3DM E90/N54 Track Car Build

[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
I actually have two build threads to create about e90/N54 track cars. An HPDE/Time Trail car, which this thread is about, and a dedicated racecar. I will create another thread about the racecar when the appropriate time comes.

I hear it all the time, if you want a reliable and affordable BMW track car you have to go e36/e46. Well, those cars won't last forever. I’ve been building and racing BMWs for over 20 years including e30s, e36s, and e46s and decided it was time to move on. After assisting others with their N54 based track cars over the years, I decided to take the plunge to develop my own n54 based track car, a 2007 e90 335i.

This goal of this build thread is twofold, to showcase the capability of an N54 powered E9X on a track and to utilize the fantastic collective knowledge of the Spoolstreet N54 community. Hopefully we can solve some of the problems that will allow the N54 to shine as a track going BMW motor!

I'll start with some high level build thoughts...

Must remain streetable: This is being built as a dual-purpose car, to drive around town for fun and at the track. This also allows for testing of parts at any time, not just at the track.

Target 450 WHP: We know the N54 can make big power, it has been proven over and over. The goal of this build is not big power, it’s a RELIABLE 450 WHP. If reliability can be solved, we have a winner. Jumping ship from an E36 or E46 M3 track car is a no brainer at that point because no amount of money will allow those cars to obtain 450 WHP and the torque to match.

Must use pump gas only: E85 is scarce at race tracks and carrying fuel to the track is a major pain in large quantities.

KISS: Keep it simple stupid… No aftermarket or piggy back DMEs. Keep as many things as possible bolt on, however some fabrication is OK.

Cooling: This is the first and foremost problem with the N54 in terms of track use. Yes, there are aftermarket radiators, auxiliary radiators, and altered target temp settings but they simply don’t keep the motor cool enough for track use. The solution to the cooling problem is a two step process. First, the DME software needs to be altered which will allow for the second process of designing proper cooling system hardware. Unfortunately, my expertise does not lie in the software side of the equation which is where I hope the Spoolstreet community can help. In fact, a lot of this has been covered in a thread I started about the cooling system here: N54 Cooling – Temp Control Logic

With the fantastic help of @RSL we concluded that the pump is running 100% to try to target a coolant temp. We can’t change the thermostat or water pump as the DME will throw codes and go into reduced power mode. If anyone knows a way to remove this so that we can try other aftermarket water pumps and thermostats that would be fantastic!

Turbos: Definitely staying with a twin setup. One major factor of track driving is the drivability of the car itself. While most of my experience is driving/racing NA motors I do have some experience driving both single and twin turbo N54 setups on the track. This topic is of course highly debatable but my experience is that twins are the way to go. There is simply too much lag with a single turbo and it makes driving at 10/10ths very difficult.

Suspension: Dampers are a modified Ohlins Road and Track setup. I’ve been using Ohlins dampers for over 10 years on various other BMWs, well before the current Road and Track system was released. In fact, I made my own “Road and Track” setup for the e46 M3 using the previous Ohlins Sportline that I modified (threaded perch and re-valved) in conjunction with an Ohlins STJ motorsport damper.

Example 335i Setup:
335iohlins.jpg



To me, Ohlins are preferred because of their motorsport heritage and attention to quality and design. Things like the inverted front strut, Dual Flow Valve, and temperature compensation bleed valve make them the perfect solution for a dual-purpose road and track car. I have been testing and developing two E9X Ohlins kits over the past few months and Ohlins will be shaker rig testing the results in a few weeks. One is a 335i specific revised Road and Track kit and the other a “Dedicated Track” kit with both M and Non M fitments. I will explain these in more detail in another thread to come. Below is an e46 M3 in action on the shaker rig.


In addition to developing the Shock/Spring packages, I’ve been working on the rear suspension kinematics. I’ve bench top mocked up both the 335i and the M3 suspensions for an in depth comparison of the camber and toe curves and other pieces of the puzzle. Again, more to come in another thread about all of this in detail very soon.

Data: I have been using AIM for many years and I chose the AIM Evo 5 for this car. The Evo 5 is a small logger that uses an additional add on dash called the GS-Dash. Keeping the logger separate from the dash allows me to collect data while on the street without having the dash in front of the OEM instrument cluster all the time. When at the track I put the dash in front of the OE cluster so I have warning and shift lights.

In addition to the normal analog sensor inputs, GPS data, and X Y Z axis accelerometers, the AIM also has CAN inputs to allow logging many parameters already being collected by the car itself via PT CAN such as brake pressures, steering angles, etc. Unfortunately, since it only logs parameters broadcast over CAN, this means detailed engine parameters like WGDC can’t be logged. This is of course where MHD comes into play. Now the issue is having two loggers to deal with which is a topic that I intend bring up in another thread.

Differential: The differential is major part of the equation for an E9X track car. I will be swapping out the open diff for a true limited slip. I have been using Dan at diffsonline for 20 years and he knows his stuff. He does it all day every day and knows how to setup a diff for track use.

E-diff side note: I don’t believe my car has the E-diff but whether it does or not I wouldn’t want it as it uses the braking components to accomplish its task. Fine for a street car but on a track car the LAST thing you want is the brakes doing something other than, well… braking.

Aero: Other than an M Sport bumper upgrade the aero will be left alone. It’s a street car. I might put a trunk lip spoiler on, we’ll see. The M sport bumper is part of the cooling equation, the stock 335i bumper air inlets have too small of a surface area for proper cooling.

Safety: A non-intrusive 4 point cage will be installed with 6 point harnesses for the driver and passenger. I have a pure race seat with halo that I intend to swap in and out when I go to the track. It’s a lot of work to swap in and out but I don’t want to be sliding around in a stock seat, it’s just not safe.


Anyways... much more to come. I hope you enjoy this thread and hope it helps with any of your E90/N54 adventures. I'm looking forward to the knowledge that I gain from this community and I especially want to thank @doublespaces for providing us with Spoolstreet.com!

Regards,
@[email protected]
 
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KevinC39

Corporal
Jun 27, 2017
151
Sweet, I'm really looking forward to seeing this all come together. I had a lot of the same stuff in mind for my own car.
 
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MDORPHN

Corporal
Jan 28, 2018
119
Barry installed Ohlins R&T on my much-tracked 1M and has made many other improvements to it. He really knows what he's doing!

Neil
 
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[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
Making some great progress! Completely revised all the linkages/pivots of the rear suspension. The car now tracks dead straight under full acceleration while still retaining rubber rear subframe mounts for tolerable NVH on the street. I will post up details soon. For now here is a fun video of some damper/spring development.

The Ohlins standard E9X kit (BMS MI00) was developed to catch all of the E9X standard cars including the 325i, 328i, 330i, and 335i. This kit is fantastic for the NA powered E9Xs but it needed some revising when it comes to a modified 335i. All 4 springs have been changed and all 4 dampers have been revalved to match.


 

veer90

Lieutenant
Nov 16, 2016
862
West Nyack, NY
Did you go with clutch type or helical LSD?

Also I'm pretty sure every e9x 335i has e-diff on by default. Can be coded out with NCS expert.
 

[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
This thread is obviously about the Street/Track Day car but at the same time some development is happening with the race car as well. Ohlins will be releasing a new product called "Dedicated Track" and I have been helping them develop the BMW setups. The following pictures and shock dyno video are of the E9X M3 Dedicated Track kit development. I'm showing you this because the same process was used for my revised street/track day 335i kit.

All dampers dismantled...

20190211_163636.jpg

The main piston on top with the DFV just below...

20190211_182637.jpg

Shims laid out in order...

20190211_164150.jpg

Validating the new valving matches the desired force curve...

 
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[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
Did you go with clutch type or helical LSD?

Also I'm pretty sure every e9x 335i has e-diff on by default. Can be coded out with NCS expert.

Haven't gotten to the diff yet. It still has the OEM open diff. I've had some discussions with Dan at diffsonline and will make a decision soon. My car is a 2007 and based on a little research I don't think it has e-diff. I think it came standard mid 2008 but someone correct me if I'm wrong please. Regardless, the Pro-Tools app, which I highly recommend, has the ability to code it out with checkbox functionality. I used the app to remove the annoying TPS monitor warning. If you have a 1M with corner brake control they have a function to remove that, too.
 

Torgus

Captain
Nov 6, 2016
1,041
Boston
Making some great progress! Completely revised all the linkages/pivots of the rear suspension. The car now tracks dead straight under full acceleration while still retaining rubber rear subframe mounts for tolerable NVH on the street. I will post up details soon. For now here is a fun video of some damper/spring development.

The Ohlins standard E9X kit (BMS MI00) was developed to catch all of the E9X standard cars including the 325i, 328i, 330i, and 335i. This kit is fantastic for the NA powered E9Xs but it needed some revising when it comes to a modified 335i. All 4 springs have been changed and all 4 dampers have been revalved to match.


I know you said you will post more details but real quick:

1) Will you be selling the rear linkages/pivots etc?
2) Are you using m3 rear arms or stock non-m? If not rear M any reason?
3) Will you or ohlins be selling the revised kit made for the 335i? When will it be available?
4) Can you let us know the spring rates?
5) How does the rear of the revised kit match up against the rear of the ohlins m3 kit? I ask as my plan was to use rear m3 arms and rear Ohlins m3 struts/springs etc.


twu43y.jpg


Looking forward to more information on what you are doing. Very exciting stuff!
 
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[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
I originally was not going to go down this path until later this year (for the racecar) but decided that it would be beneficial for the street/track day car, too. So I went ahead and started modeling the suspension. Its a work in progress (always will be of course) but i'm getting there.

Front suspension with virtual lower A-arm, steering link, and MacPherson strut

e90 front model.JPG

Rear suspension with virtual lower and upper A-arm and toe link.

e90 rear model.JPG

Initial goals are to look at toe control of the front and rear. I'm also interested in the rear anti squat for those who drag race (and of course road racing, too). Down the road I will be looking at all the other stuff like roll centers, camber curves, and KPI vs Caster settings, etc.
 

[email protected]

Corporal
Platinum Vendor
Jun 4, 2018
136
I know you said you will post more details but real quick:

1) Will you be selling the rear linkages/pivots etc?
2) Are you using m3 rear arms or stock non-m? If not rear M any reason?
3) Will you or ohlins be selling the revised kit made for the 335i? When will it be available?
4) Can you let us know the spring rates?
5) How does the rear of the revised kit match up against the rear of the ohlins m3 kit? I ask as my plan was to use rear m3 arms and rear Ohlins m3 struts/springs etc.


View attachment 22734

Looking forward to more information on what you are doing. Very exciting stuff!
I will cover this in more detail but to answer your questions...

1 and 2: Yes I will be offering the linkages and pivots. There will be a couple of variations such as modified OEM stock 335i linkages, modified OEM M3 linkages, and custom made adjustable linkages. All use factory style ball joints with ring retained dust boots, no rod ends and spherical bearings used. These factory style ball joints have been proven for over 30+ years in the OEM automotive industry . In my opinion rod ends and sphericals are best left on race cars. On street cars they get contaminated with dirt and start to wear prematurely. Yes you can try to put boots on them but I have found no good solutions, nothing like a factory style ball joint at least.

3: The revised 335i kit is a 3DM Motorsport kit only. Still working on pricing but it will be very reasonable compared to the off the shelf BMS MI00 kit. It will have the same warranty that Ohlins offers.

4: Springs are Swift brand. 70 N/mm (400 lbs/in) front and 120 N/mm (695 lbs/in) rear. The re-valved dampers will likely be available without springs. Everyone is different, different car setups, different driving styles, etc. I will do my best to cater to this.

5: In terms of the M3 vs Non M, the geometry differences are in the subframe and spindle, which are very expensive and time consuming to swap. While the M3 rear arm you mention is nice, its not worth it (in my opinion). The point of this kit is to remove the need to go through the expense and process of switching to the M3 arm.

I will be offering a re-valve service if you already own an Ohlins setup. If you have special scenarios I will be offering general re-valving services, for example catering the valving to a drag racing scenario.

I also will have a 135i kit with a slightly softer rear spring and again, valving to match. A 3DM exclusive 335iX kit is also in progress.
 
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fmorelli

Colonel
Staff member
Aug 11, 2017
2,120
Virginia
Looks like N54 cars continue to get love in all directions. Thanks for busting hump on this, Barry. My F10 can wait for Ohlins . This is good stuff.

Filippo
 

bantam

Specialist
Nov 20, 2017
80
Bizarre to see someone doing what appears to be legitimate instrumented testing in a controlled environment!

When would you anticipate these linkages coming available for sale? I was planning to do the m3 arms next for my car, but perhaps I will wait and see what your offerings are.
 
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aus335iguy

Lieutenant
Nov 18, 2017
916
This is what ive been waiting for.... M3 links seem to be the only option suspension wise and the platform needs an alternative.
Too early for “Price shipped to sydney Australia please? “:yum:
 

Panzerfaust

Sergeant
Jul 3, 2018
458
Chicago
Awesome Barry, glad to see you making such great headway! With what you've told me about already and the things in this thread that I didnt know about, I'm VERY excited to see what you end up coming out with. IMO the two things the N54 platform is still missing dynamic and multiple options for are A: suspension parts (it seems it's always either "drop dat bitch for siqq stance with our kit!" Or "offers stock M-like performance!") and driveline upgrades (aside from the LSD options, we really dont have much) so it's great to know you're putting in real research to fill those two gaping holes in the platform.

I know the reason for that is likely because the N54 is stupid easy to make up to ~500-550whp and most people dont do *real* racing, but it's still nice to see this stuff coming out. Hopefully we can convince you to do some 6hp21 work when you're done with the suspension stuff, some of us still want affordable (and basic! if were being honest) transmission mods for our cars ;)

Edit: As a side note, I know you didnt mention ignition and I know you've experimented with the BL coil kit in the past. I'm not sure if you saw my post in the thread that Filipo made about the research you and him did on getting the coils seated properly or not, but if not you should check it out. With a different PN coil you can get proper seating with very, very little modification. And since you're using an 07/MSD80 car and like to eliminate all the heat you can, the BL kit is nice to help get rid of some DME heat and help prevent/eliminate the MOSFET failures. I've had quite a few people ask me for links to the post and/or more info (including MMP) lately because they like the benefits of the BL kit but don't like the modified coil hassle, so I'd be curious to see your opinion and how they work out for you.
 
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