I didn't realize who you were when you posted originally. :P I am local and I tune on this platform. I typically tune using Goodspeeds dyno. :)

I am familiar with their dyno, good technology

But I am done remote tuning

I want a shop that has a dyno and ax ecutek license

I said nothing about their specific dyno... I said I am in Phoenix and I tune on this vehicle platform. I'll have a JRSC FR-S on the dyno next weekend. A remote tuner blew up my car... I am done with remote tuning as well obviously. I wanted to tune it my self in the first place but the license was too expensive originally. Things have changed since then.

How can I avail your tuning services if I pay joe for his dyno, can you unlock my tune and tune my car Nelson?

I need help and am willing to pay

Unlock? Nope that would be up to Perrin (I assume you are still using them correct?) if they wanted to unlock your tune or not, and I am not a huge fan of re-tuning an existing tune on a car. Doing a minor tweak or fixing something is one thing but re-tuning completely is something different.

You'll have to email me with whats going on and what you are looking for. I thought you were happy with your current setup...

Can I buy a self tuner license now, is that what you're saying and I'm missing?

Subscribed, because coming up with a rear diffuser for my car in a couple weeks and I need all the ideas I can get to help with design.

Do you have any input on your current diffuser setup? Like, does it seem to have calmed the rear end being squirmy like you mentioned?

Did you choose the bushings in the rear subframe specifically because of AutoX class rules? Correct me if I'm wrong, but the rear differential bushings you used are just the overlays of the factory bushings? And the differential outrigger bushings are the inserts, not the entire bushing replacement? How has the NVH been since installing those bushings for you?

I went straight to the replacement outrigger and differential support bushings, and I have a significant amount more of gear whine, but it's nothing I'd complain about. It reminds me of straight-cut gears, and that reminds me of racing, so I'm happy.

tl;dr Your car is fantastic!

Out of curiosity, have you considered a decklid with intergrated lip like Seibon or the very agressive Aero Jacket? The would add the nessisary functions without adding the 'tacked on' look spoilers tend to have.

Hi .. thanks for looking. I think I'll have time later this weekend to type some more about the diffuser. Meanwhile another pic with it installed:

Wow that is a crap photo. ;^)
Since the thread got revived I wanted to post about the latest with my aero 'tune up'.
@Kiske thanks for the idea. I checked out those trunklids and those are the nicest yet. For now I'm still holding out and am inspired by the bare/cleaned up look like on an F12 or a 599.

The underpanels, lip, and diffuser were added after the power mods. It needed it. And checking out the Turd Griffon project I think that is where to look since the twins have a lot of potential just with aero and light weight (plus brakes, sticky tires, chassis, and suspension etc etc). That must be the fastest car in the world at 8 or 9lb/hp.

Anyway the recent stuff that went on is a TRD "trunk stabilizer" which isn't much to look at. But I like how it fills the gap between the rear window and trunk. It should have come stock IMO. And then I am going to make some 'eyelashes' out of foam to fill the gap between the headlights and hood.

And then I'm tempted to do a basic splitter mostly for the underside to have a flat surface. I wouldn't want it to stick out very far forward of the lip where it would be scraping curbs. And looking for downforce with with a subtle wedge shape at the corners.

No autocross yet. There are great events all the time in Az but I am tied up being a dad.

Yes it's the basic Whiteline subframe bushings, maybe what you've got too. They added some NVH but when they are at their worst is soemthing like lugging gears.. say 10mph in 2nd. It sounds like a POS crap can, and I bet Toyobaru knew that people would never buy the car if they heard that on a test drive.

I don't notice the results any of the bushings, tranny support or the engine mounts in particular. They all worked together to make more of the go cart feeling. There is a really direct feeling on the throttle exiting a corner and unwinding the steering wheel, maybe from 'activating more grip' lol. I'm sure if I got back in a stock twin I'd notice how quiet it is and more civilized, like how on mine the rear view mirror will shake while idling. All worthwhile tradeoffs for me.

BRZ with Vortech on E85 - 382whp
 

Woo hoo, siting here next to a sleeping baby and on a roll today.

About diffusers: they are a 'because racecar' mod because of the conditions needed to make a zone of low pressure under the car: a low if not unstreetable ride height ideally with the front lower than the rear, and a smooth underbody. And I think we will move more and more toward designs that take into account the areas of higher temperatures around the exhaust, at least for cars outside of F1, etc where it is banned.

So for anything including the twins it really should be on a lowered car sporting some kind of underpanels. And the further forward the diffuser extends, the better.. toward where we have that chasm for the diff and control arms.

And then I don't think the term 'downforce' is very helpful when you see it measured in lbs or kg. How much downforce in these brats and burgers?
Attachment 68869

It's not all the same when there is a 'price tag' in aero drag. The cool thing about a good diffuser is that it produces negative lift AND reduces drag vs a wing whose low pressure zone comes with a bigger penalty in drag. OK that's it. The smart people can talk now.:bonk:

new pics:
:cheers:

This is just about perfect. Once I actually start modifying my car, I will be going down this route.

I'm still so impressed with the numbers you're generating with your vortech sc. That is my number #1 choice with the power it makes and CARB legal certification straight out of the box.

The cleanliness of your car visually is perfect in my eyes. Keep up the awesome work. I did some research into diffusers on the FSAE car I helped build at SDSU, and I will be building one myself in the months to come for the BRZ I just bought, but thank you for trying to at least clean up the air under your car PRIOR to reaching the diffuser with the panels you have. So many people don't do this. The smoother the air flow under the car prior to reaching the diffuser, the better the diffuser can do its job, and the better gains you will see across the board in terms of aero. :thumbup:

There's a lot more in terms of angle of attack, how the fins on the diffuser should be orientated (and how many), what velocity you're trying to optimize the flow for, etc. but at least you're out there and experimenting with it in a quality manner. Can't wait to break mine in so I can play too! :burnrubber: