2013 Subaru Impreza WRX STI - Project Log

[jedi_sol]

Originally Posted by SplatSTi

Subaru guy here too.

Have you thought about tuning yet? talk to a tuner about the 40* timing for AVCS.

Yay a new sti on ecomodder! Now I count around 3-4 sti on EM.

I have not thought about tuning yet. I've googled Avcs timing and currently reading up the articles on nasioc and iwsti

I'm just worried if I go to a tuner and talk about fuel economy, they might send me elsewhere.

[jedi_sol]

Originally Posted by UltArc

How did you make those pieces? A pretty novice question, but my experience only goes to masonry, carpentry, and cable ties :/

Medium difficult. It's basically making a Erector Set from scratch.

1) take aluminum c channel
2) measure
3) cut
4) drill, drill, drill a bunch of strategically placed holes
5) tighten with nuts and bolts
6) any sections where I cannot reach behind, I used speed nuts from home depot/lowes

You were the one that warned me not to make my undertray in a "modular" design....now it came to bite me in in the butt

This time I'm taking your advice and making a stronger one piece design that is properly anchored.

[UltArc]

I suggest a modular design in three pieces.

1) Front engine, easily removable for oil changes/engine access.
2) From section 1, to rear axle
3) From section 2, into diffuser

If there wasn't so much metal, I would suggest cable ties for support in case something goes wrong. For my metal build, I am using hose clamps. I don't trust my drilling and use of screws. I am hoping my setup will hold well. I normally go overboard, but hopefully I go overboard enough.

[SplatSTi]

Originally Posted by jedi_sol

Yay a new sti on ecomodder! Now I count around 3-4 sti on EM.

I have not thought about tuning yet. I've googled Avcs timing and currently reading up the articles on nasioc and iwsti

I'm just worried if I go to a tuner and talk about fuel economy, they might send me elsewhere.

I have had several discussions with a few tuners, Dom Dominic@turninconcepts.com who was on the West Coast and is now in Cincinnati is one of the top tuners in the country, he can help you out in theory, but he will want to protune you and I dont know how often he will be back on the west coast. I also have a tuner on the East coast ray@turbotek.com who has been working with me for economy. My 3rd tuner is giving me a standard Stage 1 tune, and he is cheaper than Dom, $600 vs $250 and its the only reason I am seeing what he can do. He did come recommend from a friend in Indiana who is very pleased with his work.

If your serious about tuning in the Cali area, look at Cobbs website as they have listing of Cobb tuners in all areas.

[jedi_sol]

So it turns out this little section of my fender pops out



Which is now giving me ideas of creating a radius of the aft edge of front wheel arches like this :

[jedi_sol]

ANOTHER BEST TANK EVER! 30.59MPG!

Not bad considering i don't have an undertray completed yet

[jedi_sol]

Re building undertray version 2.0 (rear)

Started building the rear portion of the undertray. Got underneath the car to find some mounting points.

Found some where the rear bumper bolts into the chassis




Measured the distance between the two holes to make a cross bar for the tray to bolt onto


Now I gotta connect the middle tray to the rear bumper, however the rear lower control arm is in the way. So I bent the aluminum bar for clearance.



Here is the clearance for the rear lower control arm, hopefully it's enough for the control arm to move naturally without banging on the aluminum bar.



Drilled some holes to bolt the tray onto



Drilled some holes onto the rear portion of the middle frame so I can connect the rear aluminum bar


Here is the bar bolted onto the rear bumper cross bar


Here is another shot of the cutout for the exhaust pipe



And the finished product!



Starting to cut out the actual undertray. It's 6mm coroplast, very sturdy, but also heavier than 4mm. It's harder to cut too!



Next up, bolting the tray to the frame.

[Eastwood]

What's the angle on that bend? It looks like a good start for some rear diffusers.

[jedi_sol]

The bend is 8*, so air should have attached flow.

I'm thinking putting a diffuser next to each muffler, and one in the middle.

Any other suggestion on location for diffusers?

[Eastwood]

You've probably read more about it than I have, but I would say that as long as it plays nice with the opening in the front lip, it should work well. That and just feast your eyes on plenty of other cars that have a similar front lip and diffusers to see if there is a standard, efficient relationship between the two.