Supercharging your ///M - who's on the fence

[flat_out]

Just wondering how may out there are still on the fence with regards to installing these kits to their cars. I'll admit despite someone that finishes his blessings with "N/A all the way!!! " - stats don't lye and one can clearly see the $$/bhp returns this kit brings (450 or 500hp).

I'd be keen to hear from those that have gone down this route and mainly use their cars on track.

My main concerns would be

(1) durability on track, how many track days have you done and what issues have you encountered if any

(2) Do you get consistent power figures especially when the engine gets hot over a dozen or so laps

(3) Does the VT1 suffer from heat soak given the fact that they don't come with an intercooler.

(4) How much weight does this kit add to the font of the car - just concerned about a nose heavy car (could always use the sand bag option to counter this )

Any videos on track will be useful - most i've seen seem to be short clips which don't really give a good feel of the cars characteristic change over longer tracks..

[ZStig]

1. Member Beedub has done several track days, and so has ESS, with zero issues on the kit
2-3. The vt1 will suffer from a bit more heatsoak, the vt2 heatsoaks much less. A colder climate like the UK means its even less noticeable. The car feels significantly faster or slower as temperatures rise and drop around you. To counter-act this, some have installed water/meth injection kits. Tuning may be an issue with it, if you have an 8psi pulley it will pull timing up top according to ONE person.
4. I believe it adds about 60lbs, but it does not feel heavier in the front.

Look into the engine mods sub-forum, I have a long thread, and so does Beedub, Fr8dog, and Iphoneegineer

by the way, the kit can be a BITCH to install, so don't have any cheap shop do it

[SmartBastard]

Great thread, I'm totally on the same page, the only difference is that I'm considering G-Power instead of ESS.

[Jumbosock]

Sounds like a potential headache. Definitely would never consider it!

[ZStig]

just like a hot girl, its worth the work

[JFB06M]

The VT2-500 kit was not cheap, but still think very good bang for your $$$...plus you still have a very nice car to drive every day.
I do not track my car, but I drive it hard.....and it is so much more fun with the SC. I also take my wife on Sunday drives along the river and stay at the speed limit.....something she never did with me when I had a Viper.
I now have 1200 miles since install and have had zero issues. All the stock parts and bubble wrapped in my garage and I can restore to stock at any time.....but that time is not going to happen in my lifetime.

[Beedub]

ive had stage 1 and 2 ess kits, one of the few people to do it that way, ive also had extensive time with the kits and perfecting the install to imo... as close as factory type install as possible, ive even gone to the effort of upgrading all the ESS hosing, moved things, moved things again and now i think my install is near perfect, yes it does take time BUT... how satisfying it is to get right, my shop, simpson motorsport were nothing short of astounding but the install wasnt simple or cheap by any means.....

the car itself behaves just like the stock car, just a graph higher up, in our uk climate i see some serious power from my VT2-500, ive tracked the car intotal maybe 7-10 times between the vt1 and vt2 kits and my car is just alive, the only issue is other bits soon need upgrading, the brakes definatly need doing....

all in all my vt2 will never be sold, so much fun, the s54 with boost is just a thing of beauty and that gigantic and i mean gigantic vortech v3 unit isnt even lightly stressed in this application, the sound, the performance, cooling, the drive, everying for me has been bang on....

i can cut loose my pss in the first 2 gears all the way to redline...... so much fun hearing the the tyres screaching as your accelerating, vt2 makes the z4m a mini supercar, honestly????? for most the vt1 is more than enough and i would definatly recommend starting at that point....

[iPhoneEngineer]

So, I've had more problems with my VT2-500 install than anyone else I've heard about, but I'm still pretty positive on it. My car is currently down about 2PSI on boost and dyno's 390RWHP--about 440 crank. It's quite like VT1-445 power with an intercooler.

- VT1 vs VT2: I only briefly considered the VT1. As an engineer, I was concerned enough about adding a supercharger to a motor that comes stock with one of the highest compression ratios used on a non-direct-injection gasoline engine--the same one that has the 4th highest piston speed at redline of any production motor. In addition to the intercooler, the significantly enlarged oil cooler that comes with the VT2 was a significant priority for me. Despite these measures the car still runs a bit hotter than it used to--and it's not even at full boost--so I'm glad I skipped the VT1. The VT1, to me, feels like it cuts some important corners just to be cheaper. This is an inherently big modification and needs to be done right.

- Drivability/character of the car: surprisingly close to stock, but not stock. The load of the S/C on the engine makes engine-drive deceleration noticeably more significant. The exhaust will pop in certain scenarios because the system operates without an air flow meter. Power delivery ramps up in a noticeably different way since boost rises directly with RPM, but at least is consistent, unlike a turbocharged car (I drove a 335i loaner car recently and am surprised BMW even supported such an unwieldy motor).

- If your main purpose for the car is the track, I would have some reservations about this kit. There are people who use them extensively on the track but long-term reliability figures are lacking, and I can't imagine pushing 5-7PSI at 5,000-8,000RPM for an extended period would /not/ be very difficult on the motor. I have tracked my car before the kit but not after. I won't hesitate to do so maybe twice a year, but it is not a primary goal of this car for me. That said, I have an absolutely ridiculous daily commute (2,000ft altitude change on some of the most windy mountain roads I have ever driven) and routinely push the car to its handling limits, while keeping the engine usually in the 3k-5kRPM range (usually full throttle when accelerating). I get about 16MPG, similar to Roffle Waffle in city driving, even though I'm rarely idling.

- Weight addition was not noticeable to me. Put in a lightweight battery and replace the driver's seat with a racing one and you'll have made up the difference (though not the distribution, sure; I chose to reduce the stock stagger by putting 245 tires in front and 265 in rear).

[djlogan33]

I would a S52 ///M engine, but not a S54 ///M engine.

I have owned ///M cars with both engines.

The S52 engine is almost bullet proof.
The S54 engine has had a lot of problem, especially in the early years.

[cmark8]

I would definitely do it, but I would rebuild the engine to run lower compression then boost it up even more. If you're gonna boost on a budget, then don't boost. If possible, I would even run e85, like HPF folks are starting to do right now with the ProEFI.