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Discussion Starter · #1 ·
Since my GTB topic is getting a bit offtopic with other related subjects, I figured I might aswell make a project topic with all engine mods listed.

This is the GTB topic I reffered to:
http://www.alfaowner.com/Forum/tuning-and-upgrades/250489-gtb2056v-jtdm-2-4-turbo-pics.html

So here it is:

The car, a 147 JTDm 16v from late 2006:


The goal is to reach 240 hp and 450 Nm using a GTB2056v turbo.

Setup includes:
- GTB2056v turbo modified to fit
- New stainless downpipe
- Rest of exhaust in stainless 2.5"
- EGR delete
- FMIC
- Modified intake with 80mm MAF and OEM airbox
- Of course a custom map
- Reinforced dual mass flywheel
- Reinforced sports clutch
- Q2 diff

First I mounted a downpipe and boost gauge to it:



Then I got it remapped at Squadra Tuning to 175 hp and completely shut the EGR.
This is temporary setup, meanwhile I've been busy building all the custom parts around the turbo.

The GTB2056v turbo:


And next to the OEM turbo:


Comparing turbine inlet with the OEM exhaust manifold where it should be mounted to:


Template I've made to make the parts surrounding the turbo:


Compressor housing mod:


Turbine foot mod:


Exhaust manifold mod 1:


Exhaust manifold mod 2:



Custom compressor outlet pipe:


Custom stainless steel downpipe:
 

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Discussion Starter · #2 ·
The parts fitted in the template:


Template for turbo intake pipe:


And it fits:


The MAF, a very compact 80mm piece, rated to 800kg/hr airflow. Should be enough.
Here is it next to the OEM one:


FMIC pipes:


Reinforced Valeo dual mass flywheel, rated for up to 450 Nm:


Reinforced clutch with Kevlar friction plates:


Q2 diff:


After these engine mods also mods to the handling and brakes will be done.

Any comments are welcome !
 

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I think this is reinforced clutch kit from clutch-specialists... It doesn't have springs, because this car uses dual mass flywheel and the springs are in the flywheel instead on the clutch disc... it looks just like the stock clutch disc...
 

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What about intake manifold? Standart or modifyed? What size of piping from IC to manifold?
Would you explain for me the preference of big MAF. For example - with standar maf 4.5v= 1200mg of air. With big maf 4.5v = 1700mg of air. But ecu anyway understand 4.5v as a 1200mg of air. I think, without correction via smoke map, installing big maf has no sence. Is it true or false?
 

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When you change the MAF you need to modify linearization map inside the ECU.

I dont think bigger MAF is neccessary... because even the stock one has huge reserve in measuring capacity.
There is an benefit of lower intake restriction with bigger MAF housing.

But then again, with stock airbox the inlet to MAF is quite limited.
 

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Doesn't worth, the filtration surface of cone filter is much smaller then stock one. Personally I'm going to use stock airbox with GTA stock filter, airbox cap and MAF. All rotated by 90 degs to point toward compressor inlet.
 

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Discussion Starter · #15 ·
When you change the MAF you need to modify linearization map inside the ECU.

I dont think bigger MAF is neccessary... because even the stock one has huge reserve in measuring capacity.
There is an benefit of lower intake restriction with bigger MAF housing.

But then again, with stock airbox the inlet to MAF is quite limited.
Indeed, map has to be modified, otherwise the ECU will think it gets less air with the bigger MAF.
For the 80mm MAF, well I think there's a good reason 80mm MAF are OEM at the 2.4 JTD 20v engines. Maybe the standard 70mm one will just be able to measure it with some tweaks to the acceptable voltage range, but I think accuracy will be worse.
Also, as you say, the pressure loss pre turbo will be less.

alfalv said:
There are a lot of different sized cone filters. My Green filter has a just same lenght of a standart filter with a more edged surface. So, I think difference between cone and standart filters not so dramatical.
If that's the case, then why would you bother placing an element that:
1. will allow more dirt in to your engine
2. is more expensive
??
As said already, the filter element is no bottleneck. The snorkel is, the diameter necks down to less then 50mm if I recall right. I will cut it and use a larger diameter hose for it.
 

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Discussion Starter · #17 ·
What differnce will the hose make ?

Surely the same amount of air will be going into a slightly larger hose, you would have to make the intake side of the snorkel bigger to get more air in ?
The cross sectional area of the snorkel is not even, but the smallest half way.
That smallest area dictates the maximum amount of flow at a given pressure difference.

The laws of physics applied!

 

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I see, JS, but if the snorkel gathers as much air as its inlet allows, what happens to it when it reaches the restriction ? I thought it would just be compressed, where does it go?
Doesn't work that way, in the microsecond of the turbo spooling up, it draws a chunk of air from the pipework just feeding into the turbo. This then creates low pressure, and air starts to flow into it from the rest of the system. Each rotation of the turbo it is just going to suck a small amount of air from right before the compressor. But air will not flow into this low pressure area effectively from the atmospheric pressure area (the airbox) if on the other side of the atmospheric pressure area there is another low pressure area (the filter side of that restrictive section) - if you get me. At high turbo speeds, that narrow section will not flow air into the airbox as well as a section as wide as the intake to the airbox, so it will mean that there is a slight vacuum in the airbox, and the lesser difference in pressure between the airbox and the intake to the turbo will slow the speed at which the air moves from the airbox into the turbo.

The same applies on the Twinsparks, the exact same part is restrictive in exactly the same manner and the solution is to fit the GTA snorkel, which is of uniform diameter across the whole length. A restrictive intake can be a good thing at low loads and low throttle openings on a car which is normally aspirated though, but on a diesel you want the least restriction pre-turbo as possible.
 

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I see, I cut my snorkel off and added a tube down to the opening of aftermarket enclosed filter, so it sucks in air from the snorkel as well as from the lower grille. Cant remember where I cut it off, before or after the restriction. But going to make my own enclosed filter (using, dont laugh, a flowerpot) with the tube attached to the enclosure, will make sure the tube is as large as poss, then.
 
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