| Author | Message | ||
     Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 431 Registered: 08-2007 |
Dear all, New thread as the old pulley thread is out of info... several years ago, some will remember, some members of the Forum slightly tunes the boost control system of their turbocharged cars. It's just a Saab based system without any secrets. I modified it so that it would give a rather constant 0,7 Bar (basically the recirculating limit of the valve. On a cold day this gave incredible all-range torque... I note that there were lesser sides. On a hot day the Lammerholms (Knock detectors) gave false signals to the ECU, drastically reducing power. This had nothing to do with knock. Additionally I disliked the engine ventilator system (mechanical and twin electric, the catalysing arrangement and the conservative Motronic 3.3 settings. Conservative everything: EMS, BMS and an emission control system that was state of the art in the 1990's but that can be improved. A small disaster struck when a combination of poor crankcase ventilation, fast driving and fast (engine) braking (as I understood today) sucked in the front seal in (it was hanging on the crankshaft nose)... since 50000 Km, the car virtually leaked no oil below 2500rpm, but then in fast rpm, the oil would spill on the hot exhaust. Droplets, but you do get the smell. So I decided that it was time for fun. Plan: - Get the mechanical bits overhauled fit for purpose: new modern type seal (yes see below what I mean), get the pulley fully balanced in case needed (not yet measured)... - New fans instead of the old twins (yes, I think they were inefficient in extreme South of France weather and airco - New electric fan (nothing wrong with the old but it is noisy, it vibrates and it zaps power noticeably when engaged hot) - Completely comical Boost Control system (I already had the Bosch ring-type knock detectors) but wanted to add folk to the car, see below. - Map the ECU on a rolling road (see below) - Low loss modern metal-based hot catalyser possible allowing me to remove the huge cold cat under the car while being road legal. Off we go... next posts come with the pictures... | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 657 Registered: 07-2015 |
Dear lluis ,now you have me very interested! How did you determine the lamerholms were giving false readings? Another typo I think what is it you are adding? Not folk I think? Can't wait for the pictures! Thanks Mike | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 432 Registered: 08-2007 |
Fitting pics is troublesome with the MAC... now here it goes again... I hate this customer, 1750 Nm of impact wrench would not get it moving, let alone the pryer (nota bene, in 4LE transmissions, it's dead easy to lock the flywheel removing the lower gearbox cover. So grinding and induction / Acetylene were involved...  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 433 Registered: 08-2007 |
No need to keep things long, the 5 bolt pulley puller made wonders... Here you see the process, a horror of back pain...  And finally the cover is out (easily, but you must suspend the engine, remove the front mount and unbolt the oil pan, the oil filter assembly and the turbo outlet pipe... much easier done than said, really.  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 434 Registered: 08-2007 |
Now the old type seal is simply a bad (very bad) design, sorry. First of all it seats inside possibly because possibly they used scroll seals (which would be much better for the application, I think. But they decided to replace them for the plastic ones, OK, unfortunately keeping the seal inside the cover. What could have been a 2-hour job is now 12 hours. But there is another problem... the original seal is a plastic ring in a metal ring. I admit that modifying boost systems has its risks, and when I did mine years ago, I am sure that I should have improved crankshaft ventilation. In a pressure to vacuum transition, possibly with a slightly dirty PCV switch over valve (a known issue, but I thought maintained mine well), the plastic seal was sucked into the crankcase, leave the car virtually seal-less. This will not happen with the new seal design that traps the plastic between two metal rings. Good so because the boost to vacuum transition will be harsher in my car when I am done... The Flyingspares substitute is much better, | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 435 Registered: 08-2007 |
Now, not yet there but preparing a bit the programming part, my k-l line interface, for engine and gearbox.  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 436 Registered: 08-2007 |
And looking at the cat, but this is much more complex than it seems. Not sure how much back pressure makes sense in these systems. Possibly I will go for a very low-loss catalyser, as the T04B was initially designed for cat-less systems. But I am doubting.  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 437 Registered: 08-2007 |
Any comments in particular in view of electric cooling are welcome, the maximum size so far is 400mm electric and I want to avoid twins. Instead of the twin pushers for the condenser I got a massive 350mm Spal, which will improve a lot the airflow but for the suction fan, I am not too sure so far. | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 658 Registered: 07-2015 |
Hi lluis ,I have gone back to viscous coupling fan, How did you find the knock sensor was giving false info? I am evaluating an alternative to Bosch and lamerholm. Cheers Mike | ||
| Omar M. Shams Grand Master Username: omar Post Number: 2032 Registered: 04-2009 |
where I live the thought of removing the mechanical fan is frightening. In fact I put my old cars away in the summer to remove the risk of ovrheating altogether. | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 438 Registered: 08-2007 |
Hi Michael, At Beek Auto Racing near The Hague, on a rolling road, after perfect behaviour and after heating the car retarded under vacuum and very light acceleration. I liked this to the knock sensors, and indeed changing them solved the issue, but I am totally interested in anything going back into the original M12 or the Lammerholms. So any information will be appreciated. No it's not a type, you will see what I mean by a folkloric boost control system... later | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 439 Registered: 08-2007 |
First things first: the turbocharger is visually like new, a minimal play... I will order tomorrow a blanket (which may be a good idea for you Omar as it keeps under bonnet temperatures down) and that is about it.  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 440 Registered: 08-2007 |
Ok, now the folk: supposing that I manage to get a safe and reliable boost control system there are two things I would like to do... I would like to have the usual pneumatic boost control system, with a modern and programmable ECU but with a pneumatic manual override in the open waste gate side... with a known in the dash. This would give a boost set pressure. And then a boost plenum pressure gauge. This is my gadget, from a Bristol bomber, new old stock. A Twin boost meter, two gauges in one, in those days for the twin engines, to be fit neatly and reversibly in one of the vent holes of the dash.  Please love it or hate it, but it is fun. I love it. I will use the transient solenoid to shut manually the waste gate with a push knob, for short explosions of maximum boost. | ||
| David Gore Moderator Username: david_gore Post Number: 3702 Registered: 04-2003 |
Lluis, I like your thinking - a twin boost meter! I hope you can find a way to make it work. | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 442 Registered: 08-2007 |
Back in the Forum... Today the pulley came back from the machining shop, its very nicely balanced, apparently, but I need to to paint it... I finally got everything that was on my way for a good clean up. What a tough job did this turn to be... the ancillaries must be removed, and because of the oil drizzle it's dirty. Next time, I will first clean the engine and then work. I learnt quite a bit with this. Tomorrow I will try to post some pics, and now I need to decide how far should I go. So the question is: 52020 has 150000 km... now that the front end is open, should I install a new oil pump? How far should I go replacing the myriad elements that are not accessible (including for example the radiator for an all-aluminium one, engine mounts, etc...? And advice is frankly appreciated: should I use the original cardboard seals, as I did the first time I refurbished the foam seal or would I use universal RTV? I have the impression that the RTV seals better and the paper seals will always sweat? Any opinions on this? How about the twin oil pipes and hydraulic? They seem in great shape and elastic, but it will never be as easy as this to change. However I am (frankly) worried that replacements will be of lesser quality the originals (Bentley Leusden tells me there are no new parts, and all is remanufactured by third parties)... PS: I decided to install the all-electric fan conversion within the radiator shroud. I settled for 2X 330mm suction fans + 1X 350mm pushing fan, giving in excess of 5000 m3/h for just 21 amps when at full tune and a dual simple relay controller, using the sensors in the thermostat pedestal. I thought for a while about the t7 design Pulse Wave Modulator (https://www.t7design.co.uk/12v-24v-30a-pwm-controller-0-5v-input.html) but I am worried about reliability on what is basically a kit part. Finally I will use two over-dimensioned relays: the 83 degree cut off will power the two suction fans, using 14 Amps and the 91 the pusher, in parallel with the refrigerant pressure and compressor. For a minute I even thought of using twin electric water pumps to really free all available power and remove rotating parts, but... not so sure. Once the front end is back in place, I will move to the exhaust part and turbocharger control system. Nothing wrong with the SAAB unit and transient system, other that it is not programmable, so I will keep them disconnected and use possibly a programmable unit. Thanks and see you... Lluís | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 447 Registered: 08-2007 |
Update: All is clean and back in place. In case you plan to do this typo of maintenance let me give you some advice for future users (although it must look like beginners, but please to take it into account): I should have cleaned everything thoroughly before doing this. Oil drizzle was disgusting and made the job much less satisfying that I am used to. More dismantling means less work: I tried at first to "cut corners". DO NOT, it's useless. Remove directly the cross-over pipe, hoist the engine and remove the front engine mount. This will give all clearance you need for the sump bolts which must be loosened. Post 1993 cars (at least) have a highly efficient pre-cat which is metal-based. No need for a swap to modern cats, I was impressed by its construction and low restriction design. Removing it will nevertheless facilitate the installation of the lower timing cover. The pulley was at least 20 grams our of balance and any machine shop will easily correct this, not sure how much of a difference this will made. I will post pictures later from my other computer, but now it is a true pleasure to work with a completely clean engine. I checked the crankcase and it is really very gas-tight (it still ventilates a bit as it should be. Next post I will give an idea of what is still open. | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 448 Registered: 08-2007 |
Open tasks: - Install new Knock Sensors as direct replacement instead of my crude adapter for the ring. - Open up (below the LH cabin ventilator) a connection for vacuum & boost pipes so that I can control my mechanical boost system - Install electric cables to control the knock with a led from Pin 18 in the Boost ECU (thanks Michael for the tip). - Install a wide-band lambda to follow the AFR (will increase boost to 0.7 Bar and I am not risking a piston). - Install new thermal switches at 83 and 95 °C instead of the 70°C and 105°C to control the new electric cooling system relays. They will drive separately the two new 7 Amp fans sucking and the 14 Amp pusher. This will give a massive 6000 m3/h flow when needed -possibly never- and enormous reliability. - Clean up with Citric Acid the exhaust system (yes this really works). - Install heat wrapping around oil and transmission lines. - Install a purpose made heat wrapping on the turbocharger to keep bonnet temperature low. - Book a rolling road session... Voilŕ, almost ready  | ||
| michael vass Frequent User Username: mikebentleyturbo2 Post Number: 664 Registered: 07-2015 |
Hi lluis It's pin 19 as RT said ok, I wonder is there a pin out diagram of the ecu anywhere? Cheers Mike | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 449 Registered: 08-2007 |
Noted, pin 19, but since I still have not seen the ECU I cannot tell which is which. Will check and report in due time. | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 453 Registered: 08-2007 |
Things could have gone faster, but time and the myriad components that needed replacing and ordering was an issue. I am talking about relays, thermal switches and minor ancillaries, as well are more substantive ones... I finally installed the new the turbo blanket, fitting perfectly under the original fiber heat shied. I know this is going to help keeping the temperature down in the engine bay and getting heat to the low-loss cat system.   | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 454 Registered: 08-2007 |
Then I uncowled the radiator (which seems actually to be in quite a good shape). In come a 12 Amp 2200 m3/h fan piloted by a new 82-87 switch and a 14,45 Amp of 2400 m3/h piloted by a new 90-95 switch. The front twin fans (16 Amps) have been swapped by a single 12 Amp of again 2200 m3/h working on the basis of the pressure switch of the Airco. Total flow at 28 Amps is a rather massive 7000m3/h. Possibly only one fan wil be needed in traffic, in case that Amercian V8 sites are to be believed. The electric fan conversion is something that was in my mind since long: No, my car never overheated and I only had one visco fail, but in 95% of my trips the fan is not needed and I really notice the (perfectly working) visco, I dislike the noise, it's as simple as that and when fully engaged costs quite a bit of power. This is how it looks like, when installed it also frees up a lot of room in the front of the engine bay.  | ||
| Lluís Gimeno-Fabra Frequent User Username: lluís Post Number: 455 Registered: 08-2007 |
Next steps are to quietly install the very simple and robust electric system for the fans (three fused relays plus modified pedestal switches), flush and clean the cooling system and change the transmission oil... The new silicone pipes for the new boost control system, as well as a manual override for the waste gate (bleed valve) and a manual electric hold switch for the transient are ready, together with new knock sensors and a Wideband lambda that screws 20 cm upwards of the original, just after the turbo elbow, that I can keep an eye on the AFR precisely... Two more weeks and ready to race? |
