D.Bryce
Member
Long time lurker, and Z4M tinkerer, had a bit of time and now finding these cars are starting to get a bit more common so id though id start a build thread of all the work I’ve carried out myself over the years, so here goes.
Bought the car in 2022 semi modified, Eventuri intake, KW V3s, SuperSprint rear exhaust, Genuine BBS rc337 alloys.
First port of call was to sort out the sticky front callipers, a prime opportunity for an upgrade, after a few emails with freaky parts I had a set of their Brembo callipers, brackets and braided lines.
The car stayed pretty standard after this for a while until a rattle appeared on the rear end, so it began…
Initial inspection found a broken exhaust clamp, easy fix. This then led to an inspection of the diff which was showings signs of dampness around the output seals.
As I was already in there and had access it made sense to remove it for further inspection.
Now having full view of the subframe arms and bushes, they all looked a bit tired, “while I’m in here” I thought I may Aswell drop the full lot.
No point in replacing like for like when there’s upgrades available right, full set of Powerflex and millway rear bushes were ordered, full underside was scrubbed and then sealed with clear wax. All the arms and components were powder coated and sealed before fitting the new bushes.
Onto the diff, after reading many things about the s54 being a tad sluggish off the line I managed to get a cracking deal from BMW on a 4.1 final drive crown wheel and pinion. Full diff rebuild with new seals and bearings and we were good to go.
What can I say probably the best thing I had done; the rear end was now planted and the pickup when the foot was planted was unreal, totally changed the performance of the car. So naturally took it for a drive up into the Scottish Highlands.
Change of job to overseas meant the car sat in the garage for a while and wasn’t really used for a year or so, and the thought of selling came into my head. Then I got the opportunity on a group buy for a full carbon csl plenum for haiumus racing, an opportunity too good to miss, fast forward a few months and it was delivered...
Yes, its sounds as good as it looks, all fitted perfectly except the oil dipstick requiring slight bending. The only thing I felt let these airboxes down was the lack of options for the Z4M snorkel to utilise the factory intake and I wasn’t paying for a carbon e46 one to hack up so I took to the 3d printer and after a few days of scanning and several designs I produced the first, to my knowledge, Z4M csl intake snorkel.
After this it required mapping, had heard mixed reviews about alpha N maps so it was taken to Engine 710, who worked closely with Areeve performance to get the car running properly and my god did it run, full chat intake noise is absolutely phenomenal, pickup is slightly better, noticeable power gains is hard to say but drivability was outstanding.
*For those with CSL boxes I can print one and post it to you, time and materials will cost £200 all in.
After the intake noise drowned out the exhaust noise I was keeping an eye out for some headers, nothing arose but a fellow forum member on here posted a basically new SuperSprint setup including the centre X-pipe. He wasn’t willing to split it so I bough the lot and sold my original SuperSprint back boxes.
These retained the original tone and increased the volume and bassines. A worthwhile upgrade.
Having come from a track car background I thought I’d see what the Z4 was capable of, however the 19” wheels and tyres weren’t really ideal so I managed to get a set of Konig Hyper grams in 18” 8.5J et35 front & 9.5j et35 rears from a member on the M3cutters buy/sell pages. These were subsequently wrapped in Yokohama AD09 tyres 245/40/18 fronts and 265/35/18 rears.
First track day was planned, and it wasn’t without it issues…
KW rear springs were too soft and were binding on full compression even when full hard, brakes kept overheating after 5 ish hard laps, front end wasn’t very direct and felt a bit soft. Plenty still left on the table, so I got to work.
I had always like the idea of a proper chassis mounted shifter so when coolerworx had a black Friday sale on I couldn’t say no. the only thig I will say now its fitted is I wish I had gone for the fully self-centring model. Other than that, it is a superb piece of kit.
I then jumped onto the 3d printer and designed some brake cooling duct vents o run to the disks and had a friend manufacture a backing plate to suit the ducting.
After some road testing there was still some issue with inconsistent braking, peal would be long and spongy other times it would be hard and stop great, so I done some digging and found a post about upgrading the abs unit to that of an e90, fairly simply task albeit a bit messy bench bleeding the unit.
Another track day came and went still with the same issues; this is where it took a bit of a nosedive.
Rob at RDMotorsport showed me some man math calculations regarding suspension work, specifically the KW v3s. To get all 4 dampers re-valved and upgraded to the club sport spec with to mounts and springs it would have cost circa £1500, however that was also the current market value for them, there was no issues with the coil overs, they just didn’t suit my use for them on track.
End of Part 1.
Bought the car in 2022 semi modified, Eventuri intake, KW V3s, SuperSprint rear exhaust, Genuine BBS rc337 alloys.
First port of call was to sort out the sticky front callipers, a prime opportunity for an upgrade, after a few emails with freaky parts I had a set of their Brembo callipers, brackets and braided lines.
The car stayed pretty standard after this for a while until a rattle appeared on the rear end, so it began…
Initial inspection found a broken exhaust clamp, easy fix. This then led to an inspection of the diff which was showings signs of dampness around the output seals.
As I was already in there and had access it made sense to remove it for further inspection.
Now having full view of the subframe arms and bushes, they all looked a bit tired, “while I’m in here” I thought I may Aswell drop the full lot.
No point in replacing like for like when there’s upgrades available right, full set of Powerflex and millway rear bushes were ordered, full underside was scrubbed and then sealed with clear wax. All the arms and components were powder coated and sealed before fitting the new bushes.
Onto the diff, after reading many things about the s54 being a tad sluggish off the line I managed to get a cracking deal from BMW on a 4.1 final drive crown wheel and pinion. Full diff rebuild with new seals and bearings and we were good to go.
What can I say probably the best thing I had done; the rear end was now planted and the pickup when the foot was planted was unreal, totally changed the performance of the car. So naturally took it for a drive up into the Scottish Highlands.
Change of job to overseas meant the car sat in the garage for a while and wasn’t really used for a year or so, and the thought of selling came into my head. Then I got the opportunity on a group buy for a full carbon csl plenum for haiumus racing, an opportunity too good to miss, fast forward a few months and it was delivered...
Yes, its sounds as good as it looks, all fitted perfectly except the oil dipstick requiring slight bending. The only thing I felt let these airboxes down was the lack of options for the Z4M snorkel to utilise the factory intake and I wasn’t paying for a carbon e46 one to hack up so I took to the 3d printer and after a few days of scanning and several designs I produced the first, to my knowledge, Z4M csl intake snorkel.
After this it required mapping, had heard mixed reviews about alpha N maps so it was taken to Engine 710, who worked closely with Areeve performance to get the car running properly and my god did it run, full chat intake noise is absolutely phenomenal, pickup is slightly better, noticeable power gains is hard to say but drivability was outstanding.
*For those with CSL boxes I can print one and post it to you, time and materials will cost £200 all in.
After the intake noise drowned out the exhaust noise I was keeping an eye out for some headers, nothing arose but a fellow forum member on here posted a basically new SuperSprint setup including the centre X-pipe. He wasn’t willing to split it so I bough the lot and sold my original SuperSprint back boxes.
These retained the original tone and increased the volume and bassines. A worthwhile upgrade.
Having come from a track car background I thought I’d see what the Z4 was capable of, however the 19” wheels and tyres weren’t really ideal so I managed to get a set of Konig Hyper grams in 18” 8.5J et35 front & 9.5j et35 rears from a member on the M3cutters buy/sell pages. These were subsequently wrapped in Yokohama AD09 tyres 245/40/18 fronts and 265/35/18 rears.
First track day was planned, and it wasn’t without it issues…
KW rear springs were too soft and were binding on full compression even when full hard, brakes kept overheating after 5 ish hard laps, front end wasn’t very direct and felt a bit soft. Plenty still left on the table, so I got to work.
I had always like the idea of a proper chassis mounted shifter so when coolerworx had a black Friday sale on I couldn’t say no. the only thig I will say now its fitted is I wish I had gone for the fully self-centring model. Other than that, it is a superb piece of kit.
I then jumped onto the 3d printer and designed some brake cooling duct vents o run to the disks and had a friend manufacture a backing plate to suit the ducting.
After some road testing there was still some issue with inconsistent braking, peal would be long and spongy other times it would be hard and stop great, so I done some digging and found a post about upgrading the abs unit to that of an e90, fairly simply task albeit a bit messy bench bleeding the unit.
Another track day came and went still with the same issues; this is where it took a bit of a nosedive.
Rob at RDMotorsport showed me some man math calculations regarding suspension work, specifically the KW v3s. To get all 4 dampers re-valved and upgraded to the club sport spec with to mounts and springs it would have cost circa £1500, however that was also the current market value for them, there was no issues with the coil overs, they just didn’t suit my use for them on track.
End of Part 1.
Scottish Borders
