Click here to return to the home page.
Classic Morgans
Who's Online Now
7 members (Morganmike, Barkbark, Guten, Luddite, Bitsobrits, jbk, MJF), 353 guests, and 94 robots.
Key: Admin, Global Mod, Mod
Top Posters(30 Days)
+8Rich 79
DaveW 52
Newest Members
Scot_SJI, Jimmers, Breen60, Davidmog, Stevecarr
9,596 Registered Users
Newest Topics
CX moaners
by Malachy - 02/09/26 01:20 PM
Plus 4 Steering rack gaiter
by Strathaven - 02/09/26 12:42 PM
Three BMW tales
by DaveW - 02/09/26 09:53 AM
Phone holder stl file
by Cat302 - 02/09/26 03:59 AM
CX Bonnet Belt
by moggin - 02/09/26 03:24 AM
Are Octopus screwing ev owners
by John V6 - 01/09/26 04:50 PM
4/4 Suspension Install - is this normal?
by ScotiaSteve - 31/08/26 10:52 PM
Latest Photos
Wales
Wales
by Joske Vermeule, September 1
tow bar
tow bar
by G Walker, August 24
Prescott double anniversary
Prescott double anniversary
by CooperMan, August 18
Air Crash Sites: Cairngorms
Air Crash Sites: Cairngorms
by RedThree, August 13
Four-seater luggage rack
Four-seater luggage rack
by Soleng, August 9
Forum Statistics
Forums39
Topics49,866
Posts837,608
Members9,596
Most Online1,063
Jun 14th, 2026
Today's Birthdays
There are no members with birthdays on this day.
Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
#448353 12/05/17 09:52 AM
Joined: May 2016
Posts: 541
T
Timothy Offline OP
Talk Morgan Regular
OP Offline
Talk Morgan Regular
T
Joined: May 2016
Posts: 541
I'm looking for a Cold Air Intake for my 1998 +8 with a 4.0 Anyone know where I can get one?

I found this for Range Rovers but don't know which kit mite work the best. Any ideas?
https://www.knfilters.com/mobile/cold_air_intake/land_rover_range_rover.aspx


1998 +8
SS Sport tuned exhaust

2013 M3W
Stage ll motor kit
Cats removed
Joined: Oct 2010
Posts: 163
D
L - Learner Plates On
Offline
L - Learner Plates On
D
Joined: Oct 2010
Posts: 163
I made on for my Plus 4. I just bought a suitable ITG filter box and some appropriate tubing from a automotive supplier online and a length of aluminium tube. I had to make up the brackets to support it and modify the radiator surround to get access to the air from the front. I think the ITG filter made the most difference although based on the reported temperature from the engine management system it did lower the intake temperature somewhat especially at speed. The big surprise was just how hot the air is once it gets in.

You may find on a Plus 8 that space is an issue for an air box of an appropriate size.

Dave


2008 Plus 4
Joined: May 2010
Posts: 9,545
Likes: 132
S
Needs to Get Out More!
Offline
Needs to Get Out More!
S
Joined: May 2010
Posts: 9,545
Likes: 132
I measured the incoming air temp on my 4l plus8. Connected the diagnostic meter and went for a run with live data showing. The ambient air was 15C. Measured incoming air 35C and rising slowly. No high speed racing but mixed roads with a short Mway stretch. The underbonnet temps do go up! The polished stainless airfilter box gets to well above 40C surface temp. The air intake points towards the side louvres but not a good fit/direction.
I am thinking along the lines of the roadster setup with a sealed intake to the side louvres. The roadster has reversed louvres I think.
Routing of pipes elsewhere is not easy due to lack of room. On my old 4/4 the air was taken from the inner wing but the steering column gets in the eay on the plus8. There is more room on the other side of the engine but that needs much more redesign and mods to fit the MAF and filter to the intake plenum.
The roadster option looks easier.
There are photos somewhere of the set up......anyone got some?


Plus Four MY23 Furka Rouge
Joined: Sep 2009
Posts: 7,435
Likes: 122
Talk Morgan Guru
Offline
Talk Morgan Guru
Joined: Sep 2009
Posts: 7,435
Likes: 122
Sospan, I had a Roadster S1, the idea is good but at that region you have huge underpressure. I'm not sure if it is an ideal solution.


'14 4/4 graphite grey
Joined: Dec 2008
Posts: 22,366
Likes: 354
Roadster Guru
Member of the Inner Circle
Offline
Roadster Guru
Member of the Inner Circle
Joined: Dec 2008
Posts: 22,366
Likes: 354
Heinz is correct. There's a film somewhere with strips of material which show excessive turbulence around the side louvres.

It is said that the heater box area is the best place, being a high pressure zone.


DaveW
'05 Red Roadster S1
'16 Yellow (Not the only) Narrow AR GDI Plus 4
Joined: May 2010
Posts: 9,545
Likes: 132
S
Needs to Get Out More!
Offline
Needs to Get Out More!
S
Joined: May 2010
Posts: 9,545
Likes: 132
Heinz, yes I have seen the video showing airflow. I agree with Dave about the heater box area giving a "positive" pressure.
But...on my Plus8 the air being sucked in is not pressurised but I guess at normal pressure. It is completely underbonnet so airflow around the engine itself is what it gets. My guess is just sucking in the hot air as the exhaust manifold is below the open end of the intake. I doubt if there is any positive pressure under the bonnet.
Just guessing, but I think the engine would suck in air through the louvres , even rear facing ones, if a good seal could be made to the inside bonnet surface.
It would be nice to see a repeat of the airflow test for a roadster to see if the wool threads show strong airflow in through the louvres. Care though not to suck in the wool threads!


Plus Four MY23 Furka Rouge
Joined: Jan 2009
Posts: 5,945
Likes: 28
H
Charter Member
Offline
Charter Member
H
Joined: Jan 2009
Posts: 5,945
Likes: 28
It would involve butchering a half of the bonnet but would it not be possible to cut a hole and install a forward facing scoop on one side? Is a half bonnet an expensive spare part?

That said I have looked at a number of pictures of +8 racers and none seem to be showing non standard air intakes.

Joined: Sep 2009
Posts: 7,435
Likes: 122
Talk Morgan Guru
Offline
Talk Morgan Guru
Joined: Sep 2009
Posts: 7,435
Likes: 122
I found this link below, just to have an idea if the air intake could be relocated to the heater box area. See the picture. BTW starting such a project they probably had one or two thoughts about a good location regarding the air intake, concerning what is possible at all in a tight Plus8 engine bay. And of course only they know if it works.

http://www.gomog.com/phoenix/phoenix.html


'14 4/4 graphite grey
Joined: Feb 2011
Posts: 14,009
Member of the Inner Circle
Offline
Member of the Inner Circle
Joined: Feb 2011
Posts: 14,009
Originally Posted By howard
It would involve butchering a half of the bonnet but would it not be possible to cut a hole and install a forward facing scoop on one side? Is a half bonnet an expensive spare part?

That said I have looked at a number of pictures of +8 racers and none seem to be showing non standard air intakes.


Probably around £500 plus Howard....and you can't just pluck a spare one off the shelf.

Hmmmmm......I do have a certain Italian owners bonnet sitting up in my garage rafters 😈

Last edited by Jays; 13/05/17 08:42 AM.

Jays
Former Morgan owner. Gone but hopefully not forgotten!
Joined: May 2010
Posts: 9,545
Likes: 132
S
Needs to Get Out More!
Offline
Needs to Get Out More!
S
Joined: May 2010
Posts: 9,545
Likes: 132
Heinz, the gomog Phoenix photo shows the layout under the bonnet quite well. The airbox is the same as mine ( I have no other "bling" though!). I have a K&N in mine too.The air intake pipe shown points generally towards the bonnet louvres but is a bit high and not directly at them hence it draws in the hot air coming from the engine and rising up from the exhaust manifold below it. A warm place indeed. The plenum intake is the other side of the engine. There is much more room that side to put a cool air route but plumbing is needed to accomodate the MAF etc.. Not an impossible job.
The benefits of colder air are estimated at 1% extra bhp per 7deg lowering of temperature. (Taken from Graham Bell's book on engine tuning.) So, possibly 5-10 extra bhp as a rough guide. A nice little tweek as not too ££££ but a bit of fiddling to route the intake pipework. A sharp bend will be needed too.


Plus Four MY23 Furka Rouge
Page 1 of 2 1 2

Moderated by  TalkMorgan 

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5