New Single Turbo Kit for the S55 (4N Motorsport)

[rnguyennnn]

Originally Posted by calcio

Trying to figure out where is this company located? Also interested in finding out what proven track record this company has.

This seems promising as I was looking at purchasing KRATOS kit.

I have been following this personally before it went public and i will admit that Mike at 4N has been very honest regarding the turbo kit and his knowledge on the platform itself.

For what it’s worth, i hope this takes off so that the platform can grow. Given the price point and being able to run almost any turbo you want, i would go with this kit over any other twin setup that isn’t a hybrid.

[acdf326]

wow i don't know what to get now. PS2+ or this single... Is anyone else running it? I would like to know how reliable it is

[Kilabyte]

Originally Posted by acdf326

wow i don't know what to get now. PS2+ or this single... Is anyone else running it? I would like to know how reliable it is

I'm curious to find out how much the driveability changes by switching from twins to a single.

[jpy1980]

When you guys mention driveability, what are you referring to? The lag? Isn’t driveability dependent on the tune?

[aBMWfan]

Originally Posted by acdf326

wow i don't know what to get now. PS2+ or this single... Is anyone else running it? I would like to know how reliable it is

If you’re interested in PS2+ let me know, thanks

[Kilabyte]

Originally Posted by jpy1980

When you guys mention driveability, what are you referring to? The lag? Isn’t driveability dependent on the tune?

Yes, lag, powerband for daily use, etc

[4N Motorsport]

Drivability is not an issue. Since it is twin scroll and uses a ball bearing turbo there is hardly any lag at all the Turbo begins to spool 2800-3k RPMs climbs over 600 foot pounds of torque at 3800 and hits peak torque at 4800.

[ntg44]

Originally Posted by 4N Motorsport

Drivability is not an issue. Since it is twin scroll and uses a ball bearing turbo there is hardly any lag at all the Turbo begins to spool 2800-3k RPMs climbs over 600 foot pounds of torque at 3800 and hits peak torque at 4800.

Thanks for the numbers, but that has nothing to do with turbo lag, it's just the torque curve. Poster was asking about from the time you mash the throttle in a given RPM to the time it takes to get to full boost vs the stock TT configuration.

Your product is exciting, just trying to clarify the question

[4N Motorsport]

Stock TwinTurbo typically hits full boost around 3000 RPMs this kit is hitting full boost around 3800 rpms. However at 3000 rpms I am still getting 15-20psi. At 3800 rpm's there is no lag it is instantaneous as soon as you mash the throttle the turbo spool's instantly. I will actually be increasing the A/R of the turbo for testing to actually slow the spool up down a little bit and increase peak horsepower. I'll compare logs and horsepower/torque graphs with the larger A/R.

[Ropes]

The twin scroll will combat the lag of a mono scroll. It should be similar to an upgraded n55 turbo.

[calubi]

Wow... I want to see this setup on a flex fuel tune... That would be one hell of a fun street car.

[Spun Pornhub]

You guys will need to be more specific with what kind of turbo lag you guys are inquiring about. For starters, turbo spool and throttle response are two different things.

Cruising in 4th gear at 3,000 rpm and expecting instant boost hit with a single turbo would probably be unrealistic. But if you're shifting from 1st through 4th then expect little to no lag in the middle gears. I drove a PS2 high flow car with a fully tapered low end torque to help preserve the factory rods. That car had a highly noticeable amount of delayed throttle response/boost impact for comparison.

600 ft/lbs torque at 3,800 rpm is a sure path to killing the factory connecting rods on most modern BMW engines. I know I'm preaching to the choir, but those who are seriously considering this route should have at least a built bottom end.

[ntg44]

Originally Posted by illmatik

You guys will need to be more specific with what kind of turbo lag you guys are inquiring about. For starters, turbo spool and throttle response are two different things.

Cruising in 4th gear at 3,000 rpm and expecting instant boost hit with a single turbo would probably be unrealistic. But if you're shifting from 1st through 4th then expect little to no lag in the middle gears. I drove a PS2 high flow car with a fully tapered low end torque to help preserve the factory rods. That car had a highly noticeable amount of delayed throttle response/boost impact for comparison.

Call me old school, but to me throttle response is the time it takes from changing the throttle position on the pedal, to the engine responding to that change in throttle position. Nothing to do with turbo lag or spool at all.

Turbo lag to me is always: Pick an RPM, any RPM, where the turbo makes power. While cruising, not on boost, floor it. The time from you mashing the gas pedal to the time the turbos achieve the target boost for that RPM is turbo lag.

I was asking for a comparison of my definition of turbo lag of this single turbo kit vs. stock. This to me is the most accurate definition of "lag", because everything else is just the torque curve. Lag has nothing to do with the dyno chart or as far as I'm concerned. They're different measurements.

Really don't want to make this a turbo definitions thread, but my clarification is relevant to the discussion of this kit, and I think consumers would want to know.

[4N Motorsport]

I'll make some videos to post on here so you guys can see the spool time and throttle response. Like I stated before at 3800 rpms cruising then stomping on it there is little to no lag maybe 1.5 seconds. The turbo hits peak boost set point extremely fast. Now if you stomp on it at 3k rpms it is less responsive but it does spool up fairly quickly maybe 2 seconds to about 15-20psi at 3k rpms. The A/R change will be to help reduce torque at lower rpms and increase peak hp. Also just so you guys know my internals are 100% stock just a max psi crank hub. I'll be pushing it well into the 8xxhp range. 600ftlbs torque at 3800rpms isn't an issue at all. If you guys are concerned about that it can be brought down with a larger A/R and tuning as well.

[4N Motorsport]

https://www.instagram.com/s/aGlnaGxp...16663057213443



Here is a quick video I saved from a story I posted. The second video in you'll hear me let off then jump back on it will give you an idea how fast the transient response time is. If you watch the MHD data logger on the first video you'll see it turn red that is when I initiate full throttle.

[Spun Pornhub]

Not throwing any shade, because a smaller set of hybrid twins exhibit similar turbo lag characteristics. But from a racing or spirited driving perspective, 1.5 to 2 seconds lag equates to a difference of 15-20 car lengths. Also just stating the obvious that it's not possible to brake boost with a DCT.

Things would be a whole lot different if EcuTek could somehow maintain the spool through an external PWG similar to how the BMW engineers have things configured with the factory EWG:

https://f80.bimmerpost.com/forums/sh...d.php?t=975864

So what are the differences between the EFFICIENT, SPORT and SPORT PLUS modes?

In the SPORT and SPORT PLUS modes, the waste gates remain closed under partial load and the mass flow is routed through the turbines, to ensure that the turbo chargers are already rotating at a higher base speed even in standby. Moreover, certain special engine control functions are brought into play that accelerate activation of the turbo chargers. This means that the car responds more closely to the accelerator in SPORT and SPORT PLUS modes.

To 4N, you guys are running into every known limitation on the S55 when it's not necessary. First it was the LPFP, followed by SCH. I have a feeling if you guys don't find a more experienced S55 tuner soon, then the connecting rods will go next.

[4N Motorsport]

Originally Posted by illmatik

Not throwing any shade, because a smaller set of hybrid twins exhibit similar turbo lag characteristics. But from a racing or spirited driving perspective, 1.5 to 2 seconds lag equates to a difference of 15-20 car lengths. Also just stating the obvious that it's not possible to brake boost with a DCT.

Things would be a whole lot different if EcuTek could somehow maintain the spool through an external PWG similar to how the BMW engineers have things configured with the factory EWG:

https://f80.bimmerpost.com/forums/sh...d.php?t=975864

To 4N, you guys are running into every known limitation on the S55 when it's not necessary. First it was the LPFP, followed by SCH. I have a feeling if you guys don't find a more experienced S55 tuner soon, then the connecting rods will go next.

If you watch the video link I just sent above you'll see how fast the transient response time is. I have never measured it. Me stating 1.5 seconds was just a guess but watch the video above and you'll see. My car is apart otherwise I would get that information for you. I have been data logging and pushing this car for over four months above 600 foot pounds of torque with no issues. I agree the low pressure fuel pump should've been dealt with early on. I knew about the crank hub issue just wanted to see how far I could push the stock hub. wedge performance tuning has done an amazing job on this car and will continue to do so.

[4N Motorsport]

Originally Posted by illmatik

Not throwing any shade, because a smaller set of hybrid twins exhibit similar turbo lag characteristics. But from a racing or spirited driving perspective, 1.5 to 2 seconds lag equates to a difference of 15-20 car lengths. Also just stating the obvious that it's not possible to brake boost with a DCT.

Things would be a whole lot different if EcuTek could somehow maintain the spool through an external PWG similar to how the BMW engineers have things configured with the factory EWG:

https://f80.bimmerpost.com/forums/sh...d.php?t=975864

To 4N, you guys are running into every known limitation on the S55 when it's not necessary. First it was the LPFP, followed by SCH. I have a feeling if you guys don't find a more experienced S55 tuner soon, then the connecting rods will go next.

You can brake boost with a dct from a rolling start. I'm curious where your getting your information from?

[Spun Pornhub]

Originally Posted by 4N Motorsport

You can brake boost with a dct from a rolling start. I'm curious where your getting your information from?

Like I said, I wasn't attempting to throw shade, but brake boosting would only be relevant if there were any turbo lag in the first place, correct? so it's a moot point considering there is no lag with this single turbo setup

I would pay to see someone attempt a successful brake boost with a DCT on a BMW without the DME/TCU cutting power. I'll send cold hard cash to your shop address if you guys don't mind sharing an instructional video. I'm all about donating for a good cause

[4N Motorsport]

Originally Posted by illmatik

Like I said, I wasn't attempting to throw shade, but brake boosting would only be relevant if there were any turbo lag in the first place, correct? so it's a moot point considering there is no lag with this single turbo setup

I would pay to see someone attempt a successful brake boost with a DCT on a BMW without the DME/TCU cutting power. I'll send cold hard cash to your shop address if you guys don't mind sharing an instructional video. I'm all about donating for a good cause

I've brake boosted at 3k rpms to start a log. It's never cut power for me. I'll be sure to send you a video no need to send cash

[4N Motorsport]

All right guys enjoy these pictures. 10 of them on the way from Elmer racing.

[Spun Pornhub]

Originally Posted by 4N Motorsport

I've brake boosted at 3k rpms to start a log. It's never cut power for me. I'll be sure to send you a video no need to send cash

Fair enough! I can make a donation to a charity of your choice if you can include an unmodified log snippet with said brake boost on a DCT. I'm hoping it's not just depressing the brake pedal by 5-10%, but really brake boosting by at least 30% brake pressure or higher.

I was wrong in saying the connecting rods will potentially be the next to go. I'm going to change my assessment to the factory clutch packs based on additional information.