GBMUD Posted September 28, 2006 Author Share Posted September 28, 2006 Well, I fiddled. I needed a repeatable test so I found a hill with a road sign at the bottom and made a test run passing the road sign at 30mph in top gear and then flooring it and measuring the time taken to reach the top. At 30mph the turbo was not doing anything. On my control run I made a time of 50 seconds. I then turned the smoke screw in one turn and tried again. Same run, speeed, distance etc., 50 seconds again. I turned the screw in again, one turn. 47 second this time. I turned it another half turn. 47 seconds again but I was only doing about 28-29 when I passed the sign so I guess I could call that another second off. I do not think that my test runs were very scientific, for most of the hill the turbo was running anyway so that part of the run was of little value. A better test may have been from 25mph to 40 mph using the same sign as my start point - or even running from tickover in 3rd upto a set speed. Either way, it now seems to get off the line much better and the turbo comes in a little sooner - it feels much more lively at very low speeds without having to do a jig with the clutch and gears all the time to keep the turbo singing. Smoke levels are acceptable and, since I have not adjusted the on-boost fuelling I have no EGT concerns. I still want to find a boost guage that measures upto ~1.5 bar so that I can be sure I am acheiving full boost - there may be further safe gains to be had in the top end... perhaps I should get a better snorkel too before worrying about that. Thanks for all the advice. Chris Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 28, 2006 Share Posted September 28, 2006 Smoke levels are acceptable and, since I have not adjusted the on-boost fuelling I have no EGT concerns. When I did mine some of the information I saw suggested that fiddling with the smoke screw did make a difference to EGT at the top end. I can't see how this could be the case though, because once on-boost the position of the smoke screw is irrelevant surely? you could take it out and throw it away! (well you couldn't because then your boost would leak, but if you plugged the hole you could....) Quote Link to comment Share on other sites More sharing options...
white90 Posted September 28, 2006 Share Posted September 28, 2006 Chris try it without the plastic collar and see how that goes! Quote Link to comment Share on other sites More sharing options...
Bush65 Posted September 30, 2006 Share Posted September 30, 2006 I drove a friends 200Tdi 90 a couple of weekends ago. It is similar in weight to mine but has a much larger intercooler which accounts for the much improved power over mine - it also smokes like billio when accelerating hard!... You can't make power without fuel. He obviously has higher fuelling than you, as indicated by the smoke. The intercooler will improve the amount of oxygen available to burn more fuel, but it comes down to burning more fuel. The intercooler will not help so much at low boost pressure when the turbo is spooling up. The thing that impressed me, apart from the available power at speed was the fact that the turbo seems to come on boost much sooner then mine... It is the thermal energy in the exhaust gasses that drives the turbo. To get boost sooner, you need more energy in the exhaust gasses earlier than you have now. That comes down to burning more fuel. Now I know that adjusting the star wheel down will have an impact on how quickly the fuel delivery rate rises when the boost comes in and that adjusting the diaphram affects the overall amout of fuel delivered but how do I get it on boost sooner? Would that be with the smoke screw? I guess that screwing the smoke screw in allows more fuel delivery without the turbo on boost? ... The smoke screw adusts fuel at no boost, but it is not the only adjustment. The diaphram position adjusts the fuel every where between maximum and no boost, so this should be adjusted 1st. Then adjust the starwheel and finally adjust the smoke screw. IMHO, you should start by rotating the diaphram to the maximum fuel position. Then check smoke and EGT on a good hill with your foot flat to the floor at maximum boost pressure. It is best to have some one follow you to observe the smoke. At this stage ignore smoke at low boost. Too much smoke or too high EGT means that you should rotate the diaphram back a bit. If there is no smoke and EGT is not too high, then adjust the maximum fuel screw in, but this is not likely. Don't rely on the dot being at 3 o'clock etc as the position of the dot relative to maximum fuel varies from one pump to another. Pull the diaphram and note the eccentric conical section. Note: mark the position of the diaphram before you remove it. You want the conical section to be offset as far as possible toward the rear when installed in the pump. It can be difficult to tell exactly where the maximum offset is. At the top of the pin, near the diaphram, you will see a small flat on opposite sides. These flats are aligned with the offset of the conical section. Make a mark on the top of the diaphram washer to correspond with the eccentricity of the cone. On the cone you should see a track where the cone was running against the fuel control pin in the pump. If this track does not extend fully to the top of the cone, then the plastic spacer under the diaphram may be limiting the stroke. In this case, remove the spacer. A Dawes boost controller helps to get boost earlier. Before fitting the controller, adjust the wastegate actuator to minimum pressure. The actuator should only have a small spring pressure holding the wastegate closed. The controller goes in the line between the turbo and the actuator. It does not allow boost pressure to the actuator until the valve in the controller opens. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted October 3, 2006 Author Share Posted October 3, 2006 Thanks for that John. I am not keen to increase fuel when on boost so I plan to leave the diaphram where it is. I also do not have an EGT guage and I cannot realy afford (justify at home!) the £100+ to get one just now. I think I may wind the smoke screw back a little as there is a lot more smoke than I had anticipated/realised when in "real world" conditions. I may attempt some more star-wheel adjustment in the hope of allowing more fuel on sooner without increasing the maximum fueling. Once again, I will report any changes... Chris Quote Link to comment Share on other sites More sharing options...
Turbocharger Posted October 5, 2006 Share Posted October 5, 2006 Chris, As John said above, you need fuel to make boost and boost to burn fuel. You can overfuel to build boost earlier, but you'll see smoke in the meantime. I've got the Thermoman EGT kit which you're welcome to borrow for a week or so (if you come and unbolt it!) if you want to play. I'd recommend £30 on a boost gauge though, very easy to fit. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted October 5, 2006 Author Share Posted October 5, 2006 Chris,As John said above, you need fuel to make boost and boost to burn fuel. You can overfuel to build boost earlier, but you'll see smoke in the meantime. I've got the Thermoman EGT kit which you're welcome to borrow for a week or so (if you come and unbolt it!) if you want to play. I'd recommend £30 on a boost gauge though, very easy to fit. Thanks John As I said, EGT is not an issue for me as I do not intend to burn lots of extra fuel on boost, just get boost to happen sooner. I have a boost guage on order for next week. Chris Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted October 5, 2006 Share Posted October 5, 2006 I have a EGT computer thingy (actually an air-con controller) with digital readout and settable alarm (this is actually the actuation of the air con when the temp gets too high) made by Shinko in rice-burner land. I fitted it because I tweaked my injector. The info on how to do this is still in the technical archive of the Land Rover Addict (ex LRO, ex LRE) forum. My boost gauge is standard VDO plumbed into the line from the turbo to the injector pump. I did not alter the max power setting on the pump, but found the biggest improvement was moving the diapragm 45 degrees clockwise. I originally had too high egt - going towards 800c - and backed off all my settings so that my alarm goes off at 725c and does that only rarely on long uphill climbs. The altitude of 5000' doesn't help much. But without the EGT meter I would have blown my motor long ago. It also helps when shutting down. I switch off at 199c (an arbitrary figure) as the engine at normal idle is at about 145c. For this reason I do not stop the engine at all when filling up at motorway service staions as it can take more than 5 minutes for the EGT to come down. With normal parking at the supermarket you can switch off straight away. I now have 240k kms on the turbo with no problems. Quote Link to comment Share on other sites More sharing options...
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