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Discussion Starter #1
Hi,

Thinking of changing my 147 JTDm.
Whats the best JTDM 16v you can get on a 147.

Thinking Ducati or a Q2

Cheers
 

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Either of those. The lower suspension and Q2 diff are well worth having. But with any post-2006 16V jtdm (CF4 'plastic' manifold) you must beware of the swirl flaps and if not already removed, remove them immediately.
Autolusso - Swirl Flap Delete

Love my Q2 since sorting this (and blanking the EGR and getting it mapped out). The extra 20bhp of the Ducati would be nice, but personally I detest the trashy side-stripe decals that many are fitted with.
 

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Either of those. The lower suspension and Q2 diff are well worth having. But with any post-2006 16V jtdm (CF4 'plastic' manifold) you must beware of the swirl flaps and if not already removed, remove them immediately.
Autolusso - Swirl Flap Delete

Love my Q2 since sorting this (and blanking the EGR and getting it mapped out). The extra 20bhp of the Ducati would be nice, but personally I detest the trashy side-stripe decals that many are fitted with.
We have had 4 x 1.9's in our workshop this week that have eaten their swirl flaps

They definitely need removing

Ned
 

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My GT cloverleaf JTDm has done 114000 miles with swirl flaps and I've had no problems. They were put there by Alfa for a reason. What's the impact or consequence for removing them?

Sent from my D5803 using Tapatalk
 

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My GT cloverleaf JTDm has done 114000 miles with swirl flaps and I've had no problems. They were put there by Alfa for a reason. What's the impact or consequence for removing them?

Sent from my D5803 using Tapatalk
AFIAK the flaps will all be closed when the engine is idling which helps to create more air turbulence in the intake. As the engine rpm increases the flaps begin to open and once you get to 2,000 rpm (ish), they should be parallel to the airflow thus creating no resistance at all. The purpose of swirl flaps is to control the air flow into the inlet, to make it turbulent enough for optimal fuel-air mixing even when the engine rpm is low. It's claimed to aid low-end power and torque whilst helping to eradicate some of the NOx emissions. So they were indeed put there for a good reason. The problem as we all know is that some cars have lost a flap, or two, and the tendency is for them to follow the lead of gravity and get wedged between the valves and pistons. This can write off a perfectly good car as the cost of a replacement or rebuild can be too much for many owners. Many owners report no issues at all but it is a known issue among a number of manufacturers and as most 156 based Alfa's are now out of warranty, it's a bill for the customer. The removal of swirl flaps can be made cheaper by planning it in with the cambelt change so it becomes a no-brainer really. Saying that, your swirl flaps must have good strong spot welds. :thumbs:
 

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My GT cloverleaf JTDm has done 114000 miles with swirl flaps and I've had no problems. They were put there by Alfa for a reason. What's the impact or consequence for removing them?

Sent from my D5803 using Tapatalk
Yer and I have seen cam belts do 100k too, it is just a matter of time until they come off, you have been lucky

If you do an EGR delete at the same time the benefits from the EGR delete outweigh the swirl flap removal

Ned
 

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My GT cloverleaf JTDm has done 114000 miles with swirl flaps and I've had no problems. They were put there by Alfa for a reason. What's the impact or consequence for removing them?

Sent from my D5803 using Tapatalk
Yer and I have seen cam belts do 100k too, it is just a matter of time until they come off, you have been lucky

If you do an EGR delete at the same time the benefits from the EGR delete outweigh the swirl flap removal

Ned
Having had both of these modifications done by the chaps at Autolusso (thanks again) I can say they work a treat, plus it's peace of mind that you've removed what's arguably the only real mechanical weakness of the JTD (we'll talk about water pumps another time). :thumbs:
 

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Will the quality of fuel affect how quickly the EGR and swirl flaps become 'gummed up'? For example if I use 10ppm diesel instead of 50ppm diesel would I get any real world benefit?? Locally we get Sasol 10ppm which I use in my JTDm. I mainly use 10ppm because I don't like the sulphur stench of cheaper fuels.
 

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Is there any way of checking if those flaps have been removed,i've no record from previous owner paperwork..
 

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Any degradation in engine performance from these mods?

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I've had an Autolusso remap with EGR and swirl-flap delete and I can't say that I noticed any change in low down power, I do drive it like a Twin Spark though :evil:. The idle is a bit different and it is a little (only a little) smokier but the cars emissions are within MOT requirements and its actually gained a few more mpg as a result. The main benefit is that you are no longer diverting all the burnt diesel and carbon deposits back into the inlet, one of the causes of swirl flap issues. As the inlet goes though a cleaning process to remove all the deposits it must mean that the fuel-air mixture burns cleaner and better. :thumbs: While I was up in Penrith Dan showed me a pre-processed inlet and the stuff that comes off the inside is awful, it's no small wonder that the swirl flaps decide to emigrate and house share with the valves. As mentioned when it comes to cambelt time it's worth thinking about what Ned said above, not if but when and removing them sooner that later can save a massive headache down the road. :thumbs:
 

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Any degradation in engine performance from these mods?

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With you engine (170 Cloverleaf) we can do:

Swirl flap delete
EGR delete
Hybrid turbo

For £1,300 inc VAT, if you car is the 170 BHP this will give you around 260 BHP reliably, if your car is the 150 BHP you will get around 240 BHP, the difference is in the injectors and fuel pump

Ned
 

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The thing is that swirl flaps only do anything useful because of the exhaust gas being fed through the EGR valve. The whole point of introducing exhaust gas is to spoil the fuel burning efficiency at lower revs, which reduces combustion temperatures and produces less NOx. But a side effect of that is that the deliberately poor combustion increases hydrocarbon emissions from unburnt fuel.

The swirl flaps operate to create turbulence, to better mix air and exhaust gas to try and reduce that happening. When operating, they close one of the two inlets to each cylinder so the gas enters from one side of the combustion chamber and 'swirls' to mix air with exhaust gas.

Basically they are a kludge to get around the inefficient combustion caused by using EGR to reduce NOx at low revs.

At larger throttle openings, above ~2000 rpm, the EGR closes, the swirl flaps open, and the engine runs on air alone.

Unfortunately the swirl flaps are poorly engineered and will eventually detach from their spindles.

If you only remove the swirl flaps, you will notice some loss of low-down torque from the degraded combustion. But if you also blank off the EGR, your prevent exhaust gas reaching the cylinders and the swirl flaps then serve no useful purpose. The engine is inhaling clean air alone, not soot, CO and CO2 from the exhaust.

I ran my car like that for a couple of hundred miles and it was fine, except I had a MCSF light because of the blanked EGR. Eventually I took it to Autolusso who mapped the EGR out. But that isn't, I am sure, just disabling the MCSF fault. I'm guessing AL are slightly increasing the fuel supply to match the increased amount of oxygen available once there's no exhaust gas being inhaled - in other words restoring fuel efficiency to what it should be. It made an immediately noticeable improvement to drivability at low revs. The engine pulls well from tickover without using the clutch (cruel to the DMF, but it does it, even in 2nd).

If you were to measure NOx at <2k rpm, I expect it would be somewhat worse, but that's the only downside. The upside is eliminating a whole heap of stuff that causes problems - the periodic choking-up of the EGR valve, the build-up of restrictive carbon goo on the inside of the inlet, and the hefty engine damage that will happen when one or more flaps detach and enters the combustion space. It's relatively simple to remove the inlet manifold and delete the swirl flaps on the CF4, replacing the head is a much bigger, costlier job.
 

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With you engine (170 Cloverleaf) we can do:

Swirl flap delete
EGR delete
Hybrid turbo

For £1,300 inc VAT, if you car is the 170 BHP this will give you around 260 BHP reliably, if your car is the 150 BHP you will get around 240 BHP, the difference is in the injectors and fuel pump

Ned
Hi Ned,

How much would swirl flap delete, egr blank, remap, timing belt and service be?

Car is in at a local garage in Brighouse for the timing belt and service but after reading this I may cancel as the belt needs doing and I don't want to have to do the belt twice.

Thanks

Andy
 
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It would be nice to get back on topic, as I'd also like to know people's views on the 150bhp variants and how different the 170bhp is?
 

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The 170 hp version is good. I've had both in GT version and the 170 version is a more keenly revving engine and nicer go drive

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Discussion Starter #17
Hi,
Out of interest then - what can you get BHP reliably out of an 8 Valve version JTDM and not a 16 valve version.

Thanks for the replies.
 

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Hi Ned,

How much would swirl flap delete, egr blank, remap, timing belt and service be?

Car is in at a local garage in Brighouse for the timing belt and service but after reading this I may cancel as the belt needs doing and I don't want to have to do the belt twice.

Thanks

Andy
Hi Andy

Our premium cam belt service
Air filter
Pollen filter
Air conditioning service with decontamination
Oil and oil filter & sump plug washer
Fuel filter
Cam belt & water pump
All levels check and topped up
Through check over and report

£555 inc VAT

Swirl flap delete £300 inc VAT

EGR delete FOC while we are doing the other work

Ned
 

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I don't want to have to do the belt twice.
You don't actually need to disturb the cam belt to remove the inlet manifold. The HP fuel pump drive pulley has 2 bolt holes that allow it to be bolted to the crankcase, keeping the cam belt tensioned and immobile while you remove the pump so the manifold can come out.

If the belt is due, this isn't worth bothering with, but delaying swirl flap removal because the cambelt is recent, is an imaginary excuse :)

However I did all that as the belt was mid-life, then found I had two flaps missing - one stuck in the inlet tract, the other having mashed the head and valves. So I ended up replacing the belts, idlers and tensioners anyway.
 

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You don't actually need to disturb the cam belt to remove the inlet manifold. The HP fuel pump drive pulley has 2 bolt holes that allow it to be bolted to the crankcase, keeping the cam belt tensioned and immobile while you remove the pump so the manifold can come out.

If the belt is due, this isn't worth bothering with, but delaying swirl flap removal because the cambelt is recent, is an imaginary excuse :)

However I did all that as the belt was mid-life, then found I had two flaps missing - one stuck in the inlet tract, the other having mashed the head and valves. So I ended up replacing the belts, idlers and tensioners anyway.
Fair play. Thank you for the advice. I will get the belt done at the local indie and then take it to Ned or someone who knows a what they are doing with the removal and remap.

Again thanks for the advice. No excuse now.
 
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