Knackered old Porsche with loads of natural light - Boxster!
Discussion
I think I may have done a terrible job of explaining what I meant by Cayman kit in my earlier post. Both the cars in my post are 986 Boxsters, not Caymans but they're fitted with a replacement hard top and boot lid section that essentially creates a 986 Cayman in terms of bodyshape:
These are made in GRP so likely to be an utter arse to make fit nicely as I have no idea of the tooling quality etc.
There's a couple of reasons for considering this, one is the obvious aero benefits, I'd like to do some top speed / VMAX stuff in the car eventually, if only to get there first before anyone else who's building one, but I am not massively confident in the current 25 year old well used soft top to at 180mph. It would also significantly improve some aspects of the engine access as I could make a simple (even window'd!) engine cover that could be easily accessed through the tail gate.... it also gives the option of feeding an airbox through the rear quarter glass.
I do like the OE hardtop and did consider that as an option but there a few reasons against it, not least as Escy pointed out it's got to come off everytime to access the engine.
With regards doing an actual Cayman kit, the current kit mostly bolts into a 987 so mechnaically there already is one - the electronics integration is far more significant however and the liability of reverse engineering comms with things like ABS which can have a distinct impact on the operation of the brakling and stability systems in a worst case situation is more than I'm willing to take on for the sort of volumes we're talking here. The 986 ABS system on the 2.5L pre 2000 cars is essentially stand alone and will run without MIL or drama just as it did with the original engine as long as all the vehicle speeds etc. are present and correct. The 986 kit doesn't require any modifications to the chassis loom so all this stays as it left Porsche so it's very easy to make a functional safety case or it vs the 987.
These are made in GRP so likely to be an utter arse to make fit nicely as I have no idea of the tooling quality etc.
There's a couple of reasons for considering this, one is the obvious aero benefits, I'd like to do some top speed / VMAX stuff in the car eventually, if only to get there first before anyone else who's building one, but I am not massively confident in the current 25 year old well used soft top to at 180mph. It would also significantly improve some aspects of the engine access as I could make a simple (even window'd!) engine cover that could be easily accessed through the tail gate.... it also gives the option of feeding an airbox through the rear quarter glass.
I do like the OE hardtop and did consider that as an option but there a few reasons against it, not least as Escy pointed out it's got to come off everytime to access the engine.
With regards doing an actual Cayman kit, the current kit mostly bolts into a 987 so mechnaically there already is one - the electronics integration is far more significant however and the liability of reverse engineering comms with things like ABS which can have a distinct impact on the operation of the brakling and stability systems in a worst case situation is more than I'm willing to take on for the sort of volumes we're talking here. The 986 ABS system on the 2.5L pre 2000 cars is essentially stand alone and will run without MIL or drama just as it did with the original engine as long as all the vehicle speeds etc. are present and correct. The 986 kit doesn't require any modifications to the chassis loom so all this stays as it left Porsche so it's very easy to make a functional safety case or it vs the 987.
jeremyc said:
ow about trying something a little different for the Cayman: a normally aspriated, high revving screamer installation?
It won't have the absolute power of the turbocharged version, but might be a more engaging drive and also perhaps a lower cost and more easily packaged option.
I am a big fan of high rev'ing NA engines, primarily due to my motorsport past, but the bottom line is a decent 11K RPM+ motor (which is actually high rev'ing, anything below 11K is just playing at it) is more than a Cayman. I'd love to do a VJ at circa 16K or maybe a 4 litre JUDD at 11K but then you're into some sort of significant gearbox too..... £120K drivetrain in a £20K Cayman may be a little bit OTT It won't have the absolute power of the turbocharged version, but might be a more engaging drive and also perhaps a lower cost and more easily packaged option.
poppopbangbang said:
These are made in GRP so likely to be an utter arse to make fit nicely as I have no idea of the tooling quality etc.
Is this still in production as I thought the business died long ago. Or are you going to make your own ... from scratch?
mattdavies said:
Really enjoy this thread.
On the above I am pretty sure that the seat Ibiza Cupra that first came with this enigne had this feature, I remeber a friends car making noise post shut down, therefore i am guessing an OEM style integration might be possible ( I dont know much about OEM ECU Electrickery )
When I first bought it, my Impreza had an aftermarket HKS turbo timer that ran the engine for 30 seconds after you killed the ignition. One of those maybe?On the above I am pretty sure that the seat Ibiza Cupra that first came with this enigne had this feature, I remeber a friends car making noise post shut down, therefore i am guessing an OEM style integration might be possible ( I dont know much about OEM ECU Electrickery )
Junked it as tbh if I was in an accident it would not have helped.
I like the hardtop look but also the top down. If anyone can make both work it's this man!
poppopbangbang said:
I am a big fan of high rev'ing NA engines, primarily due to my motorsport past, but the bottom line is a decent 11K RPM+ motor (which is actually high rev'ing, anything below 11K is just playing at it) is more than a Cayman. I'd love to do a VJ at circa 16K or maybe a 4 litre JUDD at 11K but then you're into some sort of significant gearbox too..... £120K drivetrain in a £20K Cayman may be a little bit OTT
There's a guy in Australia - Ian Drysdale - builds 1,000cc V8s out of two Yamaha R1 engines...just saying Marquezs Stabilisers said:
I like the hardtop look but also the top down. If anyone can make both work it's this man!
You're missing the point. He wants to remove all the soft top gubbins - like in a Cayman - to make the engine easier to access from above. In the Boxster [or Booster] you are always fighting with the soft top to get to the top of the engine. There is access but it's not brilliant.
poppopbangbang said:
I am a big fan of high rev'ing NA engines, primarily due to my motorsport past, but the bottom line is a decent 11K RPM+ motor (which is actually high rev'ing, anything below 11K is just playing at it) is more than a Cayman. I'd love to do a VJ at circa 16K or maybe a 4 litre JUDD at 11K but then you're into some sort of significant gearbox too..... £120K drivetrain in a £20K Cayman may be a little bit OTT
How about the V8 Radical engine. They were circa 400bhp. Not sure what they rev to but they do sound fantastic on open pipes!Edit, max power @ 10500
Edited by Mikeeb on Wednesday 19th June 16:09
ATM said:
Is this still in production as I thought the business died long ago. Or are you going to make your own ... from scratch?
Still made in the Far East, mostly for a US company I believe but I've used the same factory previously for some production car stuff so entirely order'able if required.... I am still undecided though, although there are some amazing name suggestions that have been made so far!
PWR doing great work as always! :
Very much looking forward to getting this on the car, I'm still deciding whether to bite 2 kg more and smoke a bigger header tank in there whilst it's apart... there is a lot of additional thermal mass in 2 kg of coolant!
With this and the new exhaust on it'll be ready for the dyno again, I'm quite excited to see how much poke it has this time around.
Very much looking forward to getting this on the car, I'm still deciding whether to bite 2 kg more and smoke a bigger header tank in there whilst it's apart... there is a lot of additional thermal mass in 2 kg of coolant!
With this and the new exhaust on it'll be ready for the dyno again, I'm quite excited to see how much poke it has this time around.
Still my fave current thread...
poppopbangbang said:
PWR doing great work as always! :
Very much looking forward to getting this on the car, I'm still deciding whether to bite 2 kg more and smoke a bigger header tank in there whilst it's apart... there is a lot of additional thermal mass in 2 kg of coolant!
Gaining 8400J/degC thermal capacity in the coolant side - oh, just do it!Very much looking forward to getting this on the car, I'm still deciding whether to bite 2 kg more and smoke a bigger header tank in there whilst it's apart... there is a lot of additional thermal mass in 2 kg of coolant!
ricola said:
'Home built by Jeff' on youtube fitted one of those roof kits on his audi V8 converted boxster track car. Looks an arse of a job to do it nicely!
I've seen the car but had missed the video of him fitting it, found it earlier and it's about as bad as I thought it would be Thanks for giving me the heads up on it
Charge cooler rad is fitted:
It positively walked on there so fair play to PWR for holding the tolerances specificed on the original drawing so well!
With the rad duct on it'll be hard to tell its not an air-con rad once it's weathered in a little. Definitley no room to do anything bigger than this in the duct in terms of core thickness
I'm going to a 2.5L header tank (which I should have finished over the next couple of days) and I'll implement a strategy to run the low speed fans when the vehicle speed is below 10 kph which should also help with heat soak from the coolant rad.
All in all I'm very happy how the charge cooling has come together on this, high boost mid engined cars are an arse to make work nicely (especially without chopping things about or doing an RS200 roof mounted IC) and the setup now should see it sub 40 degrees charge temp in nearly all use cases.
Once I've polished this off it's time to crack on with the exhaust
It positively walked on there so fair play to PWR for holding the tolerances specificed on the original drawing so well!
With the rad duct on it'll be hard to tell its not an air-con rad once it's weathered in a little. Definitley no room to do anything bigger than this in the duct in terms of core thickness
I'm going to a 2.5L header tank (which I should have finished over the next couple of days) and I'll implement a strategy to run the low speed fans when the vehicle speed is below 10 kph which should also help with heat soak from the coolant rad.
All in all I'm very happy how the charge cooling has come together on this, high boost mid engined cars are an arse to make work nicely (especially without chopping things about or doing an RS200 roof mounted IC) and the setup now should see it sub 40 degrees charge temp in nearly all use cases.
Once I've polished this off it's time to crack on with the exhaust
ATM said:
Not sure if mentioned already but the guy who built the CLR lightweight cut some holes in the arch liners behind the rads to help airflow. The later cars have this out the box-ster or booster. I can get some pics from my 981 if you like. Let me know.
I think the rear rad ducts are also quite different on the 997 etc. to support this as the standard fan shroud on the 986 and 996 are enclosed and duct into the floor infront of the arch. I'll have a look on the parts diagrams to see - good suggestion! Don't really have to worry about wheel arch positive pressure on road cars Tanks done!
2.5L capacity so around 2L more coolant in the system than previously.
Just a cheapy off the shelf generic tank modified to fit with some 19mm skin fittings and a 3D printed cap.... the later because I don't have any bar stock the correct size to spin one up on the lathe and it's not going to arrive until Friday. I'll swap it out in due course.
It's mounted via a 3D printed bracket off the bottom inner surface of the crash bar which puts it in about the only position it will fit in due to the extra length and width of the tank.
Bit of evidence on the crash bar of a few different options explored but it's all basically lightweighting so all good Fill is via the under frunk expansion tank that sits up in the corner of the frunk, so if it is ever neccesary to drain the system down from the rear of the car then it can be refilled without removing the front bumper etc.
On the subject of front bumper that's gone to paint which should freshen the front end up a little, it has been very badly painted in the past so it should rather sort things out. The rest of the car is pretty decent with the usual patina for 25 years of use so it'll be nice see it fairly presentable
Time for a bit of welding next to fab the new exhaust....
2.5L capacity so around 2L more coolant in the system than previously.
Just a cheapy off the shelf generic tank modified to fit with some 19mm skin fittings and a 3D printed cap.... the later because I don't have any bar stock the correct size to spin one up on the lathe and it's not going to arrive until Friday. I'll swap it out in due course.
It's mounted via a 3D printed bracket off the bottom inner surface of the crash bar which puts it in about the only position it will fit in due to the extra length and width of the tank.
Bit of evidence on the crash bar of a few different options explored but it's all basically lightweighting so all good
Fill is via the under frunk expansion tank that sits up in the corner of the frunk, so if it is ever neccesary to drain the system down from the rear of the car then it can be refilled without removing the front bumper etc. On the subject of front bumper that's gone to paint which should freshen the front end up a little, it has been very badly painted in the past so it should rather sort things out. The rest of the car is pretty decent with the usual patina for 25 years of use so it'll be nice see it fairly presentable
Time for a bit of welding next to fab the new exhaust....
Well this lot looks good, I just need to turn it into an exhaust now! The chaps at Jetex managed to find me an exhaust tailpipe that is extremely similar to the original Boxster one so it should all be pretty stealthy looks wise..... noise wise it may be a little different
The tight 180 required may impact gas flow a bit but it's about the only way to package this given the space available and it'll be a considerable improvement on the standard 2.5L back box regardless.
Aiming to fire the welder up this weekend
Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff