The Roadster NA Journey Begins

[Magpie]

When I get the time, I really like studying your data, not enough guys are generating this sort of useful information for their own benefit - yet!

At WTAC somebody was saying that nobody in clubsprint collects/uses data other than GPS/lap time (basics). The person was then pointed in my direction

I will not boost the car so I need to get smarter to get faster. There is a limit and when I get there then I will look at power options.

[Magpie]

Quite day so decided to play around with a door... Current rules require that the OEM door be used as well as the door cards. Removing the winder and opener maybe a pain so at the moment they are staying.

Without glass, winders, motors etc it weights 15.9 kg
DSCN4878 by Eipeip, on Flickr

DSCN4879 by Eipeip, on Flickr

A few simple cuts (intrusion bars removed) it is down to 12.7. Have not done any 'serious' cuts yet.
DSCN4880 by Eipeip, on Flickr

DSCN4881 by Eipeip, on Flickr

Next part is to remove the extra metal at the top of the door.

[Magpie]

Spent the Sunday ticking off a few jobs off the list, and adding some new ones The door project was consigned to the back of the shed.

Still unsure about Lakeside track day on 06/11, still need to get work time off. If the 'gods' allow the AR-1's will be used on 8" rims.

New - small flat flap off the boot to reduce drag

Tick - fix boot vertical movement. Did this with some hard plastic packers. This worked a treat, boot needs a decent 'slam' to close now. But significantly less vertical movement. If this works will 'pin' the boot. However looking at a new wing design, either from Singular or a local custom job


New - radiator ducting
The radiator developed a very small leak during WTAC so was pulled out and repaired. So decided to make the ducts to stop the air going around/under the radiator. Good chance that this should also reduce drag and control the air a lot better. Next step will be venting the air from inside the wheel arches.

Passenger side - before


Drivers side after
From the mouth - will make these from CF soon. I am considering bringing the brake duct intakes onto the new side panels and 'blank' off the holes on the air dam. Could also use the space under the radiator for an air duct for the intake. Will use double sided tape to hold the bottom part of the duct to the radiator and tape down the leading edge to make it lokk pretty.



The PWR radiator takes about 800ml of oil so this was filled as well as the lines primed before everything was connected back up. COPS were disconnected and the engine cranked to get some oil pressure up and circulate the oil.

This is a great tool to fill and 'burp' the radiator. Each year this has been taken to WTAC it has been borrowed by numerous teams...





​​​​​​​

[Lokiel]

Is that the Lisle Spill Free Funnel (aka "Magic Funnel")?

I bought a Lisle Spill Free Funnel for my TSE radiator since filling with a regular funnel took forever just to fill the radiator - not surprised it got a lot of users.

[Magpie]

Yes it is

http://www.lislecorp.com/divisions/products/?product=606

[Eunos_Frogster]

However looking at a new wing design, either from Singular or a local custom job ​​​​​​​

Hey magpie I'll buy your apr wing if you decide to sell it

[Magpie]

Hey magpie I'll buy your apr wing if you decide to sell it

There is a list already of interested people, it started a while ago . Discussing local options today, possibly a dual element 2D wing... Will require a review of the current aero to make more front downforce as a 2D dual element will create a lot more downforce. Not to mention suspension setup.

[Eunos_Frogster]

There is a list already of interested people, it started a while ago . Discussing local options today, possibly a dual element 2D wing... Will require a review of the current aero to make more front downforce as a 2D dual element will create a lot more downforce. Not to mention suspension setup.

Sounds like serious business with the 2D wing


Sent from my iPad using Tapatalk

[Magpie]

Sounds like serious business with the 2D wing

You could say that, and there are a few things I am not saying about it. Plan for 2018 is about reducing drag and weight so where to get the best bang for buck.

Clubsprint rules are restrictive in how many OEM parts you can replace and what aero you can run

I could go CF hardtop (with non glass rear window), CF doors, CF boot lid etc this would save maybe 100kg but would require the installation of a full cage (weight back in). A stab in the dark for a 60kg weight saving it could cost about $8k, not good value for money ($133/kg).

A heated windscreen, that adds no additional weight but would allow the removal of about 7kg of 'stuff' (fans, heater core, HVAC) would cost about $800 ($114/kg) so slightly better value but still expensive in $/kg.

A complete rewire with say Racepak Smartwire may save 10kg at a cost of $3k (system + wire + plugs etc) at $300/kg, this is not very cost effective.

Saving weight will allow the car to accelerate faster where as drag will allow a faster speed.

With respect to drag, these are cheaper and easier options to test, evaluate, do and undo. Not being road registered anymore does make testing a little more difficult (coast down tests) but at general practice at QR it is possible to do coast down tests, albeit only in one direction.

1. Radiator ducting, stop air passing around/under radiator. This will make the air going into the engine bay/wheel arches more predicable/manageable.
2. Remove rear bumper/difusser and test if drag is reduced. If 'better' then cut bumper down (or remove completely). Then consider if a difusser can be designed to improve aero. With a dual element wing a difusser may not be required.
3. Change vortex generators on hardtop to smaller ones. This can be done with wool tuft testing. The issue is the current vortex generators maybe stopping sufficient air from passing under the wing. This could go some way to explain why increasing the wing AoA has given a benefit. Conversely the additional rear wing AoA was because there was not enough in the past...
4. Removing the air from inside the wheel arches. Having a spare set of front fenders allows some testing to be carried out. However, some differential air pressure tests would need to be done to confirm if effective.
5. Making a mold of the current air dam and making if from CF and smoothing it out (make it look neater). Again this would be done to reduce drag by moving the brake duct holes to inside the 'mouth'. Further, the mouth size could be reduced. Reducing the mouth size is easy to test.
6. Canards to improve from downforce, again this will be a major consideration if a dual element wing is used.
7. Making covers for the headlights, again to reduce drag.
8. Remove rear mudguards (done)

Finally I could just increase RWHP, but until such time as I feel I have reached the limits (within some constraints) no more power will be added.

[Magpie]

2017 is almost finished, have King of QR event to do on 16/11/17 and hopefully will get to the MX5 Car Club motorsport awards on the evening of 16/11/17. Have received an email that says I'm up for a trophy

Just in case anybody is wondering what is going on in 2018.

Hmmm by Eipeip, on Flickr

[greenMachine]

SMP GP Circuit?

[Magpie]

SMP GP Circuit?

Yes and the orange line is about 8 secs faster than my PB despite the less main straight speed. It is very interesting how this could be achieved WITHOUT changing the cars power!

[Magpie]

SMP GP Circuit?

Apologies, it is the blue line that is 8 secs faster (1:36.19), my bad. The orange is (1:41.15). Decreasing drag by 10% could achieve a lap time of 1:44.61, if I could drive it as per the simulation...

[Magpie]

Playing with the Racepak software managed to setup a quick way to check how changes have impacted the car. Instead of using the inbuilt ACCEL G function I created a maths Chanel called ACCEL = 'Accel G'*9.80665. This converts the Accel G into acceleration m/sec², then I smoothed it to 100.

I may play around with the smoothing but it is looking promising. The Racepak software is very clunky and no where near the ease of use of the Motec stuff, but I'm getting used to it and it is not as bad as I first thought.

What it does show is at Sydney Motorsport park the blue (2017) was accelerating faster than red (2015) at the same speed. I will run this against the recent data on the National to see if the theory holds.


ACCEL by Eipeip, on Flickr

[StillIC]

....
I could go CF hardtop (with non glass rear window), CF doors, CF boot lid etc this would save maybe 100kg but would require the installation of a full cage (weight back in). A stab in the dark for a 60kg weight saving it could cost about $8k, not good value for money ($133/kg).

A heated windscreen, that adds no additional weight but would allow the removal of about 7kg of 'stuff' (fans, heater core, HVAC) would cost about $800 ($114/kg) so slightly better value but still expensive in $/kg.

A complete rewire with say Racepak Smartwire may save 10kg at a cost of $3k (system + wire + plugs etc) at $300/kg, this is not very cost effective.
....

I have been using a performance/dollar factor to determine what is worth doing to my car since its second engine rebuild about 4 years ago. Last week my $200 lead acid battery died, so I replaced it with a $460 LiFePO4 battery. Saved 9.0kg. I am going to call that a $260 expense, therefore $29/kg. This is a little better than the performance gains from spending many thousands on my engine. I have been using a factor of $33/kg as a 'must do' decision point (which equates very approximately to $333/1% improvement in power:weight), where any spending above this must be scrutinised for some added value beyond power or weight. But the thought of pulling the motor apart to get more power, or heaven forbid building another, means I can probably spend more than $33/kg and still be in front. The Li battery really makes light weight wheels, seats, body panels and most other light weight race car stuff, seem like terrible value.