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Anyone have ideas for getting more power out of my mint condition stock '80 450SL? I'm thinking there some emmissions tweaks and timing changes that would be beneficial. I'm not interested in rebuilding the engine for higher compression or getting too far from factory but I suspect the factory intended more from this car than 160hp. <br> <br>
 

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Discussion Starter #2
Hi Jeff,<br>
<br>
There are some simple mods that would add a few ponies to rear wheels without been too extreme or outrageous, particularly with this type of vehicle. The Federalisation of these cars reduces the BHP considerably from the Euro model 217 BHP for the standard 450 down to 160 for USA model.<br>
<br>
Consider K&N air filter, Bosch Platinum Super-4 spark plugs, replace viscofan which takes 8% of engine power with a Kenlowe 16' (see pic) (you would need to modify thermostat to prevent overheating in city traffic), set timing to 5º BTDC, replace standard coil Bosch No. 0 221 122 01 (blue label) and the switching unit TSZ-4 (which requires ballast series resistors) with coil Bosch No. 0 221 118 329, DB part No. 000 158 45 03 (green label) and switching unit TSZ-8 for high performance and high ignition capacity. (The coils are not interchangeable without the switching units).<br>
<br>
Install Direct-Hit capacitors (see http://www.directhits.com ). These simple mods would make the engine more responsive and possibly add 20BHP to the old lump.<br>
<br>
Regards<br>
<br>
 

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Great message, just what I've was looking for. I'll try it when I get my latest puzzle solved. <br> <br> Perhaps you could help me with my other problem. I replaced the radio and suddenly the car runs rough with even less power. The roughness is noticeable at idle and under load and the same whether cold or hot. Spark plugs show its running very rich. I'm thinking that the electronics in the fuel injection are confused-Lamda control, sensors, relays, etc. My Haynes manual doesn't seem to cover any of the CIS electronics so I don't know what to check. Probably need a decent manual as well as advise.
 

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Re: '80 450SL, Running Rough

Jeff,<br> <br> The new problem I dont think it is related to the radio replacement. The radio takes its feed from fuse No.14 5A which does not supply power to anything else even if you bugged the connections.<br> The appearance of this new problem seems to be only coincidental with the radio replacement (unless you messed something else in the process).<br> <br> The symptoms strike me as fuel/ignition related and the first port of call would be to disconnect the cold-start valve wire from the thermoswitch and start the car. If still running rough and rich, with the wire still disconnected from the thermoswitch bridge the two pin connectors and try again. If the problem persist, you will have eliminated the thermoswitch from being the culprit.<br> <br> Then back to basics:- these symptoms bay be due to several factors but second points to check would be distributr cap (might be tracking)and rotor arm together with the HT leads. Try to start engine with hood open on a dark place to see whether the HT wires are arching somewhere.<br> <br> Third are of investigation would be vacum connections to the warm-up compensator and to the ignition advance bell on the distributor body.<br> <br> Fourth place to look is the idle-speed adjustor and the electronic unit. Try initially those points mentioned above then we can proceed to other areas.<br> <br> Hope his helps.<br> <br> Regards<br> <br> <br> <br>
 

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Re: '80 450SL, Running Rough

OK, here's what I got so far...<br> <br> 1) cold start valve disconnected. No change.<br> 2) shorted pin connectors on valve. No change.<br> 3) removed and inspected distributer cap and rotor. No problems.<br> 4) inspected running engine in the dark. No arcing.<br> 5) checked vauum connections to the warm-up compensator. This was odd but may not be the problem. Vacuum lines matched diagram under hood but not in my manual with 2 lines coming from opposite sides of the base. A vacuum line on the top is not shown in the diagram but is shown in the manual as going to the hose connecting idle speed air distributor and supplementary air valve. This vacuum line on my car is a hooked shaped contoured hose that goes nowhere.<br> 6) looked at idle speed adjuster but found nothing unusual.<br> <br> I'm thinking it might be the control unit. The only link to installing the radio was that I had to remove the cover under the floor boards to run a speaker wire to the rear speakers. I also had removed the cover under the dashboard on the passenger side. I visually checked the relays and 2 fuses under there but found nothing unusual. There is a red wire that goes to the radio to supply memory power when the ignition is off. Its possible I may have shorted it to ground although no fuse blew and it still has power. If the control unit got pulsed, it may have fried. Any way to check the control unit? Any other places to look?<br> <br> Jumping a little ahead, if the control unit needs to be replaced, I see that Jet Performance sells a compter upgrade which is supposed to add 18hp. Seems too good to be true.<br> http://www.jetchip.com/imports/computerpackage.cfm<br> Any experience?<br>
 

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Re: '80 450SL, Running Rough

Jeff,<br>
<br>
Which of these idle speed adjuster you have? (note the vacuum pipe from the warm-up compensator)
 

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Re: '80 450SL, Running Rough

My idle speed adjuster looks like the first photo but the contoured hose from the idle speed adjuster to the supplementary air valve does not have a port for the vacuum line which is shown in the upper right quadrant next to the steel eyelet.<br> <br> In the second photo, the warm up governor is 180deg. turned from mine. The vacuum line just below the electrical connection shows the black bent tube which on mine goes nowhere and is not shown on the vacuum diagram under the hood.<br> <br> Also in the second photo, I can see the junction where 4 vacuum lines come together and one of them appears to have a check valve. This is on my car but buried down low and not easily seen. <br> <br> My car is a late model '80. I think they made some changes mid-year. It is also a California version.<br> <br> -Jeff
 

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Re: '80 450SL, Running Rough

I took 2 photos of the engine last night but was unable to upload. The forum feature is 'Temporarily Disabled'.
 

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Re: '80 450SL, Running Rough

OK Jeff,<br>
<br>
The the idle speed control you have is not the electronic type, therefore you do not have an idle speed control unit (the control unit you refer to is the ignition switching unit, and that does not play a part on the proceedings, yet). This makes life a lot easier. If I am not mistaken, the type of installation you have in your model (180º offset) is as the attached pic. The rubber boot coming out of the warmup compensator is connected to the inlet manifold just below and to the right of the the contoured pipe on the auxiliary air valve. It would help of you could confirm when last replaced the fuel filter and fuel accumulator, and if you could check the vacuum pipe underneath the fuel pressure regulator, that it is well connected and the line is not baked, check also the vacuum line to the right bank rocker cover to the ventilation rubber pipe to air filter, then we can take a step further.
 

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Re: '80 450SL, Running Rough

Hi Rasputin,<br> <br> I replaced the fuel filter right after the problem started as well as the sparkplugs. I did not replace the fuel accumulator. Car has 56k miles and probably went through normal 30k service before I bought it. No record. Fuel pump is louder than it should be but sounds like a fuel pump. Is accumulator a maintenance item?<br> <br> I will check the other vacuum lines you suggested tonight. Arrow in your photo is pointing to the mystery vacuum line on my car which goes nowhere. I'll check for a connection to the intake manifold. Could be the problem.<br> <br> I'm comparing your photo to the photo I took last night and they are similiar. Warm-up compensator is rotated 90deg. CCW on mine not the 180deg. I wrote before. Everything else looks the same including auxiliary air valve and idle speed air screw. If you provide an Email, I can send you my photo. In the meantime, I've contacted the forum about the upload problem.<br> <br> -Jeff
 

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Re: '80 450SL, Running Rough

Hi Rasputin,<br> <br> I checked the vacuum line that runs from the right rocker cover vent pipe to the underside of the fuel pressure regulator. This line is in good condition all the way through. I inspected all the vacuum lines and found no problem. There doesn't seem to be a place to connect the warm up compensator to the manifold so, I suspect, that this is not needed with the other controls in place.<br> <br> As I mentioned, Pictures attached. I'm finding that my car has additional equipment for emissions: Oxygen sensor, Lambda control unit, frequency valve, throttle valve switch, temperature switch, and of course catalysts. The mechanical CIS has been modified for EPA emmissions as a closed loop control of the fuel mixture by using the frequency valve as a pressure bleed off for the fuel distributer controlled by the unit under the passenger floor. I'm thinking I should check the pulses going to the frequency valve to see if its running around 50% duty cycle. If so, how? Or what's the next step?<br> <br> -Jeff<br>
 

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Hi, Rasputin! I have 560SL!

Hi, Rasputin. Thank you for very valueable information about 450SL. I have 1989 560SL in Japan and would like to squeeze out all the power from my motor as much as possible. So I am planning to take cappling with fan out and install Electronic fan(16inch with 2175cfm).<br>
<br>
You mentioned about thermostad modification in your mail, I would like to know what you have done to your thermostad. I am thinking to use thermista to locate in the radiater core to control fan. How do you think?
 

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Re: Hi, Rasputin! I have 560SL!

Ohio gozaimasu Ezzy San, ogenki desuka?<br> <br> Fan Thermoswitch:- You can use the existing auxiliary fan thermoswitch on top of the water pump (it there is not one installed, there is a blanking bolt which you can remove and install the thermosiwtch). Alternatively you can install the thermostat which comes with the fan on the neck of the top hose on the radiator and connected to the new thermoswich supplied with the fan.<br> <br> Water pump thermostat:- Without the viscofan there is no constant cooling when in traffic and the electric fan will be running all the time at 100ºC with engine always very hot. The pump thermostat have two closing plates, one for the bypass duct (recirculating coolant around the engine only) and another to the radiator duct via bottom hose. The thermostat needs to be modified by releasing the bracket which holds the spring closing the plate to the bottom hose from the radiator. There are several types of thermostats, one which you can push and release the bracket ('V' shape)and others that need to be cut.<br> <br> This bracket release reduces the presure on the spring an permits the closing plate to stay open much longer as long as coolant is over 75ºC and reduces the time that fan is on avoing it to work overtime!<br> <br> Yoroshiku onegai shimasu.
 

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Thank you!

Thank you for your information.<br> Since my SL already has a thermo switch top of thermostat housing which activate at 105C and deactivate at 100C which is too high to use as a primary fan. So I might drill a small hole on the housing to add a new switch.<br> <br> Anyway, I will test drive my car WIHTOUT Cappling fan at this weekend to see how much HP increase i can feel. if there is not much difference I can feel, I might stay with cappling fan.<br> <br> Thank you for your great information.<br> <br> Regards, Ezzy.
 

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Re: Viscofan!

Ezzy,<br> <br> You can swap the auxiliary thermoswitch for 100ºC one. It is not too high for main fan (with modified thermostat) anything lower will keep the fan running 85% of the time.<br> <br> CAUTION!:- If you remove the viscofan make sure you insert spacers or nuts of same thickness as the viscofan flange on the 10mm bolts to the pump pulley, otherwise you will shred the pump hounsing to pieces when you start the car due to the extra length of the bolts without the viscofan. Also note that the advantages of electric fan are not just extra HP, but better warming up time, quicker engine revs, quieter running and better mpg.
 

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Thermostat!

Rasputin, <br> <br> Thank you for your reply.<br> I was looking for thermostat pics and which one would you recommend?<br> http://img.eautopartscatalog.com/live/G400115462WAH.JPG<br> or<br> http://img.eautopartscatalog.com/live/G400115462BEH.JPG<br> <br> Also, about fan switch, is this the one with 100C?<br> http://img.eautopartscatalog.com/live/G503012319BEH.JPG
 

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Re: Thermostat!

Ezzy,<br> <br> Water pump thermostat type G400115462BEH, this thermostat bracket of main closing plate can be pushed and twisted to release spring pressure.<br> Fan thermoswitch:- If you have A/C and auxiliary air fan in front of the radiator, they are wired to disconnect the A/C compressor at 100ºC and you would want the retain the existing thermoswitch for this function. To install a main electric fan to replace viscofan would suggest to install additional thermostat type which installs inside the top hose of the radiator and a separate electric thermoswitch which can be manually regulated to desired optimal temp.
 

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Re: Thermostat!

Rasputin,<br> <br> Thank you again for your advise.<br> I ahve a question about to modify thermostat.<br> If I use adjustable fan contoller, why I still need to mod a thermostat? If I set fan starting temp as 90c or 95c which pretty the same temp as viscofan start working, thermstat should work as same as with viscofan?<br> <br> I am thining to use this contoller.<br> http://www.derale.com/derale/img/adjustablecontroller.jpg<br> as you can see, this one control by not water temp switch, thermista on the radiater. How do you think if this is O.K.?
 

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Re: Thermostat!

Ezzy,<br> <br> The viscofan is ALWAYS on. At ambient temp below 95ºC (heat emanating from the rad and engine bay) the 'clutch' is disengaged and the fan only revs at 600 rpm regardless of engine revs. At ambient temp above 95ºC the bymetallic strip push the 'clutch' against the spindle and the fan can rev at engine revs (up to engine speed of 3800 rpm, then it disengages due to the centrifugal force on the spring that blocks the viscuous oil passage).<br> <br> At low engine revs (city traffic congestion) 500-700 rpm the fan is not going any faster than the engine even if it is engaged, then at coolant temp 105ºC the auxiliary fan comes on as the viscofan can not cope with cooling requirements.<br> <br> Once you remove the viscofan there is not cooling at low revs and therefore you have to allow coolant circulation to radiator for longer period by the thermostat mod. If you lower the thermoswitch to trigger the new electric fan at 90ºC, this will cause the fan to work 95% of the time in traffic. The 16' fan consumes twice the amps and watts of a 13' auxiliary fan (about 225 watts). If you keep the fan running at very low engine revs for long periods the consumption of the fan is greater than the output of the alternator and pretty soon you will have a flat battery.<br> <br> The thermoswitch in your pic for external application is not suitable for a 5 liters Mercedes with multiple radiators as the external rad temp have an discrepancy of real coolant temp of about 25% and you will have engine overheating as the corresponding coolant temp will be around 115-120ºC. <br>
 
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