I have the GTA pipe fitted and airbox cone removed (standard exhaust and air filter) and cannot say I noticed a huge difference either.

The engine feels slightly less smooth at lower revs and slightly more rorty at the top end, though its still nowt special really.

I will probably put the cone back in soon as most of my driving is at fairly low revs anyway these days, apparently it does something with pulse waves that is the subject of some debate!

Strange these TS's...my 155 sounded far better than both my GTV's or the current 156 ever did, perhaps it was just down to the exhaust design?

 

I have the GTA pipe fitted and airbox cone removed (standard exhaust and air filter) and cannot say I noticed a huge difference either.

The engine feels slightly less smooth at lower revs and slightly more rorty at the top end, though its still nowt special really.

I will probably put the cone back in soon as most of my driving is at fairly low revs anyway these days, apparently it does something with pulse waves that is the subject of some debate!

Strange these TS's...my 155 sounded far better than both my GTV's or the current 156 ever did, perhaps it was just down to the exhaust design?

Probably down to the fact that the early TS 16v engines breathe a little better - they have the little fifth EGR pipe on the exhaust manifold, and also the straight pipe (without resonator) on the inlet manifold piping. It all helps.

 

I went through a huge range of iterations on my 2.0 Sele some years back.

Changing the intake resonator to a GTA plain unresonated pipe adds some sound to intake. Bit like an old carb fed engine. Removing the cone in the box adds more noise, but affects low end drive ability. Changing to an aftermarket oiled filter ruins the MAF sensor, but again adds volume.

I ended up with a GTA intake pipe, a Pipercross foam filter, with the finest spray of oil rubbed in. And the cone in the box. Best added noise, without taking away any power.

These mods add no power at all. They are pure noise.

Agreed on 155 sounding better. I had a 2.5 155 that sound excellent. Even better when the tail box failed and I pulled all the sound deadening wool stuff out. Sounded great.

 

I changed to a GTA intake on my 156 TS and it made no difference at all from what I could tell, it even sounded the same.


The reason that the cone in the airbox is there is to reflect pressure waves back into the engine to increase its volumetric efficiency.

If the pressure waves arrive back at the engine at the right time then it will assist in filling the cylinders with air.

The 2 stage variable intake manifold on the TS makes this happen at a wider RPM range.

 

Hi there,
Might be the placebo effect, but I just noticed a split second advance on the power and a bit more engine noise, pipe only cost £25 and was fun to fit! (An easy mod, not much swearing;-)) all in all, it's just fun working on the car and the problem not being 'terminal' I like the mod, it's cheap ads 0.1 second to reaction time on pressing the pedal and makes you hold the gear shift just that second longer to hear that little extra growl!

 

If folk have the ackers and time to fit it, fine. I've considered it, but it seems more beneficial to fit better brake pads.

 

True...I've never had an Alfa with such poor brakes, the ABS is far too easily provoked and I've had a couple of proper brown trouser moments having to get out of lane to avoid hitting things!

I've had to adjust my driving style to suit as I just have no confidence in the brakes to slow the car predictably when pressing on...which sort of spoils the enjoyment of driving the thing

Looks good out of the window though, currently sat between a Nissan Juke and a ratty old Renault Megane which helps too...

 

:thumbs:

 

Oh! One point to mention from the picture...... Note the position of the hangers! One by my thumb, other by the spot on the pavement! god bless cable ties!

 

I've decided to put a wing on the back of my SW, apparently it'll boost power and the MW reception. :cheese:

 

Does anyone really think the GTA intake mod is worth it on twin sparks?

Why ask questions?????.......

 

In short...not really aside from some extra noise perhaps, and the satisfaction of doing some tinkering imho.

Your pic in post 6 looks like a standard V6 pipe to me though?
The GTA pipe I fitted was significantly larger and had a constant diameter throughout, cost £38 with all the proper fixings from Mango's at the back end of last year.

 

I actually ordered a GTA intake, but when I was trying to slot it in, even with silicone, it just wouldn't go. I should've kept going but I felt weak! (hungover). After I'd ordered the GTA intake, typically, I found the intake off my GT V6. Having been fitted before, it slotted in much easier, was a little bit shorter and a tad bit smaller in bore diameter. I'll stick the GTA one on at some point.

I think there is a small difference, but it's so small, you think it's placebo effect. I'd hoped for a considerable difference, but as others have said, it's always fun tinkering. Just need to do my driver's door strap and I'm done with anything other than servicing on my GT and 156.

p.s. Gazza- thanks for the guide on your site.

 

It's going back a bit now. But when I owned my 2.0 TS i did the GTA mod and de-coned the air box.

What did I notice apart from the sound, which was glorious?

Well where I live there is a steep bank that I had to travel up every day. It is one of those banks that you feel the need to hit at full tilt, you come off T- junction then a flat straight 300 metres before the climb that get increasingly steeper for a further 300 metres.

For those who doubt that such a mod can make a difference....

All I can tell you is, Pre-mod, I could only get up in 4th gear with the engine revs holding steady stable during the climb and 65mph max no matter how much speed I carried from the junction.
Post -mod... I could do the same bank in 5th gear with the revs still rising and +70mph

I think that puts it into real world driving terms that it does make a difference

Hope this helps

 

It is one of those banks that you feel the need to hit at full tilt, you come off T- junction then a flat straight 300 metres before the climb that get increasingly steeper for a further 300 metres.

For those who doubt that such a mod can make a difference....

I've a similar hill, except I have to drop into 3rd, I'll try the filter without the cone and see if I can make it up in 4th or 5th.

To be fair Graham, I think most of us doubters were mainly on the sound front, I expected a noticeable difference. Trouble is, most things sound limp compared to a V6, esp when it's got a CDA on

 

Yes, I do.

 

If the ABS is coming in early either you have very poor tyre grip or it is likely that one of the sensors is sending duff information to the ABS ECU

I had a similar problem on a Rover 800 and one of the sensors had been hit with a stone and was further from the toothed reluctor ring on the hub than it should be.

Once it was back in position proper braking was resumed...

They are also magnetic and metal particles from the brake disc can get picked up by them.

 

Sorry for Hijacking the thread,

alcooker, where did you get your GTA snorkel from? every week i'm pestering autolusso's second hand parts department but it seems impossible to get hold of a used one without paying £40+ for a new one from the dealer.

Just a quick one, the 'cone' that's fitted inside the air filter housing is known as a venturi cone. its designed to increase pressure after the restriction. if you take it out you will increase the volume of air entering the engine, but you can't get the cold air into the engine quickly without the 'venturi' because there is no pressure to force the cold air in.

the venturi cone is there also to give an even dirt wear across the air filter, if you take it out then dirt will build up in one place where the air enters the air box and hits the filter because that's the shortest path as there is no cone there.

that's what iv'e learnt that what the venturi is for and what it does, any one that has a better explanation on what its for i'm all ears.

Ta guys

 

Hi Chris. Venturi tubes are used to create a low pressure area at the constriction rather than a high pressure area after the constriction. A carburettor (anyone remember them?) is a venturi and the low pressure generated by air passing (accelerating) through the 'throat' or throttle of the carb sucks fuel into the airstream through a selection of jets (precise diameter holes) at hopefully the correct ratios.

The pressure after the venturi (in this case the alfa cone) is always less than atmospheric pressure before the venturi (within the air box). If it wasn't the air would be going the other way and blowing out into the airbox. Air always travels from high to low pressure areas - the engine is creating a vacuum and the air at atmospheric pressure is rushing in to equalise the pressure.

The purpose of the cone has been touched on before. I think it has two purposes. One, it is a bell-mouth for the induction system. The curved and radiused bell mouth opening will flow a lot more air than a 'straight cut' pipe opening. I've attached a couple of pics and a graph to show what I mean. I don't think it is the great impedament to air flow that lots of people think it is as the it would greatly reduce turbulence (drag) of air entering the induction pipe. The cone is an extension of the curved induction pipe which suggest it is designed to deliver smooth laminar flow (unturbulent air) past the MAF to provide accurate fuel metering. Turbulence kills airflow and effectively reduces the diameter of the tube the air is travelling through (see blue areas of dead air adhering to the walls of the pipe opening below).

Two (although a long shot due to the attenuation caused by the modular manifold), it may act as pulse reflector/inverter. When inlet valves open they create pulse negative wave that travels back through the airflow at the speed of sound. The taper of the cone would refect positive pressure waves back up the pipe, effectively harnessing the resonance within the system to increase pressure at the inlet valve.

Removing the cone may or may not give you a small boost at peak rpm depending upon whether the cone is bigger bottleneck (from a fluid dynamics perspective -see turbulence above) than any other component in the induction system at full flow. Then again its is likely to provide no benefit at the speeds and rpm that you do 98% of your driving (where the biggest constriction is the throttle butterfly) and may negatively effect power and fuel efficiency.

Remember the most inaccurate dyno on earth is usually located in a driver's ass.

 

Hi Chris,

I tried AL too, but ended up having to get a new one from Mangoletsi for about £40. Back in 2005 the same part was around £15. HAve you tried doing an online search of scrap dealers? I can't remember the site, but you put what you want in and the scrap dealers come back to you with quotes.

 

Partsgateway.

Its a struggle to find one of these 2nd hand - a GTA has to die to provide and as they've held steady at £4k+ for years now there aren't many being broken up. A new one at £40 is not so bad.

 

Get a 2.5 v6 one

John

 

You can just do without the intake pipe bit entirely and just avoid big puddles! I ran my Sele for a few months without the intake pipe when the V6 pipe fell off due to rubbish securing.

 

The ABS is progressive or should be, when you have one wheel lose grip you get a gentle tickle to the foot, two gets a touch more immediate, all four and then I get the toffee hammers bit.

I have only experienced the all four wheels battling for traction while braking bit once or twice. If you're getting that frequently, I'd suggest looking at ABS sensors first because that ain't right!

Quickest and safest way to big brakes is a K Sport kit.

Their 6 pot, 304mm disc version to fit regular 156, 147 and GT is £885 all in and would fit 16" wheels. Or for £899 you could have an 8 pot 330mm disc kit that'll need at least 17" wheels.

 

Or for £899 you could have an 8 pot 330mm disc kit that'll need at least 17" wheels.

I have this kit, you need to budget at least another £220+ for decent pads, the K-Sport ones are poor. This pad size is very expensive, also replacement rotors for the 2-piece discs are very expensive too. But otherwise its a good kit.

 

I had a good spin in the car last night and it definitely goes better from 70 to 100, I didn't even realise I was at 100. Lower down the gears I'd now say the car is a bit meatier, no much but the intake change seems to have just taken the edge off the thinness I got from revving.

I've spent a lot of money on this car lately, prob about 3 grand, bit crazy but still cheaper than buying something and not knowing where you are with it. So I was a bit gutted when my Wife got home and told me that "part of he car is missing". Turns out she'd pulled out of a garage and had gone over a grate and curb ripping half a side skirt off. She says she didn't hear the sill getting ripped off, said it was like a speed bump scrape noise! So she didn't stop to collect the sill. Muffins here had to drive 12 miles to see if it was there, found it and its underside is smashed up but the bit on show is okay so I can poss fix it. That's Karma for spending money on a pro detail.

Here's a pick of the garage exit, god knows why she went over the drain but she did because there's a Toyo T1R tread imprinted in the snow by the drain. A bollard would be a good idea is what I suggested to the garage sales assistant who didn't give a crap.

 

Oh dear Al... Sorry to hear that mate.... It is typical though... you sort one thing out and the car runs sweet, then someone or something comes along and ruins your fun:lol:

Hope you get it sorted soon mate.

PS. Did you try it up hill yet?
It does make a difference doesn't it... Not as laboured as it was, so to speak

 

TS sound great with a bit of induction noise. Also means when your not giving it the beans it just sounds normal.
Not like those clowns with mega exhausts.

Power Slightly improves with inductions kits usually. Not so much on the power front maybe free's up a few ponies. But usually the lower end torque is improved. hence the engine before comes flexible.

The shorter the induction the more power, the longer with less bends usually helps torque.

 

Well having just done 150 mainly motorway miles in the 156, i can genuinely say I'm really glad I put the intake on and with the K&N air filter. Really felt good about the car today, so smooth.

 

Just been tidying up the garage and came across by old resonator box. So before it goes to the tip tomorrow I thought I'd do a bit of measuring!

The GTA intake pipe gives a 56% increase in cross sectional area over the standard resonator box and does away with one very restrictive 90 degree bend too.

Throttle response is definately sharper and overtaking seems a bit easier.

I got mine by messaging people breaking GTA's in Ebay and picked it up for £15 including postage.

 

Can the GTA intake be fitted to a GT JTS?

 

No, completely different intake system on the 147/GT (except for the 3.2v6).

 

Right, thanks David.

 

I was just thinking about this thread earlier today. I think I said at some point I hadn't noticed much difference when doing this Mod, but a while ago my Wife accused me of doing something to make the car louder. So I was busted. It's when it hits 3,000 rpm that the increase in noise occurs for me, it's a nice noise, but sometimes on motorway cruises there's a bit of a drone that I didn't get with the original intake. I'm defo starting to think that Alfa's ways are better than any mods I've had done.