[shaneguags]

Hey guys, 4 months ago I bought an M2 that came with a stage 3 Speedtech big turbo kit. The kit currently is running a Borgwarner 8374 turbo and seeking help for what to do for power.

I'm pretty new to having a big turbo and funny enough I bought the car without knowing it came with an upgraded turbo. This week I had maintenance done to fix my boost issues. I had my local shop (ACI Dynamix) fix and weld the waste gate bracket on properly and reroute the tubing. I am still dialing down on the performance and making sure I am FBO before pushing higher PSI. However, I am still not educated about fueling upgrades. As of now, I am on a custom MHD stage 2 conservative tune with pretty much FBO minus intercooler, charge pipe, and boost. Since my car is already at the shop, this week I plan on getting the FTP charge and boost pipe paired with a 5.5 CSF intercooler installed ASAP before I leave for college. As well, I am going to get a custom MHD retune tune by my local shop (ACI Dynamix) to up the boost. However, for now since I don't have upgraded fueling, I was wondering if anyone had a rough idea of what the max crank hp and torque I can achieve with 93 pump gas on stock fueling with the upgraded turbo I'm running ? I would run mix fueling but unfortunately the closest gas station with e85 near me is 50 minutes and not easily accessible for me using the car as a daily.

I plan on adding more power next summer when I come back from college but unsure what route to take. I'm looking for roughly 500-600 crank hp max as it is a daily. As well, I'm looking for the most inexpensive route. I obviously want to have fun by increasing the boost but I don't want to go crazy. I was recommended port injection and a lpfp upgrade but like I said as of now I am unsure what route I want to take. If anyone has any suggestions on what to do it would really help a lot !

Current performance mods currently installed :

- Speedtech N55 BMW M2 with Borgwarner 8374 Turbo Kit

- FI-Exhaust with titanium tips and catless downpipe

- Eventuri V1 blue kevlar open box intake

- MHD Stage 2 custom tune

[ZM2]

I’m guessing around 430whp on the stock HPFP.

[shaneguags]

Originally Posted by ZM2

I'm guessing around 430whp on the stock HPFP.

so roughly 500 crank ? what setup would I have to run though ?

[ZM2]

Originally Posted by shaneguags

so roughly 500 crank ? what setup would I have to run though ?

Pick your poison.

No matter what you put on the car you’ll be limited by the stock HPFP and will have to custom “detune” to keep HPFP drop outs from happening. Kinda pointless to spend money on tuning without a larger HPFP.

If you put on a larger HPFP and then custom tune, I think you’d hit 450whp on 93 with a Stage 3 setup, while staying conservative enough for summertime IATs and pump gas. But then you’d also be set for E85 mixes, racegas, and higher boost in the future.

The Stage 3 guys should chime in on all this tho.

[AmuroRay]

Skip on the intake, it’s a worthless sound generator, and consider a bigger intercooler (contingent on region and planned boost)

But if you plan on running E85, you’ll want a Stage 2 HPFP, with your stock pump, expect 430-450whp and pump gas

[detroitm2]

Wait, so you bought an M2 with a stage 3 turbo and zero supporting mods?

Hopefully whoever did the install knew what they were doing, because whoever decided to go that route probably had zero clue.

You should be FBO before even thinking about the turbo.

Your horsepower question was already answered above, and I'll echo the sentiment that fueling will be your number 1 limiting factor. You absolutely need a stage 2 HPFP if you want to be able to push that turbo. XDI, Dorch, or Nostrum. All good options. Port injection is also an option, but the main reason you see a lot of N55s going that route is that there wasn't many HPFP options up until the last couple years. With what we have today, I'd recommend going with an HPFP before messing with port injection.

If you decide to upgrade the LPFP as well, keep in mind that the oem EKP module is prone to overheating on higher power pumps. An after market solution exists, but it's not cheap. I found that the Walbro 485 unit I run seems to be fine with the OEM EKPM, but there are reports of people nuking theirs when running the larger Walbro pumps.

The last thing in the fueling chain is injectors. If you're not running E85, it's probably not needed. But during some pump testing we did, we did notice that the OEM Bosch injectors had a hard time keeping up with upgrading pumps on full E85. The only aftermarket injectors I'm aware of are by Nostrum, and that's what in running in my car (their Stage 1 S55 injectors). There's a few other guys on here using OEM injectors from other engines that have had good results, and I believe Dorch has some in the works as well. But this likely won't be a huge concern until you get all the above taken care of (and are running a high concentration of ethanol).

Hope this helps!

[shaneguags]

Originally Posted by AmuroRay

Skip on the intake, it’s a worthless sound generator, and consider a bigger intercooler (contingent on region and planned boost)

But if you plan on running E85, you’ll want a Stage 2 HPFP, with your stock pump, expect 430-450whp and pump gas

I already bought an intake which is fine but okay yea that's roughly what I'd be looking to get power wise

[shaneguags]

Originally Posted by detroitm2

Wait, so you bought an M2 with a stage 3 turbo and zero supporting mods?

Hopefully whoever did the install knew what they were doing, because whoever decided to go that route probably had zero clue.

You should be FBO before even thinking about the turbo.

Your horsepower question was already answered above, and I'll echo the sentiment that fueling will be your number 1 limiting factor. You absolutely need a stage 2 HPFP if you want to be able to push that turbo. XDI, Dorch, or Nostrum. All good options. Port injection is also an option, but the main reason you see a lot of N55s going that route is that there wasn't many HPFP options up until the last couple years. With what we have today, I'd recommend going with an HPFP before messing with port injection.

If you decide to upgrade the LPFP as well, keep in mind that the oem EKP module is prone to overheating on higher power pumps. An after market solution exists, but it's not cheap. I found that the Walbro 485 unit I run seems to be fine with the OEM EKPM, but there are reports of people nuking theirs when running the larger Walbro pumps.

The last thing in the fueling chain is injectors. If you're not running E85, it's probably not needed. But during some pump testing we did, we did notice that the OEM Bosch injectors had a hard time keeping up with upgrading pumps on full E85. The only aftermarket injectors I'm aware of are by Nostrum, and that's what in running in my car (their Stage 1 S55 injectors). There's a few other guys on here using OEM injectors from other engines that have had good results, and I believe Dorch has some in the works as well. But this likely won't be a huge concern until you get all the above taken care of (and are running a high concentration of ethanol).

Hope this helps!

thanks man this was super informative and helpful I really appreciate the detailed response ! so to get this straight, only a hpfp would be needed if I wanted to ramp the power easy and a lpfp upgraded might be needed down the road but not necessary ? Also, I only plan to stick to pump so I think injectors will be staying the same.

[shaneguags]

Originally Posted by ZM2

Pick your poison.

No matter what you put on the car you'll be limited by the stock HPFP and will have to custom "detune" to keep HPFP drop outs from happening. Kinda pointless to spend money on tuning without a larger HPFP.

If you put on a larger HPFP and then custom tune, I think you'd hit 450whp on 93 with a Stage 3 setup, while staying conservative enough for summertime IATs and pump gas. But then you'd also be set for E85 mixes, racegas, and higher boost in the future.

The Stage 3 guys should chime in on all this tho.

so basically if I just got dorch hpfp and complete being FBO I'd be okay to ramp boost and nothing else would be needed ? 450WHP would be more than enough to satisfy me to be totally honest

[detroitm2]

Originally Posted by shaneguags

thanks man this was super informative and helpful I really appreciate the detailed response ! so to get this straight, only a hpfp would be needed if I wanted to ramp the power easy and a lpfp upgraded might be needed down the road but not necessary ? Also, I only plan to stick to pump so I think injectors will be staying the same.

Yup. Unless you're doing port injection or high levels of ethanol, the oem LPFP is generally fine.

HPFP and complete FBO. get yourself a custom tune.

On that topic, it might be worthwhile to hook up a flex fuel sensor while you're doing all this. And then getting yourself a flex fuel tune.

That will allow you to run regular 93 pump gas, all the way up to full ethanol on occasion if you'd like.

Bend Calibration makes a nice flex fuel kit with a nice mounting bracket and high quality filter. It's pricey, but we'll worth it. They can also do your custom tune if you'd like. They're arguably one of the best tuners around for the N55 platform.

[detroitm2]

Originally Posted by shaneguags

so basically if I just got dorch hpfp and complete being FBO I'd be okay to ramp boost and nothing else would be needed ? 450WHP would be more than enough to satisfy me to be totally honest

With FBO mods and HPFP, you'll be able to easily push close to 500 on pump gas. Over 500 on E85.

[shaneguags]

Originally Posted by detroitm2

Yup. Unless you're doing port injection or high levels of ethanol, the oem LPFP is generally fine.

HPFP and complete FBO. get yourself a custom tune.

On that topic, it might be worthwhile to hook up a flex fuel sensor while you're doing all this. And then getting yourself a flex fuel tune.

That will allow you to run regular 93 pump gas, all the way up to full ethanol on occasion if you'd like.

Bend Calibration makes a nice flex fuel kit with a nice mounting bracket and high quality filter. It's pricey, but we'll worth it. They can also do your custom tune if you'd like. They're arguably one of the best tuners around for the N55 platform.

okay awesome ! personally, I think I'll stick to pump for now just to see how things go. if I do end up getting the hpfp upgrade, do you think a bigger intercooler may be needed ? I was told 5.5 is too small and that it's fine to run. not really sure who to trust. people keep saying to get the evo 3 but if I'm not looking to push that crazy amount of power, I don't see why the 5.5 won't work

[shaneguags]

Originally Posted by detroitm2

With FBO mods and HPFP, you'll be able to easily push close to 500 on pump gas. Over 500 on E85.

okay yea that's perfectly enough for me. I wasn't looking to even have that much😂 that sounds like the plan to me then !

[detroitm2]

Originally Posted by shaneguags

okay awesome ! personally, I think I'll stick to pump for now just to see how things go. if I do end up getting the hpfp upgrade, do you think a bigger intercooler may be needed ? I was told 5.5 is too small and that it's fine to run. not really sure who to trust. people keep saying to get the evo 3 but if I'm not looking to push that crazy amount of power, I don't see why the 5.5 won't work

I'll push that question off to someone who knows more about intercoolers. I personally run a CSF bit I also do not run a stage 3 turbo. I know that bigger isn't always better.

[shaneguags]

Originally Posted by detroitm2

I'll push that question off to someone who knows more about intercoolers. I personally run a CSF bit I also do not run a stage 3 turbo. I know that bigger isn't always better.

yea I mean my shop said 5.5" is fine and other people are seeming to agree as well but then they are saying once I get the hpfp, I pretty much need the 6.5" - 7.5" FMIC which I'm not sure if that is exactly true. if that's the case though, I wouldn't see why I would want the 5.5" if I'm just switching it out later and spending more money

[boldy1]

i run a stage 3 turbo and the wagner evo 3 is an upstanding cooler and the one i use its more expensive than some but come complete with new charge and turbo pipes

[shaneguags]

Originally Posted by boldy1

i run a stage 3 turbo and the wagner evo 3 is an upstanding cooler and the one i use its more expensive than some but come complete with new charge and turbo pipes

don't you have to cut the brace and take it out tho ?

[boldy1]

Originally Posted by shaneguags

don't you have to cut the brace and take it out tho ?

i changed the brace with a 235i wordes and im getting air guides made for the bottom section. the evo 3 is the perfect cooler for a stage 3, i had the csf before this and the wagner is better

[shaneguags]

Originally Posted by boldy1

i changed the brace with a 235i wordes and im getting air guides made for the bottom section. the evo 3 is the perfect cooler for a stage 3, i had the csf before this and the wagner is better

I mean if I run just CSF 5.5" with just a hpfp upgrade am I fine or will that do bad to the car ? because dropping another like $1k on an intercooler really going to kill my wallet 😅 also, it just seems like a pain to do all that extra stuff. according to nvmotorsports in the UK they ran a stage 3 upgraded turbo with stock fueling, no meth, and achieved 453bhp and 670nm with I think CSF's but they didn't specified whether they upgraded or not. He said the intake were fine however those numbers were the stock limitations. With the stage 2 hpfp he ran meth and achieved 625bhp and I think he used the same intercooler 😳

[shaneguags]

Originally Posted by boldy1

i changed the brace with a 235i wordes and im getting air guides made for the bottom section. the evo 3 is the perfect cooler for a stage 3, i had the csf before this and the wagner is better

Stage 3 big turbo dyno video link :

[boldy1]

Originally Posted by shaneguags

Stage 3 big turbo dyno video link :

I know the car and been to the tuning shop, the evo 3 is a better cooler for a full frame. i have had both and 3 different turbos on my car

[shaneguags]

Originally Posted by boldy1

I know the car and been to the tuning shop, the evo 3 is a better cooler for a full frame. i have had both and 3 different turbos on my car

do I need the evo 3 with just a hpfp though ? seems a bit extra for that setup