DIY ventilation improvements: search not working

[fb2]

Hi all,

Planning to take the griff to france in the summer and would like to think it's possible to improve the amount of heating/cooling I get into the car so today I've mostly been stripping down the ventilation system on my precat. Quite remarkable that I was getting any ventilation at all! Certainly not TVR's best bit of design.

I know a few have done this and have been using previous posts to guide me so thanks all. Sadly the search isn't working now so I can't find them again and I have a few questions.....

The heater matrix on mine is plastic (did others have cardboard????). From what I can tell the fan is supposed to push air over the wheel arch and from there there are (supposed to be only) 2 holes into the footwell - one a feed to the heater matrix and one to the pipe supplying the dash vents. The opening to my heater matrix is not in any way sealed so won't really be being effective at all. Should I remove the matrix to seal this - if so, how - I can see the retaining screws at the front but are there others? When I remove the screws it still seems held in place. Alternatively I can try to fill the gap with it in-situ but I don't know how successful that would be.

I can feel the air directing flap inside the matrix - seems almost completely useless. Is there any point in trying to improve this or would I be fighting a losing battle?

Finally, the water valve works in that I can see it moving but it doesn't seem to stop hot water flowing into the matrix. Has anyone fixed one that doesn't work or do I need to buy a new one?

Sorry for so many questions!

Duncan

[HRG]

The seal on the valve breaks internally. It's a VW part available from your local branch of GSF. It needs to be modified a little but that's easy enough. The part number is in here somewhere when the search function returns!

[AntonyJ]

If you are serious about improving the precat heater box, rip it out and install a 500 one.
The direction flap inside is much better, also look at moving the fan to the inner wing like the 500.
I did alot of work on mine, and in hindsight I should have just done the above.

[350Matt]

fb2 said:

Hi all,

Planning to take the griff to france in the summer and would like to think it's possible to improve the amount of heating/cooling I get into the car so today I've mostly been stripping down the ventilation system on my precat. Quite remarkable that I was getting any ventilation at all! Certainly not TVR's best bit of design.

I know a few have done this and have been using previous posts to guide me so thanks all. Sadly the search isn't working now so I can't find them again and I have a few questions.....

The heater matrix on mine is plastic (did others have cardboard????). From what I can tell the fan is supposed to push air over the wheel arch and from there there are (supposed to be only) 2 holes into the footwell - one a feed to the heater matrix and one to the pipe supplying the dash vents. The opening to my heater matrix is not in any way sealed so won't really be being effective at all. Should I remove the matrix to seal this - if so, how - I can see the retaining screws at the front but are there others? When I remove the screws it still seems held in place. Alternatively I can try to fill the gap with it in-situ but I don't know how successful that would be.

I can feel the air directing flap inside the matrix - seems almost completely useless. Is there any point in trying to improve this or would I be fighting a losing battle?

Finally, the water valve works in that I can see it moving but it doesn't seem to stop hot water flowing into the matrix. Has anyone fixed one that doesn't work or do I need to buy a new one?

Sorry for so many questions!

Duncan

The heater box is only held in with the 3 screws at the front and the jubilee clip onto the big hose, undo the dash bolts a bit so you can raise the passenger side (no need to remove the dash entirely).

Remove the battery and box, you should then be able to wiggle it out and it'll all become clearer.

I made an adaptor from bits of plumbing and sheet ally to run from the fan outlet to a flexible hose over the wing and then into another manifold onto the front of the matrix.

I ran a separate pipe from the fan outlet to serve the dash vents.

All this has massively improved the airflow, however I wish now that I'd fixed the seal inside the heater box as the apportioning valve only has a small effect on switching between feet and screen.

The water valve should close off with the motor, and its possible to adjust the valve position on the motor shaft so its possible its just slipped.
It was a fair bit of work to get mine to blow better and probably the easiest route would be to fit a 500 set-up and benefit from the extra re-circ valve then have and the better heater controls

Matt