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Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

I've always wondered about IATs when it comes to the IC sprayer in particular. I use it pretty liberally before autox and time attack runs and I've always been curious whether it would be better to spray a ton... ie near constantly while in line for my run... or if it would make more sense to spray, let it evaporate, spray again, wait again, etc.
 

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Discussion Starter #942
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

I've always wondered about IATs when it comes to the IC sprayer in particular. I use it pretty liberally before autox and time attack runs and I've always been curious whether it would be better to spray a ton... ie near constantly while in line for my run... or if it would make more sense to spray, let it evaporate, spray again, wait again, etc.
Spraying while stationary is probably better than not as its providing "some cooling" on the TMIC while there is no airflow.

Finding that magic piont would have to do specifically with how hot the IC is and how fast the water is evaporating... Ideally you would only spray it as fast as its evaporating otherwise you're reducing the IC efficiency by filling up the fins with water. It would probably take a lot of testing to try to find some kind of measurable point where the it changes from more is better, to more is worse. There are also some factors that would effect that change over point such as average rpm/throttle versus speed. The faster you're going the more you would need to spray as you would have a lot more air passing over the IC...

That said, I ran my IC sprayer continuously on my last auto-x. Since heat soaking is a prominent issue with the TMIC setup at low speed events with a lot of sitting stationary between runs. I figured even if I cross that threshold a little bit into diminishing returns, lowering the IAT is good for the engine/tune/reliability, but also might help battle the heat soak for the next run. I figure even if its not optimized, its probably still better than not spraying at all ¯\_(ツ)_/¯

If you spray continuously on a road course with the USDM tank, you will find your self empty before you are halfway through the first session though LOL
 

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Discussion Starter #944
BlueScooby's 06 STI - Diffuser/Underbody RE-DO

A good high pressure setup made to atomize the water should do well, especially in dry climates.


That would certainly be very cool! Not sure how you would go about that though...
 

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Discussion Starter #945
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

After taking a few weeks off from the underbody project, I finally made some kind of progress. I finished trimming out the first piece that hangs under the cabin, drilled and mounted it! I wound up having to trim out a decent little hole under the downpipe since the panel had to curl upwards a touch to mate up to the beatrush undertray but I'm not too worried about it. I hate that I still had to cut a hole but I'm not going to modify the downpipe which is a plug-n-play part right now. The hole is far enough forward that it hopefully won't be an issue.

The panel is sagging just a touch in the middle so I'm going to have to add some reinforcements to stiffen it up, but otherwise fits great!



 

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Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

Dang, you've been busy while I've been away! Nice that you're revisiting the undertray and trying to improve upon it. It'll be nice to see the finished product.
 

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Discussion Starter #948 (Edited)
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

Thanks guys! Hopefully its going to be MUCH more functional this time around :tup:


This weekend I managed to get in the garage a little and do a couple more things.

I pulled the cabin panel back down again to work on it a little. Here you can see the two additional solid supports I added. Originally I only had those two smaller pieces available (I could've sworn I had some more laying around...) and tried it but I don't think they did anything. So adding the two solid pieces made a noticeable difference in stiffness. There was still just a touch of sag at the far back end but I will be using the next panel as the support for that so no need to add more bracing.


Added rubber trim to the downpipe hole to minimize cuts, whistling air noises, and to generally make it look better :)


Started working on the next panel, which goes under the gas tanks/diff. Added the supports up front this time. Decided to add one at the very front and back to be a support for the connections to the cabin panel and the diffuser, plus one more in the middle for good measure. This is also before I notched out those corners as marked in the picture.


Started hanging the new panel up and it went much smoother than I thought it would. Turns out since this panel is so rigid and covers the whole area (as opposed to the separate pieces I used in the V1 configuration) that I didn't need tons of supports. I added two rivnuts to bolt the panel to the cabin panel, then two wind-splitter-bars in the rear. So basically 4 simple attachment points and a very rigid installation. This is exactly the sort of thing I was hoping to improve upon with mounting points, and I'm really happy that I was able to improve so easily on this section. To mount the wind-splitter-bars there was a small hole on the passenger side of the rear subframe that I just threaded the mounting bolt through, and I just tac-welded the mounting bracket on the drivers side (no hole for some reason?). Also added the rubber skirting to the sides before installing.




I need to pull this panel back down to trim it a little as I'm just touching the exhaust when it warms up (the support brackets to be specific), but this panel is otherwise basically good to go! Much easier than the last panel :cool:

Next will be to start working on the diffuser and the end-fences. I want to extend the end-fences forward up to the the gas tank, but I haven't figured that out just yet.
 

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Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

I'll send you the car over Aaron and you know what to do then :D

Looking good! Can't wait to see V2 in it's all finished glory :cool::tup:
 

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Discussion Starter #950
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

I'll send you the car over Aaron and you know what to do then :D

Looking good! Can't wait to see V2 in it's all finished glory :cool::tup:
haha, just send me one of those sweet BBK's with it ;)
 

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Discussion Starter #951
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

Didnt have a lot of time this weekend since we had a birthday party for my boy on saturday, but I still got some stuff done nonetheless.

Made the small adjustments/trimming needed on the panel under the gas tanks and made a custom jack-point block to fill the void between the rear diff and the panel. I contemplated just cutting a hole like I did on the V1 setup and covering the hole with a sheet of rubber, but I just couldn't bring myself to cut holes into my brand new solid panel...

The block is made of two sheets of half inch thick high-density polyethylene and two sheets of 1/8" thick viton gasket sheeting. The viton is to deal with the extreme nature of being outdoors/weather resistant, high temperature resitant, and high chemical/oil resistance. Viton holds up extremely well to compression forces with very little deflection, which was another concern for building this block.

Originally I tried to find a solid block of viton or something similar, but thats basically impossible to find and also, VERY expensive. In total, this cost me like $25 to make this block. :tup:



I also painted a jack-point marker on the bottom of the panel so I know where to jack the car up with this is all sealed up... haha


Lowered the car down off the jack stands using the block with the panel in place and it worked quite well. No real deflection of the panel and the block didn't crush or anything, so pretty successful installation :)
 

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Discussion Starter #954
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

question about fuel pumps for you guys. I dropped my car off at the shop yesterday for them to diag why I'm seeing feedback knock periodically, and the answer was: my fuel pump isn't super consistent with fuel pressure anymore (after 150xxx miles). So they recommended either an AEM or DeatschWerks 320 lph unit.

I'm fine with the sizing choice, my question is more what experience do you guys have with pumps from these two brands? I trust the shop's opinion on parts advice I just wanted to learn a bit more about them before I pulled the trigger.

Also, my fueling setup is currently 100% stock. But I am interested in upping my fuel filter to something better while I'm at it.

TIA :)
 

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Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

I really like the E85 AEM 310 Pump in the GD. I've had one DW fail on me, I replaced it with the same for ease of tuning but I've got an AEM 310 waiting to go in eventually.

which fuel filter are you thinking of doing? I really like the Injector Dynamics one, have you thought about upgrading to top feed, ditching TGVs and going to all new lines? I've helped a bunch of guys do the conversion.
 

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Discussion Starter #956
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

Good to know. So +1 for AEM :tup:

I haven't looked into filter options yet but I remember Jason had a pretty nice setup on his car. I currently have gutted OEM TGVs but I'm still side feed. If I ever upgrade the injectors I probably will switch to topfeed and go with Injector Dynamics.
 

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Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

That underbody looking pretty badass!!!
 

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Discussion Starter #959
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

So talked with the shop a little more about the fuel filter idea and we are going to go with a relocated OEM filter in the engine bay. Basically whats more important being able to change the filter more frequently. Although if I needed I could upgrade the filter later. Will put in the AEM pump at the same time.

and because the car is a DD and has some busted speakers, I'm looking into upgrading to 6.5" rear speakers over the dinky oem ones. yay projects n stuff. haha
 

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Discussion Starter #960
Re: BlueScooby's 06 STI - Diffuser/Underbody RE-DO

Ever so briefly worked on the rear diffuser this weekend. Got the rivnuts mounted on the forward edge to attach to the previous panel and contemplated what to do next. I tired to figure out where I want to mount the main support bar on the back side but I'm still a little up in the air about that. Partially because my garage isn't flat so I hadn't "set" the angle of the diffuser yet. Once I get that figured I can mount the support bar and the splitter rods to hold it up. :tup:




I also mounted up the ~$5 voltmeter so I could have live monitoring without taking up a vital place on the accessport screen. Its not the most accurate thing in the world, but its enough to know whether or not the alternator is performing properly. (picture doesn't really due justice, its much easier to read than what it looks like)
 
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