GBMUD Posted September 26, 2006 Share Posted September 26, 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! 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 making it much more driveable off-road or in traffic. 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? Presumably, one stops screwing it in when the engine becomes smokey at tickover? So to EGT. As I understand it, EGT is a measure of the combustion temperature and that if the EGT gets too high then the piston crowns melt? I had an RD125 whose party piece was melting pistons. Is there anything one can do to allow higher EGTs in a Tdi? For example, if i were to re-build mine with new pistons, is there something on the market which will allow the running of highter EGTs? Different material, shape, some sort of oil cooling system perhaps? Thanks Chris Quote Link to comment Share on other sites More sharing options...
Guest diesel_jim Posted September 26, 2006 Share Posted September 26, 2006 I've heard of some engines (not sure what though) that pump in more fuel on the power stroke to keep the piston cool (it's then expelled on the exhaust stroke i assume). don't think this will do much for your economy though! Quote Link to comment Share on other sites More sharing options...
ciderman Posted September 26, 2006 Share Posted September 26, 2006 Be careful if you are tweaking with your pumps , To much diesel pumped into the cylinders tends to wash the lubrication from the bores causing self destruction . Quote Link to comment Share on other sites More sharing options...
Steve 90 Posted September 26, 2006 Share Posted September 26, 2006 Yea, Jase is right. Extra fuel is good power but excess fuel will cause bore wash and less power in a few thousand mile's. Its a case of getting it just right. I think Diesel Jim is talking about dual stage injection which is the norm on common rail injection diesels. It tends to put in lots of small amounts of fuel to along with the main injection. Its to try and make them run quieter and stop some of the harsh diesel knock that you get with direct injection diesels. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 26, 2006 Share Posted September 26, 2006 Yes the smoke screw adjusts the off boost fuelling. Though a tweak on the full power screw increases everything too In theory you should stop screwing when it starts smoking (ooer!) but in practice - and I don't understand why - you still get more power (and smoke) even after the onset of smoke. If you adjust it to the "full Jap spec Mitsubishi" levels of smoke then it goes like stink but it's a bit indecent and in your part of the world probably highly illegal? EGT's, fit water injection Quote Link to comment Share on other sites More sharing options...
white90 Posted September 26, 2006 Share Posted September 26, 2006 first probs with too higher EGT is a cracked exhaust manifold. smoke screw for off boost power star wheel for increased fuel for less boost, make sure your getting the full 1bar at the manifold to begin with. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted September 26, 2006 Author Share Posted September 26, 2006 make sure your ggetting the full 1bar at the manifold to begin with. Yup, I was wondering about that, any top tips for measuring it without spending cash on a boost guage? Chris Quote Link to comment Share on other sites More sharing options...
TJ101 Posted September 26, 2006 Share Posted September 26, 2006 it also smokes like billio when accelerating hard! Yep,, not wrong there, shame for the poor sod, following Quote Link to comment Share on other sites More sharing options...
white90 Posted September 26, 2006 Share Posted September 26, 2006 Without a gauge no they aren't expensive, mine was calibrated and I now run at 18-21psi as required. with an Allisport intercooler. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted September 27, 2006 Share Posted September 27, 2006 Yup, I was wondering about that, any top tips for measuring it without spending cash on a boost guage?Chris I made one out of a £10 halfords tyre pressure gauge, six feet of window washer tubing and a plastic T piece I nicked from somewhere.... all bound together with insulating tape. Works a treat and for one off use you can keep the tyre pressure gauge for its original role afterwards, they are very good gauges seem accurate and graduated in 1psi increments on a nice clear analogue dial Quote Link to comment Share on other sites More sharing options...
GBMUD Posted September 27, 2006 Author Share Posted September 27, 2006 Yep,, not wrong there, shame for the poor sod, following Sorry Tim. I will go see what Halfrauds have on the shelf by way of a proper boost guage I think. I would like to develop a greater understanding of what the turbo is doing and when. Chris Quote Link to comment Share on other sites More sharing options...
Exmoor Beast Posted September 27, 2006 Share Posted September 27, 2006 any easy way of checking EGT without buying a guage? I suppose the answer is no as you need to check it under heavy load to get the max figure. I would love to know what my 200TDi is producing powerwise, I have tweaked the pump and it really flies, a mate followed me up a local 1in4 a few weeks ago in a 300TDi truck cab 90 and I left him for dead, he was amazed to see the back of the 110 completely full of tools and junk. I am sure its going to die soon. Will ) Quote Link to comment Share on other sites More sharing options...
stripy Posted September 27, 2006 Share Posted September 27, 2006 egt gauges are a must when playing with your fueling, when i fitted my guage the egt was much to high but with a little adjustment it came back to sensible levels this may help http://www.red-ibex.com/EGTgauge.htm Quote Link to comment Share on other sites More sharing options...
will_warne Posted September 27, 2006 Share Posted September 27, 2006 Yeah, an EGT is a must. Here's the gauge I use and I've been very happy with it. Its not expensive (about £150), comes in a vaiety of differant colours (one does not want to clash ) and is superb quality. As far as making the engine survive high EGT it is possible but its hard to do. The thing the internals mostly suffer from is heat, not temperature; a couple of seconds of 1000 degrees is OK, 5 minutes of 900 is not! This is why I chose not to run a particularly large I/C as I'll use the power in short bursts (step away from the keyboard Bish ), not for long periods like a road car. Appart from the cast manifolds which tend to crack under highish temperatures. The best way to solve this is with a custom made, SS, manifold (not cheap, though). As I understand it, to help with short burts of high EGT pistons and bores can be ceramically lined (££££££££££) as this'll stop the initial conduction of heat into the metal. However, once the ceramic's heated up you're back to square one. Turbos will also be an issue at high EGT. They don't like high temperatures either! AFAIK race pistons won't help that much, the main reason for them is to give better ballance making the engine smoother and pickup faster. Basically, you just need to try and get the coolest possible air in and the exhaust gases out as fast as possible. The later will also mean faster turbo spool up but will reduce turbo life. Quote Link to comment Share on other sites More sharing options...
GBMUD Posted September 27, 2006 Author Share Posted September 27, 2006 What I am really after, at least in the shorter term, is to get the turbo to wake up a little sooner. I had the head gas flowed in the hopes of imropvement but there was little forthcoming. I went into Halfrauds earlier to look at boost guages. The only one they had hits the red line at 0.6 bar and tops out at 1 bar so it may not be that much use to me. Higher power, mega fuelling and larger intercoolers can come later - probably in the engines next life - as with 176k on her I do not want to over do it. I am not after ultimate power, just improving/gaining useful power. Thanks all Chris Quote Link to comment Share on other sites More sharing options...
white90 Posted September 27, 2006 Share Posted September 27, 2006 remove plastic collar from under the diaphram try and see how it goes Quote Link to comment Share on other sites More sharing options...
Andy Posted September 27, 2006 Share Posted September 27, 2006 my local car shop does 'tim' gauges. they stock ones up to 1bar, but can order a 2bar one - which i have. for reference i believe 1bar is 15psi. 300s run 15psi as stock & 200s only run 12psi. from memory i paid £35 for the gauge. Quote Link to comment Share on other sites More sharing options...
white90 Posted September 27, 2006 Share Posted September 27, 2006 Tim ones are worth having calibrated as they can be tad off. a forum member did mine for me unsure if he would do others. Quote Link to comment Share on other sites More sharing options...
Porny Posted September 27, 2006 Share Posted September 27, 2006 Tim ones are worth having calibratedas they can be tad off. a forum member did mine for me unsure if he would do others. He probably would Though it's not that easy to calibrate some of them, but can accurately tell you the error. Is a pain to strip some of them and reset the needle. Ian Quote Link to comment Share on other sites More sharing options...
white90 Posted September 27, 2006 Share Posted September 27, 2006 How kind! I didn't want to drop your name and get you aload of requests that you didn't want. When the wastegate pipe perished on mine it was only the boost gauge showing nigh on 2bar that brought it to my attention. (plus it was going rather well) Quote Link to comment Share on other sites More sharing options...
Andy Posted September 27, 2006 Share Posted September 27, 2006 does the boost pressure change as an engine wears? im assuming my gauge isnt to far out as it was displaying the correct pressure for a stock engine till i fiddled with the wastegate. Quote Link to comment Share on other sites More sharing options...
Porny Posted September 27, 2006 Share Posted September 27, 2006 does the boost pressure change as an engine wears? im assuming my gauge isnt to far out as it was displaying the correct pressure for a stock engine till i fiddled with the wastegate. yes, as the actuator will get slightly softer, so will open at a lower pressure. Quote Link to comment Share on other sites More sharing options...
Tonk Posted September 28, 2006 Share Posted September 28, 2006 The thing the internals mostly suffer from is heat, not temperature Will, wot are you on?! Quote Link to comment Share on other sites More sharing options...
will_warne Posted September 28, 2006 Share Posted September 28, 2006 Will, wot are you on?! M, temperature is an indication of how much kinetic energy the gas/solid/liquid has on a molecular level, heat is a measure of how much actual energy the system has ie a grinder spark has high temperature but low heat. Yeah, I know its a bit strange but I don't make the rules Quote Link to comment Share on other sites More sharing options...
Tonk Posted September 28, 2006 Share Posted September 28, 2006 I don't make the rules Will, u dont make anything Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.