Wrapping the exhaust before the turbo
 

Hello

I just bought a 1985 300SD and was devistated to find out it was a Kalifornistani version :( . There is a lot of bare metal before the exhaust flows into the turbo and therefore a lot of energy wasted before it reaches the turbo. I was wondering if anyone has tried wrapping the exhaust and cat before the turbo with header wrapping tape. I really would like to know if this has helped any.

Also I'm getting about 21mpg, is this normal for the Kalifornistani verson? My 79 300SD got 28mpg before my crank cracked.

Any other ways to boost the mpg of the CARB crippled Mercedes?

BTW a new air filter just cost me $70. Anybody find a suitable cross for this yet?


thanks Conn

Here's your air filter for $53:

http://catalog.eautopartscatalog.com/mercedesshop/sophio/quote.jsp?clientid=catalog.mercedesshop&cookieid=1CQ0J3JZ41O511O4WO&baseurl=http://catalog.peachparts.com/&partner=mercedesshop&year=1985&product=B1000-28564&application=000005551

I have a 85 Cali 300D Turbo and I get about the same fuel mileage around town. Then again, i havent adjusted the valves for the 12K miles that I've owned it. I've never heard of header wrapping tape or whatever, the car runs fine for me, though there is a good amount of turbo lag.

Craig, thanks for the tip on the air filter. I was still hoping for a cross to a FRAM or something. I did see an air hog filter that looked to be about the same size. Mabey I should bring in an old filter and a tape measure the next time I go to the parts store.


Ara T. ,

header wrapping tape http://www.designengineering.com/products.asp?m=sc&cid=3

The idea is to keep the heat(energy) in the exhaust gasses before it enters the turbo. This way it the turbo has more energy to extract power from. It should have the additional advantage of sheilding the intake manifold from the heat as well. This should also boost power and efficiency.


Conn

Air Filter
 

BTW, TheBenzBin.com has your Mahle (OEM) air filter (P/N: B1000-28564) for $49.98 with no S/H...

Turbo Heat Shield
 

The outfit at the link below sells a "Turbo Heat Shield" for $75.00. I'm not sure I'd bother though with it or header tape. Performance increases are likely to be negligible...

http://wade************************/diesel.html

Autozone sells the air filter for much less.

I saw that product once before. I hesitate about wrapping up the turbo, the berrings in those things are exposed to enough heat as it is. Besides trapping the heat thats in the turbo won't do a lot compared to trapping the heat thats lost before it gets there. Also the exhaust manifold is much closer to the intake manifold and has more surface area. Insulating this seems to be the best option if your going to do anything. A roll of header tape is $35, so its cheaper too.

If an effect will be seen it will be seen with the tape.

Conn

Correct me if I'm wrong but aren't the catalysts already heat shielded? Catalyst, fiberglass, sheetmetal. This is done to keep the temps up in the catalyst to keep it active as turbodiesel exhaust is not as hot as gas engines by several hundred degrees. Given the relatively low temp of diesel exhaust, as well as the relatively short path of the intake / exhaust manifolds I don't see any gains from wrapping anything. You'd likely end up with a negative bang for the buck.

Only relevant factors for turbo function are mass and speed of the air going through the turbine. I don't know what the california modifications are but if they divert part of the gases that normally go into the turbo that will screw you up. Obviously hot will give you a little greater pressure and speed but the exhaust should stay very hot when up to temp. If you are really worried about performance check the intakes and filter which you sound like you are taking care of.

If you aren't in california I would see if there is some way to retrofit. If I had a cali diesel I would see if I could pull together the appropriate parts and fix it right. Has anyone done this or know if it is possbile? I assume you would just take the exhaust, intake, air filter, and maybe turbo system from another turbo diesel and bolt it on. I can't imagine that wouldn't work. I know you could easily do that in georgia since diesels do not have to take emissions tests.

Yeah, but they're not the OEM filter(s)...

Actually the temp of the exhaust gasses does have something to do with the amount of boost you get. Turbines actually convert some of the heat to work energy. As far as the cat being insulated, it isn't good enough in my oppinion.

As far as converting it to a non-Kalifornistani car, I could probably do it and it has been done before. I'm going to look at legal options first though. Then mabey the less obvious changes such as plugging EGR vaccum hose.....errr I mean making sure its not plugged. Yep, you have to make sure that EGR valve gets a vaccum or it won't open :rolleyes: .

You cannot convert heat directly to work. Yes it does help maintain the velocity of the gases. The only factors that matter is the massflow through the turbine. The exhaust just happens to be a convienentt gas source. A turbo charger does not reuse heat. Yes it does effect boost but I doubt you are losing enough heat for that to be the primary factor

Actually a cold turbo charger gives you more air flow on the intake. Everyone else is trying to cool their turbos on their diesel and you are trying to heat yours up. I would not wrap the turbo. You will gain nothing except make your engine to hot. Run diesel purge, fix your air filters. Make sure everything else is optimal before you mess with the turbo