Week Twelve

This week we had our third project presentation and I am pleased to say that it went well. We were able to present the class with tangible practical results which lets be honest they were waiting for. We proved to the class that our project woks as a concept. However we had done pressure calculation from our results and found out that the maximum pressure achieved by us was 0.5 PSI. This is disappointing figure as we were expecting figures of about 30 - 60 PSI.

Doing some thinking I realized that we had used our exhaust flap and blocked the end of the exhaust (as we couldn't really block it behind the turbo). Now exhaust pressure behind the turbo would be much higher compared to the pressure at the end of the exhaust. This theory is based on pressure drops. Since the exhaust air travels through a series of bends and restrictions (CAT and Mufflers) exhaust pressure drops. I still believe that if we were to block the exhaust behind the turbo we would achieve the high pressure readings which we are looking for.

Week Eleven

This week  we had no official class as such but me and Richard did go to uni to do our practical tests on the common rail diesel engine. The technician has finished installing the prob on it so we put our boots on, met up with Anura and went to the engine. Before we start practical it is important to have a plan and inspect the engine we are testing with. We discovered that the engine we are using is having a variable vane turbo charger. This means that turbo pressure and flow changes in relation to engine rpm and load.

We did pressure tests at 1000 RPM to 3000 RPM while having 500 RPM intervals. We tested the exhaust pressure with a exhaust brake and without a exhaust brake. I am happy to say that after testing we have proved that out concept works! Now it is time for some calculations.

Week Ten

I have mixed feelings regarding this week. Firstly our second stage presentation was due in. Although we had some good theory information to present; the lack of practical work still made me feel as if we haven't progressed much. I believe practical is an important part of this project, and yet so far we haven't done any. But things were about to change.

We met up with Anura on Thursday and he suggested that we do a metal hardness test on an existing exhaust brake flap. He kindly sourced one out for us from a Mercedes Benz truck. Materials being Jone's subject we went to him for guidance on how to do a hardness test. To our surprise Jone seemed clue less on how to use the hardness tester. He suggested that we take is back to Anura and let him guide us. I am really suspicious as to if Jone is dumb or just plain lazy. Anyways Anura guided us through the test and we finally had some practical work done.

As mentioned on an earlier weeks post, we have a Mercedes Benz common rail diesel engine to use. We had a technician look at it an install a prob behind the turbo exhaust housing. This meant that we were now able to use a manometer and do some pressure testing. Id say this has been a good week!  

Week Nine

Nothing really to mention here. Project progress is rather slow and I know I am slacking behind. Guess I need to stop prioritizing other thing and take this project more seriously. Time is running out and we are just stagnating. Come on Jal what are you doing!!!!!

Week Eight

This week we had a second group of people doing their presentations. In short there was no need for us to go to class today. Me and Richard went into uni today to meet up with Anura and discuss the issues regarding our project. 

We brought forwards all of the issues being raised in class the previous week and to our surprise Anura discarded all of them. Firstly the turbo spool up effect. Anura told us that a diesel turbo has seals made out of aluminum alloy and are rather very strong. Thus upon the incident of a turbo spool there would be no damage caused to the turbocharger. The second issue we had was regarding heat dissipation. For this issue Anura brought our attention to the current sytems running in trucks. He mentioned to us that they do not require heat dissipation so neither should our exhaust brake. 

Lastly Anura suggested us to have some tangible information (practical work). He mentioned to us that Unitec has a common rail Mercedes Benz diesel engine which would be perfect for our project. We could use this engine and do exhaust pressure testing. These results would certainly make doing our calculations much easier. Also I believe doing practical work is far better than doing research as by doing this we physically learn and see where we are in regards to our issue and our project.  

Week Seven

This week we had another presentation due and I must say I was quite nervous about it. I believe this is due to my lack of input within our project. I have recently experienced a death in the family. This has somewhat demotivated me to work. But like they say the show must go on. I would like to mention my partner Richard as he was the star with our  presentation. He helped me out when I got stuck and really pulled my weight along with him. 

As normal we let the class ask us any concerns they have in regards to our project. Surprisingly this time it was Gerry who saw a possible flaw with our design. He told us that if we put our exhaust brake behind the turbo then we would be spooling up the turbo more. To further explain his point he linked his concern with a vacuum cleaner. What happens to a vacuum cleaner when u block the opening? It speeds up right. He suggested that by placing our exhaust brake behind the turbo we would cause serious damage to the turbo.

Other issues pointed out by the class were heat dissipation, the size of the area of the exhaust bypass and a possible fail safe system. Unfortunately Anura was not present in the class today to give us feedback upon what we have done. No matter tho we have an appointment with him on Thursday so we will discuss it then.

I would like to leave here today with some good news. Richard finally has solid works onto his computer. This means we can finally get started onto designing our exhaust brake virtually. 

Week Six

This week we decided to not go into class and work on our project at home. We are still in the research area regarding to the project. I must say it is still very hard to find good information regarding the project. Yes there are kits available out there but it seems to me that the companies which develop those kits are keeping all of the information to themselves.

Within our research we found out that the retro fit exhaust brakes were fitted to vehicles with relatively large diesel engines. For example a cummis 3litre 6cylinder diesel engine. New Zealand being a small nation has a small fleet of vehicles. We seem to like our small diesel engines and not many of us have large diesel engines. Will our project work for small diesel engines too? Will small diesel engines need an exhaust brake kit? So many question with no means to answers them. Looks like we need to discuss these points with Anura.

Lastly we have decided that our project will be virtual therefore we require the use of solid-works. Quest for finding someone with solid-works has begun.