Well, I had a chance to collect objective data on the weekend.

Driving speed between 60 and 80kph ( mostly 60kph) generally keeping between 2000 and 3000 RPM

Driving time for initial temp test 15mins

Outside temp 21degrees C

Vent position selected - outside air , 18degress ( minimum selected), fan speed at about 20% ( window open)

Tested 43degrees C (at floor vent ) next to drivers foot.


What do you reckon????

Buzz

 

OOPs forgot that vent position was at face NOT floor

Buzz

 

My 06 Roadster has the same problem.... I think they all do. I had a look a 370 roadster today that was up on wheel stands/ramps at a dealer. The catalytic converters looked exactly the same as the 350z - same design, same location, same crappy insulation. I couldn't believe it... what were Nissan thinking, aren't they listening to owners?

Anyway, I have installed heat shielding around my cats. The shielding is in 2 parts given the elbow shape of the cats. The shielding is secured onto the cats via welded braces. This has helped reduce some of the heat transfer into the cabin. The only problem is there is very little room between the cats and floor. I have had the shielding adjusted 3 times so far because of rattling/vibration when the engine is under torque. It's a matter of putting it up on a hoist and getting a crow bar in to push the heat shield away from the body of the car. I have just about eliminated all of the rattles. Most annoying! Was it worth it? If I can completely eliminate any rattles, then yes. I think it has reduced the heat by 30%. I have two further options - replace the cats with high low cats. High flow cats are smaller than the stock cats. I can get them placed so that they are not so damn close to the floor. As they do not have the the pre-chamber section that is adjacent to the firewall this should also cut down the heat transfer through the firewall. When I put the cats in I will put in as much heat shielding as I can - some on the body of the car and some on the cats and pipes themselves. I have been quoted about $1100 Australian for the new cats, pipes and shielding. My second option would be to put under carpet heat insulation. I have had a quote for supply and fit "Cool Mat" and "Cool Pad" for $1000 Australian. There is another source of heat coming into the car - through small holes in the firewall which is allowing heat to pass into the car. When I get the under carpet insulation I will make sure that the firewall is completely blocked up. It might be coming from the connection to the steering column as well.
Yes the air vents blow hot air into the car.... the vents must be heating up somewhere in the engine bay before it air enters the cabin.

 

AT LAST someone who has initiative to investigate the problem further. It would be good if we could find someone else who has tackled the problem and insulated the cat/floor heat issue.

Thankyou for your post on all the work you have done.

Then there will be a lot of happy Z drivers around!

P.S. Has anyone thought of using Heat tape (what motorcyclists use on their exhaust pipes so they dont burn their legs). Would that be a good compromise?

Buzz

 

Would seem like a good idea, but I'm no expert in this sort of thing.

 

now... ^^^^ that is a really good idea. I have some lying around that I didn't use for my bike. I might have to try that this week. I'll post any findings if I can get some time to get it up on the lift. (BTW if anyone tries this remember this ONE thing... wear long sleeves. That stuff is made of fiberglass and feels really really wonderful all stuck into your forearms. )

 

I'm not sure how easy the taping is going to be, as I havent had a chance to get under the Z yet ( only purchased a couple of weeks ago). I use to work with a generator company and when genset was installed in a plantroom, we would " lag" the exhaust pipes from the genset to the external wall to minimise the heat escaping into the room. ( heavy duty insulation ).....In principle, am assuming you could do the same thing???

Anyone else had experience with this??

Buzz

 

Further to the heat issue. ... Put 2003 Z on hoist on the w/end and logged heat data of exhaust system with thermal gun.

Manifold 165 degrees C

Cat converter 160 degrees C

Middle portion exhaust pipe 90 degrees C

Muffler 70 degrees C

End exhaust Pipe 40 degrees C

Obviously the heat permeating into the interior is the cat converter. The heat shield is so small .... more a token effort.

Is the heat shield in the 2003 model the same size as a later model or did Nissan re engineer the pipework/heat???

Surprised no one has tackled a remedy for this yet..??

Buzz

 

Hi Buzz350, any luck with the heat problem? I think to eliminate the radiant heat and heat leaking through the firewall is to spend some money. I enjoy the car - I think it is worth spending a bit of cash to get it the way you want it. A couple of grand is not much in the long run. I am determined to fix this problem. The next thing will be to install under carpet insulation and block off the leaks coming through the firewall. If you want to eliminate or reduce the heat you are going to have to insulate the floor/firewall.

 

hey bud you're absolutely about the floor warming up AND the incoming air from the vents are warm..even when it's 60 degrees outside.

yes, I can turn the A/C on. But that's not the solution.

I'll try heat insulation under the carpet for my feet. Have you found the reason why the incoming air from the vents are warm?