Single Turbo Vs pure stage 2 (Drift Car Build)

[KBM5]

Hello guys,

I am aware this subject is very widely and thoroughly covered. However most of the builds out there are drag builds of street builds pushing high horsepower.

On the other hand here I have a manual 2008 135i RWD with 180,000 KMs on it. The car is destined to be a full on drift car. I'm at the point in my build where I have to take the decisions wether to do a single turbo build or a twin turbo build. I'm looking for a healthy 550 WHP RELIABLY.

What are the pros and cons for each set up?

What set up would you recommend for a drift car?

Is port injection required at those power levels?

What other mods should go with the car to sustain this level of power?

Thank you for anyone taking the time to answer this thread and help me make this important decision.

[Skotcoop]

S65 swap. But on a serious note, if you're looking for reliability you'd probably want a single turbo and run lower boost. There are dozens of builds on here that would likely give you the information you're looking for. Or even a looking at CES or DOC racing ST kits on their sites that tell you what other supporting mods you'd need. I don't know how much different a track build would be from a drift build but check out Berno's build. https://www.1addicts.com/forums/show....php?t=1434671

[Petro135]

Last year at this time i just finished a hybrid twin installation. This year im preparing to go single turbo. The price isnt much different if you do it right. I did not buy new oil and coolant lines for my turbos, even though i used new o-rings ive been back in there fixing leaks a few times now. Which are a pain in the ass to get to. You still need the proper supporting mods for either. Fmic, upgraded pcv system, proper exhaust to let it breath, a tune or a jb4 to control everything. 3.5 bar tmap if you want to boost over 20psi. At least a double walbro bucket. Id say to guard against the misfires that are bound to pop up once you add that power. Upgraded coils, 2 step colder plugs, index 12 injectors. A good installation kit. Twins need inlets and outlets too which are separate. Single kits come with the inlet and outlet.
Oh and you realize how squishy the reat end of a 135i is once you hot the gas with that much power. Im sure drifters use a certain type of suspension setup not sure what that is but start with rsfb, diff bush, tran mounts and motor mounts.
Im going single and just ordered the doc race bottom mount kit due out next month. Its installation or changing any part can be done with the subframe in. Every part is warrantied for life. Only 1 oil line in and 1 oil line out takes away the chance of any of the 8 lines running in and out of twins leaking.
550whp is doable with either setup. In twins I believe to get there you will tax them much more. I have stg2 RB's to hit 550whp id have to run a e85 mix and push them a little harder than id like to. I keep them on 93 oct and 22psi and a single nozzle meth in the 425 whp range. But bigger twins will than mine will get you there.
Im adding PI and that has to be managed so its either a port controller or a jb4 port add on unit. 550whp you want is on the fence of needing PI. You would have to run it and log and see how your fuel is.
Either way you go if you dont do all the upgrades to everything else and handle ALL the maintenence first you will be doing it later. My turbos are barely at 5k miles in a year because of how many times my car was down to fix stuff. I normally would put more than twice that mileage in a year.
Both options are expensive. Both options have their pluses and minuses.
I know a couple drifters and both of them use single turbo setups.
Good luck either way.

[Hybrid G]

Single turbo all the way especially for a drift car.... as previous poster indicated try to stay at or below 20psi... otherwise you be fixing her more than drifting her.

[ErvGotti]

I'm in the same boat as Petro135, I have upgraded twins and the FBO, fuel pump, PR coils, and Clutch/flywheel, and I'm planning to go single. I have a small leak on my return line and it's a pita to access, they're brand new lines.

A single turbo if installed correctly especially top mount would make maintenance so much easier, especially if you plan on beating on it as a drift car. IMHO do all the preventative mx first, oil pan gasket, oil filter housing gasket, valve cover is prone to cracks, ect.. all that add up.

[ShocknAwe]

If you have a good machine shop and exhaust fabricator I recommend importing a N53 head, port matching it, and building custom turbofolds for some reliable TD04 twins. Allows for 550-650 on 93 pump.

Reliability is relative. Everything breaks if run outside its efficiency range. I was going to go bottom mount single until I read about the N53 head which finally allows twins to breathe efficiently at over 500.

[turbo v6]

Maybe you can eventually add your car to this list: https://www.roadandtrack.com/car-cul...st-drift-cars/

Or just purchase a 240sx or 350z, a lot more drift oriented and supported. Reliable???

[iminhell1]

100% stock block/head. No reason to modify. Assuming it's in good shape, compression is solid (180'ish is a good condition engine).

WHP isn't what a drift car is after. It's TQ. The better the TQ response the less clutch kick of handbrake you need to use. Less ware on parts. Less driver loss of concentration. Just makes for a better driver.

And on that, twins. The faster spool and faster TQ punch is what you really want. The problem is all the heat. Coat, wrap, sleeve everything. As long as there's air moving that heat away you shouldn't have any big issues.

Tune so you cut power based on oil and coolant temps (yes it can be done on stock ECU). Stock the oil temp is too high IMO.

The basic path of FBO is a good base. Big intercooler, upgraded radiator, oil cooler/thermostat. Cooling is the car's downfall.
You being manual, you're going to have to think about clutch heat also. That area is where all the heat centralizes. Vents in the hood that push air down the firewall past the trans, might not be a bad idea.
Or if you do a rear mount radiator might also help. not sure how extreme you're thinking of going here.

On the fuel side, you'll want one of those Spool Helix or PFS Pod HPFP overdrives. You'll be taxing the stock pump heavily and be at it's limit. Spin it faster and you've got more room for error. Injectors and whatnot will be fine if in good shape. Get the stockers cleaned/flowed just for piece of mind.

Ignition, Eldor coils or the B58 coils. Don't need anything super fancy.
I personally like the S55 BMW plugs.


When you do the cage, mind the fuel and brake lines. This chassis and the cages available are junk. The plate behind the driver is right over the fuel and brake lines. Not a point you want to skimp on or underplate. Protect that area well. Overplate it.