rambo006jr

does anyone have any experience with tuning chips on a 96 or later w140? I am trying to decide on different companys: Powerchip, SpeedtuningUSA and Upsolute.

There seems to be conflicting info from other forums. I want to know if anyone here has experience and can share their opinion. thanks.

Sledelman

I recently installed a Renntech power chip in my 1995 S500. Price: about $490
I get a definite boost in performance, problably around an additional 15 hp. Engine acceleration is less noisy and the engine feels more responsive. The chip does nothing more than throw more fuel into the engine under load. It does not alter shifting speeds.
I have also installed K&N filters which also has improved performance. I'm guessing I probably get an additional 1-2 HP from the installation.
When I purchased the car last Ocober, I was very disappointed in lower end acceleration. It felt very sluggish in comparison to the 1991 560SEC I had previously owned. By installing the chip and filters I get comparable acceleration to that model. However, top end performance, in my opinion is much better in the S500 than the 560SEC.
I am planning on installing the Renntech cold air intake but it is a bit pricey, around $900 plus. Renntech states the system will add 10 hp to engine performance I will drive the care with what I have installed for a while before going for this upgrade.
I might add that an easy way to get the a little better acceleration is to raise the cold temperature tire pressure to 36 psi front and 38 psi rear. My mechanic told me that there is a design flaw in the steering system that contributes to a slight amount of vibration at low speeds, even after changing the rack busings. This pressure was recommended, by the factory, to alleviate the problem. Seems to work, plus I get a little extra acceleration for free.
So if you add the chip, K&N filters and add in a cold air intake , you probably add around 25 more hp. Increase air pressure as well, and you will problably reduce your 0-60 time by a small amount byreduced rolling the car's rolling resistance.
However nothing is for free. You will probablly loose fuel efficiency around town of about 2 mpg and about 1 on the highway when you add the power chip. The other improvements may offset these losses, but not fully.

ksbnz

Sledelman,
What you mean by design flaw that contributes to low speed vibration? At what speed does it occured? My 95 s500 returned with vibration at 50-65 mph after long repair session from mb deler(cost me 4.5k) whiteplains ,NY. I brought back in again and they hold it for two more days to find what caused to vibration. They did check all drive terrain and wheel balanced, rebalanced, retourqed hear and there but couldn't determined the point and just said it could be wrong tire size. Tire size is 225 michelin pilot with 85% thread remained(235recomended). And recomended pressure is cold 28 front 29 rear said on the door.Isn't 35,36 too high? I am confused now don't now what to do. I am just desperate to get rid of the vibration.

regards,

Sledelman

I would raise the cold tire pressure to 34 front and 36 rear. I have been driving around with them set at 36 fron and 38 rear The ride is a bit too hard for me. However, the vibration that I experienced at 45 to 55 went away. It was worse before I had the stearing rack bushings replaced, which is not very expensive. If yours have never been changed and you have over 100000 miles on the car, it should make a noticeable difference. The next items are the control arm bushings. If they are bad, you will get front end vibration. My mechanic checked mine out and said they looked OK, but I'm tempted to replace them since I still feel a bit of of a vibration hum from 40 to 60 mph (the wheels have been rebalanced).
My feeling is that stering rack bushings and control arm bushings probably should be replaced every 100000 miles and my car has 155000 on the odometer.
Steve

s0vietbenz

45 - 55??????? Doesn't it say our tire pressure should be set at 27 in the front and 29 in the rear???? I'm so comfused right now???

ksbnz

45-55 means mph the speed where the vibration is occured. He set the pressure 36/38. My 95 s500 is 84000 mile. The MB dealer service replaced rear shock, control arm bushing, 4 wheels alignment, 4 wheel balanced, rebalanced,thighten bolts hear and there . They spent two days and finally determined the tires are wrong size or bad. But tires looking good almost new. However recomended size is 235. Mine is 225. Is that caused to vibration? Is it pros job to change steering rod bushing? How is it performed? I would like to know anyway.

Thanks, johny s.

Sledelman

The pressure indicated on your car is what the factory recommends, however,
if you want to reduce tire wear, improve mileage, improve handling and reduce any inherent sterring vibration, you can raise the tire pressure. Just don't exceed the cold pressure indicated on the tire (probably around 40 psi). Play around with the psi until you find a combination that you think works best for the car's handling and your driving style. As a general rule, I have always increased the tire pressure at least 4 pounds, over the factory specs, with every car I have owned.
The factory sets the pressure that low to provide the driver with the most comfortable ride, thats all.
The steering rack bushings cost about $160 to install, parts and labor included. Don't know if you can do that yourself.
I don't know if the wrong tire size is part of your problem. But, in my opinion, oversize tires place more stress on the front suspension and steering than intended by factory design. Over time, it will contribute to more rapid wear and thus be a contributing factor to front-end vibration.

ksbnz

Thanks a million for your advice.Every word is a useful. I raise the pressure to 36 and vibration is still the same but I fill like the car performes better.Now I will work on the steering rack bushing.By the way this thread is for cheap experince. Sorry for headed wrong direction.

Happy driving, johny s yun

Sledelman

I just got a report back from my mechanic. I need new hydrolic engine mounts as well as a new transmission mount. I had the wheels rebalanced, using Mercedes Benz weights and the wheel vibration has gone away. The rest of the vibrations, that I felt under my seat should, disappear once the engine and transmission mounts are repalced. I don't know why a wheel balance with Mercedes Benz OEM weights works better, burt I'm pleased with the result.
I'm now just experiencing a bit of a thump when the rear wheels hit a bump.
I've been told that the rear shock bushings or rear suspension mount bushings may need to be replaced. Will keep you posted

Peter Guenther

Ok guys, my 92 500 SEL started this vib crap in 94, maybe I never drove at 40/45. The dealer(s) under warranty replaced upper control arms , steering dampers, drive shaft, rear end, and both hydraulic struts in the back. They aligned it with the modified settings, removed the origional Pirelli tires and installed Michelins. They all admitted there was a ddesign flaw in the car, in 95 models the factory did some suspension changes and lowered the cars by 10mm I think, no issues after that.
Back to the point, they reduced the vib to a minimun by balancing the tires while on the car after spinning them, that would only last so long. Out of warranty I lived with it, recently I replaced the motor mounts, lower control arm bushings, sway bar links, and steering damper. This is the first time I have not had Michelin MXV4, and went to Firestore Turanza (balanced on a road force balancer the same one MB uses), raised the pressure to 36 all the way around, and am happy.
The "road force" balance spins the tire and then puts a wheel agaist it to see if the tire is out of round. This is very similar to the way tires were balanced by spinning on the axle with a sensor on the control arm, and strobe showing where the imbalance is. I have seen this on commercial applications with shafts driving fan turbines.