[ANLV]

Bought the car and winter pics..

We had just sold our E46 M3 build November 2020 and it was time for a new tracktoy which we will build at HAIMUS RACING and I can enter in the local championships.

New year was approaching, so on 22nd of December I went to look at this thing.





Financed it, drove it home the next day! My New Year present on 28th of December.




The thing is a snowmobile on good tires.



Plans for the car over the next couple of years:
This will be our development clubsport build, so it has to be good. Me and my team will use this platform to build and develop parts which will be tested on the racetrack. Here is the plan:


- Develop a full Suspension package for it
- Develop full kinematics kit for it
- Develop Haimus Racing seats and slider adapters for F8X / E9X
- Carbon bonnet, bootlid, door cards and center console
- Design and engineer a full turbo kit for it with emissions compliant downpipe for 500+hp
- Intercooler / Chargepipe / Boostpipe by Do88
- Debut the Haimus Racing Forged Rims 9.5j front / 10.5j rear
- Develop the Haimus Racing GT Rear Wing
- Rear underbody aero
- Develop a plastic front splitter for track cars and plastic canards.
- Front underbody aero from the GTS


Before any of these, decided to test the car on track in spring 2020, get used to it and see the best time I could give on the local track with a stock car. Did a bunch of trackdays, finished 3rd in one of the local championships as well - it was a good year.

Best time on a stock car with Zestino 80TW Semi-Slicks - 1.07.378



And a small video with passenger from one of these laps:

Some notes from half a season driving the car stock and getting used to it:



The good:

- Stock brakes are really good. Just pads and its good for the track
- Car chassis is more rigid than a fully caged E36 in feel.
- Chassis communicates really well what is going on
- Steering feel is good, not perfect.

The bad:

- Front end is a bit overwhelmed on corner entry.
- Rear is a bit wheel hoppy and over steery mid corner
- Front end divebombs when hard on the brakes - too soft.
- Car desperately needs camber, tires are worn bad on outer edges.
- Front axle roll is a bit too much

[ANLV]

Suspension Development Begins...

Mid 2021 I started developing a suspension package with my team for the car. We dynod the stock shocks and the shock damping curves were very similar to an Ohlins R/T on mid settings...

!!!So damping is good!!!


Spring rates however, were really soft on the front, and progressive getting supper stiff on the rear. I started to understand where some of the problems I experienced come from.

- On corner entry, the front just hits the bump-stops and rides them until mid-corner if you trail-brake. Front end weight transfer is good for getting the nose in, but once you hit the bump stop the car just pushes wide. Front gets overwhelmed rather than underwhelmed.

- Rear end squats and gets into the stiff part of the spring on corner exit. This gives a wheel-hoppy, twitchy feeling when exiting the corner.

It was obvious we will go full coilovers at some point, but as a first we decided to build a HAS-style spring kit for performance, rather than just lowering, which would be especially good for people with EDC shocks on the M3/M4 and M2CS chassis.

So development and prototypes began...

We used this setup for prototyping, to find the best spring rates for the platform. We bought 5-6 spring rates for each axle, changed them over and went to the track on the same tires each time to test... All tests were done at stock ride-height so that we observe the benefit only from the changed rates.





And we found success... 4 tenths better laptime- 1.06.87 on the same, now battered Zestino tires




By analysis of our track telemetry we were gaining time in the quicker corners, in the braking zones. Average corner speed was similar, but corner exit onto the straight improved resulting in a 1.2km/h quicker car down the straight.

Overall, we had the spring rates down. We now had to chose the right springs to give the correct lowering, chose the right bump-stops, the right dust boots etc.


Here are some more photos from 2021:


Improvement in dive under braking:



Improvement in roll:



Comparing side-to-side roll characteristics between a stock M2 Comp and our car.





2021 ended on a high note with a 1.07.3XX on Goodyear Street Tires. To give you a comparison I barely managed 1.07.8 on street tires when the car was fully stock. And it was back to the winter setup and more developments.



We had to finish the GT Spring Kit and decided to go on with kinematics and AERO.

Winter 2021 and Spring 2022 were busy!

In March 2022 we did a photo session for "Baba Marta" - a traditional Bulgarian custom. During Baba Marta we give each other red and white "Martenitsi" which are usually a small male and female doll which you can attach to your clothes. Red Symbolises blood and life, while white symbolizes purity, new beginning.

This is the last time the car will be anything close to a standard M2. Here are the photos.



Me and my team were busy during the winter months. Worked on the GT Spring Kit and Kinematics.

GT Spring Kit was now getting tested on an M4 with EDC from our car stack. We made new cups this time from INOX, instead of zinc-plated steel like others are on the market, excluding any rust / degradation possibilities down the lifetime of the cars.



We also started working on Camber Plates to finish off the spring kit:




Rear Toe arms to give us more rear camber adjustment...



Front Kinematics...

Front Camber Arms:



Front Caster Arms:




Car was going to be used on the street as well, so we needed a kinematics solution where dust and debris will not go into the rose joints and destroy them. We used encapsulated pillow-balls wherever it was possible.


We had a prototype wing made as well...




2022 Season Started!

Move forward to April, and we were prepping the car for the race. We were almost done just the day before, but good enough...

- Front lip mount wasn't figured out yet, so we just placed 2 holders so it wouldn't droop too much.
- Filter changed
- Mosselman OIL thermostat was placed
- Kinematics was placed on the car for testing
- Suspension was placed in its final form on the M2 and the M4 EDC
- Rear wing was placed





We had in testing:

- Final Variant of the GT Spring Kit on the M2 and on the EDC M4 (both are different as the EDC shocks have different valving)
- New Nankang Rubber on the M4's
- Full Kinematics Kit to test
- Rear Wing
- New development front lip


Was a super fun day at the track.

Another build we have a huge impact on - the M2 Comp - set the fastest laptime of any BMW on the track - quicker than an M4 GT4 which had lapped last year.

We had both our M4's on track and my M2.

Well, results were:



- Class Advanced 3000cc+
Gold Medal - M2C HMR - 1.01.8

- Class Street Modified 3000cc+
Gold Medal - M4 HMR - 1.05.8
Silver Medal - M4C HMR - 1.06.0
Bronze Medal - M2 HMR - 1.07.1 (street tires from last year)



Some pics of the other cars from Haimus Racing Team:

M2C By Pavel Yovev - 1.01.8



The HMR M4 and M4C




Anyways it was a fun day. Car showed so much potential. Talking points:

- Goodyears were at the end of their life, so they didn't feel grippy. Going for Nankangs next race for sure
- Car felt so much more stable with more camber and tires didn't wear on the outer edges this time
- Car definately needs a little bit of rake to work properly. 5mm rake felt perfect.
- Front Axle grip was immense now, especially with the wider track from the kinematics kit.

A week later we made a new lip holder, and took some photos of the suspension and kinematics kit we had produced.


Spring kit and camber plates:



Front Axle kinematics:









Rear Axle Kinematics:




Next steps for us were to make new wing supports, as I really do not like the look of these ones, and new wing endplates. We also will be trying different TOE, front step, caster and rake angles to see what works best. Having a great platform is just the start - understanding it and setting it up properly will be this years plan.

Two more races happened since then and we might have broken a few records with the car, but more on that in the next post!