Q: Bottom Mount Single Turbo Responsive Setup


Dec 2, 2019
Sure, here are a couple. They're not the cleanest, but they're the best I could find in my mountain of saved logs. I'd go out and grab a few better ones for you, but sadly my tires are showing cords, so it'll have to wait

3rd gear:

4th gear:

No worries, that is perfect, thank you! Looks like good 500RPM slower spool, but probably a ton more airflow.
What AR were you running on that log? 18 psi at 3.1k rpm is absolutely awesome for a ST.

This is 0.83 T3 divided. It's definitely responsive and fun to beat around town. Will see how it feels with E85!


Jun 17, 2018
TBH, I don't know why you're looking at swapping to a single. Mildly upgraded twins will fit your requirement much better and give far better transient. Also there is far more of a tuning base history as well as being lower cost of entry.
These engines are not spinners. The low grunt is where they excel. Use that.
  • Agree
Reactions: langsbr


Aug 17, 2017
Somerville, Ma
07 bmw 335i
I am running the ces motorsport bottom mount kit with garrett gtx4088 turbo on full e85. Car has no/to little lag tuned by @V8bait. I have seen many n54 single turbo cars and you need to get close to 4k rpm to wake the car up or to start spinning the tires. I run 315 size tires in the rear and car rips as soon as you get on the gas pedal. Unfortunately i can’t provide with good data as my built motor that i ordered from Ghassan never ran good from day one, smoked like a chimney and cylinder two fills with oil on idle. It has tons of correction so i never went past 20psi so i don't grenade the motor. Motor will be sent to a real engine builder @Billiam and will get fixed pretty soon.

In my opinion if you want a daily single turbo you need to get a bottom mount twinscroll (manifold and turbo) to enjoy the car. For drag race you can always use a nos shot to wake the turbo up on top mount setup.
  • Informative
Reactions: Torgus