The Intelligent Money Racing 718 Cayman build thread!
Discussion
More slow progress here at IM Racing HQ. Hopefully we will be able to get out and rest some time in mid-March depending on which map Boris introduces tomorrow.
I’ve been tinkering round with various bits including tidying some wiring, fitting some roll cage foam and wrapping it where it gets scuffed each time I get in and out. I’ve fitted the pitlane timer and the transponder, finalised the seat position and put a protective front edge on the splitter; I’ll take some more photos this morning.
Every time I get one job done, I spot another one but it’s coming on ok I think.
There’s two main jobs left that I’d like done before we start testing, livery and mapping.
Andy from BG Install, aka TheConverted, is underway with turning Chris @racerdesigns’ layout into a wrap for the livery, it looks fantastic on paper so I can’t wait to see the finished result on the car!
After that the plan is to get it down to Quantum Tuning to get the map optimised. This has to be just right because we’re racing in a power/weight class with a maximum of 240bhp/ton. To add to the complication of this while everyone knows that all dynos read differently, the championship dyno takes a reading directly at the hubs where most tuning dynos convert a rolling road number into a calculated flywheel figure. So basically we have to set it up on one using a guestimated adjustment to the other
.
One slight curveball that we weren’t counting on was that the car is about 50kg heavier than we realised
. The official weight is taken after the race so the fuel tank will be pretty much empty. When we got the car it showed a full tank and so we allowed for that in the weights, until it refused to start one day and I found it had run out of fuel! This is both good and bad news, bad because nobody likes a porky race car even when it is a Porker, good because this car should handle weight pretty well and more weight means we are allowed more power 
.
A bit of investigation in the tank led me to find this -
It would appear that in it’s original accident the sender unit snapped off and has been sat at the bottom of the tank in the full position ever since
. Not wanting any more terror/hilarity at Porsche parts prices and remembering that this is supposed to be a home-build I improvised a repair which should do the trick nicely 
.
So that’s back in now and we can see how it holds when we finally get out to test!
So the car with driver (and an empty tank) weighs just over 1400kg meaning we can get away with up to 335bhp at the hubs. The general wisdom seems to be that this number will be somewhere between 5-10% lower than the flywheel figure so we can probably aim at about 360bhp at the fly to be well optimised in class. We then get to go on the official dyno at the start of April to do their power run which will then determine if we have got the numbers right or if we will need to drop power or add ballast to compensate.
I’ve been tinkering round with various bits including tidying some wiring, fitting some roll cage foam and wrapping it where it gets scuffed each time I get in and out. I’ve fitted the pitlane timer and the transponder, finalised the seat position and put a protective front edge on the splitter; I’ll take some more photos this morning.
Every time I get one job done, I spot another one but it’s coming on ok I think.
There’s two main jobs left that I’d like done before we start testing, livery and mapping.
Andy from BG Install, aka TheConverted, is underway with turning Chris @racerdesigns’ layout into a wrap for the livery, it looks fantastic on paper so I can’t wait to see the finished result on the car!
After that the plan is to get it down to Quantum Tuning to get the map optimised. This has to be just right because we’re racing in a power/weight class with a maximum of 240bhp/ton. To add to the complication of this while everyone knows that all dynos read differently, the championship dyno takes a reading directly at the hubs where most tuning dynos convert a rolling road number into a calculated flywheel figure. So basically we have to set it up on one using a guestimated adjustment to the other
.One slight curveball that we weren’t counting on was that the car is about 50kg heavier than we realised
. The official weight is taken after the race so the fuel tank will be pretty much empty. When we got the car it showed a full tank and so we allowed for that in the weights, until it refused to start one day and I found it had run out of fuel! This is both good and bad news, bad because nobody likes a porky race car even when it is a Porker, good because this car should handle weight pretty well and more weight means we are allowed more power .A bit of investigation in the tank led me to find this -
It would appear that in it’s original accident the sender unit snapped off and has been sat at the bottom of the tank in the full position ever since
. Not wanting any more terror/hilarity at Porsche parts prices and remembering that this is supposed to be a home-build I improvised a repair which should do the trick nicely .So that’s back in now and we can see how it holds when we finally get out to test!
So the car with driver (and an empty tank) weighs just over 1400kg meaning we can get away with up to 335bhp at the hubs. The general wisdom seems to be that this number will be somewhere between 5-10% lower than the flywheel figure so we can probably aim at about 360bhp at the fly to be well optimised in class. We then get to go on the official dyno at the start of April to do their power run which will then determine if we have got the numbers right or if we will need to drop power or add ballast to compensate.
Hi Paul. Yep, you can get wheels and fly but hub is a different reading again. Hub dynos remove the wheels and bolt directly to the hub which bypasses the significant losses through the tyres, typically it will result in a figure somewhere between wheels and fly.
Different dynos can give significantly different readings anyway but this is an extra complication that we need to allow for.
Different dynos can give significantly different readings anyway but this is an extra complication that we need to allow for.
Steve H said:
Hi Paul. Yep, you can get wheels and fly but hub is a different reading again. Hub dynos remove the wheels and bolt directly to the hub which bypasses the significant losses through the tyres, typically it will result in a figure somewhere between wheels and fly.
Yeah, of course. I think I must have still been half asleep when I commented earlier. Didn’t even think about the tyre losses which I guess can be relatively significant. (And quite variable depending on things like tyre pressure and even how tightly strapped down the car is)Gallons Per Mile said:
Once you've got it mapped couldn't you find somewhere with a hub dyno so you're going in to the official one with at least a reasonably good idea of power? That might save some hassle down the line?
Even the hub dynos vary unfortunately. Power testing is a lottery, too many variables but it’s the best of the bad options for this kind of racing. We should be able to get pretty close this way and trim weight to suit if necessary.
So after weeks of tweaking and trimming and messing with bits where you hardly see the difference even after hours of work, we had some big progress on Tuesday..........
PHers Andy @bginstall and Chris @racerdesigns came up trumps with the livery, it looks amazing!
Next up is a trip down south at the weekend to drop it off to Quantum Tuning to get the mapping setup and then it’s a countdown to the very very long awaited track debut that’s planned for March 7th at Oulton Park.
PHers Andy @bginstall and Chris @racerdesigns came up trumps with the livery, it looks amazing!
Next up is a trip down south at the weekend to drop it off to Quantum Tuning to get the mapping setup and then it’s a countdown to the very very long awaited track debut that’s planned for March 7th at Oulton Park
.
It’s finally been on track!!
All loaded up and tucked away in the workshop last night-
And landed at Oulton Park this morning-
And it also had the official dyno run for the championship-
And the results have been excellent
No failures in 120 miles of running, all temps ok and handling is brilliant with fantastic levels of grip.
The only issue I had all day was when I came to fit the new wheels that I’d got for the second set of tyres and found they had been machined wrongly and don’t fit
.
Other than that an excellent day out and as long as it all looks ok when I check it over tomorrow I’m back out again on Friday at Silverstone
All loaded up and tucked away in the workshop last night-
And landed at Oulton Park this morning-
And it also had the official dyno run for the championship-
And the results have been excellent
No failures in 120 miles of running, all temps ok and handling is brilliant with fantastic levels of grip.
The only issue I had all day was when I came to fit the new wheels that I’d got for the second set of tyres and found they had been machined wrongly and don’t fit
.Other than that an excellent day out and as long as it all looks ok when I check it over tomorrow I’m back out again on Friday at Silverstone
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