Looking to Supercharge, A Couple Questions

[WilliamLawlis]

Well everything isnt quite in place yet, but I convinced my parents to loan me an old beater while I get a BEAUTIFUL 2003 540/6 speed M-tech lined up (will post pics soon!).

Basically I live in the southern part of California's central valley, and it gets very hot here in the summer (105+ regularly, last year hit 118). In addition, it is 90+ degrees for a considerable portion of the year. I've heard and read from various sources that supercharging isnt really even worth the dough unless its intercooled in such warm a climate.

Is there any truth to this? I was eyeballing the VF kit but since it isnt intercooled, I may have to reconsider this whole S/C thing altogether.

If we're talking a loss of ~10 horses then I'm not worried. If its more like ~40 then I might want to reconsider this.

[nickMANDERFIELD]

40 if not more.. you need it to get a lot of cold to the charger

youll need to cool it. expect to shell

[thetinpusher]

It is true that hot outside air temps will degrade the performance of a centrifigal S/C. A couple of companies make good units for the 540 but I havent seen one yet that intercools. I am sure you could build a custom system, but this would be some big bucks......

[DocPeters540]

Please explain about the intercooling. More boost must be ran, how do the stock M62 internals hold up? Must it be fabricated? Intercooling is a complex subject. Let's explore!

[thetinpusher]

Basically if you want the best performance from a FI engine, you need to control the intake air temps (IAT). The best solution is to intercool the air going into the intake to keep it at a constant temp before injecting it into the cylinder. As IAT's rise, the ECU will begin pulling timing checks, if the IAT gets too high, the ECU will begin to retard timing to avoid cylinder detonation. If it gets really high, it will start to shut off injectors. These engines have safeguards built into the ECU to prevent engine damage and this is one of the factors that you have to consider when boosting these engines.

There are air to air systems, and air to water. All use a heat exchanger in the front of the vehicle to take hot coolant (either air or water) out of the engine, cool it and then cycle it back into the engine. Check out the Forced induction forum, there are some really knowledgable folks over there and you will learn a lot. I am no expert, but there are some that post regularly on that forum and will be a lot of help to you.

[pbonsalb]

Water injection would help. It can do as good a job cooling the air as intercooling, but only when it is spraying. It does not spray all the time because you are not in boost all of the time or in boost above the WI spray threshold of typically 4 psi. WI is not as good as intercooling in off boost and low boost driving since even under those conditions, all air still passes through the intercooler, keeping the air consistently reasonably close to ambient. Most driving will be done off boost or in low boost, so the WI will not be working and inlet air temps will be rising since the supercharger gets very hot and all air to the engine passes through it.

I think that even with WI, you would feel heatsoak in your climate. I think it would be considerable. No intercooler options appear to be available for the 540i. Custom may be possible but would probably be expensive unless you are an advanced fabricator. There are two people you might PM to ask. One is DIRT11 and the other is BigM62. Both have bored stroked supercharged 540i with intercooling, but their projects have been no expense spared (i.e., far more than the cost of your entire car).

Probably the best option is to enjoy the 540i for a couple of years and then get your parents to help you move up again to an E39 M5. In your climate, it may be the best bet.

[DocPeters540]

I envy DIRT11 and BigM62. Their projects are a distant dream for me. And I live by Rebello Racing!

[WilliamLawlis]

Hmm well this is a little disheartening...

Just an off question, how much slower is the 540 compared to the M5 from a seat of the pants feel?

I've driven both (briefly in the 540, didnt get to really wind it out at all) and am just wondering if after getting a taste of M5 if I'm going to be SEVERELY disappointed with this 540?

My main reason for going with the 540 is that this will be my daily driver, and my brother has had quite a few problems with this M5 in the past. Drivetrain problems mainly. I dont need a rocket ship, but I want something thats quite a bit quicker than my 525 :)

thanks.

[jhstealth]

I think you really need to drive a 540 first. The 540's have allot of torque and i think will give you fun for quite some time.

[e24mpwr]

I think a 540 is plenty of car for most people, and any ///M car is going to be hungrier for your wallet than you are probably able to handle if you are still in school. I'd spend money on performance driving schools before I'd start bolting stuff on what is already a fine and fast car. I've found that the biggest performance bump you can make to a car (especially in bang for the buck) is to upgrade the driver :). I've got many stories where I had the "faster" car, only to be left behind by drivers who had great skills and knew their cars well.

If you ever do go with FI, I'd also factor in the cost of upgrading the suspension, braking components, etc. to handle the performance you are adding to the car.

[DocPeters540]

There is a 105 hp difference between the E39 M5 and 540. The M5 is much faster and is by far a superior car, and they are also remarkably expensive to repair. And all of them are guaranteed to need a raft of new parts (as well as expensive repairs) as mileage accumulates. They are definately money pits. Some aren't, but that's just luck.

The 540 is the more affordable of the two. Just watch out for cooling issues. Replace the water pump, pulley, thermostat + housing, fan and fan clutch every 30k miles, and replace the radiator + expansion tank and hoses every 90k. Otherwise, BMW's version of a claymore mine will go off in your engine bay and cause $2000 in damage. Do a search, it happens all too often. Your best bet against this would be to go with all metal components (water pump, t-stat, pulley), and a Zionsville aluminum radiator (has alum. exp. tank, and an internal fan) for $1200 +. Oh yeah, the oil pump bolts can back out and cause a loss in oil pressure. Fix that also before it happens.

The M5 is much worse, but also in different ways.

About FI; you don't need to upgrade anything. It is a good idea, but you don't have to. It will perform well on a stock 540.

But, regardless, your new 540 will be leagues faster than your 525.

[5mall5nail5]

A typical VF/ESS/etc supercharger kit would be great, and then go add a snow performance water/methanol injection kit. Chemical intercooling like W/I is great - you can even add a little nitromethane and make some more power.

[thetinpusher]

Rocket pods (or JATO bottles) are always fun too:eek:

[5mall5nail5]

Dude I'll supply some THAAD missiles, cmon.

[thetinpusher]

Dude I'll supply some THAAD missiles, cmon.


Lol....

[OJwerks]

I say go VF kit with Water-Meth kit.... thats my plan if all goes well

[DocPeters540]

Haha, funny guys.

The stock hypereutectics are too brittle to handle that much power (talking nitro+FI). If you don't know what that means then you're already waiting to blow your motor.

=)

[OJwerks]

Haha, funny guys.

The stock hypereutectics are too brittle to handle that much power (talking nitro+FI). If you don't know what that means then you're already waiting to blow your motor.

=)

Who is this post referring to?

Im very positive my car handle 6psi of boost with water/methanol injection .. i doubt my pistons will disintegrate

[5mall5nail5]

I don't think the stock pistons are hypereutectic - just cast.