SL/R129: Performance chips
Thread Starter
Newbie
Joined: May 2023
Posts: 8
Likes: 0
1995 500SL
Performance chips
Hello everyone.
I own a 1995 SL500 & it seems to run quite well. Recently had it serviced & we cleaned the distributor caps & that got rid of the shuddering miss. I recently read about 'performance chips you can plug into the engine which increase hp & torque. Has anyone had any experience of these & what are they like? This benz is a UK import to Australia & has the 4 speed auto. It's build date is early '95. There's 107,000 miles on the clock.
Still has the original wiring harness but that seems ok & thus far all electrics good.
I own a 1995 SL500 & it seems to run quite well. Recently had it serviced & we cleaned the distributor caps & that got rid of the shuddering miss. I recently read about 'performance chips you can plug into the engine which increase hp & torque. Has anyone had any experience of these & what are they like? This benz is a UK import to Australia & has the 4 speed auto. It's build date is early '95. There's 107,000 miles on the clock.
Still has the original wiring harness but that seems ok & thus far all electrics good.
Senior Member
Joined: Oct 2017
Posts: 368
Likes: 73
SL600
Take another look, the wiring harness is dead.
There is no extra pony inside the chip, but you will get rid of the speed limit, if this is important down under. And, if I remember correctly, the high rev is switched off on cold starts.
There is no extra pony inside the chip, but you will get rid of the speed limit, if this is important down under. And, if I remember correctly, the high rev is switched off on cold starts.
Thread Starter
Newbie
Joined: May 2023
Posts: 8
Likes: 0
1995 500SL
Thanks for the reply.
Strange how you see all these ads about chips supplying increased hp & torque, so assume from your experience that's all bs.
As to the harness, disagree. If it was 'dead' the car wouldn't function too well & it does.
I think warmer climates have a more deleterious effect on these things than colder ones & this is a cold climate car.
Out of interest, sounds like you're speaking from experience re the harness.
Nobody here seems to sell them - do you know where I can source one?
Best
Steve
Strange how you see all these ads about chips supplying increased hp & torque, so assume from your experience that's all bs.
As to the harness, disagree. If it was 'dead' the car wouldn't function too well & it does.
I think warmer climates have a more deleterious effect on these things than colder ones & this is a cold climate car.
Out of interest, sounds like you're speaking from experience re the harness.
Nobody here seems to sell them - do you know where I can source one?
Best
Steve
Senior Member
Joined: Oct 2017
Posts: 368
Likes: 73
SL600
I live in Germany, so for me, the Vmax part was interesting 
Take a closer look at the wiring, start with the easy to reach wires at the temperature sensors. Dont look at the black insulation, look at the coloured ones direkt at the connections. Bend them slightly, if there is nothing, do this with the one at the fuel injectors, too. Not because i want you be unhappy but prevent your car from burning.
If your dealer cant sell anymore, there a some companys (here) who rebuild them like this one: https://kurth-classics-autoparts.de/.../model-MB+R129
Take a closer look at the wiring, start with the easy to reach wires at the temperature sensors. Dont look at the black insulation, look at the coloured ones direkt at the connections. Bend them slightly, if there is nothing, do this with the one at the fuel injectors, too. Not because i want you be unhappy but prevent your car from burning.
If your dealer cant sell anymore, there a some companys (here) who rebuild them like this one: https://kurth-classics-autoparts.de/.../model-MB+R129
Super Member
Joined: Aug 2019
Posts: 701
Likes: 207
From: Lutz, FL
1997 MB SL600
There are a few chip horror stories on the other site.
One of the stories isn't so horrible, but the mods are similar to what Andreas mentions above. Speed limit removal, octane fixing (93, but you have to have 93), temp and fuel mapping. You have to send off your engine management computers (V12) and hope nothing goes wrong (see horror stories). There were outright modules for the older cars, but its a little late to go that route and expect a good outcome. You would really have to know what you were doing.
ChrisUFGator had his redone at a local to him (FL) shop which I didn't pursue (I live in FL too). I went with the traditional upgrades like: intake and exhaust improvements to make my changes. When I got my RENNtech carbon fiber intakes, there were also upgraded engine management modules, but I passed on them.
We are all a little late to the R129 party and "inexpensive" upgrades are difficult to come by.
Still, it's your car, so have fun and let us know how it goes.
One of the stories isn't so horrible, but the mods are similar to what Andreas mentions above. Speed limit removal, octane fixing (93, but you have to have 93), temp and fuel mapping. You have to send off your engine management computers (V12) and hope nothing goes wrong (see horror stories). There were outright modules for the older cars, but its a little late to go that route and expect a good outcome. You would really have to know what you were doing.
ChrisUFGator had his redone at a local to him (FL) shop which I didn't pursue (I live in FL too). I went with the traditional upgrades like: intake and exhaust improvements to make my changes. When I got my RENNtech carbon fiber intakes, there were also upgraded engine management modules, but I passed on them.
We are all a little late to the R129 party and "inexpensive" upgrades are difficult to come by.
Still, it's your car, so have fun and let us know how it goes.
Last edited by mahunt; May 31, 2023 at 04:04 PM.
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Thread Starter
Newbie
Joined: May 2023
Posts: 8
Likes: 0
1995 500SL
Hi
Finding this a bit confusing as to which engine harness I need.
there's the one from the site you recommended ( https://kurth-classics-autoparts.de/...295401405.html )engine wiring harness A1295401405
Suitable for the Mercedes R129 with M119 engine with KE-Jetronic
& there's this one from delphi in america
93-95 Mercedes Benz 500SL SL500 Updated Delphi Engine Wiring Harness 1295407705
( https://www.ebay.com.au/itm/284235671589 )
The number are different.
The car is a 95 model 500Sl with the 4 speed gearbox & was built in the first 5 months of '1995.
Have no idea if it's a KE Jetronic versionAny ideas?
Best
Steve
Finding this a bit confusing as to which engine harness I need.
there's the one from the site you recommended ( https://kurth-classics-autoparts.de/...295401405.html )engine wiring harness A1295401405
Suitable for the Mercedes R129 with M119 engine with KE-Jetronic
& there's this one from delphi in america
93-95 Mercedes Benz 500SL SL500 Updated Delphi Engine Wiring Harness 1295407705
( https://www.ebay.com.au/itm/284235671589 )
The number are different.
The car is a 95 model 500Sl with the 4 speed gearbox & was built in the first 5 months of '1995.
Have no idea if it's a KE Jetronic versionAny ideas?
Best
Steve
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