Notices
Projects For Serious DIY Car Projects

GC8 Track Aero - Double Deck Rear Diffuser

Thread Tools
 
Search this Thread
 
Old 05 February 2018, 02:20 PM
  #61  
Jonny Cut Corners
Scooby Regular
 
Jonny Cut Corners's Avatar
 
Join Date: Nov 2015
Location: Leicestershire, UK
Posts: 191
Received 18 Likes on 17 Posts
Default

Originally Posted by MY94BlueWRX
We were running with them until I did the testing, and they actually were causing air to enter the engine bay... not the other way around!

Wow, very interesting. I think I owe you a few beers for all this info!
Old 05 February 2018, 09:30 PM
  #62  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

No problem, happy to help... if you have any more question just ask?
Old 16 August 2018, 10:41 PM
  #63  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default 6 Months Goes Fast!

Well it’s been 6 months since I last posted, and unfortunately not much has happened with the car, as I’ve been building a new home for it... a purpose built garage that can accommodate a two post lift and a workshop.

I'm coming close to the end but these things take more time than you realise, especially when I had to build another structure first to house all the existing garage crap!

Anyway... regarding the car, I have altered the geometry to suit the Avon slick tyres, as I had it way off causing the car to roll massively as it tried to sit flat on the contact patch, really need to get the tyre temp monitoring system set up, as this would have told me straight away!! You live and learn I guess...

Plus I’ve swapped out the sh*tty comp brake biasing valve going to the rear brakes with a proper AP Racing item, as I don’t think the comp brake thing was doing anything, which was causing the rears to lock up... not great when you’re on the edge already lol 😂

Hopefully in the coming months I can get back onto the car development, once I’ve got our entire setup moved home... till then 👍

Old 20 August 2018, 09:51 PM
  #64  
sunny1989
Scooby Regular
 
sunny1989's Avatar
 
Join Date: Aug 2010
Location: 35,000 ft
Posts: 692
Likes: 0
Received 0 Likes on 0 Posts
Default

looking forward to seeing the latest developments and the new workshop
Old 17 September 2018, 05:03 PM
  #65  
Ash Webster
Scooby Regular
 
Ash Webster's Avatar
 
Join Date: Dec 2013
Location: Lytham St Annes
Posts: 975
Received 2 Likes on 2 Posts
Default

where did you get the front diffuser from? looking at a very similar direction with mine .....

also i assume you have cold air feeds going up from each of your fog light covers?
Old 17 September 2018, 08:20 PM
  #66  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

Hi Ash,

The front diffuser is a combination of a Seibon Carbon Lip, coupled with a custom made under tray and end plates.

The fog light inlets are actually brake ducts that feed air into the back of the hubs/bells.

Regards,
Kim
Old 18 September 2018, 11:07 AM
  #67  
Ash Webster
Scooby Regular
 
Ash Webster's Avatar
 
Join Date: Dec 2013
Location: Lytham St Annes
Posts: 975
Received 2 Likes on 2 Posts
Default

Originally Posted by MY94BlueWRX
Hi Ash,

The front diffuser is a combination of a Seibon Carbon Lip, coupled with a custom made under tray and end plates.

The fog light inlets are actually brake ducts that feed air into the back of the hubs/bells.

Regards,
Kim
Interesting. The bumper I have has brake duct vents also linked into the wheel arch lining too... never thought about directing even more air through there too, too focussed on getting cold(er) air to the turbo!

Thanks for the info. Ill look into crafting one myself.

Ash
Old 20 September 2018, 04:14 PM
  #68  
powered by vodka
Scooby Regular
 
powered by vodka's Avatar
 
Join Date: May 2003
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

amazing work

I always wanted to duct the hot rad air out of the side vents, but running lateral rad/ic combo its just impossible as there is no space to work with
I ended up fabbing front undertray to create high/low pressure for the rad/ic to work properly, but I did notice my oil temps went up few degrees, probably because there is no incoming air to cool the pan now, and I doubt my hood current configuration is able to suck all of that hot air out








I am thinking of making a vent with a lip in the undertray to help suck the hot radiator air out, but not sure if it will make things better or worse
Old 20 September 2018, 05:11 PM
  #69  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

Nice work 👍

It’s still worth adding a vent into your undertray, as the low pressure air going under your car will draw the high pressure hot air out of the engine bay.

I’m going to be doing something similar, but I need to separate it from the underfloor air flow so it doesn’t disturb the rear diffuser air flow.
Old 20 September 2018, 06:48 PM
  #70  
powered by vodka
Scooby Regular
 
powered by vodka's Avatar
 
Join Date: May 2003
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

flat floor and rear diffuser is in my plans, just need to find time and inspiration

I am concerned that the underfloor low pressure air will be sucking air from the hood vents if I open up the undertray lol
Old 20 September 2018, 08:09 PM
  #71  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

If that’s the case then happy days, as you’ll have a through flow and your cooling issues are sorted.

Providing you achieve a flow out of the engine bay, to above or below then you’re sorted... obviously you need a feed/s into the engine bay to create high pressure, then it will always escape to the easiest low pressure region.
Old 21 September 2018, 01:23 PM
  #72  
powered by vodka
Scooby Regular
 
powered by vodka's Avatar
 
Join Date: May 2003
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

I might get those hvac louvers since there are sold in any house appliances stores, and rivet them to the bottom of the underteay

next question I have in mind is location - put it right after the rad or move it backwards under the exhaust manifold
if I put it directly after the rad this could prevent air go towards the oil pan and it might heat up even more from the manifold
another concern is the decrease in downforce if you are pushing air through the bonnet to the ground

I need to build a wind tunnel

Last edited by powered by vodka; 21 September 2018 at 01:58 PM.
Old 21 September 2018, 03:25 PM
  #73  
mikelatz
Scooby Regular
iTrader: (1)
 
mikelatz's Avatar
 
Join Date: Nov 2010
Location: barańain, basque country
Posts: 142
Likes: 0
Received 0 Likes on 0 Posts
Default

Really nice build mate, awesome track car congratulations
Old 29 October 2018, 09:32 PM
  #74  
powered by vodka
Scooby Regular
 
powered by vodka's Avatar
 
Join Date: May 2003
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

I've been meaning to ask you, have you logged any data prior and after your hood vent duct mod?
Old 29 October 2018, 11:29 PM
  #75  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

At the time (a couple of years now) when testing with a magnahelic gauge, we just recorded the numbers by hand... so no log of data I’m afraid
Old 29 October 2018, 11:33 PM
  #76  
powered by vodka
Scooby Regular
 
powered by vodka's Avatar
 
Join Date: May 2003
Posts: 127
Likes: 0
Received 0 Likes on 0 Posts
Default

what about temperature changes?
Old 30 October 2018, 07:38 AM
  #77  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

Which modification are you referring to, as there are three different vents that have been changed, all at different times for different reasons?

Last edited by MY94BlueWRX; 30 October 2018 at 07:38 AM. Reason: Spelling
Old 06 November 2018, 10:27 PM
  #78  
Floyd
Scooby Regular
iTrader: (9)
 
Floyd's Avatar
 
Join Date: Apr 2000
Posts: 5,470
Received 9 Likes on 5 Posts
Default

Love this project.
Old 15 February 2019, 09:59 AM
  #79  
Itamar_M
Scooby Regular
 
Itamar_M's Avatar
 
Join Date: Jan 2019
Location: Israel
Posts: 195
Received 31 Likes on 22 Posts
Default

It's always nice seeing original "out of the box" work!

Awesome car!
Old 05 September 2021, 12:08 PM
  #80  
4slidn
Scooby Newbie
 
4slidn's Avatar
 
Join Date: Sep 2021
Location: Sydney
Posts: 1
Received 0 Likes on 0 Posts
Default Hi

Originally Posted by MY94BlueWRX
Morning Guys,


After lots of design, development and fabrication, we have eventually got close to the completion of the underbody aero for our GC8 track car, or at least the latest version of it anyway!


Many iterations of exhaust placement and diffuser configurations have led us to our latest version of the front splitter, flat underfloor and double deck rear diffuser. We have completed some tuft testing (albeit fairly crude) however the results speak for themselves, in terms of the airflow that we are now getting through both upper and lower parts of the rear diffuser.

Version 1 Airflow - https://youtu.be/ZD0DIKG9sXk


Version 2 Airflow - https://youtu.be/0jEYFyu8Yt8

Two venturi tunnels have been added into the flat floor to provide an airflow path for the upper deck, as we had a big issue with exhaust fumes entering the car with the previous design. This has hopefully been resolved with a side exit exhaust and the redesigned double deck diffuser.


Any questions, comments or suggestions, from anyone that has also travelled down the Aero path would be gratefully received?


Cheers,
Kim.







hi are you selling these setups
Old 05 September 2021, 09:58 PM
  #81  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

Hi there, I wasn’t looking at selling these on a small commercial scale… but this particular setup (floor & diffuser) might be available for sale shortly?

Send me a PM if you’re interested?
Old 07 September 2021, 12:19 AM
  #82  
johnnybon
Scooby Regular
iTrader: (70)
 
johnnybon's Avatar
 
Join Date: Feb 2008
Location: london
Posts: 3,221
Likes: 0
Received 4 Likes on 3 Posts
Default

Hi guys I have sent you a pm 👍
Old 19 September 2021, 08:40 AM
  #83  
adam.pah
Scooby Regular
 
adam.pah's Avatar
 
Join Date: Aug 2012
Location: Herts/Essex
Posts: 1,056
Received 453 Likes on 306 Posts
Default

Just read through this whole thread, what an amazing job you’ve done with this car, hats off!

subscribed from now on!
Old 22 September 2021, 10:49 PM
  #84  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default It’s been too long!

After a very long break, once I had finished the garage/workshop… I am back working on the car and have tackled lots of refurbishment projects over the last couple of years to keep the car running for many years to come.

This all started when I was fitting the gearbox oil cooler & pump, and found metal chips in the drained oil… Everything that follows was a result of this!

1. Rebuilt the gearbox including straight cut 3rd & 4th, full set of new synchros and every bearing possible, refurbished case and custom stainless snout
2. New front Driveshafts
3. Complete strip down and refurbished propshaft with new spicer u-joints and centre bearing, all blasted, powder coated and balanced
4. Refurbished & rebuilt rear diff with Tecno5 LSD
5. Complete strip down and refurbished rear driveshafts, with hi temp competition grease and new boots
6. New hand brake cables
7. Complete strip down and refurbished rear hubs with new bearings, machined hub flange and new studs
8. New adjustable rear lateral arms
9. Complete strip down, blasted and powder coated gearbox cradle, rear subframe and rear diff cradle
10. New Superpro rear bushes everywhere!
11. Fully cleaned and under sealed from front to back before re-assembly.

Then if that wasn’t enough, I decided to design and build a new tall shifter that would put the gear shift closer to the steering wheel, this has worked out really well! 👍🏻

















Old 23 September 2021, 04:32 PM
  #85  
GT_MAXER
Scooby Regular
 
GT_MAXER's Avatar
 
Join Date: Nov 2008
Posts: 146
Received 6 Likes on 5 Posts
Default

that looks like a sequential gear shifter, i assume you have an extension added to the standard gearshift with one of those units that convert sequenctial shifts into the correct pattern?

amazing, id love a shifter closer to the steering for mid corner shifts.
Old 23 September 2021, 04:33 PM
  #86  
GT_MAXER
Scooby Regular
 
GT_MAXER's Avatar
 
Join Date: Nov 2008
Posts: 146
Received 6 Likes on 5 Posts
Default

ps love the danger sign
Old 23 September 2021, 09:01 PM
  #87  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

It’s actually still a H Pattern shifter, just engineered to lift the shift **** and shorten the throw. Similar to the CAE Ultra Shifter but not Ł1000+.

Sequential is next on the list! 👍
The following users liked this post:
Old 06 October 2021, 06:44 PM
  #88  
GT_MAXER
Scooby Regular
 
GT_MAXER's Avatar
 
Join Date: Nov 2008
Posts: 146
Received 6 Likes on 5 Posts
Default

Originally Posted by MY94BlueWRX;[url=tel:11956788
11956788[/url]]Morning Guys,


After lots of design, development and fabrication, we have eventually got close to the completion of the underbody aero for our GC8 track car, or at least the latest version of it anyway!


Many iterations of exhaust placement and diffuser configurations have led us to our latest version of the front splitter, flat underfloor and double deck rear diffuser. We have completed some tuft testing (albeit fairly crude) however the results speak for themselves, in terms of the airflow that we are now getting through both upper and lower parts of the rear diffuser.

Version 1 Airflow - https://youtu.be/ZD0DIKG9sXk


Version 2 Airflow - https://youtu.be/0jEYFyu8Yt8

Two venturi tunnels have been added into the flat floor to provide an airflow path for the upper deck, as we had a big issue with exhaust fumes entering the car with the previous design. This has hopefully been resolved with a side exit exhaust and the redesigned double deck diffuser.


Any questions, comments or suggestions, from anyone that has also travelled down the Aero path would be gratefully received?


Cheers,
Kim.







What size tyres and width do you guys run with those arches
Old 06 October 2021, 06:51 PM
  #89  
MY94BlueWRX
Scooby Regular
Thread Starter
 
MY94BlueWRX's Avatar
 
Join Date: Jul 2005
Posts: 178
Likes: 0
Received 6 Likes on 4 Posts
Default

We’re running 255/40/R17 and 265/35/R18 on different sets of rims. All rim widths are 9.75”
Old 06 October 2021, 07:44 PM
  #90  
GT_MAXER
Scooby Regular
 
GT_MAXER's Avatar
 
Join Date: Nov 2008
Posts: 146
Received 6 Likes on 5 Posts
Default

Originally Posted by MY94BlueWRX;[url=tel:12111332
12111332[/url]]We’re running 255/40/R17 and 265/35/R18 on different sets of rims. All rim widths are 9.75”
hi any spacers needed. What alloy wheel
offset works there for the 18”?


Quick Reply: GC8 Track Aero - Double Deck Rear Diffuser



All times are GMT +1. The time now is 03:21 AM.