has anyone got any info about tunnel mod

[rsnoble]

i have renoved the floor due to the car filling up with water when driveing, has anyone got any info on the tunnel mod as i may as well do it while i have the floor pan off, also is there any thing else to look for while im at it????

[gadgeroonie]

i hear its a waste of time and can actually fill the car with water if you go through a deep puddle


but if the floor is off - it might be worth doing

[Adrian W]

gadgeroonie said:

i hear its a waste of time and can actually fill the car with water if you go through a deep puddle


but if the floor is off - it might be worth doing

If the puddle was deep enough to do that I think you would have other problems.

Why is it a waste of time?

[RobP]

gadgeroonie said:

i hear its a waste of time and can actually fill the car with water if you go through a deep puddle


but if the floor is off - it might be worth doing

Where did you hear that?
What the tunnel mod does is allow air to flow through and cool the front turbo at the same time as preventing very hot air from the turbo entering the cabin, particularly when a window is opened (hot air from around the front turbo is sucked back through gear lever and handbrake gaiters under negative pressure and fries the occupants). In any car with the mod the gear lever and handbrake will remain cool under all circumstances; without the mod these can get so hot (eg on track in summer) that you are barely able to touch them.
Another simple design mod that should have been on a Mk 2 M12.

[Adrian W]

awww I wanted to see why he thought it was a waste of time

[mgbond]

I'm interested to know exactly what to do as I intend to do it soon.

On the 2.5 the fron air ducts only had ducting in one position on each. I have utilised the spare ones to duct air to the brakes. So is this what you do...

Using the 2 ducts that run to the heater
1. run one of them down the tunnel to the front turb and then block the turbo end of the tunnel around the ducting. 2. Then run the othe heater duct to the front of the tunnel and then block the front of the tunnel off around now two bits of ducting?

Or do you only do 1?

Bondy

[paulcundy]

Pictures here.

http://paulcundy.smugmug.com/gallery/359222#P-8-12

regards
paul c

[hollowpockets]

Your pictures are really good Paul, might pick your brain for ideas/advice when cash permits some upgrades!

[Adrian W]

paulcundy said:

Pictures here.

http://paulcundy.smugmug.com/gallery/359222#P-8-12

regards
paul c

could'nt be more clear, on mine I have used two hoses to the tunnel and two to the heater.I also attached a little flick up on the front turbo heatsheild to make sure the air from the tunnel hits the front turbo.

[mgbond]

Paul, does that one just feed the tunnel or goes right to the end?

So If I did (2) would the heater still work (not that I ever use it)?

Bondy

[paulcundy]

mgbond said:

Paul, does that one just feed the tunnel or goes right to the end?

So If I did (2) would the heater still work (not that I ever use it)?

Bondy

No it just goes as far as the blanking plate. i can't see the point of taking it all the way back, all you are doing is pressurising the whole tunnel so that the flow (normally from engine bay forwards into the tunnel and then out via the cabin) is reversed. thus you only need to pressurise it from the front end.

As far as I know several people have used two pipes with no adverse effect on the heater.

Regards
Paul C

[mgbond]

paulcundy said:

mgbond said:

Paul, does that one just feed the tunnel or goes right to the end?

So If I did (2) would the heater still work (not that I ever use it)?

Bondy

No it just goes as far as the blanking plate. i can't see the point of taking it all the way back, all you are doing is pressurising the whole tunnel so that the flow (normally from engine bay forwards into the tunnel and then out via the cabin) is reversed. thus you only need to pressurise it from the front end.

As far as I know several people have used two pipes with no adverse effect on the heater.

Regards
Paul C

So you leave the end in the engine bay open. So running the second one would only be for the front turbo cooling and not blank the engine bay end off.

Bondy

[paulcundy]

mgbond said:

So you leave the end in the engine bay open. So running the second one would only be for the front turbo cooling and not blank the engine bay end off.

Bondy

Correct. You are forcing massive amounts of new cool air into the tunnel, it needs somewhere to go.

Regards
Paul C

[Mike Tuckwood]

RobP said:

What the tunnel mod does is allow air to flow through and cool the front turbo..........

And why might you want to do that?


Mike.

[RobP]

Mike Tuckwood said:

RobP said:

What the tunnel mod does is allow air to flow through and cool the front turbo..........

And why might you want to do that?


Mike.

So you can fry your steaks on the heatshield without burning them, I think is the main reason

[Adrian W]

Mike Tuckwood said:

RobP said:

What the tunnel mod does is allow air to flow through and cool the front turbo..........

And why might you want to do that?


Mike.

Because: - against the normal theories relating to running Turbo’s as hot as you can, the tunnel mod was proven to reduce front turbo mortality, a side benefit is that it reduces engine bay temperatures, which in a Noble can only be a good thing.

[NobleGuy]

I've touched the handbrake with the skin of my arm previously and got a bit of a shock from the heat. Never does it any more. I've been through a deep puddle during the floods last year which caused the radiator to steam madly and also managed to rip off the alternator belt, but got no water in the cabin.

It's almost a no-cost mod as you're just re-using bits you already have.

P.S. I've only got one tube going to the heater due to losing one of the remaining air hoses during a drive and the heater is now a bit weak, but I barely use mine anyway.

[Mike Tuckwood]

Adrian W said:

Because: - against the normal theories relating to running Turbo’s as hot as you can, the tunnel mod was proven to reduce front turbo mortality, a side benefit is that it reduces engine bay temperatures, which in a Noble can only be a good thing.

How much (in degrees C) does it reduce temperatures by, and under what circumstances and ambient temps?
By what specific unit of measure was front Turbo mortality reduced?

What were engine bay temperatures reduced from and to?
Why can it only be a good thing?
What is the normal/most suitable engine bay temp pre and post "mod"? (what's the difference between the 2)?

Now, I'll say that I'm more than perepared to put figures to some of these tests, but I suspect (as is not uncommon) that a whole variety of factors have been attributed to this "mod" which it doesn't desereve.

Think about it, while some of this is speculation I think you will see the basic theory:- Is all that heat is coming from the front turbo? (How do we know it is)?
Putting air across it will cool the Turbo, but transfer that heat, everything else around is likely to be hotter in the engine bay not cooler?

I refuse to believe that anyone has been able to directly attribute/measure Turbo mortality to the suggested mod. Unless someone can prove implicitly that they have.

Don't get me wrong, Turbocharged cars are ALL about good thermal management, while it's not impossible this mod does reduce cabin/transmission tunnel temps, I doubt very much it has a beneficial effect anywhere else at all, probably entirely the contrary in fact!

I have to admit, I haven't seen this problem at all yet (04 reg 3R), and I would suggest that fitting a good quality exhaust blanket to both Turbo's would be FAR more beneficial in all areas?

I also have a suspicion (which I will undoubtedly put some figures to in the future) that better carriers and heat sheathing on the radiator coolant transfer pipes running down the transmission tunnel would again be more effective as I suspect that's where a decent amount of heat is coming from.

I'll not even get started on the "negative pressure" Etc. type comments.


Mike

[NobleGuy]

I know on mine that air is sucked back into the cabin from the engine bay simply
because I could smell the burning oil that was leaking from my turbo. But only on decelleration. Under acceleration I got no smell, which I guess would make perfect sense really with air flowing through from the front.

As for turbo lifetime and temps, dunno.....
My front turbo seemed awfully happy to die anyway, although I don't know how far gone it was before I did the mod.

[rsnoble]

maybe what you say is true, tho my waster pipes have been insulated and i get next to no heat from them, yet my gear and break leaver got hot enuf to cook an egg on at times, and like anything if you have a flow of air thing will become cooler!!!

Mike Tuckwood said:

Adrian W said:

Because: - against the normal theories relating to running Turbo’s as hot as you can, the tunnel mod was proven to reduce front turbo mortality, a side benefit is that it reduces engine bay temperatures, which in a Noble can only be a good thing.

How much (in degrees C) does it reduce temperatures by, and under what circumstances and ambient temps?
By what specific unit of measure was front Turbo mortality reduced?

What were engine bay temperatures reduced from and to?
Why can it only be a good thing?
What is the normal/most suitable engine bay temp pre and post "mod"? (what's the difference between the 2)?

Now, I'll say that I'm more than perepared to put figures to some of these tests, but I suspect (as is not uncommon) that a whole variety of factors have been attributed to this "mod" which it doesn't desereve.

Think about it, while some of this is speculation I think you will see the basic theory:- Is all that heat is coming from the front turbo? (How do we know it is)?
Putting air across it will cool the Turbo, but transfer that heat, everything else around is likely to be hotter in the engine bay not cooler?

I refuse to believe that anyone has been able to directly attribute/measure Turbo mortality to the suggested mod. Unless someone can prove implicitly that they have.

Don't get me wrong, Turbocharged cars are ALL about good thermal management, while it's not impossible this mod does reduce cabin/transmission tunnel temps, I doubt very much it has a beneficial effect anywhere else at all, probably entirely the contrary in fact!

I have to admit, I haven't seen this problem at all yet (04 reg 3R), and I would suggest that fitting a good quality exhaust blanket to both Turbo's would be FAR more beneficial in all areas?

I also have a suspicion (which I will undoubtedly put some figures to in the future) that better carriers and heat sheathing on the radiator coolant transfer pipes running down the transmission tunnel would again be more effective as I suspect that's where a decent amount of heat is coming from.

I'll not even get started on the "negative pressure" Etc. type comments.


Mike