is it possible that the various pulley upgrades give you a different level of boost of hp/torque - that is, it seems like kleemann and wetterrauer has sort of the same increase factor... but renntech's has a much greater torque increase (where i'd have expected a 227lb-ft torque rating). is that possible?

kleemann steel pulley kit
220hp/227lb-ft

kleemann alloy pulley kit
232hp/239lb-ft

renntech pulley kit
220hp/248lb-ft

wetterrauer pulley kit
230hp/236lb-ft

väth pulley kit
165 kW = 225 PS (basis 193 PS),
168 kW = 228 PS (basis 197 PS)
320 Nm of 2.800 U/min

 

Considering the relationship between HP and torque, I think you are correct. The RENNtech one shouldn't deliver more torque than the others.



BT

 

The only factors that a pulley kit can alter is diameter and weight. Some kits alter the numbers a little bit by providing bonus goodies. Wetteraraur provides an intake, Kleemann provides a larger altenator pulley, Renntech gives you a foam air filter and Carlson wins the bonus prize by giving you an alternator pulley, an idler pulley and new air filter. My thought is these bonuses don't add up to much. All the pulley companies say you don't need the bonuses that the other's provide. Just call them and ask, it funny. Kleemann says air filter don't make a difference, Renntech says alternator pullies don't make a difference.

As for diameter you are kinda stuck in that the crankshaft pulley can't be bigger than about 8 3/4" at the belt before the S/C belt between the crankshaft pulley and the idler pulley rubs against the waterpump pulley. Of course the pulley can be smaller. There's a way to make the pulley bigger by making the idler pulley larger (this pushes the belt away from the waterpump pulley) and the only pulley kit that I've seen this on is Carlson (correct me if I'm wrong) but I have no info on the Carlson and it's not available in the U.S. and they won't export. So next is weight. The lighter you make any rotating component between the crankshaft and the tires will make more rear wheel HP, even lighter wheels, driveshaft, flywheel and tires. It takes energy to spin the pulley and a lighter pulley requires less energy. So an all alloy pulley would have a distinct advantage over a steel pulley. People with non-supercharged cars employ alloy pullies to make more HP not only to underdrive the accesories but becuase of weight.

There is one other possibility and that's to make the rear plane smaller so that it underdrives the waterpump, power steering pump, AC and conserves energy that way. I don't know if anyone is doing this. It would probably cause fault codes.

The reason different tuners get different results is simple, every car produces different dyno results and a dyno on the same car on different days gives different results. I varied my dyno by a few hp just by moving a fan around by the intercooler. Also the fuel people put in their cars vary amoung brands and times of the year. For example, if I dynoed my car in the winter california oxygenation season it would produce different results than in the summer season. Also temperature, altitude and humidity make a difference on forced induction cars that can't be compensated for by the dyno. Blow 60 degree air into your intercooler and you will get more HP than blowing 90 degree air. Also dyno's vary greatly. My car base dyno'ed at 159hp on a Dynomax and 168hp on a Dynojet but the torque numbers were much better on the Dynomax. Also the age of the car makes a difference, too new and you get less HP, too old and you get less. Base dyno when car is new, sprinkle fairy dust on the car and wait 10k miles and dyno again and walla, fairy dust produces 5hp, new product. Also what octane fuel are they running? I can't get better than 91 at a street pump in So Cal yet most of the country can get 93 and even 94 at Sunoco.

So that's why I take these numbers with a grain of salt and do my own testing to satisfy my curiousity. I'm not calling these tuner's liars, just clever marketing types. I just wish the vail of secrecy was lifted and they told you the exact diameter and weight of their pulley so that you can make an informed decision. I can tell you after an alloy pulley install you can definitely tell there's way more power.

BTW, the difference on the Vaeth pulley is the 225 is for the pre-2001 and the 228 is for the newer cars. Also keep in mind that in Europe they get higher octane fuel and Vaeth makes this a requirement.

 

the renntech kit can come w/ or w/out the ITG filter (-$200 for w/out)

Larger Crankshaft Pulley, Idler Pulley Belt, ITG Air Filter. i've been told that the k&n filter may be just as good. i didn't realize that the renntech kit doesn't include a new alternator pulley. but it maintains the harmonic balancer. - the question is, does it come w/ RENNTECH letters to put on!

(note that the renntechmercedes site has numbers for the w202 c230k sedan)

 

It's a damper not a harmonic balancer. I actually had a mercedes design harmonic balancer in my Harley. It's made by a company in LA called Fischer and is used for wusses like me that can't stand vibration. Some markup, the ITG airfilter cost about $55 and Evosport sells them, the belt is $18 at Pep Boys. The pulley can't be larger. They sell a pulley, a belt and an air filter for $1,649 on their website. It actually must be smaller as they only advertise 20hp increase with the pulley and air filter.

As for numbers for a C230K sedan that would be in their favor. The factory pulley on the W202 is much smaller than than the factory pulley on you Coupe. This means that if you put a similar size pulley on both, the boost on the C230K sedan would be higher although the overall HP may be lower because the C230K sedan started life as 185hp vs. our 192hp. Because of the shape of the waterpump pulley you can get a slightly larger pulley on the W202.

 

Kleemann does not claim any hp increase from the alternator pulley. It is there to maintain the original speed of the alternator.

The posted octane numbers in Europe are the Research Octane Numbers (RON). The beaurocracy of the United States somehow decided that the average of the Research Octane Number (RON) and the Motor Octane Number (MON) would impart more information to consumers than just posting the RON. 93 octane in the US is the same as 97 octane in Europe.

 

well, the renntechmercedes.com site has some different numbers.

for the c230k sportcoupe - from 192bhp/200 lbs-ft:
Larger Crankshaft Pulley Kit, Renntech Air Filters
212bhp/220lbs-ft

for the c230k sedan w202 from 185 bhp/200 lbs-ft:
Larger supercharger pulley,Renntech air filters
200bhp/220lbs-ft

--
some questions for you buellwinkle:

how much is the warranty worth to you? i'd pay more for a better warranty. you previously said that renntech has a warranty against damage to the engine - not just the parts. i can't find that reference.

is the pulley belt an off-the shelf belt? if so, why replace it from the oem belt? btw, i can't stand crapboys...

is the harmonic damper necessary? why do other pulley makes drop it?

 

Great information here, thank you Buelly and others.

Smoky

 

Lynn,

Vaeth recommends 98 RON octane or 94 R+M/2 octane, I'm in So Cal where the best pump gas I can get is 91 octane and even at that it has so many government mandate additives that I don't call it gasoline anymore. I realise that Sunoco sells 94 octane gasoline in some areas but not in the west. Can you please send me some 94 octane gasoline? I need about a tank a week, or a barrel a month will do! Maybe you can start the barrel of the month club (LOL).

Young,

Told you about the Renntech not producing as much power as other pulley kits, 20HP at the motor or about 17hp at the rear wheel. If you can find out the diameter and weight it would probably explain the reason. It may just be a conservative number or one done on a very hot and humid Florida day. Maybe they have crap gas in Florida like California. I'm surprised about the W202 gettig only 15hp more.

The belt I'm using is an ordinary 6 rib belt you can get off the shelf. I've found it cheaper on the internet for about $17 so you can avoid Manny, Moe and Jack if they offend you. It's about 2 1/2" bigger than the stock belt to compensate for the larger pulley which is about 1 1/2" bigger diameter making it almost 5" bigger circumference, since the belt wraps around that pulley about half the circumference it calls for a belt about 2 1/2" longer. It terms of fitment, all 6 rib belts are the same.

I've heard about the warranttee about the Renntech pulley but I've never seen it. Can you call them and ask exactly what the warrantte covers so it put's this issue to bed. Of course all the performance parts companies likely guaranttee their goodies to be free of manufacturing defects and stuff like that, not that it won't fry your motor. That applies to exhausts, intakes, chips, NO2, cams, injectors, intercoolers, powered by honda stickers and all that stuff.

 

Buellwinkle,

When are you gonna come down to San Diego again? I'm running out of car to play with...lol.

 

I left my oil filter cover at the dyno shop. Arrgghh! Can you see if they found it. It was against the wall next to the dyno computer.

Hopefully I'll be out there again on Saturday. The K&N filter was a bust. K&N told me it would fit but it's a square filter, not the rectangle in the coupe.

 

ok, i was sent the renntech warrantee which is 2 years unless the car is still under warranty. in which case:

B. FOR VECHICLES COVERED BY THE ORIGINAL MANUFACTURERS NEW CAR WARRANTY.
This warranty extends to the original owner and is transferable. The warranty begins on the date of part purchase. If the vehicle is currently covered by the original vehicle manufacturer’s new car warranty, RENNtech products are warranted for twenty four (24) months or for the remaining term of the original manufacturers’ warranty, whichever is longer. RENNtech will pay for the replacement part (new or remanufactured) and labor at the official Mercedes Benz standard warranty labor rate. Labor will only be covered under this warranty, if the original installation was performed at a RENNtech authorized facility

my interpretation is for me, 3.5 years of warrantee. and they will pay for labor of installation of the new pulley.

 

Young, that's the most important part for you. Might mean that you'd have to make that trip to AC! Hopefully, Eileen would buy the excuse.

 

well, the referrals were provided by renntech and of course, they are mb dealers - so it's got to be approved. right?

but i'm planning for nothing to go wrong like i always do.

 

Sounds right, but might want to give them a quick call before it's intalled, to make sure.

BTW: what's the new avatar?

 

Young, when you get the Renntech pulley, weigh it and measure it. I'm just curious why they only put out 20hp at the engine.

What are they charging you for the pulley installed? It should be less than an hour's labor just to replace the pulley since there's nothing else that comes with the kit (since you are not getting their $200 air filter).

Are you going to do a before/after dyno?