firebert

Mods: My apologies if I posted this in the wrong forum, please move this thread to the correct forum if I did. Please understand I am doing all that I can to adhere to all rules on this forum.

Our shop is contemplating the idea of producing a universal type rear diffuser. This diffuser can be affixed on any vehicle with custom mounting brackets and some minor cutting (to clear exhaust piping, etc). We currently have a prototype at the shop and will start a limited production using FRP if there is enough interest in the product.

Here is a sample picture of the product


please post your thoughts.

In following forum rule about vendor advertising I so not think I can post the name of the shop. But I can mention we are a JDM importer located in the Bay Area specializing in JDM, VIP, and Exotics auto styling and performance.

Ayuaddict

bay area, thats cool. because of the gas tank placement diffusers wont do much but look cool (on S13s that is). but there are interesting.

Helghast

Uh...
Wing + Rear Diffusers..You better be breaking 200mph.

I mean, it looks cool.
Whatev.

Looks like it drops low too..
so with lowered cars, it'll scrape?

I'd rock it..never.
why?

Cause no one drives GT cars on street.
and if you buy "fake" diffusers..you don't need em.

"I'm just saying."


OP, how's the VIP scene up in nor.cal?
It's picking up down here, but I still don't see much.
I wanna see Previa's already.

Jersey Fresh

what type of place is this? it looks like a white skyline in the gas station across the street in the pic

CharlesJ

Technically speaking, this is in the grey area of breaking the vendor rules as we do not allow promotion. As long as you do not offer pricing, more production/shop information, or ordering information though, it can stand.

Now I will put in my thoughts. A nice diffuser would be interesting. I am into functional diffusers like the one we are building for the club240 time attack car, but style diffusers are not all bad, and this may have some function. To those that are not fully aware of what a diffuser can do, they can reduce lift significantly and help with downforce at normal track speeds. For example, the little *** plastic diffuser that comes stock on an 06 sti effectively allows for another 50lbs of downforce at 100mph.

I am generally not a fan of universal diffusers as there is no way to make them very functional for many different cars. This one seems to sit a bit low and have a large gap in front of the side sections

bucket240

I think its japan, look at the rear wiper on the s14!! USDM dont have those.

201Motorsports

iTrader: (5)

That sure is a Skyline sitting pretty across the street

My vote for those diffuser is yes and no... part of me loves the look in the picture you posted and part of me doesn't. I can't seem to put my finger on it

firebert

Thank You for all your honest opinions. Yes the stock photo is taken in Japan installed on a real S14 Silvia that runs Tsukaba regularly. As far as function goes I'll be honest to say it has not been wind tunnel tested. You could think of it as a body kit as far as aesthetics, ground clearance and function goes. It hangs slightly below the exhaust line so if you scrape the canister often this probably wouldn't be best for you. I'm also contemplating about producing only the center part.. kinda get a 06 Sti/ Evo 9 look going on. I do understand how real functional diffusers works and this particular one does not entirely block out the bottom rear portion of the car like ones from say.. APR. Nor would I claim it's entirely useless because it does help channel some of the air from getting trapped in the rear bumper. In order to keep our profit margin up, we cannot make a full fitting air diffuser that is still aesthetically pleasing for every car like the aforementioned companies but I hope I’m not breaking any rules when I say ours would around be half the price.


Thank You for allowing this thread stand! I took some time reading over your rules before making my initial post and it did feel iffy. I'll be sure not to release any shop or pricing info for now, but we are thinking about becoming a vendor here in the future if there are enough intrest in our products. Currently we do not carry too many products for 240's/180's/Silvias but we do have our own line of universal racing seats (FIA/non FIA) with rails for S13/S14 and we regularly import rare new and used wheels from japan. Also I took a look at youy 240 build thread earlier and I must say I'm impressed and cannot wait to see it finished

gabe30

aerodynamics takes full effect slightly after 60mph and for sure at 80 mph.. they also take effect during the pull of g-force so whether or not you need to break 200 mph, the diffuser will be resourceful through turns.

my reference for this source is from skip barber's going faster and it is probably the only book you will ever need to know about racing. [without gaining experience]

firebert

^^^hmm I'll check that book out sometimes. Sounds like a good read.
Allow me to add; if you are trying to break 200MPH it'll probably be more beneficial to take off the rear wing because it creates drag. A diffuser creates a low pressure area underneath the car creating downforce without affecting the drag coefficient as much..

While were at the subject of books heres some books I read/in the middle of reading and would recommend (especially for other engineering students):
"Competition Car Aerodynamics" - Simon McBeath
"Race Car Vehicle Dynamics" - William Milliken
"An Introduction to Race Car Engineering" - Warren Rowley

CharlesJ

I would even guess that some completely enclosed diffusers could improve the coeficient of drag.

Either way, as mentioned these are more body kit type diffusers. I am sure there are show types that would want them, you just happen to hit the probably vocal minority of those that are more concerned about the function. Any type of functional univeral one would be nice, just probably hard to do.

firebert

That's true, what I meant to say is a diffuser wouldn't add to the drag coefficient like a rear spoiler.

Sorry for bringing this thread back from the dead but I was flipping through the current (aug07) issue of SCC and saw this S13.5 in japan with a simular diffuser. Even though intrest dosen't seem to be great here I am still making plans on going ahead with a limited production of it.. I'm gambeling on hope that it'll catch on with the recent JDM time attack craze.

http://www.sportcompactcarweb.com/fe...ack/index.html
pics arn't great on the website.

enjoy