[Tomball335is]

Hello all,
First post here, although I have been on a lot of the 335i Facebook groups.

I need some help choosing the right turbo upgrade. I’ve done years of research, and still can’t decided on what to get.

Let me give you a little backstory on my n54 platform experience.

I purchased an 08 e92 335i from a small mom and pop dealership back in Nov 2017 with cash. Long story short, they didn’t legally own the car (wrote a hot check to the auction and never paid up), and never got the title or the plates. I sued them, and just recently won my lawsuit (yes, a whole two years later). I won 4x the purchase price. And, in Texas, dealerships are required to carry a $25k surety bond, which is similar to insurance, but to protect the consumer from shady activity by dealerships, so I actually got paid., and get to keep the car. My original plan for the car was to be a weekend single turbo car pushing 700whp, but I never got around to that because of the lawsuit and not knowing what was going to happen to the car. I built the car to FBO, with a stage 2 lpfp, before realizing there was a title issue.

Out of the lawsuit, I get to keep the car, but will never be able to register it. My plan for the car is to sell it after stripping off none, some, or all of the FBO pieces, depending on my current build.

I just purchased a 2012 e93 335is DCT in LeMans Blue a few weeks ago. She only has 29k miles on her, and I’m itching to start building.

My goal is 600+whp, that can be daily driven 30-40k miles a year. E85 maps are fine, since there are locations all around my area.

I’m having a real hard time choosing between turbo kits, including ST kits and upgraded twins.

My budget is $5k, give or take (told the fiance I would only be spending about $4k). I will be performing the work myself. I can pull some parts from my old car such as FMIC, charge pipe, BOV, LPFP, downpipes, etc to help cut costs down. But keep in mind, the more I pull from that car, the less $$$ I’m going to get when selling it. Selling that car is going to help fund my upgraded turbo build. I’m estimating I can get about $3k for it. It’s an 08 e92 6spd with 129,000 miles, FBO, full exhaust, M3 bumper. Body is straight, engine + trans is good, runs and pulls hard with no issues currently other than a faulty wheel speed sensor. Does the $3k figure sound about right for a car with no title?

I realize the ST kits will be better for reliability, and much easier to change out the turbo should anything ever happen to it. And will obviously make more power than twins, and also be a bit easier on the DCT, since it is low end torque that gets to them. But the DocRace kit is just out of my price range.
The on3 kit with upgraded WG, BOV, and turbo would be good, but last I heard they were back ordered on a few pieces (downpipe, and WG dump I believe?). Does anyone know if these are still backordered?
I’m also looking at the SpeedTech ST kit, but have not seen much of any reviews or user experiences with it, which worries me. Any other ST kits on the market I’m leaving out? I won’t consider JPworks or YouWish.

As for upgraded twins, I have not heard good things about them in general for long term reliability. MMP is literally less than a mile away from my home, but again, I have not heard good things. The lower prices of these units, easier install, and OEM drivability is attractive through.

Talk about longer term reliability, if you have experience with it please. Most of the time I see people talking about how their tubs ahve been holding up great, but they're always sub 10k, or 20k miles.

Most important things to me;
1. reliability
2. staying around $5k
3. not waiting 6 months for a kit (I’ve already waited 2 damn years)
4. making 600+whp

Any guidance would be fantastic. I am planning on starting to order parts towards the end of August.

Attached below is my new 335is, my e92 that I discussed above, and my Model S 60.

[hellokitty]

A fellow E93 335is owner woohoo.

Depending on whether you can wait, doc race was discounting their kit $500 a few weeks ago. Next sale would be for Black Friday.

I like the idea of a single turbo but pure released their Pure 600 turbos which are swaying me since you can get them for under 2k at n54 tuning dot com.

My goal is probably 575 whp / 550 wtq to keep the dct happy. Don’t feel like dropping another few grand on SSP clutches haha.

[hellokitty]

Oh yeah, I’d factor in the new spool performance helix overdrive kit - add another $850 or so to cover your fueling setup. Kit will be coming out soon.

[Tomball335is]

Originally Posted by hellokitty

Oh yeah, I’d factor in the new spool performance helix overdrive kit - add another $850 or so to cover your fueling setup. Kit will be coming out soon.

I was considering buying that. Been reading up on the real long thread about it here. I think that, with the LPFP will be more than enough to support my fueling needs without having to go full on PI.

[hellokitty]

Originally Posted by Tomball335is

I was considering buying that. Been reading up on the real long thread about it here. I think that, with the LPFP will be more than enough to support my fueling needs without having to go full on PI.

What fuel will you be using? I’d check out the helix thread on spool street for more information.

[tisdrew]

Go single 100%

[Jeff@TopGearSolutions]

Consider putting Pure Stage 2's on your list.

[mweisdorfer]

You could easily be under $3900.00 if you went with RB EVO 19T's. That price includes an install kit, inlets, outlets, upgraded to the already upgraded wastegate, and upgraded PCV Valve & cap. If you pay him by check or cashiers check, he will knock off $300.00 off the price. The EVO 19t is his top of the line turbo set.

RB was one of the original pioneers on the N54 platform when talking about turbo upgrades.

Needles to say, there's no substitute for experience.

Once I get to the point, and I think I'm maybe a year away, I'll be getting RB's. I'm still on original turbos 168,000 miles in. 😉.

[Aceway]

I've had the speedtech kit on my 335i for around 11k miles. Communication was very good and I got the kit within the promised turnaround time. Most of the miles I've driven was on pump pushing around 500 whp. Just recently started running 100% e85 and now pushing around 700 whp. Had a 135i before with VTT stage 2+ for around 10k miles.

Personally, I'd recommend single turbo for your setup. Reason is there's a lot more low end torque from twins and my experience with BMW DCT's, they don't last very long when you push a ton of torque. Your clutch packs will be toast within a year if you plan on pushing 600hp daily driving 40k miles a year. I'm not sure how heavy your foot is on the throttle though so maybe you'll have different experience. Budget for single turbo for you would probably be around 5500-6000 depending on how you source items. From what you say you already have seems like you'll need port injection/helix hpfp, stage 3 lpfp, upgraded fuel lines at the minimum.

With upgraded turbos on these engines, I've come to learn that so many things break and can be a huge headache sometimes. Restricting your budget to 5k and chasing more than 500 whp on a daily will be very difficult.

[hellokitty]

Originally Posted by Aceway

I've had the speedtech kit on my 335i for around 11k miles. Communication was very good and I got the kit within the promised turnaround time. Most of the miles I've driven was on pump pushing around 500 whp. Just recently started running 100% e85 and now pushing around 700 whp. Had a 135i before with VTT stage 2+ for around 10k miles.

Personally, I'd recommend single turbo for your setup. Reason is there's a lot more low end torque from twins and my experience with BMW DCT's, they don't last very long when you push a ton of torque. Your clutch packs will be toast within a year if you plan on pushing 600hp daily driving 40k miles a year. I'm not sure how heavy your foot is on the throttle though so maybe you'll have different experience. Budget for single turbo for you would probably be around 5500-6000 depending on how you source items. From what you say you already have seems like you'll need port injection/helix hpfp, stage 3 lpfp, upgraded fuel lines at the minimum.

With upgraded turbos on these engines, I've come to learn that so many things break and can be a huge headache sometimes. Restricting your budget to 5k and chasing more than 500 whp on a daily will be very difficult.

How is the fitment of speedtech? Seems like a much simpler design. Price isn't bad either.

[Aceway]

Originally Posted by hellokitty

How is the fitment of speedtech? Seems like a much simpler design. Price isn't bad either.

Fitment was good, everything lined up. The space down there is really tight for a bottom mount though. Took a lot longer to install than the twins. There's a lot more feedback on the Speedtech kit on the other forums.

[nicky dj]

If the DCT clutches wear out that quick with 600hp, how the hell does the 6AT hold up with upgraded turbos...?

[RnmEvo9]

6at will become a maintenance item with that much power (replace it when it starts slipping or swap to 6mt for reliability)