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Old 07-29-2011, 09:44 AM   #1
tino
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Default Rear diffuser benfits..

So i have decided to modify my HKS kansai rear diffuser. To me the diffuser needs to extend all the way to the side of the bumper to provide greatest benefit, so i am going to extend the diffuser to cover these regions.

The questions i pose was there a reason that HKS decided not to extend to the bumper?

Could this be detrimental in the benefit of the diffuser. I know that having a diffuser with no underbody aero (i am going to make a flat bottom out of carbon) may really not be beneficial to begin with.









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Old 07-29-2011, 09:52 AM   #2
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The air is probably so dirty there that it's of minimal benefit. (That being said.. what you're doing isn't going to hurt and I would probably have designed one to be like that in the first place.)

- Jon
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Old 07-29-2011, 09:56 AM   #3
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cardboard looks good, just hit it with some black rattle-can....
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Old 07-29-2011, 10:03 AM   #4
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Quote:
Originally Posted by racerjon1 View Post
The air is probably so dirty there that it's of minimal benefit. (That being said.. what you're doing isn't going to hurt and I would probably have designed one to be like that in the first place.)

- Jon
Yeh I thought this would be the case, I am going to try and alleviate the dirty air later down the track with a flat underpanel.

But as youve also agreed that this is how it should have been designed in the first place..

Quote:
Originally Posted by blaze wrx View Post
cardboard looks good, just hit it with some black rattle-can....
Hahaha yes cardboard mockups best friend..

I'm taking it to my carbon guy tomorrow to integrate it with the diffuser..
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Old 07-29-2011, 01:35 PM   #5
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Well you're trying to channel the air down the center of the car where it has a smooth path. The edges of the bumper are blocked by the rear wheels but there is huge air coming off those rear tires. Just make sure if you extend it to that part that you're giving a path for the air to escape out the bumper and not end up acting like a parachute for the tire air.
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Old 07-29-2011, 04:13 PM   #6
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check out the APR one, that goes out to the edges.
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Old 07-29-2011, 04:30 PM   #7
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Quote:
Originally Posted by vicious_fishes View Post
check out the APR one, that goes out to the edges.
That's because it's supposed to look nice and finished on your street car. It's rare on any race car for it to extend past the wheels.






Now I'm not saying you can't do it. For instance if you were building a double diffuser then you can try and use the air off the wheels to create DF by having the air travel on top of the diffuser.
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Old 07-29-2011, 06:09 PM   #8
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Quote:
Originally Posted by Element Tuning View Post
Well you're trying to channel the air down the center of the car where it has a smooth path. The edges of the bumper are blocked by the rear wheels but there is huge air coming off those rear tires. Just make sure if you extend it to that part that you're giving a path for the air to escape out the bumper and not end up acting like a parachute for the tire air.
Thanks for your reply. I didn't take into account the effect the rear wheels would have. Now if I put a vertical channel on the front of the diffuser (end that bolts up near the rear wheels) which is similar to how the diffuser bolts up to the bumper, would this direct the air from the wheel wheel to go under the diffuser rather than on top of it?
If I did this would I have to seal the diffuser against the underside of the car to ensure that no air can get past??
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Old 07-29-2011, 06:36 PM   #9
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or you can create own like Duncan@Race Dynamix,he create own Diffuser with full flat floor,for full benefit you will need go route of full flat floor like Ferrari Enzo

Enzo flat floor with diffuser



And Duncan@Race dynamix






Jura
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Old 07-29-2011, 07:02 PM   #10
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I hope he's not actually using bc racing coilovers. ugh.

Sierra Sierra's new diffuser is pretty rad:



http://www.motoiq.com/magazine_artic...11-update.aspx
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Old 07-29-2011, 07:12 PM   #11
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Quote:
Originally Posted by jamal View Post
I hope he's not actually using bc racing coilovers. ugh.

Sierra Sierra's new diffuser is pretty rad:



http://www.motoiq.com/magazine_artic...11-update.aspx
Yes and he using aswell K-sport brakes etc.

And he win UK TA 2010

http://speedhunters.com/archive/2011...g-impreza.aspx



Jura
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Old 07-29-2011, 08:24 PM   #12
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Nothing like a near limitless budget with that SSE team. Thats sexy as hell straight off their old formula atlantic car modded to fit the evo. Crazy stuff, 1.2 million and climbing invested in that car.
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Old 07-30-2011, 10:13 PM   #13
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Quote:
Originally Posted by jamal View Post
I hope he's not actually using bc racing coilovers. ugh.
What's wrong with the BC Racing coliovers? Phil from Element Tuning is using BC Racing c/o and he's one of the fastest at VIR.
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Old 07-30-2011, 10:40 PM   #14
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His are re valved with swift springs i thought. However the quality looks nice. I have never used them.
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Old 07-30-2011, 11:18 PM   #15
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Quote:
Originally Posted by bhhamblin View Post
His are re valved with swift springs i thought. However the quality looks nice. I have never used them.
Still BC Coilovers that you can purchase custom from Element Tuning. Its like any product, it can be improved from specific model R&D and we've developed suspension options from BC that have broken records and set the fastest times for any car any any suspension ....at any price.

We take pride in the fact that we've built a race car that uses parts anyone has access to at an affordable price. It has never been our goal to build the fastest racer with ab unlimited budget but to build a car that showcases the products we sell to our customers.
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Old 07-30-2011, 11:19 PM   #16
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What's wrong with the BC Racing coliovers? Phil from Element Tuning is using BC Racing c/o and he's one of the fastest at VIR.
1) Im sure their is funding from the manufacture being involved to have those units on the car. Money talks, especially when it comes to racing and funding.
2) I dont see a single car running at the top level in the World Time Attack in Australia using BC

and this went off topic fast hahaha

And SSE new aero looks crazy!

As for rear aero going outside of the car. These guys seem to be pushing it to the very limit. I would assume that the FIA sporting regs mandate that its withen the body lines.
The more surface area that you can put out to increase down force with as little drag as possible along with being able to maintain proper air flow over and into proper locations will be a benefit.

Last edited by snowman4us; 07-30-2011 at 11:33 PM.
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Old 07-30-2011, 11:56 PM   #17
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Quote:
Originally Posted by Element Tuning View Post
Still BC Coilovers that you can purchase custom from Element Tuning. Its like any product, it can be improved from specific model R&D and we've developed suspension options from BC that have broken records and set the fastest times for any car any any suspension ....at any price.

We take pride in the fact that we've built a race car that uses parts anyone has access to at an affordable price. It has never been our goal to build the fastest racer with ab unlimited budget but to build a car that showcases the products we sell to our customers.
Wasnt talking down on them by any means. Just stating that they are not the OTS coilovers from BC racing. Im sure when built to your specs they perform great.
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Old 07-31-2011, 08:53 AM   #18
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Okay well i was looking at putting a plate at the end of the diffuser that goes to the bottom of the underbody..

But i have a question...

If the air is going past it will hit the top of the plate then be forced back down and then under/past the diffuser. Will this be a negative issue??
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Old 07-31-2011, 03:41 PM   #19
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not sure what you mean but anything that smooths the underside out is beneficial...
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Old 07-31-2011, 08:39 PM   #20
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Quote:
Originally Posted by mug23 View Post
What's wrong with the BC Racing coliovers? Phil from Element Tuning is using BC Racing c/o and he's one of the fastest at VIR.
Nothing wrong with BC's,but mostly guys in TA here in UK using the BC racing ER,not cheapest version of BC

But most of people use here Exe-tc,AST or KW,Ohlins..

Jura

Quote:
Originally Posted by tino View Post
Okay well i was looking at putting a plate at the end of the diffuser that goes to the bottom of the underbody..

But i have a question...

If the air is going past it will hit the top of the plate then be forced back down and then under/past the diffuser. Will this be a negative issue??
Ok for what reason you want Diffuser and you will be travel on Track more than 90mph and more,and you are want properly working Diffuser ,because you will need also Flat floor,without this is just pointless?

If your question is no,i wouldn't fit Diffuser...

If you want this just for look,fit something which is less screw aero(front aero splitter and smoother front bumper without the edges)


Jura
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Old 07-31-2011, 09:00 PM   #21
tino
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Quote:
Originally Posted by vicious_fishes View Post
not sure what you mean but anything that smooths the underside out is beneficial...

I will get a pic up of what i want to do to explain it better..

Quote:
Originally Posted by jura11 View Post
Nothing wrong with BC's,but mostly guys in TA here in UK using the BC racing ER,not cheapest version of BC

But most of people use here Exe-tc,AST or KW,Ohlins..

Jura



Ok for what reason you want Diffuser and you will be travel on Track more than 90mph and more,and you are want properly working Diffuser ,because you will need also Flat floor,without this is just pointless?

If your question is no,i wouldn't fit Diffuser...

If you want this just for look,fit something which is less screw aero(front aero splitter and smoother front bumper without the edges)


Jura

I im wanting to do the time attack next year in Sydney. i will go with a flat bottom panel at some stage but now im just trying to sort out the diffuser..

With the track work i do i will easily be hitting over 90 mph..
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Old 07-31-2011, 09:12 PM   #22
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Quote:
Originally Posted by tino View Post
I will get a pic up of what i want to do to explain it better..




I im wanting to do the time attack next year in Sydney. i will go with a flat bottom panel at some stage but now im just trying to sort out the diffuser..

With the track work i do i will easily be hitting over 90 mph..
Best bet is trying design own diffuser which will be yours not aftermarket,which are just addons,if you are looking at HKS etc,they're just for look.

Here is posted few and depends how you are skilled working with Carbon and can been done easily,about the flat under-body must be first and from this i would go for diffuser,because flat floor will be channeling air to diffuser.

Jura
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Old 08-01-2011, 12:16 AM   #23
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Quote:
Originally Posted by mug23 View Post
What's wrong with the BC Racing coliovers? Phil from Element Tuning is using BC Racing c/o and he's one of the fastest at VIR.
didn't they get beat by TIC the other day?

Haven't seen any cars win west coast events (Superlap, RTA, GTA...) on BC-racing stuff.

Last edited by jamal; 08-01-2011 at 12:28 AM.
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Old 08-01-2011, 12:53 AM   #24
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If you go back to the Grassroot Motorsports UTC thread, TIC did win the Fastest Subaru Trophy with a 2:01.309 official timed and Element Tuning ran a 1:56.xxx unofficial timed and Phil got DQ for something I forgot.

The point I'm making is you can get a within reasonable priced true custom c/o to your specs for the non-sponsored, mere-mortal like the rest of us working class people and still able to be competitive without braking the bank. Also Phil have already recorded many track miles and testing on these c/o and provide support for the c/o is well worth the price.
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Old 08-01-2011, 03:04 AM   #25
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there are plenty of actual good shocks that "mere-mortals" can afford- KW clubsport, AST 4100/4200, etc. And look at what people are dumping into engine and turbo setups- that car pictured above has a fancy block with cosworth internals, a dry sump, crazy carbon aero bits, but then has the cheapest and crappiest suspension and brakes in the world. I just don't get it.
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