more advance is only good if there isn't enough to start with. Excessive advance is just as detrimental to power output as insufficient advance but it's also potentially much more harmful to the engine. In fact the better the engine design the less the advance that is required and, other things being equal, an engine that requires less advance will produce more power.

Copyright David Baker and Puma Race Engines


Why Don't The OE Manufacturers Get It Right?

Well that depends on your point of view. The OE manufacturers have a number of criteria other than just maximising power. They need to retain reliability, good fuel economy, allow for poor fuel, hot and cold operating conditions and what happens to the engine as it wears. Setting the fuel mixture to exactly 12.6 and the ignition timing to the optimum for best power is all well and good if everything else stays perfect. But if the engine overheats or you fill up with a bad tank of fuel those settings might cause detonation and consequent engine damage. Using a fuel/air ratio of 13 or 13.5 instead of 12.6 might lose only 2% power but gain 5% economy. Using a couple of degrees less than the optimum ignition advance allows a safety margin for low octane fuel or engine overheating with again only a minor loss of power. The standard calibration settings are what they feel is the best balance of reliability, economy and power. In my own opinion, most OE engine calibration settings are a very good compromise and not worth messing around with.

Copyright David Baker and Puma Race Engines


Chip Tuning

The chip is where the fuel and ignition maps are stored in the ECU of a modern engine. The aim of non standard chips is to take advantage of any compromises the OE manufacturer has made to the standard calibration settings which reduce power in favour of economy or reliability. The scope for improvements is usually very small though. The best that can normally be achieved is to remove any flat spots in the power curve and find a couple of % extra power by richening the mixture up to 12.6 and losing any safety margin in the ignition timing settings. The penalty is often significantly worse fuel consumption, unreliability, poor starting and the power increase is often not even noticeable. It takes a day or less of dyno time to establish the new map settings for a particular vehicle and each chip costs a couple of pounds. Total development cost is perhaps a few hundred pounds. The selling price of £200 to £400 from then on for a chip costing £2 means a huge amount of profit for both the chip company and the fitting agent. To keep those sales rolling along nicely, it isn't surprising that the power claims tend to be somewhat inflated.

Why people are prepared to spend so much on a 'performance' chip is beyond me. Everyone nowadays is familiar with how much computer components cost. A PC motherboard is maybe £60 and a complex piece of software that took £millions to develop might be £30. For a map that took a day to develop when each new chip itself costs £2, strikes me that to pay £200 or more is madness.. Still it's your money I guess.

On a turbocharged engine the chip might also control the boost pressure. There are genuine possibilities for good power increases in this case although it isn't really any more complex than adjusting a mechanical wastegate. The penalty for excessive boost pressure is detonation and engine life measured in weeks though. On a normally aspirated engine the chip can't make any difference to how the engine physically operates and can't increase the airflow potential. You therefore can't just "bolt on power" with a chip swap - it is purely a calibration device, not a tuning device. No different in principle to getting a carb jetted properly. Claims of 30% extra power from chip tuning is purest nonsense - 3% is more like it****. If the OE manufacturers were that bad at calibrating their cars considering the £millions they spend on doing it, they'd be out of business in weeks.

Copyright David Baker and Puma Race Engines


Calibrating A Modified Engine

Any time the airflow potential of an engine is substantially modified - by that I mean ported cylinder head, exhaust system, different carb or manifold, longer duration camshaft etc - the fuel and ignition requirements also change. Whether the engine has carbs and a distributor, or ECU controlled fuel and ignition, the principles of calibration are the same. The best place to get this sort of work done is on a rolling road dyno or engine dyno.

The engine is operated under load and the fuel/air ratio and power are measured. Adjustments are then made to bring the mixture back to the optimum settings. On a carb by changing the jets and in an ECU system by changing the internal map (or chip) that the ECU works from. The ignition advance can then also be altered a couple of degrees at a time to see if power goes up or down at different rpm.

An engine can be modified in an infinite number of different ways. Even similar sounding specs might work very differently. For instance a ported head might increase airflow by nothing at all if it has been done badly or 30% if it has been done well. The settings from someone else's similar sounding engine might be nothing like right for your own. By the same token a "performance chip" designed to squeeze a couple of % extra power out of a standard engine is useless for a modified engine if the map settings it contains are not what the modified engine now wants. Sadly it seems to be commonplace for people to believe that a chip is a performance item in its own right and that by fitting one it will magically make any possible combination of cam, exhaust and head mods work properly together. Nothing could be further from the truth.

Copyright David Baker and Puma Race Engines


Performance Increases From Modified Chips

So far I haven't seen a single definitive test where the acceleration of a "chipped" standard normally aspirated car actually improved. I've seen plenty of rolling road tests showing supposed increases in power and comments about improved "driveability" during road testing. Bring out the stopwatch though and these improvements seem to be rather harder to pin down. Several years ago one of the car magazines did a reasonably scientific test on a BMW as I recall. Performance chips from two different manufacturers were tested against the standard item in a 0-60 sprint at a test track. 5 runs were performed for each chip and the times averaged to remove any bias. Within a tenth of a second they stayed the same in all cases despite the extra horsepower claims. If anyone knows of a properly conducted test that shows the opposite I'd be interested to read it.

Copyright David Baker and Puma Race Engines



*** This is why TS ignition improves the burn and thus gives more power.

**** Agreed 100% having seen countless examples on the rolling road.
 
#16 ·
You can find the full spec of this 155 on the 155 Forum. The car is coming up for sale very shortly. Of course it has been remapped - specifically once all the engine mods had been done!
 
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