The V8 Bike Bus
Discussion
Err, less character to the overall car and even more of an image problem with other road users if that kind of thing bothers you.
Spec wise they were both very high and sat near the top of their manufacturer's ranges when new. Both were really well optioned with the BMW being £68k but the 957 TT being six figures with its options. They have similar tech and do similar stuff. The BMW felt slightly end-of-lifecycle with it being at the end of E53 production and some tech having been carried right through. The Porsche feels more of its age and with seemingly more recent iterations to its tech. I think the aftermarket high-end Carplay install mine has probably skews that feeling though.
To drive, the BMW feels better in many ways. It's more driver focused. The steering is better weighted, has more feel and is less corrupted. It feels almost RWD at times. The Cayenne's steering is lighter and over-assisted, it's less precise and is corrupted by the wheels being driven and feels very 4WD when modulating or applying power. I think the Porsche would benefit from more camber and a play with some toe.
The Porsche is much quicker, obviously. The BMW lifted its skirts well for an old, big girl and could still punch when needed and make a gap or overtake with ease. The Porsche is on a different level though and for such a big bus piles on speed really well. It has incredible traction too and it'd take something serious or electric to really trouble it in a TLGP. Figures seem to differ for it but tend to be quoted at 4.7 - 5.0 for 0-60 and that feels perfectly feasible. in something so big that makes you very aware of the mass and inertia that's building if you keep your foot in for extended periods. Luckily the brakes are incredible. The BMW, like all contemporary BMWs had brakes that were marginal for the performance of the car. Conversely, with huge Brembo 6 pots on the front, 4 pots on the rear and massive discs the Porsche brakes are spec'd to meet the car's needs properly as per most Porsches.
The worst thing about the Porsche, other than its image, is the noise it makes. The ridiculously good sound the 4.8is made only makes this worse. I've gone from that incredible burbling v8 rumble to something that sounds like a washing machine. I can imagine that some would choose the GTS for that reason alone, but you'd miss out on a pile of performance. I'm hoping with some changes I can make it sound much better than it does too.
I've already made quite a few changes but the next ones are to address its voice and make it sound appropriate and hopefully free up a 100 or maybe 200bhp more.
Spec wise they were both very high and sat near the top of their manufacturer's ranges when new. Both were really well optioned with the BMW being £68k but the 957 TT being six figures with its options. They have similar tech and do similar stuff. The BMW felt slightly end-of-lifecycle with it being at the end of E53 production and some tech having been carried right through. The Porsche feels more of its age and with seemingly more recent iterations to its tech. I think the aftermarket high-end Carplay install mine has probably skews that feeling though.
To drive, the BMW feels better in many ways. It's more driver focused. The steering is better weighted, has more feel and is less corrupted. It feels almost RWD at times. The Cayenne's steering is lighter and over-assisted, it's less precise and is corrupted by the wheels being driven and feels very 4WD when modulating or applying power. I think the Porsche would benefit from more camber and a play with some toe.
The Porsche is much quicker, obviously. The BMW lifted its skirts well for an old, big girl and could still punch when needed and make a gap or overtake with ease. The Porsche is on a different level though and for such a big bus piles on speed really well. It has incredible traction too and it'd take something serious or electric to really trouble it in a TLGP. Figures seem to differ for it but tend to be quoted at 4.7 - 5.0 for 0-60 and that feels perfectly feasible. in something so big that makes you very aware of the mass and inertia that's building if you keep your foot in for extended periods. Luckily the brakes are incredible. The BMW, like all contemporary BMWs had brakes that were marginal for the performance of the car. Conversely, with huge Brembo 6 pots on the front, 4 pots on the rear and massive discs the Porsche brakes are spec'd to meet the car's needs properly as per most Porsches.
The worst thing about the Porsche, other than its image, is the noise it makes. The ridiculously good sound the 4.8is made only makes this worse. I've gone from that incredible burbling v8 rumble to something that sounds like a washing machine. I can imagine that some would choose the GTS for that reason alone, but you'd miss out on a pile of performance. I'm hoping with some changes I can make it sound much better than it does too.
I've already made quite a few changes but the next ones are to address its voice and make it sound appropriate and hopefully free up a 100 or maybe 200bhp more.
Edited by 573 on Tuesday 9th February 14:41
I could put some stuff in here I guess. It's still a V8 and most certainly a bike bus.
Ride is similar between them both. I've compromised both by lowering the air suspnsion and fitting spacers. The actual kit under the Cayenne is pretty impressive though. The air struts have massively more volume and much more range of adjustment. It's also smarter and will adjust its height dynamically with speed and in conjunction with the optional PDCC that it has fitted. This obviously stiffens the springs but also stiffens the ARBs and does some dynamic levelling. It tows ridiculously well and loaded with bikes hung off the back like a huge lever its attitude on the road doesn't change at all.
The Cayenne also has proper off-road credentials. It's terrain mode lifts it right up giving it huge clearance but it also has diff locks front, rear and centre.
Ride is similar between them both. I've compromised both by lowering the air suspnsion and fitting spacers. The actual kit under the Cayenne is pretty impressive though. The air struts have massively more volume and much more range of adjustment. It's also smarter and will adjust its height dynamically with speed and in conjunction with the optional PDCC that it has fitted. This obviously stiffens the springs but also stiffens the ARBs and does some dynamic levelling. It tows ridiculously well and loaded with bikes hung off the back like a huge lever its attitude on the road doesn't change at all.
The Cayenne also has proper off-road credentials. It's terrain mode lifts it right up giving it huge clearance but it also has diff locks front, rear and centre.
Alright, I'll add a few things to bring it up to where I am with it now...
It was empty when I collected it so I quickly sought out some Optimax and assumed the position that I seem to be in fairly often with this thing.
I went for this particular one because it had relatively low miles (69k), FSH and a very good spec, highlights being things like - alcantara trimmed headlining, pillars etc, extended leather including dashboard, Bose sound, 21" Sport wheels, heated front and rear seats, sports memory seats, Sport body trim (arch extensions etc), dynamic headlights, PDCC (active body control etc.) Mainly though I wanted black with a black interior. Ideally I wanted one with the GTS blackout pack for the chrome but they seem very rare and I also wanted a factory towbar. This hasn't got the towbar, but it did have 'Preparation for detachable trailer coupling' which means the wiring for towbar wiring is in place from the front fuse box to the boot area where it's terminated. Hopefully making retrofit easier.
The previous owner had updated the media by fitting an aftermarket Pioneer Carplay system. I'm not really into aftermarket looking stereos but actually this really brings the user experience of the car up-to-date. I use Waze and Spotify seamlessly with it. It also has an integrated reversing cam.
The stereo with Bose upgrade seems good. In the boot under the incredibly neat tools and compressor (which is for the suspension but also has an outlet to use tools or inflate tyres) there's a sub neatly stashed which seems to integrate well.
Obviously the main event is the 4.8l twin turbo V8. It allegedly makes ~500hp / 700NM.
Traction is impressive as you'd imagine with huge tyres and 4wd and according to the figures at the time 0-60 is ~4.7s and the limiter is set at 171mph. As you're aware of how much mass is being hauled along and that growing sense of inertia building, it feels genuinely quick when you stand on the throttle from standstill.
It was empty when I collected it so I quickly sought out some Optimax and assumed the position that I seem to be in fairly often with this thing.
I went for this particular one because it had relatively low miles (69k), FSH and a very good spec, highlights being things like - alcantara trimmed headlining, pillars etc, extended leather including dashboard, Bose sound, 21" Sport wheels, heated front and rear seats, sports memory seats, Sport body trim (arch extensions etc), dynamic headlights, PDCC (active body control etc.) Mainly though I wanted black with a black interior. Ideally I wanted one with the GTS blackout pack for the chrome but they seem very rare and I also wanted a factory towbar. This hasn't got the towbar, but it did have 'Preparation for detachable trailer coupling' which means the wiring for towbar wiring is in place from the front fuse box to the boot area where it's terminated. Hopefully making retrofit easier.
The previous owner had updated the media by fitting an aftermarket Pioneer Carplay system. I'm not really into aftermarket looking stereos but actually this really brings the user experience of the car up-to-date. I use Waze and Spotify seamlessly with it. It also has an integrated reversing cam.
The stereo with Bose upgrade seems good. In the boot under the incredibly neat tools and compressor (which is for the suspension but also has an outlet to use tools or inflate tyres) there's a sub neatly stashed which seems to integrate well.
Obviously the main event is the 4.8l twin turbo V8. It allegedly makes ~500hp / 700NM.
Traction is impressive as you'd imagine with huge tyres and 4wd and according to the figures at the time 0-60 is ~4.7s and the limiter is set at 171mph. As you're aware of how much mass is being hauled along and that growing sense of inertia building, it feels genuinely quick when you stand on the throttle from standstill.
It had a few minor issues with it. For some reason the OSR exhaust trim piece was missing and it also had a 'headlight fault' warning on the dash. I was assured that this was because it had recently had a new headlight control unit (it has one per side) and this hadn't been coded to the car. I was happy to believe this or deal with it if it turned out to be more involved, especially after negotiating the price down.
I ordered the exhaust trim...
...and clicked it into place.
And then got on with the actual important stuff; Making it sit properly. So as a starter I fitted lowering links. These are a simple adjustable link, fitted in place of a fixed length one, to fit to the level sensor at each wheel that trick the car into thinking it's higher than it is. It then self-levels itself to a lower height. The longer you make the link, the lower that corner of the car ends up.
There's an element of trial and error with these but on this car the suspension travel is so much that I could raise it to an off-road height and access the links and pop them on and off for adjustment without even needing to jack the car up.
The added complexity on this car is that it also adjusts its own rideheight dynamically with speed. Exceed 80 mph or select 'Sport' dynamic mode and it lowers the suspension. I needed to account for that to maintain sufficient ride height and bump clearance.
This was an initial stab which was too low.
I ordered the exhaust trim...
...and clicked it into place.
And then got on with the actual important stuff; Making it sit properly. So as a starter I fitted lowering links. These are a simple adjustable link, fitted in place of a fixed length one, to fit to the level sensor at each wheel that trick the car into thinking it's higher than it is. It then self-levels itself to a lower height. The longer you make the link, the lower that corner of the car ends up.
There's an element of trial and error with these but on this car the suspension travel is so much that I could raise it to an off-road height and access the links and pop them on and off for adjustment without even needing to jack the car up.
The added complexity on this car is that it also adjusts its own rideheight dynamically with speed. Exceed 80 mph or select 'Sport' dynamic mode and it lowers the suspension. I needed to account for that to maintain sufficient ride height and bump clearance.
This was an initial stab which was too low.
Next, spacers. I did lots of measuring and decided on a 25mm front 27mm rear. Interestingly Porsche sold 14mm rear spacers for these as an option. I was interested in filling those big arches properly and giving the car a more purposeful stance. This is largely for aesthetics but obviously has dynamic consequences. In theory you reduce the effective spring rate of the roadspring (air in this case), increase track and also change numerous things to do with bump / scrub etc that most of you here understand more than most people who bolt spacers to cars just for aesthetics. I want this to drive well so I'm after a balance between standard, making changes I can for aesthetic reasons and balancing them with functionality.
Spacers fitted and the suspension height iterated for about the 5th time I was starting to finally feel the look was how I wanted it.
Spacers fitted and the suspension height iterated for about the 5th time I was starting to finally feel the look was how I wanted it.
573 said:
Next, spacers. I did lots of measuring and decided on a 25mm front 27mm rear. Interestingly Porsche sold 14mm rear spacers for these as an option. I was interested in filling those big arches properly and giving the car a more purposeful stance. This is largely for aesthetics but obviously has dynamic consequences. In theory you reduce the effective spring rate of the roadspring (air in this case), increase track and also change numerous things to do with bump / scrub etc that most of you here understand more than most people who bolt spacers to cars just for aesthetics. I want this to drive well so I'm after a balance between standard, making changes I can for aesthetic reasons and balancing them with functionality.
Spacers fitted and the suspension height iterated for about the 5th time I was starting to finally feel the look was how I wanted it.
None of your images are showing as you do not have a valid SSL certificate on your private hosting.Spacers fitted and the suspension height iterated for about the 5th time I was starting to finally feel the look was how I wanted it.
Next drive out a weird noise turned into a very loud clunk. I stopped and saw this.
I got it in the garage and started to investigate.
This was what I found.
Most parts were either completely missing, presumably smashed up and ejected out the hole or completely mangled.
The handbrake shoe was twisted out of shape and the friction material was completely missing.
I had a worry that the spacers had caused this so I measured the new studs vs the OEM ones and established that they protruded no further into the hub. In fact there was loads of clearance in that area. So I stripped the other side down to see if that would give me any clues.
The friction material was very tired and seemed to be breaking up.
...and in fact was hardly attached and could easily lift.
This allowed the broken piece of friction material to slide over the rest of the shoe and jam the disc. I have no way of knowing if this is actually what happened but it felt plausible. With the handbrake jammed and 700NM turning it all I imagine it would start to fail quite quickly. Any pieces that broke up would end up inside the 'handbrake drum' of the disc bell and start to collide and jam with more parts causing a catastrophic failure. I imagine if I hadn't have stopped fairly quickly the disc would have completely failed and caused further damage to the caliper and other things in a chain reaction.
I got away with just needing to replace the broken and missing parts and fit new discs, pads and of course, handbrake shoes.
I got it in the garage and started to investigate.
This was what I found.
Most parts were either completely missing, presumably smashed up and ejected out the hole or completely mangled.
The handbrake shoe was twisted out of shape and the friction material was completely missing.
I had a worry that the spacers had caused this so I measured the new studs vs the OEM ones and established that they protruded no further into the hub. In fact there was loads of clearance in that area. So I stripped the other side down to see if that would give me any clues.
The friction material was very tired and seemed to be breaking up.
...and in fact was hardly attached and could easily lift.
This allowed the broken piece of friction material to slide over the rest of the shoe and jam the disc. I have no way of knowing if this is actually what happened but it felt plausible. With the handbrake jammed and 700NM turning it all I imagine it would start to fail quite quickly. Any pieces that broke up would end up inside the 'handbrake drum' of the disc bell and start to collide and jam with more parts causing a catastrophic failure. I imagine if I hadn't have stopped fairly quickly the disc would have completely failed and caused further damage to the caliper and other things in a chain reaction.
I got away with just needing to replace the broken and missing parts and fit new discs, pads and of course, handbrake shoes.
I really needed this to have a towbar and it didn't have one. I did a bit of research and found that the factory detachable one is a Westfalia. I found that you could buy the exact kit the factory fits and also buy a Westfalia loom that in theory should connect very easily with the prep Porsche had already done when building the car. The intention was to do everything with the parts it would have had from the factory to make it indistinguishable from a car that had the towbar fitted by Porsche during build.
The main issue that this was during 1st lockdown when the world and his wife had decided cycling was a great thing. All bicycles and all cycling accessories were sold out and this extended to bike carriers and towbars. I had to really search about to find the proper wiring kit and eventually struggled so hard to find the actual towbar kit that I ended up speaking to Westfalia themselves who said they were making them as fast as they could. Once they had one I managed to secure it and get it sent to the UK.
Both the wiring kit and towbar kit came with fantastic, detailed instructions and both parts were fairly straightforward to fit. As per all modern cars though there was just a long list of external and internal parts to remove, in sequence in order to do a proper job of the installation.
Main mechanical change was obviously to swap the aluminium bumper bar to a steel one with a towbar receiver.
Everything I came across was in good order but I still took the opportunity to Bilt Hamber 'Electrox', zinc everything relevant and get loads of Dynax into cavities and finally cover anything susceptible with ACF-50.
The only bit the instructions didn't cover was the cut out in the bumper to allow access for the towbar. I tried to find as many pics as I could to inform me and work out where I needed to cut but it was really hard to find anything of use. I ordered a flap from Porsche that I assumed fitted in after the hole was cut but this turned out to be for a completely different bumper, maybe a non-turbo. So I made some educated assumptions, cut a big hole in the bumper and fitted it.
Luckily it turned out to be perfect.
With the towbar removed everything is completely hidden as intended.
Once the trim was removed, the wiring was as straightforward as hoped. There was even a space for the relay block ready in a space in a rack of other electrical boxes in the side of the boot.
And the removable towbar fitted perfectly into the space designed for it.
Finally I could stick the bike carrier on and throw a bike on the back.
The main issue that this was during 1st lockdown when the world and his wife had decided cycling was a great thing. All bicycles and all cycling accessories were sold out and this extended to bike carriers and towbars. I had to really search about to find the proper wiring kit and eventually struggled so hard to find the actual towbar kit that I ended up speaking to Westfalia themselves who said they were making them as fast as they could. Once they had one I managed to secure it and get it sent to the UK.
Both the wiring kit and towbar kit came with fantastic, detailed instructions and both parts were fairly straightforward to fit. As per all modern cars though there was just a long list of external and internal parts to remove, in sequence in order to do a proper job of the installation.
Main mechanical change was obviously to swap the aluminium bumper bar to a steel one with a towbar receiver.
Everything I came across was in good order but I still took the opportunity to Bilt Hamber 'Electrox', zinc everything relevant and get loads of Dynax into cavities and finally cover anything susceptible with ACF-50.
The only bit the instructions didn't cover was the cut out in the bumper to allow access for the towbar. I tried to find as many pics as I could to inform me and work out where I needed to cut but it was really hard to find anything of use. I ordered a flap from Porsche that I assumed fitted in after the hole was cut but this turned out to be for a completely different bumper, maybe a non-turbo. So I made some educated assumptions, cut a big hole in the bumper and fitted it.
Luckily it turned out to be perfect.
With the towbar removed everything is completely hidden as intended.
Once the trim was removed, the wiring was as straightforward as hoped. There was even a space for the relay block ready in a space in a rack of other electrical boxes in the side of the boot.
And the removable towbar fitted perfectly into the space designed for it.
Finally I could stick the bike carrier on and throw a bike on the back.
I really wanted the Cayenne to have the GTS trim option. That sees the window surrounds and pillar trims in satin black rather than the silver. I hate the silver trim and as you can imagine all the proper bits in black adds up to a huge amount from Porsche. I considered getting it painted but one day found myself near a local vinyl place that I knew had done some great work wrapping some racecars. I inquired and they gave me a very reasonable price to wrap all the silver bits in satin black vinyl to the correct automotive / exterior grade.
So I dropped it off, rode my bike home...
.....and returned later and collected it.
I'm very pleased with the outcome, especially for the price. I think it takes years off the car.
So I dropped it off, rode my bike home...
.....and returned later and collected it.
I'm very pleased with the outcome, especially for the price. I think it takes years off the car.
573 said:
I'll sort it, thanks. However Edge isn't really a browser is it 
. Firefox, Chrome, Safari etc all manage.
Chromium Edge is like Chrome, just faster, less resource hogging, stripped of all google tracking and apparently more secure. So yes it is a real browser and one that a lot of people are starting to use over Chrome FF etc . Firefox, Chrome, Safari etc all manage. 
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff