➜ advanced search
Add a more detailed reply Start a new thread in the Exterior forum
Home -> Forums -> Exterior -> Rear Diffuser

displaying posts 1 to 25 of 112

Pages (5): [1] 2 3 .. last

Author Subject: Rear Diffuser
eddy_gti6

Seasoned Pro

Location: Durham

Registered: 20 Oct 2008

Posts: 8,716

Status: Offline
Post #1
Been looking into making a rear diffuser for my car while its off the road. Been looking this morning to see what i could find for a 306 but there is nothing.
Been thinking of the idea for a little while now to fill in that big gap under the boot where the spare wheel is suppose to be what really just acts like a parachute slowing you down no end. Having a rear diffuser will help smooth the airflow under the car thus increaseing grip levels.

Having a rear diffuser eases high velocity air back to normal velocity and also helps fill in the area behind the car making the whole underbody a more efficient downforce producing device by reducing drag on the car and increasing downforce. The diffuser also imparts upward momentum to the air which further increases downforce.

Closest thing i have seen to something good is the diffuser cherry has on his 106 turbo:


________________________________________


Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
Posted 26th Apr 2012 at 09:36
Profile
dangti6

aka JKshooter

Location: Taunton, Somerset

Registered: 15 Jun 2006

Posts: 10,305

Status: Offline
Post #2
Don't forget to fold your back seats down also.

________________________________________

  • Senior Test Automation Engineer for the 306GTi6 Owners Club Forum Wizard

    • Posted 26th Apr 2012 at 09:55
    Profile
    eddy_gti6

    Seasoned Pro

    Location: Durham

    Registered: 20 Oct 2008

    Posts: 8,716

    Status: Offline
    Post #3
    dangti6 wrote:
    Don't forget to fold your back seats down also.


    What back seats? i dont have any Crazy

    ________________________________________


    Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
    Posted 26th Apr 2012 at 10:21
    Profile
    rallye1999

    Senior User

    Location: redcar

    Registered: 05 Jul 2009

    Posts: 718

    Status: Offline
    Post #4
    if your going to do that you may aswel try and to the floor flat also
    Posted 26th Apr 2012 at 12:48
    Profile
    phillipm

    Seasoned Pro

    Location: Rotherham

    Registered: 15 Oct 2006

    Posts: 20,607

    Status: Offline
    Post #5
    Waste of time without a flat floor anyway. Really big waste of time if it's as high as the one on that 106 and doesn't extend past the boundary layer on the rear bodywork.

    Especially when someone's stuck an exhaust under it.

    ________________________________________

    - Bespoke rollcages/additions/adjustments. Half cages right up to complete custom spaceframes - MSA/FIA spec, CDS, ROPT, T45, etc - PM me
    Email me!
    Custom-made polybushes available - need an odd size or fitment? - anything from batch work to one-off pieces.
    Posted 26th Apr 2012 at 12:59
    Profile
    eddy_gti6

    Seasoned Pro

    Location: Durham

    Registered: 20 Oct 2008

    Posts: 8,716

    Status: Offline
    Post #6
    I was planning on doing the whole underside of my car. He doesnt have that diffuser no more, he has a new one and thr exhaust has been moved to a side exit aswell so its out of the way. Just realy wanting to know if there is anyone that has put one on a 306 before?

    ________________________________________


    Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
    Posted 26th Apr 2012 at 14:34
    Profile
    dangti6

    aka JKshooter

    Location: Taunton, Somerset

    Registered: 15 Jun 2006

    Posts: 10,305

    Status: Offline
    Post #7
    Are you going down the High Boost route?

    ________________________________________

  • Senior Test Automation Engineer for the 306GTi6 Owners Club Forum Wizard

    • Posted 26th Apr 2012 at 14:43
    Profile
    eddy_gti6

    Seasoned Pro

    Location: Durham

    Registered: 20 Oct 2008

    Posts: 8,716

    Status: Offline
    Post #8
    No i will be going N/A power. Jenvey bodys with a rebuilt engine... Whistle

    ________________________________________


    Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
    Posted 26th Apr 2012 at 14:47
    Profile
    welshpug!

    Capt Pedantic

    Location: Bigend, Wales.

    Registered: 27 Mar 2007

    Posts: 25,838

    Status: Offline
    Post #9
    I would imagine Ash might have looked into it for his high boost race car if it was feasible.


    you'd probably benefit more from a proper kitcar spoiler like the 106 and saxo's ran, though to make the most of any mods like this you need to be carrying some serious speed....

    ________________________________________

    need a part number? get on here - http://public.servicebox.peugeot.com

    Bring on the Trumpets.

    Posted 26th Apr 2012 at 14:47
    Profile
    eliotrw

    Seasoned Pro

    Location: Southwark

    Registered: 18 Jul 2010

    Posts: 4,864

    Status: Offline
    Post #10
    I thought about getting that piece from a 309 or 405 (One of the two cant remember which) But theres a plastic bit that goes from the bumper and under the beam which maybe could help things if it was modified a bit.

    ________________________________________

    Ex- Phase 3 China GTi-6 T-Reg
    Posted 26th Apr 2012 at 15:41
    Profile
    welshpug!

    Capt Pedantic

    Location: Bigend, Wales.

    Registered: 27 Mar 2007

    Posts: 25,838

    Status: Offline
    Post #11
    neither had a full rear undertray, but both have a small plastic bit between the fuel tank and the spare wheel, and the MI16's spare wheel carrier has a sheet of metal on the bottom.

    ________________________________________

    need a part number? get on here - http://public.servicebox.peugeot.com

    Bring on the Trumpets.

    Posted 26th Apr 2012 at 15:46
    Profile
    eliotrw

    Seasoned Pro

    Location: Southwark

    Registered: 18 Jul 2010

    Posts: 4,864

    Status: Offline
    Post #12
    Would be good to see if you could make a flat piece of plastic into a decent shape and fix it to the car somehow

    ________________________________________

    Ex- Phase 3 China GTi-6 T-Reg
    Posted 26th Apr 2012 at 15:54
    Profile
    stan_306gti6 Forum Admin

    Location: Kent

    Registered: 18 Jan 2004

    Posts: 21,768

    Status: Offline
    Post #13
    I'm with Welshpug on this...

    Unless you're carrying some real serious speed through fast bends, downforce isn't going to come into it. However, I would be interested to see what your results are if you manage to implement such a thing. Yes

    ________________________________________

    "Supercharged - 454.1bhp/317.5lb/ft"
    Peugeot 306 GTi-6
    2000 (X), Moonstone Love
    Posted 26th Apr 2012 at 16:24
    Profile
    welshpug!

    Capt Pedantic

    Location: Bigend, Wales.

    Registered: 27 Mar 2007

    Posts: 25,838

    Status: Offline
    Post #14
    Maxi's only had the rear wing as they spent a fair bit of time airborne LOL

    ________________________________________

    need a part number? get on here - http://public.servicebox.peugeot.com

    Bring on the Trumpets.

    Posted 26th Apr 2012 at 16:34
    Profile
    smegal

    Seasoned Pro

    Location: Leeds

    Registered: 26 Dec 2005

    Posts: 5,940

    Status: Offline
    Post #15
    Downforce is not a concern but reducing drag may be.

    ________________________________________

    Ex SC-6

    Now in a Megane R26
    Posted 26th Apr 2012 at 17:05
    Profile
    daveyboy

    aka Jim Davey

    Location: Southampton

    Registered: 01 Oct 2007

    Posts: 8,648

    Status: Offline
    Post #16
    smegal wrote:
    Downforce is not a concern but reducing drag may be.


    +1

    I don't think it's going to save you much, 2-3 mph at the top end maybe, but they look cool and might give a slight increase in rear end stability at speed (Look at the tiny sonic the hedgehog wingleys the put in the roof of recent EVOs)Dunno

    ________________________________________

    R H Davey Welding Supplies. I sell new and used welding equipment in the Hampshire area. I take on welding jobs in the evenings, ally casting repairs are one of my specialities but I can weld pretty much anything. PM me with your requirements.

    Some of my services: (See my for sale threads)
    Engine mount/chassis repair
    Solid Beam Mounts BACK IN PRODUCTION
    Harness bars
    Posted 26th Apr 2012 at 17:43
    Profile
    eliotrw

    Seasoned Pro

    Location: Southwark

    Registered: 18 Jul 2010

    Posts: 4,864

    Status: Offline
    Post #17
    Well allegedly a clio 200 benefits from its diffuser

    Also if air is able to travel faster above the car than below then it could create lift in theory.
    I reckon its worth pursuing a way to stop the parachute effect.

    ________________________________________

    Ex- Phase 3 China GTi-6 T-Reg
    Posted 26th Apr 2012 at 18:01
    Profile
    eddy_gti6

    Seasoned Pro

    Location: Durham

    Registered: 20 Oct 2008

    Posts: 8,716

    Status: Offline
    Post #18
    I will draw something up and see what i need and how much parts will cost. Also have been thinking of using some sort of plastic but needs to be hear resistan really as will be right under the exhauat, other thing i could use would be some thin sheet metal of some sort. Not sure how high i would take it so it doesnt look stupid when its fitted.

    ________________________________________


    Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
    Posted 26th Apr 2012 at 18:48
    Profile
    Lowercase

    Regular

    Location: Uckfield

    Registered: 24 Apr 2012

    Posts: 227

    Status: Offline
    Post #19
    you could use composite aluminium. really light and strong. its about 2-3mm thick, aluminium core with a plastic sheet on either side (or the other way around, i didnt take a good look at it). a bit of heat resistant foil or something near the exhaust should stop it melting

    reducing the drag is worth doing, i took my rear arch liners out the other day to stone chip the shell and havent put them back in yet/cant decide if i will, and i can hear the drag thats being caused with the exposed bits now the crud guards gone. so i might cut a few small pannels of comp.aluminium and blank them off. should reduce the wind noise and drag a bit..

    or i could just put the arch liners back in.. Wink

    ________________________________________

    1992 205 Rallye - S2 Rallye Engine
    Posted 26th Apr 2012 at 19:04
    Profile
    atterz

    Seasoned Pro

    Location: Stafford

    Registered: 18 Feb 2011

    Posts: 1,134

    Status: Offline
    Post #20
    It may reduce the noise/corrosion on the back end as well especially with rear seats out!

    ________________________________________

    owain wrote:
    A GTI-6 with a good dashboard and the seats down can outsprint an E46 M3 in July.
    Posted 26th Apr 2012 at 19:11
    Profile
    yanni

    Regular

    Location: Thessaloniki

    Registered: 02 Nov 2006

    Posts: 309

    Status: Offline
    Post #21
    I was thinking of that for some time too. The idea was to use the rear diffuser from a Clio Rs and extend it all the way to the front creating a sleek flat under body.
    What about the exhaust tunnel though? Can you seal the exhaust in the under tray and how? Otherwise what's the point of having everything hanging under thereDunno Plus you need a way to channel the air from the front to the back for the full effect!

    Bear with me i don't agree nor fancy the idea in terms of aesthetics but the benefits sounds good.

    ________________________________________

    Major stock holder of group P.S.A.
    I live to pay and support the French industry.
    Posted 26th Apr 2012 at 19:43
    Profile
    eddy_gti6

    Seasoned Pro

    Location: Durham

    Registered: 20 Oct 2008

    Posts: 8,716

    Status: Offline
    Post #22
    I will sort something out. Need to get the underside of the car measured up so i know what i need. Will try find time over the weekend.

    ________________________________________


    Clicky: [url =http://www.306gti6.com]click here[/url] remove the space between [url & =
    Posted 26th Apr 2012 at 20:56
    Profile
    pugheaven

    Seasoned Pro

    Location: Fareham

    Registered: 17 Dec 2006

    Posts: 4,602

    Status: Offline
    Post #23
    Ideally you would want a box section welded along side the side sill with either riv nuts, captive nuts..
    I was looking to do this to the dimma's rear bumper using the new shape scoobys rear diffuser as that already has the undertray for the boot floor.
    Posted 26th Apr 2012 at 21:51
    Profile
    daveyboy

    aka Jim Davey

    Location: Southampton

    Registered: 01 Oct 2007

    Posts: 8,648

    Status: Offline
    Post #24
    welshpug! wrote:
    I would imagine Ash might have looked into it for his high boost race car if it was feasible.


    you'd probably benefit more from a proper kitcar spoiler like the 106 and saxo's ran, though to make the most of any mods like this you need to be carrying some serious speed....


    Pretty sure flat floors are illegal in DMN or he would probably have done it, he has cut away a large section of rear bumper to lessen the parachute effect though.

    Yo can see a pic of it in the NUR carbon/kevlar thread, but I can't seem to copy the image link.

    ________________________________________

    R H Davey Welding Supplies. I sell new and used welding equipment in the Hampshire area. I take on welding jobs in the evenings, ally casting repairs are one of my specialities but I can weld pretty much anything. PM me with your requirements.

    Some of my services: (See my for sale threads)
    Engine mount/chassis repair
    Solid Beam Mounts BACK IN PRODUCTION
    Harness bars
    Posted 28th Apr 2012 at 12:09
    Profile
    buzzbrightyear

    Seasoned Pro

    Location: hiding all receipts for car

    Registered: 09 Jul 2008

    Posts: 11,901

    Status: Offline
    Post #25
    the rear bumper since I removed the spare wheel looks like a parachute to me, the differences would be minimum but I reckon if you've got some power, then there will be a benefit, has anybody sen underneath a Ferrari ? I was looking around one and i liked what they had done underneath, the whole underside was smooth, and it had like fins and things, it was the only part of the car that I thought was a work of art. I would love to be able to make something similar out of carbon or something, sadly I don't have the skills.
    Surely it has to do something but unless you have the skills to make it yourself then forget it because you could probably fit a supercharger or turbo for what it would cost.

    ________________________________________

    andrew315rawson@live.co.uk
    Moonstone phase 7 gti6
    My Project thread: http://www.306gti6.com/forum/showthread.php?id=119992&page=1
    Posted 28th Apr 2012 at 12:12
    Profile
    Home -> Forums -> Exterior -> Rear Diffuser

    Pages (5): [1] 2 3 .. last

    All times are GMT. The time is now 05:23

    The Peugeot GTi-6 & Rallye Owners Club - ©2024 all rights reserved.

    Please Note: The views and opinions found herein are those of individuals, and not of The Peugeot 306 GTi-6 & Rallye Owners Club or any individuals involved.
    No responsibility is taken or assumed for any comments or statements made on, or in relation to, this website. Please see our updated privacy policy.