159 2.4 JTDM Airbox Mods or CDA? - Alfa Romeo Forum
You are currently unregistered, register for more features.    
Tuning & Upgrades Discuss performance enhancements for your Alfa Romeo

 
Thread Tools
(Post Link) post #1 of 13 Old 22-10-13 Thread Starter
Status: The Boost Beast lives!
Club Member
Membro Premio
 
JabawokJayUK's Avatar
 
Join Date: Jul 2011
Location: United Kingdom
County: Cambridgeshire
Posts: 3,475
Garage
159 2.4 JTDM Airbox Mods or CDA?

I am after some advice on a direction to take. I am in the process of having some mods sorted to the turbo and exhaust, and am looking at the intake side of things as well. FMIC is planned from spring, but for now I am looking at either replacing the whole intake assembly with a BMC CDA or modifying the current intake to increase airflow.

elearn.png

If you look at the eLearn diagram, I can either remove the resonator (3) and cut and modify the airbox (2) to open a larger intake hole for the pipe (1) to be refitted and then use a K&N or other panel filter.

OR,

I could just replace the whole lot past the MAF with a large BMC CDA whcih would give a shielded intake that maximises flow without suffering from heatsoak issues. I would wrap the intake in heat reflective tape for added insulation as well btw.

ThumbGen.jpg

I realise a standard cone outside of a Carbon intake box would be useless due to heat soak issues, but the CDA's offer the same level if not better heat protection than the stock airboxes.

What are peoples experience / thoughts?


2008 159 TI 2.4 JTDM QTRONIC
My Car Details______https://jabawoki.com/2014/07/07/alfa-159-ti/
Project Halo Wiki____https://jabawoki.com/projects/project-halo/
Project Halo Page____https://www.facebook.com/ProjectHaloUK
JabawokJayUK is offline  
Sponsored Links
Advertisement
 
Status: Race cars in progress
AO Silver Member
 
Gertie's Avatar
 
Join Date: Oct 2007
Location: South Africa
County: Gauteng
Posts: 5,994
Garage
The filter unit is the same big cylindrical filter used in GT 3.2 V6 - I think it should suffice. I don't think a CDA performs any better... A friend removed his CDA a few days after installing

Modifying the piping a bit to get rid of the resonator and straighten the corners could help. I am of the opinion it helped my 3.0L somewhat.

K&N Products by Vehicle Search - Year, Make, Model, Engine Search
Vehicle applications for K&N Part E-9281
Gertie is offline  
Status: To err is human, but feel is divine!
AO Member
 
dusanGT's Avatar
 
Join Date: Feb 2008
Location: Novi Sad
County: Serbia
Posts: 782

Member car:

GT JTDm + Q2

Only as idea, because I made BMC-CDA mod for my remaped GT JTDm Q2 which has different position of compressor inlet.
Driving impressions: spool in low/mid rpm zone is obvious better and results of measurement point to the approx. 5% better airflow with BMC-CDA (570kg/h vs. 600kg/h) on 4500rpm. Sound is better in high rpm area with nice low frequency note in start circumstances...
Attached Images
File Type: jpg BMC - CDA - Resize.jpg (118.1 KB, 113 views)
dusanGT is offline  
Status: Alfaless!!
AO Silver Member
 
phil-gtv6's Avatar
 
Join Date: Aug 2006
Location: United Kingdom
County: West Sussex
Posts: 3,090
Garage

Member car:

E82 125i

I imagine the intercooler and associated pipework to be the most restrictive parts of the system
phil-gtv6 is offline  
(Post Link) post #5 of 13 Old 22-10-13 Thread Starter
Status: The Boost Beast lives!
Club Member
Membro Premio
 
JabawokJayUK's Avatar
 
Join Date: Jul 2011
Location: United Kingdom
County: Cambridgeshire
Posts: 3,475
Garage
Quote:
Originally Posted by phil-gtv6 View Post
I imagine the intercooler and associated pipework to be the most restrictive parts of the system
Agreed, that is in scope for next spring to change to the RS500 60mm core approach that Clogz, JB & Coxy all took. for now I am just looking at what would need to happen to the intake in preparation given the larger turbo and de catted exhaust that is going on shortly. Its winter after-all, so a don't have to worry as much about inter-cooler efficiency just yet

Modifying the box is one way, but if a CDA can achieve better results overall I can sort the install now ahead of the FMIC.
JabawokJayUK is offline  
Status: To err is human, but feel is divine!
AO Member
 
dusanGT's Avatar
 
Join Date: Feb 2008
Location: Novi Sad
County: Serbia
Posts: 782

Member car:

GT JTDm + Q2

My next step is 550mmx140mm FMIC and this will be maximum for 24/7 use of GT.
Similar things I made for my former 147 JTD 8v...
https://www.alfaowner.com/Forum/tunin...-9-jtd-8v.html
https://www.alfaowner.com/Forum/tunin...e-removed.html
dusanGT is offline  
Status: 329 hp
Club Member
Membro Medio
 
JS JTD's Avatar
 
Club Member Number: 1004
Join Date: May 2009
Location: Netherlands
County: Noord Brabant
Posts: 1,713
My experience is different with th BMC CDA on the 1.9 JTD 8v engine. I had a similair airbox position as Dusan, but I had no gains in terms of airflow and boost compared to my modified stock airbox with 16v snorkel. Did a lot of logs at the time.
I did experience a small difference in driving, with the standard airbox it felt stronger in the 1000-2000 rpm (prespool) area.

Now with my 240+ hp 1.9 JTDm 16v, I also modified the standard airbox and intake manifold and the difference is more or less zero.
I'm confident the stock 1.9 JTD intake system is a very effective design with no restriction even with 100 hp over the stock output. Looking at the picture of the 2.4 20v design, to me it looks even better than the 1.9 system with a more straight flow through setup with few bends.
Sure, if you're after a sporty sound or cool looks, get the BMC, but if you're interested in performance only, leave it as it is.

147 JTDm 16v - GTB2060v - 329 hp/578 Nm
JS JTD is offline  
(Post Link) post #8 of 13 Old 25-10-13 Thread Starter
Status: The Boost Beast lives!
Club Member
Membro Premio
 
JabawokJayUK's Avatar
 
Join Date: Jul 2011
Location: United Kingdom
County: Cambridgeshire
Posts: 3,475
Garage
Thanks for all the input. Given the cost of the CDA is well over 250 I think I am best performing some small intake mods to the current set-up to improve initial air throughput and stick with my K&N replacement filter. I am going to bypass the resonator this weekend and see what impact it has on the sound.
JabawokJayUK is offline  
Status: To err is human, but feel is divine!
AO Member
 
dusanGT's Avatar
 
Join Date: Feb 2008
Location: Novi Sad
County: Serbia
Posts: 782

Member car:

GT JTDm + Q2

Some additional remarks about justification of BMC-CDA upgrade...

This is my second used BMC-CDA - the first one is in my former 147 1.9 JTD 8v: in such case difference between factory airbox and BMC-CDA were only measurable by diagnostic software, but impressions in driving were similar. I think that main reason for this was fact that need for airflow in case of 8v can be fulfilled by standard airbox and filter.

Now, with 1.9 JTDm 16v, which has more need for air and allows more airflow, I notice obvious difference and in this sense 16v environment is more real for comparison of factory airbox and BMC-CDA.

And finally, very interesting thing: after my BMC-CDA upgrade, one phenomenon described in Joel's topic becomes more emphasized in comparison with factory airbox state: https://www.alfaowner.com/Forum/tunin...ml#post6587498. Maybe explanation is that now, with BMC-CDA, I have more airflow and consequently more boost and higher rate of boost rising than before...
dusanGT is offline  
Status: To GTB or not to GTB?
AO Silver Member
 
TribesMan's Avatar
 
Join Date: Nov 2007
Location: Slovenia
County: -
Posts: 2,289
I have had CDA on my 16V JTD... I have removed it because it sounded too loud, and engine response below 2000rpm was noticeably worse than with stock airbox. Also fuel consumption was up by 5%.
The resonator on the stock airbox is carefully calculated to offer the best performance with the least noise.

There was maybe a bit of improvement in the top end, but that was not enough to compensate for other drawbacks.
TribesMan is online now  
Status: To err is human, but feel is divine!
AO Member
 
dusanGT's Avatar
 
Join Date: Feb 2008
Location: Novi Sad
County: Serbia
Posts: 782

Member car:

GT JTDm + Q2

I remember our earlier discussion about this...
Choice of proper type of BMC-CDA and shape of intake pipe system play important role in possible benefit of performance... Air Intake of my BMC-CDA 85-150 is fully open and located near to the front grill (the best source of cold fresh air) and pipe system (80mm) has only one elbow before inlet of compressor.

Position of original factory air duct (blocked under bonnet) is slightly weird for me, but... maybe something from area of fluid mechanics gives valid explanation for this...
dusanGT is offline  
Status: 329 hp
Club Member
Membro Medio
 
JS JTD's Avatar
 
Club Member Number: 1004
Join Date: May 2009
Location: Netherlands
County: Noord Brabant
Posts: 1,713
Quote:
Originally Posted by dusanGT View Post
I remember our earlier discussion about this...
Choice of proper type of BMC-CDA and shape of intake pipe system play important role in possible benefit of performance... Air Intake of my BMC-CDA 85-150 is fully open and located near to the front grill (the best source of cold fresh air) and pipe system (80mm) has only one elbow before inlet of compressor.

Position of original factory air duct (blocked under bonnet) is slightly weird for me, but... maybe something from area of fluid mechanics gives valid explanation for this...
I agree the total picture matters for the end result.
But still, the fact that earlier mentioned upgrades, like a bigger diameter snorkel, bigger intake hose and increased diameter of manifold made no difference with my 240+ hp JTD 16v engine, tells me enough.

Imo, if you want to make a change, focus on the exhaust side. There's a lot of gains to be had.
JS JTD is offline  
(Post Link) post #13 of 13 Old 05-11-14 Thread Starter
Status: The Boost Beast lives!
Club Member
Membro Premio
 
JabawokJayUK's Avatar
 
Join Date: Jul 2011
Location: United Kingdom
County: Cambridgeshire
Posts: 3,475
Garage
I am coming back to this thread as I am going to have an FMIC installed soon to mate with the new GTB2056 Hybrid turbo and that will mean that the original airbox intake will no longer be able to exist where it does now.

For ease, I am planning on pulling the stock airbox off and replacing it with a ITG Maxogen Cylindrical filter located as high up in original location as can be achieved to restrict chances of water ingress.

The maf is 80mm right? if so I guess I am going to need a short silicon junction to attack the ITG.
JabawokJayUK is offline  
Reply

Go Back   Alfa Romeo Forum > Supported Alfa Romeo Models > Technical & Vehicle Assistance > Tuning & Upgrades

Tags
159 , airbox , cda , jtdm , mods

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome