A few bits and pieces and a trip to Spa - New Windscreen
- Thread starter Mikey_Boy
- Start date
Mikey_Boy said:Beedub said:buzyg said:Nice to read that you enjoyed Spa. I took my ///MR there in 2011. Fabulous place. Don't tell any one, but I ran out of petrol and had to be towed back to the pits.
Spa was simply fantastic - I have been lucky enough to go there a few times with work in the past so to be able to drive it was real bucket list stuff - can’t wait to get back there…!
beanie said:
For sure it’s the law of diminishing returns, but I’d love to squeeze just a bit more out of the engine as I know there’s more there to come - I know it’s easier and better hp/£ with super charging, but I want to keep this car N/A for that throttle response and old school feel.
It’s either cams or a V10…..
the blower is just porn.... absolutely no difference to throttle response or power curve.... its literally identical just way higher up the graph , its literally feels like a v10 engine swap. Best thing i ever did to the car , infact best thing ive ever done to any car, but i wouldn't do it again.
Mikey_Boy said:Beedub - I LOVE the contradiction:
‘Best thing I ever did to a car, in fact, best thing I’ve done to any car, but I wouldn’t do it again’….!
How much power are you making? Do you have a build thread at all? I’m curious…. :?
love it but.... put short really glad i i did it but....... i look back at the cost and i could have had a new kitchen , lol.
car made 527hp..... very similar build to yours i even went as far as magnesium wheel nuts
, its also won a few concours shows too, but i originally built it around the sprint track scene which i really love, the car was competing for a good while, then life took over. here's a really short crappy tik tok i did.. but next year i promise i will do a proper video of this car, its long over due. it will be in the shop anyway being PPF'd so ill use that as an opportunity to do some proper filming. Its also going through another set of changes as we speak.
https://www.youtube.com/watch?v=7rISI95dJcY
I believe TomK has schrick cams and an airbox on his and a map took it to something in the region of 385bhp? I would love to do cams, but have had to prioritise childcare next year for my 10month old!
I don't have anything against supercharging and I do think it's a cracking mod, and I've experienced a centrifugal charger in other cars, but for me I prefer the s54 engine in n/a form - I'd rather do cams than supercharge. Probably just me though
I don't have anything against supercharging and I do think it's a cracking mod, and I've experienced a centrifugal charger in other cars, but for me I prefer the s54 engine in n/a form - I'd rather do cams than supercharge. Probably just me though
The strut brace from the top will do little to nothing to prevent vertical forces from underneath damaging the tower metal.Beedub said:
Gt4 & GT3 suffer a different issue as their strut towers are aluminium, so yeah they fail completely rather than mushrooming. Neither is ideal, but at least you'll have some kind of 'warning' with our steel towers.
You're missing the correct answer to this problem; a stroked s65 :wink:Mikey_Boy said:It’s either cams or a V10…..
It's probably something like 370 (numbers came in at 383 but who knows). Imho you're never really going to have enough power, so for me what is more important is how the power I do have is delivered. The cams make the last 1000 rpm even more exciting than stock and of course the airbox adds the (all important) noise (and is the reason why I would never supercharge an S54).Ed Doe said:
TomK said:
Yeah dyno numbers are never truly reliable unless you hoik the engine out and whack that on an engine dyno, but certainly from the vids of yours I've watched it looks pretty strong!
Absolutely agree with what you've said - airbox is on my eventual list - but for me cams first!
Also a Stroked S65 would be an epic idea - I assume you've seen a chap on youtube called 'jangobipbip' who does a lot of Ring lap videos - he has a Schirmer M3 with a stroked 4.4 S65 - I believe it makes something in the region of 560bhp? Sounds incredible, plus being a v8 it's effectively a shorter block than the S54, so could be mounted further back in the engine bay, potentially improving weight distribution and handling. Sticking an S65 into my Z4M is one definitely of my 'if I won the lottery' projects !
Ed Doe said:TomK said:
Yeah dyno numbers are never truly reliable unless you hoik the engine out and whack that on an engine dyno, but certainly from the vids of yours I've watched it looks pretty strong!
Absolutely agree with what you've said - airbox is on my eventual list - but for me cams first!
Also a Stroked S65 would be an epic idea - I assume you've seen a chap on youtube called 'jangobipbip' who does a lot of Ring lap videos - he has a Schirmer M3 with a stroked 4.4 S65 - I believe it makes something in the region of 560bhp? Sounds incredible, plus being a v8 it's effectively a shorter block than the S54, so could be mounted further back in the engine bay, potentially improving weight distribution and handling. Sticking an S65 into my Z4M is one definitely of my 'if I won the lottery' projects !
I’ve seen some bad engine dynos spurting out garbage in my time…..
Isn’t the S65 a bit tall for a Z4 engine bay? :? Sounds like an epic conversion if it’s possible…
Someone I know is shoehorning one into an E30… :evil: I’m just a sucker for a V10 as a favourite engine noise, but a carbon airbox’d S54 at 8000rpm is a close second - like Tom, my S54 is going to stay NA - wilder cams are an aspiration for sure.
Mikey_Boy said:Isn’t the S65 a bit tall for a Z4 engine bay? :? Sounds like an epic conversion if it’s possible…
I’m just a sucker for a V10 as a favourite engine noise, but a carbon airbox’d S54 at 8000rpm is a close second - like Tom, my S54 is going to stay NA - wilder cams are an aspiration for sure.
I think height wise the V8 and V10 would be very similar (isn't the S65 just an S85 with 2 cylinders lopped off)? Either way both have been done a number of times, for me it would be the V8 as it would be the same weight as the s54 but shorter. There was quite a good build thread on here but not sure it ever got finished sadly https://z4-forum.com/forum/viewtopic.php?t=96046
Supersprint have a whole section for S65 converted Z4M (albeit probably for LHD, I imagine the headers and steering column will be tricky) where you can spend even more money
https://www.supersprint.com/ww-en/supersprint-performance-sport-exhaust-bmw-z4-m-gt3.aspx
TomK said:The strut brace from the top will do little to nothing to prevent vertical forces from underneath damaging the tower metal.Beedub said:
Gt4 & GT3 suffer a different issue as their strut towers are aluminium, so yeah they fail completely rather than mushrooming. Neither is ideal, but at least you'll have some kind of 'warning' with our steel towers.
You're missing the correct answer to this problem; a stroked s65 :wink:Mikey_Boy said:It’s either cams or a V10…..
It's probably something like 370 (numbers came in at 383 but who knows). Imho you're never really going to have enough power, so for me what is more important is how the power I do have is delivered. The cams make the last 1000 rpm even more exciting than stock and of course the airbox adds the (all important) noise (and is the reason why I would never supercharge an S54).Ed Doe said:
agree to disagree on that one, from a engineering point of view the strut brace is transfering the loads, so a vertical shock should in theory still travel along the bar and displace, that's why accidents with a SB are not good, they transfer the shock to the other side and will cause damage if the impact is big enough, i know thats a different load direction but the theory is still the same. most of all, its cheap insurance.
i get what you all say R.E supercharging, its not for everyone and has some Cons.... but personally i love the sound it creates with the s54 metallic thrash, i love it.... i totally understand why one would not want to add a blower.
always great to see threads from the OGs of the forum , this is a great post and one i'm really enjoying reading, well done mikey .
TomK said:I think height wise the V8 and V10 would be very similar (isn't the S65 just an S85 with 2 cylinders lopped off)? Either way both have been done a number of times, for me it would be the V8 as it would be the same weight as the s54 but shorter. There was quite a good build thread on here but not sure it ever got finished sadly https://z4-forum.com/forum/viewtopic.php?t=96046
Supersprint have a whole section for S65 converted Z4M (albeit probably for LHD, I imagine the headers and steering column will be tricky) where you can spend even more money
https://www.supersprint.com/ww-en/supersprint-performance-sport-exhaust-bmw-z4-m-gt3.aspx
Wowsers - don’t give me ideas Tom….! :lol: Makes sense on the S65 dimensions and weights… Now stop it and let me save up for cams rather than diverting off onto dangerous tangents!! :evil:
Can we all please stoppp talking about s65 swaps, it's making me lust after one :lol:
Tom that's what I'd heard - s65 is essentially an s85 with two cylinders lopped off - iirc it has the same issues with Rod bearing tolerances being very fine hence the issues both engines have with rod bearings.
A 4.4 or 4.5 stroked s65 on a set of naughty cams would just be absolute porn in a z4 I reckon.
Alternatively another route I'd fancied going down is a stroked s54 - vac motorsport, hack engineering (and I think schirmer) do stroker kits out to 3.5l - with a set of naughty cams to suit I believe a reliable 450bhp is achievable which is nuts, and they sound amazing too
Tom that's what I'd heard - s65 is essentially an s85 with two cylinders lopped off - iirc it has the same issues with Rod bearing tolerances being very fine hence the issues both engines have with rod bearings.
A 4.4 or 4.5 stroked s65 on a set of naughty cams would just be absolute porn in a z4 I reckon.
Alternatively another route I'd fancied going down is a stroked s54 - vac motorsport, hack engineering (and I think schirmer) do stroker kits out to 3.5l - with a set of naughty cams to suit I believe a reliable 450bhp is achievable which is nuts, and they sound amazing too
Lots of lovely future mods to consider….!
For now I think a little financial recovery and remedial work to get things straight on mine before hitting the track as soon as possible!
400hp+ would be fantastic, but once you start chasing power, it’s a slippery slope…
Adverts for the 224M wheels & tyres and Bilstein B10 suspension coming soon in the relevant section on here…
For now I think a little financial recovery and remedial work to get things straight on mine before hitting the track as soon as possible!
400hp+ would be fantastic, but once you start chasing power, it’s a slippery slope…
Adverts for the 224M wheels & tyres and Bilstein B10 suspension coming soon in the relevant section on here…
Can I just say Mikey, for me this has to be one of the most interesting threads on the forum in a long time. Really enjoying reading about someone modifying their car and properly letting it 'off the leash' on track, and also to read the input from other members as well. The discussion it generates about functional modifications to improve the way they drive are great to read and discuss 
For the record, I absolutely don't have a downer on owners using these cars in a more normal capacity on the road (they are road cars after all!) just this thread is what floats my boat when it comes to sports car ownership
Would you mind sharing the detail you sent to Intrax in order to spec your suspension up btw? My 1k2s are LONG overdue a refurb and I was considering getting mine revalved to breathe a little better on the road as well as working on track. Mine will be fitted to 18s though, so possibly a little different, and my 1k2s don't have the ARC... Apologies if covered already, but what final geo settings are you running too? I've still got quite a conservative setup on mine, but planning to get a much more track-oriented setup back on it when the suspension is rebuilt and put back on.
For the record, I absolutely don't have a downer on owners using these cars in a more normal capacity on the road (they are road cars after all!) just this thread is what floats my boat when it comes to sports car ownership
Would you mind sharing the detail you sent to Intrax in order to spec your suspension up btw? My 1k2s are LONG overdue a refurb and I was considering getting mine revalved to breathe a little better on the road as well as working on track. Mine will be fitted to 18s though, so possibly a little different, and my 1k2s don't have the ARC... Apologies if covered already, but what final geo settings are you running too? I've still got quite a conservative setup on mine, but planning to get a much more track-oriented setup back on it when the suspension is rebuilt and put back on.
Ed - that’s really kind of you to say - thank you! The Z4 is a super car to keep ‘as is’ or modify as you see fit I reckon. What I did see when I bought mine was potential - lots and lots of potential. The first thing I did was take it on a road trip to France absolutely bone stock and was really impressed with it, but then the engineer in me took hold and I realised there were a few tweaks here and there that could be done to improve the car.
My aim is to get to a car that can be driven comfortably on the street, pass emissions and be taken on road trips with all creature comforts intact without embarrassing itself on track - I think I’m nearly there now honestly. I understand it’s always a compromise - if I wanted a more track focussed car, I would be doing something very different. I keep coming back to the idea of a ‘Z4M CSL’ if that makes sense.
For the Intrax coil over kit, I detailed the following with them:
Vehicle weight (standard in my case)
Wheel size and type, tyre sizes and profiles
Type of driving - I detailed driving UK roads to and from circuits as well as ability to drive at Spa and Nurburgring (bumpy circuits)
What brakes installed front and rear (for unsprung weight)
Vehicle power (weight transfer)
In terms of Geometry - that’s as below. I haven’t tried it yet and likely I’ll tweak it a bit. Like you, I’ve gone through a couple of geometry iterations to try to get the car to turn-in better without being too nervous on the road. From experience with other BMWs, I know they can tolerate quite a bit of front camber and castor to aid dynamic camber change:
Front Camber: -2.7 Degrees
Front Toe: 0.5mm toe in
Front Right Caster: - 8 Degrees
Front Left Caster: -8.5 degrees
Rear Camber: -1.8 degrees
Rear Toe: 1mm toe in
Likewise, whatever folks choose to do with their cars is absolutely fine by me- Everybody has their own car story to tell and that’s what makes our hobby and forums like this so interesting to be a part of….
My aim is to get to a car that can be driven comfortably on the street, pass emissions and be taken on road trips with all creature comforts intact without embarrassing itself on track - I think I’m nearly there now honestly. I understand it’s always a compromise - if I wanted a more track focussed car, I would be doing something very different. I keep coming back to the idea of a ‘Z4M CSL’ if that makes sense.
For the Intrax coil over kit, I detailed the following with them:
Vehicle weight (standard in my case)
Wheel size and type, tyre sizes and profiles
Type of driving - I detailed driving UK roads to and from circuits as well as ability to drive at Spa and Nurburgring (bumpy circuits)
What brakes installed front and rear (for unsprung weight)
Vehicle power (weight transfer)
In terms of Geometry - that’s as below. I haven’t tried it yet and likely I’ll tweak it a bit. Like you, I’ve gone through a couple of geometry iterations to try to get the car to turn-in better without being too nervous on the road. From experience with other BMWs, I know they can tolerate quite a bit of front camber and castor to aid dynamic camber change:
Front Camber: -2.7 Degrees
Front Toe: 0.5mm toe in
Front Right Caster: - 8 Degrees
Front Left Caster: -8.5 degrees
Rear Camber: -1.8 degrees
Rear Toe: 1mm toe in
Likewise, whatever folks choose to do with their cars is absolutely fine by me- Everybody has their own car story to tell and that’s what makes our hobby and forums like this so interesting to be a part of….
Guys , thought some of you may be interested in this . Got a Porsche Carrera S in the shop currently , decided to take some measurements.....
Really interesting to see the ARB thickness . Thinner than expected , then again check out the layout of the suspension , really nice setup but a large amount of rubber bushing to deflect and deform under cornering.
27mm front z4m
Porsche front 25.5
Z4m rear 22.5 roadster 21.5
Porsche 23.5
Really interesting to see the ARB thickness . Thinner than expected , then again check out the layout of the suspension , really nice setup but a large amount of rubber bushing to deflect and deform under cornering.
27mm front z4m
Porsche front 25.5
Z4m rear 22.5 roadster 21.5
Porsche 23.5
