tedale

interested in increasing power and control. renntech has a chip plus pulley , and springs ($5000.00). evosport has a similar set up but how much does it cost/? are the two comparable in quality and performance or is the renntech simply overpriced for the same thing offered by evosport.


thanks

AmgBoy

I would personally go with Evosport. They have proven themselves by setting up track sessions, great service, dyno numbers, and happy customers. The only down side to them is I beleive they only have one location which is in So. Cal area? Renntech on the other hand is definetly overpriced and I beleive not used as much by the "true enthusiast".

Once again I gotta give it up to Evosport.

-Amgboy

kenny

What makes you think Renntech is "overpriced" ? Just because it costs more than an inferior product? Perhaps the evosport pulleys are underpriced, because they are under-developed, under-tested, and are not as good quality as the renntech pulleys.

The lack of a harmonic balancer in their pulley design is pretty troubling, AMG obviously included it when they designed their pulleys because there was a need for them. To explain away this lack of planning in the design process with the argument that they are lightweight for better power is truly sad.

If I were to modify my engine in any way, I would, without hesitation go with renntech. They have obviously done much more R&D with their package as they do not need to ghetto rig an "intercooler upgrade" to have their pulleys/ecu work.

SteveL

You clearly have no idea what the heck you are talking about. I don't see Evosport doing anything like the CLK-GTX or any other major engine converison like 3.7 conversions or high boost supercharging. Evosport's most serious work is simply reselling Kleeman stuff which might be good but it is simpy bolt on stuff.

Both have their niche but to say Renntech is not used by the true enthusiast shows that this must be the only forum you read. I'm pretty confident in saying the Renntech has modified hundreds if not thousands of MBs more than Evosport and has been doing it for much longer.

If you want to save some money and take more risk, sure, go with Evosport. But remember, you get what you pay for.

bverotti

From what I hear from other tuners (not renntech or evosport) there definately is an issue with the intercooler at peak performance after modding the engine.
From what I read, Evosport has dealt with this issue (just as MKB and Carlsson). REnntech has seems to have 'forgotten' this problem to date.

I would be pleased to see some reactions of those who have their car modded by any of the above companies.

Thx

otoupalik

This is funny! Actually if you were to do ANY R&D on the C32 then you would understand why we do things our way! Of course you are more then welcome to your opinion, but this one just makes me laugh as you have no clue what type of R&D we OR Renntech actually do!

Marketing does not = R&D or testing. Higher price does not mean a better product.

Proof is in the numbers and in the reliability.

Time will tell the story.

Actually, we are and do do engine conversions. We also build full race motros for BMW and Ferrari. We can and do the full Kleemann and MKB conversions as well.

In fact, we are building a CLK 6.3 with a Kleemann compressor that will be over 650HP and will be entered into the Magazine's tuner challenge's this year.

Just because you have not heard about it, does not mean it does not exist!

Thanks

Brad

goalie_k

Tedale,

You will NEVER get an honest answer on this board since it is owned by Evosport. Drive on over to some other message boards and post your questions there.

Nothing aganist evosport, but the reason this board exisits is for them to sell product.

otoupalik

Goalie_K,

Let's talk about honesty - why don't you post your connection to RENNTech so the readers can see the bias.

Further, nowhere have he bashed anything from RENNtech or anyone else in this thread, just respondig to some questions and comments, would you rather have them go unanswered? That really helps the truth, huh?

Also, this board existed FAR before evosport, so wrong again!

We let anyone debate the issues, if Renntech wants to get more involved, they have been given the invitation more than once.

Thanks

Brad

rage2

With just the pulley mods, there is no problem with the stock intercooler, even on a warm day and low octane fuel (91 octane California stuff).

With Renntech's ECU upgrade along with the pulley upgrade, there is an issue on 91 octane fuel, but the ECU dials back the timing (not the safest way to go) to resist detonation. The reason is because they've leaned out the mixture to get a few hp's, and by doing so increased combustion chamber temperatures enough to begin pinging on 91 octane. There is no issue with 93 octane (timing well within safe limits). Power begins to stabilize once you hit the 95 octane level (approximately) meaning you'll get the full ECU/pulley potential with ~95 octane fuel.

With added more coolant capacity in the intercooling system, it only helps to a point... when all that coolant gets as hot as the stock amount of coolant, you'll have the exact same heat soak issue. It'll also take longer to cool the larger amounts of coolant down, so if you do reach the point where you get heat soak, it'll take much longer to recover.

Renntech is talking about releasing a full IC upgrade, but I have yet to hear an official announcement from them.

I helped install the kit, as well as investigate the intercooler issue for a friend's Renntech C32, so yes I've done my share of R&D before anyone bashes my comments .

Zeppelin

I believe that when you bolt on the Renntech pulley that it bolts through the harmonic balancer to the center hub. This elininates the purpose of the dampner, making it solid like one piece.

Actually the stock pulleys could benefit from an intercooler upgrade. The stock system is truly poor.

I don't know why people have to trash other manufacturers products. If you have proof that they are bad then lets see it. If you like Renntech and want to buy all your parts from them, then go ahead. I personally will buy from all different vendors based on price, performance, and quality.

AmgBoy

Maybe my comment about "Renntech not being used by the true enthusiast AS MUCH" is not very accurate. But the fact is Evosport does countless hours of R&D and they know what they are doing. Read Outpalik's post to see what I am talking about.

To whomever said that I didn't know what I was talking about, it looks like you talked TOO SOON.

Vadim @ evosport

For those of you who have not been on this board for some time, I would highly recommend doing a search for "R&D".

You will find the history, along with data, of ODPS development.
You will also find that the kit Renntech sells is the same kit sold by other tuners, Brabus, MKB and so on. The kit is made in Germany and resold to everyone else. It was offered to us, when we were at Essen Motor Show in 2001.

Personally I had problems with the way kit is made and lack of any IC upgrades. This is why ODPS come with IC upgrade. Do a search and it will tell you why.

The main reason we are doing our own R&D has to do with empty promises made by a lot of tuners of MB and BMW. Over a number of years we have seen a lot of tuned cars barely reaching stock HP levels. I can not name names for obvious reasons.

Our philosophy has always included dynoing cars before and after tuning. If the product that we sell cannot produce advertised gains, than what the point of carrying them.

rage2

On a stock C32/SLK32, there is no need for an upgraded intercooler. If you were led to believe it does, you were being misled .

What AMG has provided works as intended on the car (unless you're using some really low octane fuel). Even on 91 octane vs 103 octane, there is no difference in power. Higher octane fuel resists detonation at higher temps, detonation retards timing, thus power loss.

On a very hot day, the SLK 32 will pull consistant runs over and over again. No need for cooldown, even though the water temperature is pegged at 100C. Even after adding water wetter, with temps down to 90C, there was no gain in performance. IAT on the OBDII scanner was lower as well which showed the lower water temps affecting air temps. Timing numbers didn't change either.

As to evosport requiring a IC mod, maybe their pulley is larger than the Renntech/other tuner's pulleys? At higher boost, the octane requirements change, therefore it's more susceptable to high intake air temps, thus causing power loss.

rrf

Rage2, you live in Canada, don't you find the SLK32 runs a little better because it is cooler there?

Does your OBDII have logging? What is the highest IAT you have logged/recorded, before and after Renntech pulley please. Can you show us some plots after several runs?

rage2

Not at this altitude (3700ft). When the car was in Vancouver, it was a totally different beast even on a really hot day. The trap speed went up by 5mph (104 to 109).

If you're feeling a performance difference on a hot day vs a cold day, it's not that the IC is inefficient, it's because on a cold day the air is more dense... meaning more O2 in the same volume of air, meaning more fuel is injected, meaning more power . Ambient air pressure has a moderate effect on power as well. On a really good Calgary day, the SLK 32 can clock 105mph trap speeds. On most days it'll clock 103-104mph trap speeds.

Lucas

Vadim is right, and this is what I have tried to tell this board for a year now, none of the German tuners do anything themselves.

Small software companies crack the soft ware, small " real good guys " develop the hard ware, and the big guys do the advertising and colect all the $$$$$$.

I know for a fact that RENNTECH do not do any research on displacement engines, MKB ( which are nice guys ) do all the dirty
work, RENNTECH buy the parts from MKB in Germany with a nice discount from German list price and sell it in the US for double German list price.
This is what you pay for.

Renntech is old friends with MKB from the old days at AMG, MKB
was doing the fine engine work, Renntech was cleaning the toilets.
This is why MKB today do more or less all the engine work for all
the " FANTASTIC GERMAN TUNERS " and Renntech.

Most of MKB fantastic clients are unfortunately not so faithfull to them, they order 1 kit and then they copy.

Surprised, but this is why they charge you extra, better quality ???? more research ?????.

slkride

why don't we just purchase directly from the source and bypass all the advertising markup fees? anyone have any contact w/ these companies?

Vadim @ evosport

Rage2: Doing R&D, hardly can be called misleading. Many CA and NV C32 owners noticed that on a hot day the car would loose significant power.

Mine was doing the same. Again read R&D posts and they will shed more light for you.

One thing to remember is that AMG's R&D is done in Northern Europe with temps rarely above 75F and fuel octane never below 97RON.

In CA, current 91 (R+M/2) is more like 89 with MON below 85. On the scanner DME constantly retards timing to keep detanation at bay.

When more boost is added via larger pulley. Intake temperatures go up above 150F and stay there for some time. By adding and additional capacity to the system we were able to keep the temperatures below 150F and cool down to below 100F within 15 seconds. This keeps DME a lot happier. Again more info and dyno graphs can be found under search.

Lucas: Thanks for backup. This is what kind of shocked us, when we were at Essen.

otoupalik

I will tell you that the mega-buck Snap-On diagnostic scanner hooked into our C32 via the OBDII port does NOT mislead. This gives us REAL-TIME temperature and diagnostic readings, which we have taken stock and modified on the street and the track. There IS a gain to a larger inter-cooler, even stock! Numbers and temps from a scanner do not lie, this is HARD data and is tough to argue with.

Now while this might not impact your back to back runs, it does have an impact on the car in the long run. You can get away with a lot of bad ***** for short periods, even sometimes a bit longer, but engines do not react well to heat over long periods of time.

A classic example is in the race motors we build. You build a sprint motor to the limits as it will only be run for less then an hour at a time. You can go more extreme and get closer to the envelope. However, on enduro motors, for races up to 24 hours, you have to be much more concerned about temps and heat soak as it adds up and can ruin your day (or race in hour 23).

Now, I will tell you two motors with the same HP but different approaches to cooling might have the same lap times or drag runs, for a while, maybe even a few hours, but eventually the motor that does not deal with heat issues will start to breakdown or even fail. This is not rocket science, it is just fact. Heat IS the enemy of a motor.

Oh, and SLKride, you can order MKB direct from us. We will not and have never taken someone else's product and slapped our label on to make more money! Not our style!

Thanks

Brad

rrf

Rage2, you said on a good day in Vancouver your Renntech? SLK could trap 109.

So an Evosport C32 trapping 108 in CA on 91octane is doing pretty well, right? Straight up, the SLK should have several tenths on the C32.

ODPS is pretty new and this I believe is the first guy to try the 1/4. He is not a "driver" just a normal guy, on a "slow track" (his 60ft was over 2 sec too). He was on 19's. Performance-wise the pulley looks like maybe 30HP at the wheels (Vadim never promised but 20-25 RWHP

We are all benefiting from the increased competition in the Benz- tuner arena. Let's all enjoy that.

The Evo guys don't normally "bang" on the Renntech products at all. You can't blame them for defending their own work though. I have seen the Evo pulley kit and it looks absolutely beautiful.

rage2

Here's the R&D that I've done. I basically did all this to see if there was any improvement I can make while maintaining my car in stock class under SCCA rules, and not get bumped to street prepared. The C32 tests were done pretty much just to see if it was worth moving into the more competitive street prepared class. I'm not promoting Renntech products, I'm not promoting Evosport products. I'm just disagreeing with some of the things that have been said in the threads that I read here. I don't sell anything, so I believe I'm not biased. Here goes :

I have my OBDII scanner hooked up to a bone stock SLK 32's OBDII port. Timing numbers I saw were in the 19-21 degree range on a 3rd gear WOT run. We ran the car hard, at the track, on the dyno, on the street, you name it. 19-21 degrees of timing, no change. We ran the car on the dyno to get a baseline reading. We bled the cooling system and added water wetter. Water temps dropped from a peak of 100C to 90C. IAT's dropped about 8 degrees on average. Timing was at 19-21 degrees, no change. Power wasn't changed either. This led to the conclusion that the stock intercooler is sufficient for the car. I really wish I had an EGT meter to read exhaust temps on different days/conditions. I would be able to judge "reliability" a lot better with proper EGT readings. From experience though, IAT's don't change EGT's too much. It's only when IAT's are to the point where there's detonation, timing gets retarded, which causes EGT's to start going up, and affecting the reliability of exhaust parts (valves, headers, exhaust, etc).

Next up was the C32 a few months ago. The owner ordered the Renntech kit from a friend's shop, and I asked if I could get some readings off it. Stock, on the dyno, timing was at 19-21 degrees. With the air filters installed, the car made an additional 4hp peak, timing again was at 19-21 degrees. With the pulleys installed, peak hp was up another 17hp. This time, timing numbers changed, and dropped down to 17-19 range. We took the car off the dyno and ran it on the road (18C day) and the timing was once again at the 19-21 degree range. Obviously, there was not enough airflow to the intercooler's radiator on the dyno, causing light detonation, and the ECU retarding timing. On the road, it was fine, meaning the pulley'd 32 motor with stock intercooler was running close to the limits of 91 octane fuel.

Finally, the ECU was installed in the C32. What did the ECU change? On a stock C32, the A/F ratio runs at around the 11.9:1 to about 12.1:1. What Renntech (or whoever they get their software from) did was lean out the mixture to approx. 12.5:1 to 12.7:1, gaining a few HP. They've also made the ignition curve a bit more agressive at lower rpms and part throttle, therefore the car feels more "peppier". Here's where I ran into the first problem.

On initial testing on 91 octane fuel, the ECU retarded timing heavily, down to 13-15 degrees! Makes sense, leaner A/F mixture results in higher combustion chamber temperatures, therefore causing the mixture to detonate, and the ECU pulling back timing. Any tuner would agree with me that these are dangerous levels (I sure wouldn't drive the car hard with these timing numbers on a lapping day). The tank was then drained, and 103 octane fuel was added. Timing went back up to 20-22 degrees. After a few more days of mixing fuel, we got around 93.5 octane mix (rough guesstimate) and saw timing in the 17-20 range. Safe, but not optimal. We haven't nailed down a good mix of fuels yet, but I'm guessing at around 95 octane we'll see the timing numbers level out at 20-22 degrees. Peak water temperatures the same at 100C no matter what fuel we use.

In conclusion, with the Renntech ECU and pulleys, if you were to use 91 octane fuel, yes you would benefit from a IC upgrade. If you had access to higher octane fuel (94 octane?) the benefits of an upgraded IC just isn't there. It's obvious that the kit was tuned under higher octane fuel that what I can get here (91). Brad, I completely agree with you regarding heat == motor's enemy. But small changes in IAT (what I've seen) does not change combustion temperatures and exhaust gas temperatures too much. Water temps were consistent, so I do not believe that there is an excessive heat issue with the motor, even with the pulleys and ECU mods.

There ya go, flame away .

rage2

My car is completely stock, as is Kenny's. He trapped 109mph in Vancouver bone stock.

It doesn't take much to drive fast in a straight line, especially in an automatic, so I don't think driver skill plays a role at all. As for 60ft time, it doesn't affect trap speed much. Kenny's car pulls 2.1 to 2.2 sec 60 ft times.

otoupalik

Rage,

No flames, and thanks for the post. I can tell you though that your findings are NOT universal. As Vadim has said, we did see timing pulled out on CA 91 more then once, even with stock pulleys, etc.

Interesting, but there are so many different variables, such as methods for octane rating, temp, etc., that it is difficult to see what is what.

You and Vadim should chat offline to share results and details to see if any conclusions could be made or to see if there is anyway to rectify the two very different results we have seen.

Thanks

Brad

Vadim @ evosport

Rage2: I find your results very interesting.

1. Your first car is SLK32. It is about 300lbs. lighter, so it runs a more aggressive timing curve. A CA C32 is in 12-14 degrees range.

2. You used a Water Wetter. Great product, but in our use in the past 10 years and experience of other shops, racers and customers, we are yet to see any difference in temperature. It works great as anti-corrosion agent and when mixed with distilled water. But when used with anti-freeze I have not seen or heard it to make any difference. We use it pretty much on every car that has been through the shop. Well over 2000, from Yugos to Ferraris.

3. As far as stock IC being adequate for the car, I have to disagree. On one run the IAT was over 180F. Way too high to be useful for power production. The problem is that stock system is tied into cooling system. Cooling system runs 195-200F, so when you get a lot of heat build up, your backup is very hot. Here is the link to R&D posts.

R&D Posts

Please read all of them, they will answer a lot questions for you.

P.S. I did not know they sell CA 91 gas in Canada.

Pierre32///AMG

Well, I have followed this topic point by point because I have the H&S ECU+BMC filters and I would like to upgrade my car for more. Evo’s pulley for me is the way to go not the Renntech one, although the completely kit that they offer is good.
Currently, I am living in Colorado 5,450 fts and this is my Dyno Air/flue chart:
http://groups.msn.com/Mercedes2003C3...hoto&PhotoID=9
I wonder whether or not the addition of a pulley at this altitude with my current configuration (ECU/Filters) may work?
Thanks.