Tunnel Cooling Mod - Parts/Tools Required

[david.mt]

I have read the various threads about what it is and the benefits (whether proven or otherwise). Therefore whilst doing other jobs such as removing and resealing the floor pan and replacing the radiator I may as well do this.

Now I presume that no parts are really required and you can just rivet the ducting to the tunnel access plate without the need to remove it using the existing fittings .

However a couple of additional questions:

• Do you/should you seal the pipes into the air box and if so what is best to use?
• Is the access plate just sheet aluminium so a metal hole saw is the only tool required?
• Has anyone tried using a Y piece in the ducting to leave the pipes connected to the air box and also to the tunnel - would this provide enough air flow?
• What does the mod do to the heater/air conditioning in the cabin?

Thanks

[TuxMan]

Hi Dave , job should have been easy but it turned into a pain in the arse as the 63mm hose i found is the same dia as the front scoops and the bulkhead mounts !!!in the end i got some heat shrink joiners front merlin motorsport witch sorted out the issues !!! yes the plate on the bulkhead is a piece of thin alloy its a bit of a arse to get out but once out it east to cut .

I blocked the heater box with a couple of blanking plugs which Marc got me ,but i,m sure you can get 60mm plugs from somewere .

if you look at your front air scoops they are covered in so i openned them up to give more airflow to both the heater box and tunnel !!!hope this helps !!simon

[mgbond]

At some point I'm also going to do this. I know people say it doesn't do much but both of my front air intakes are used one goes to heater box and the other to the brake calipers for cooling.

However, if you look at the Rossion Pics they have managed to secure another (smaller diameter) air take pipe to the duct so I was going to do that instead.

Bondy

[david.mt]

mgbond said:

At some point I'm also going to do this. I know people say it doesn't do much but both of my front air intakes are used one goes to heater box and the other to the brake calipers for cooling.

However, if you look at the Rossion Pics they have managed to secure another (smaller diameter) air take pipe to the duct so I was going to do that instead.

Bondy

I quite like the idea of adding a couple of Y pieces to the existing ducting and adding a couple of extra lengths to the tunnel plate - you could also do the same for the calipers but presume the more you add the less efficient the entire system but still better than nothing.

[JULIEDIX]

hi david ours has at each side one pipe going to the brakes and the other pipe going into the tunnel through the alloy plate with a 65 mm dia hole ducting held in place by a p clip to top of the holes and a tie wire also the baffle plates have been removed from the air intake scoops and heater box has a fine gauze mesh over the 4 holes

[Jim O.]

david.mt said:

I quite like the idea of adding a couple of Y pieces to the existing ducting and adding a couple of extra lengths to the tunnel plate - you could also do the same for the calipers but presume the more you add the less efficient the entire system but still better than nothing.

No real need for the Y pieces. The heater box is just a box with four nipples on the bottom - there's really no difference between feeding it with one hose or two. What we do on our cars is to use two of the existing ducts for brake cooling, and the other two for tunnel cooling. For the heater box, we cap the nipples with some filter material, to keep out dust and rocks. Since the heater box has a fan inside, there's really no need to duct air to it from the front scoops - it seems to work just fine drawing in air using the fan.

[david.mt]

Jim O. said:

david.mt said:

I quite like the idea of adding a couple of Y pieces to the existing ducting and adding a couple of extra lengths to the tunnel plate - you could also do the same for the calipers but presume the more you add the less efficient the entire system but still better than nothing.

No real need for the Y pieces. The heater box is just a box with four nipples on the bottom - there's really no difference between feeding it with one hose or two. What we do on our cars is to use two of the existing ducts for brake cooling, and the other two for tunnel cooling. For the heater box, we cap the nipples with some filter material, to keep out dust and rocks. Since the heater box has a fan inside, there's really no need to duct air to it from the front scoops - it seems to work just fine drawing in air using the fan.

Excellent thanks - my list of jobs is getting bigger!

[david.mt]

What have people used for the brake cooling - have you just cable tied the duct to point at the brakes or is there a more professional solution and how is it used. Lots of motorsport stores will sell you a universal duct but can't really see if that will give any benefit. Surely you need to ensure that the airflow is targeted at the hot area in the centre to have benefit at all - if there is any real need in the first instance.

Any photos of how the ducting is secured to flow air on the brakes would be appreciated. What about a funnel on the end of the duct to focus the airflow or is this really a waste of time

[TuxMan]

I'm led to believe the discs pull air in from the center through the wheel and expel out through the disc , don't know what sort of help directing air at the disc will do .

[northnoble]

After reading countless threads about the Tunnel Mod, decided to get my local garage to do it when I took the car in a few weeks ago. ( I am a complete DIY retard when it comes to cars!). Job done in less than three hours (£120) and apparently only problem was getting at and removing the screws that hold the blanking plate.

Result - no more fume smell in the cabin and a cold gearstick even after a long run (bit rubbish in this weather!! but bring on the summer)....wish I had done it earlier.

[david.mt]

When I dismantled the front of the car only 2 of the 4 hoses were actually connected to the heater box and the other 2 just hanging down. The hoses had several holes so decided to take them out completely and replace with some new silicone ducting that matches the new water hoses.

Haven't decided yet whether to run one hose to the heater and one to the tunnel or just 2 to the tunnel. Anyone just tried one hose?

I was going to cut a hole in the tunnel plate and fasten an air outlet (or 2) to it to conect the ducting - I like to keep things tidy

Any issues with opening up the air scoops - there's already mesh at the front on the clam so can't see an issue?

Has anyone found any decent fastenings or duct to fit the end of the hose for the brake cooling - any photos?

[alex s]

David,

When I did mine, I used just one hose to the tunnel, used a 63mm hole saw to cut the hole, then fixed one of these to the panel - http://www.revotec.com/details.asp?ID=40, then fixed the hose to this with tie wrap and silicon. 4 years on and still there. I also used the 63mm cutout bit of ali to use as a blanking plate on the heater box.

[david.mt]

Alright....is there some trick to getting the tunnel panel out?

I have removed the 4 self tappers holding it in but it is shaped to fit and there is a brake line running tight across the face of it.

Before I just get my hands on it and pull - what is the proper way?

Thanks

[alex s]

david.mt said:

Alright....is there some trick to getting the tunnel panel out?

I have removed the 4 self tappers holding it in but it is shaped to fit and there is a brake line running tight across the face of it.

Before I just get my hands on it and pull - what is the proper way?

Thanks

Just do it in situ. I did no problem.

[TuxMan]

Dave are you sure you have all the screws out , i found a couple behind the supports to the steering rack !!! had to loosen them off and move them round a bit , its a bit of a arse of a job to get it out !!!