E34 M5 track toy progress

[Crash_Nemesis]

My previous best on the track was a 2.20.6 before we did a few upgrades on the car

Times in counter clockwise (Reverse) at Redstar are always slower. Don't beat yourself about it. That is a good time for your first time driving that layout. It is much more difficult.

 

[Benji]

Times in counter clockwise (Reverse) at Redstar are always slower. Don't beat yourself about it. That is a good time for your first time driving that layout. It is much more difficult.

Thank you, that is good to know as I was starting to doubt the very meaning of life

 

[Benji]

Ooh, what have we here...

ISC coilovers finally arrived so we can start fitting them - we had to go for the shortest front spring due to space constraints which means the hardest available spring at 12k. The rear is still an 8k spring which I am worried might introduce even more understeer? I know one can adjust the dampers to try find a better balance, but logic dictates that the springs should at least be in a similar ballpark for neutral handling?

With the red M5 sold now, there should be more time and funds available to focus on this car

 

[Benji]

There has been criminally little time spent on this car, so we could not make the Time trail in February. Bummer. Made some time this past weekend to fit the ISC coilovers. I must commend Mo from Ultra Racing who has been exceptionally excellent to deal with. He helped me fit the coilovers, and made several trips to me to provide us with an optimal solution. The car "needs" to be very low and there is extremely limited space at the front for the coil spring since we are running a wide wheel and the spring perch needs to be fully above the front tyre. Car sitting suitably low:


We had way too much forward bias on the brakes as the rear brakes are still stock items and were badly warped and in need of replacement. Locking up under braking really saps your confidence and destroys tyres. We did a few sums, found some "should" and "maybe" forums online, so bit the bullet and bought a set of E46 M3 rear calipers and discs. The disc bolts right up (even the handbrake works) but we had to build a bracket for the caliper. Slap it all on with some new braided hoses, and bob is your uncle.




Why the heavy E46 M3 rear brakes? Mainly, the piston is 2mm larger than the stock M5 calipers, which moves the bias nicely to the rear, but not as much as readily available alternatives such as F30 2-pots etc. The M3 disc also has the aluminium centre hat, which saves a bit of weight (still 1.5 kg heavier per corner) and is easily available. But mostly because we found a set of front and rear calipers with decent but skimmed discs for R2000. As per correct engineering methodology, we bought the parts first, and then did the research to determine if they suit our application after.

Also replaced the centre silencer/resonator, I have no idea what could do this to a silencer? Maybe some pretty epic backfires...it does like to shoot flames sometimes.

 

[FISAACS]

There has been criminally little time spent on this car, so we could not make the Time trail in February. Bummer. Made some time this past weekend to fit the ISC coilovers. I must commend Mo from Ultra Racing who has been exceptionally excellent to deal with. He helped me fit the coilovers, and made several trips to me to provide us with an optimal solution. The car "needs" to be very low and there is extremely limited space at the front for the coil spring since we are running a wide wheel and the spring perch needs to be fully above the front tyre. Car sitting suitably low:
View attachment 21972

We had way too much forward bias on the brakes as the rear brakes are still stock items and were badly warped and in need of replacement. Locking up under braking really saps your confidence and destroys tyres. We did a few sums, found some "should" and "maybe" forums online, so bit the bullet and bought a set of E46 M3 rear calipers and discs. The disc bolts right up (even the handbrake works) but we had to build a bracket for the caliper. Slap it all on with some new braided hoses, and bob is your uncle.
View attachment 21973
View attachment 21974
View attachment 21975

Why the heavy E46 M3 rear brakes? Mainly, the piston is 2mm larger than the stock M5 calipers, which moves the bias nicely to the rear, but not as much as readily available alternatives such as F30 2-pots etc. The M3 disc also has the aluminium centre hat, which saves a bit of weight (still 1.5 kg heavier per corner) and is easily available. But mostly because we found a set of front and rear calipers with decent but skimmed discs for R2000. As per correct engineering methodology, we bought the parts first, and then did the research to determine if they suit our application after.

Also replaced the centre silencer/resonator, I have no idea what could do this to a silencer? Maybe some pretty epic backfires...it does like to shoot flames sometimes.
View attachment 21976

Hi Benji, the effort and money you put into BMWs you really ought to be sponsored by BMW SA. I can't think of a better brand ambassador, even if it's just for the classics as I know you're not a fan of the contemporary stuff. Have you considered starting a YouTube channel?

 

[Benji]

Hi Benji, the effort and money you put into BMWs you really ought to be sponsored by BMW SA. I can't think of a better brand ambassador, even if it's just for the classics as I know you're not a fan of the contemporary stuff. Have you considered starting a YouTube channel?

I do feel like I could do with a sponsor! Sure would help these projects move a little faster...I have considered doing something on youtube, but I am an ugly, mumbly old drunkard, I dont think there are many people out there that would find me very entertaining also my projects move at such a glacial pace, Project Binky would be lightning fast in comparison...

 

[VinceM]

Come on, surely you can beat “The 50’s kid”


Sent from my iPhone using Tapatalk Pro

 

[Sabretooth tiger]

Just be the Scotty of south Africa. That oke usually sounds like hes had a few.

 

[Alex/M5]

Decent progress. What does the acceleration feel like with all the weight reduction?

 

[Spanky]

As per correct engineering methodology, we bought the parts first, and then did the research to determine if they suit our application after.

 

[Benji]

Decent progress. What does the acceleration feel like with all the weight reduction?

It is definitely faster than a stock one, but not as large a difference as one would have expected...I suspect mostly due to it running a Diktator management which we will get tuned again at some point...

We actually booked the car in for a dyno vs the stock M5, but a injector wire decided that was the perfect time to lose connection so we dynod it on 5cyls and it made a laughable 90-odd kW pretty embarrassing as it looks so serious and made so much noise - probably the loudest car at that dyno day

 

[Bernard///M3]

Hey Benji.

You ready for track day on 19 May?

Hope to see it in action with all the upgrades

 

[Benji]

Hey Benji.

You ready for track day on 19 May?

Hope to see it in action with all the upgrades

Yes, will be there!

 

[Fordkoppie]

It is definitely faster than a stock one, but not as large a difference as one would have expected...I suspect mostly due to it running a Diktator management which we will get tuned again at some point...

We actually booked the car in for a dyno vs the stock M5, but a injector wire decided that was the perfect time to lose connection so we dynod it on 5cyls and it made a laughable 90-odd kW pretty embarrassing as it looks so serious and made so much noise - probably the loudest car at that dyno day

I have a stock ECU if you ever want to revert👀

 

[Benji]

I have a stock ECU if you ever want to revert👀

That is tempting...unfortunately there is nothing left of the stock wiring loom - all the wiring was redone

 

[Benji]

We attended another brilliant day at Zwartkops for the timetrail. Mo from Ultra racing came through for the morning to help us set the car up and brought some rather quite delicious samoosas with! What a gent! My first session was thwarted by the exhaust falling off on lap 3, the dampers felt a bit soft and we had some rubbing on the front tyres. I had managed an encouraging 1.16 in those exploratory laps.

With the dampers turned up a few clicks, coat hanger repurposed, front fenders clearanced, Mark went out and immediately put the car in the kitty litter (LOL) but also set his fastest ever time! The brakes feel a lot better, but not as good as we were hoping for, they still lock up too easily and there is still a really bad shudder, I am convinced that the "new" skimmed rear discs are warped as the brake pedal feels very spongey on first application. The theory is that the warped discs are pushing the pad away from the disc causing the soft pedal. This will need to be investigated further. We have also noticed the oil leaks are picking up pace at an alarming rate...so we will have to do a gearbox-out job, again 😖

The car feels a lot more neutral and predictable in its handling, however, the shuddering brakes are slowing things down a bit, I basically had the whole track to myself during the last session of the day and could put in a few "bangers", but my best time was a rather disappointing 1.14.1. That is 2 whole tenths quicker than my previous best time, I was expecting to get into the low 1.13s at least. Due to the brakes, it is also really hard to put in consistent lap times.



We had the pleasure of partaking in the classic car parade 😎


Also, flames 😈

 

[Benji]

We decided to buy a new set of E38 750iL rear discs. Once these are heat treated and slotted, they work out to half the price of E46 M3 discs, however, they are 900g heavier per side and will have worse cooling since they are non-floating, but they should be more robust on the track. However, we still have the brake shudder and one can feel it through the steering wheel, so there is an issue with the front brakes which we need to investigate.



We built some "Porsche inspired" brake cooling scoops. It is hard to say if they work, but rear brake disc temps are now always lower than front brake temps - previously at Zwartkops, they were slightly higher.



Bump steer correction plates were installed - a ball hair clearance is still clearance... We got new disc bells made to space the disc out 5mm and to distance the soon-to-be-changed lower control arm balljoint from the hot disc.


We removed 15kgs from the car by gutting the rear doors, removing the SLS system and ABS pump which was bypassed anyway. This weight loss nicely offsets the weight gain of the muppet behind the steering wheel. Embarrassingly, the car went for its first wheel alignment...the toe was all over the place. We went for a rather conservative front/rear total toe of 0.08/0.27 and camber -3/-1.5. We have plans to get a bit more camber at the front by building an offset bump steer plate... Car drives much better now, there is so much more feel through the steering wheel and it is more communicative before sliding. It is much more obedient on the track which does wonders for your confidence and therefore lap times (hopefully). Previously we were just along for the ride, now we feel like we are actually in control sometimes.


This past weekend was the last round of the generally excellent Time Trail at Redstar raceway. It was a bit of a weird day for me as my first and second sessions were red flagged, so I only had the last session to get to grips with the car. Murphy's law also dictated that both my phone app and the transponders didnt work, so I have no idea what lap times I did. Mark significantly beat his PBs. Annoyingly, the cars top speed on the back straight was 180 kph whereas last outing we hit 200, so there is some power that has gone on a walkies. I believe it has something to do with the Go Tech ECU probably needing the trash can, but will most likely get a retune. The car does do some funny things sometimes and is definetely running too rich.





As always, the car needs more work, but it is a successful day when you can drive the car home in one piece

 

[Benji]

We took the M5 to Zwartkops for our first "open day" in some time. We had forgotten the value of the open day in terms of getting more seat time where both of us are able to do a "full day" of driving where we drive in 2 different classes.

The M5 is a beast, doing 20min on track, pulling into the pits for a driver change and then another 20min in ambient conditions over 35C without any complaints or wavering of temperatures. How is that for a basically stock 33 year old machine with close to 300k km! German engineering at its peak.

Brake shudder was horrendous, so we took the front discs in to Vari again to get them rebalanced and skimmed. Also, as per every single post since we got this car; we really need to get some cabin ventilation going. Otherwise the car was faultless and we had a lot of fun!

I found some 10mm wheel spacers lying around...so did the right thing and pulled out the 4 pound hammer, some heavy steel and a crowbar for a spot of light massaging. There may or not be rubbing, but it looks fu#king awesome! Doubt there will be any performance benefit, but at least the Stance guys will approve.

 

[M3boi]

Pity you can't get these wheels anymore, they look fantastic.

Do you know what the specs on them are?

 

[Benji]

Pity you can't get these wheels anymore, they look fantastic.

Do you know what the specs on them are?

They are also really heavy...They are 9.5J square setup running 265/35/18, but completely the wrong offset - et35 iirc, hence the need for some substantial spacers