Australia

I posted for advice on whether to get a Renntech or Speedriven upgrade to 650-690 HP, and hope somebody coud help me out on which one has the best air cleaner system, intercooler upgrade, and is there any difference in what they do to the ECU/TCU in general. And which is easiest to install and most reliable.

Dr Matt

I have never used either so I can't help you out, but have you talked to either company to ask them the advantages of their products? I can give you my opinion FWIW, and hopefully someone who has used the parts you are considering will chime in here or in the W215 AMG forum.

I have a couple Speedriven pulleys and I believe their stuff is very good quality and well engineered, with the exception of their "scorpion" intake. In my experience a "Hot air intake" may make great power on the dyno but they are not good for real world stop and go driving. Now I admit I have not ever used one, but just saying drawing hot under hood air into your engine is never as good as ambient air from outside the engine compartment in real world driving situations.

The problem is getting good flow from outside the engine compartment. Several of us have made our own intakes, but I don't know of any that are really "ideal" due to packaging constraints with the W215.

I'm sure Renntech stuff is very good too, their prices just seem ridiculous to me.

Speedriven1

I have to disagree with the "hot air intake" comment by Dr. Matt, and would suggest that he (and many of the other people on this board who like to champion a front-mounted "cold air intake") take real-world measurements. He'll find, like we have, that the Scorpion solution is superior to the front-mount, as the hot ambient engine air is rapidly displaced by incoming "fresh" air at just about anything above 35 mph ... granted, however, the best way is to cut NACA ducts into the hood- but no one's been brave enough for that quite yet.

In any event, if all you're doing is an ECU tune on an otherwise stock car, there's really no difference between the major tuners. These V12s have been around since 2003, and they are, by this time, very well-known quantities. What you're really looking for is a relationship that fits your needs. If you're upgrading the car in stages, for example, Speedriven won't charge you to modify your tune later when you order downpipes or billet turbos, for example. RT might, but they don't offer nearly the breadth and depth of product SD does for the V12.

As for the intercooler system, definitely step #1 is upgrading the factory pump. Virtually everyone uses a version of the Pierburg/BMW or SLS unit. We machine the housings on them before shipping them out, but I don't believe there is a material difference between our pump and RT's (excepting, of course, the $1000 upcharge for their logo- LOL!).

RaceHorse

Are you saying you have data logs for intake air temps, or temps measuring heat under the hood compared to temp in front of it? Do you have the plastic belly pans off underneath to allow heat to be pulled off from air passing under the car? It is such a tight fit under the hood with little to no place for heat generated by the turbos to escape. It is very hard to believe, that at such low speeds, all the heat escapes providing temps no different than the ambient air outside the car. Also were your findings with or without the killer chiller setup? In summer driving it will be even worse. Maybe the assistance of the KC is what is giving you comparable IATs?

Welwynnick

I figured that a lot of the V12TT performance and reliability issues were associated with high temperatures under hood. I tried to get a little bit scientific about it, and although I can't say yes to your questions, I did try two things:

I applied (peak hold) temperature sensitive tape to various parts of the engine, and drove around for a while. It was pretty clear that, apart from the turbos and exhaust, everything under the hood runs at coolant temperature. I saw 80 - 90 deg C everywhere.

The other thing I did was add an in-line temperature sensor to the IC system, and fitted a Tecomotive thermostatic pump controller that displays coolant temp. That gave a good indicator of pump and HE efficiency, but one thing really stuck out. Its parking that affects heat soak more than anything else. I would normally see IC temps of around 30 deg C depending on ambient, but once I'd warmed the engine up, and parked it for an hour, the temps went off the scale (over 50 deg C) and it took several miles of driving to get them back down again.

Its not scientific, but it gave me some clues to what's going on under the hood, and its not very nice. I appreciate everything that the tuners do, but I would not, under any circumstances, use a hot air intake. Almost ALL the air in the engine compartment has passed through the engine radiator, and gets heated up a lot. Then you put that air through another heat exchanger to cool it back down again. That doesn't make sense to me.

Nick