818Rasmus E Modified

[Rasmus]

Seatbelt hole?! Phsssha, those are speedholes.

[metros]

Looking for some measurements on the harness slots you made on the firewall. I don't have my seats or harnesses yet but would like to set up the firewall so I can have it powdered and finished.

Measurement from edge of firewall to first (driver side) slot and then measurement from edge of firewall (passenger side) to slot. Approximate length of the passenger slot.

I noticed that both slots are different lengths. I'm assuming because the driver side is set up perfectly for you and the passenger side is more general for a variety of passengers.

[Rasmus]

You might not want my measurements. Recall that I offset the drivers seat from the FFR position to better center it with the steering column shift I did.

But I'll still take some photos for you.

[Rasmus]

I didn't resize these photos. So they're super big. Just right click on any one of them and select "View Image" and you get it full resolution.


Overall


Passenger side


Driver side. I stood about 20 feet back and took all the photos with the telephoto lens. Thus parallax for the measurements should be at a minimum.

[metros]

I had forgotten about your shifting the driver seat a little bit. Thanks for the heads up and thanks for the pictures!

[Rasmus]

Cut out the battery tray. I'm moving whatever battery I finally select to the passenger foot well.

Based on the dimensions: 10" x 8.5" x 16gauge the steel battery tray should come in around 667 grams. Maybe 675 with welds.

GO MATH! 685 grams of mass removed.


Also pulled the fans out of the shed. Tested them. Then blew them apart to de-rust a few of the metal parts that have that red-orange hue. I should probably consider painting the exterior of the car rust color.

[Frank818]

Ditch those plastic (ABS?) fans and get some full carbon fiber fans, they are much lighter (and may not exist yet, but you can fab them )

[MrDude_1]

Ditch those plastic (ABS?) fans and get some full carbon fiber fans, they are much lighter (and may not exist yet, but you can fab them )

I know you're joking, but random off topic pet peeve:
I hate how people take lightweight, cheap plastic parts, and make them "carbon fiber" copies. They are not lighter. The part wasnt redesigned to use less material. its just epoxy plastic with carbon stuck in it.. its not a different magically lighter material.
on the other side of this coin.. i hate when people take would could be a lightweight design, then replace the part with billet aluminum... great. you added weight and did nothing to help.

end rant.


Now that that's off my chest.. I love this build. no bull****. just smart removal of what you dont need.. and modding what you do need to be more reasonable.

[Mechie3]

i hate when people take would could be a lightweight design, then replace the part with billet aluminum.

I see that all the time. lb per lb aluminum (6061) is weaker than steel. If you make a 1:1 copy you've made it lighter, but it might be made too weak. If you make it to the same strength it can be lighter, but only if geometry allows (ie: truss structure vs stamped steel). Sometimes it doesn't make sense to replace parts.

[RM1SepEx]

And aluminum breaks while steel bends... Aluminum is only lighter when designed to take advantage of the materials properties.

[Rasmus]

Had a PM asking about how I selected my turbo.

Thought I paste my response down for public critiquing:

Rasmus,

We are looking at the Borg Warner S200SX line of twin scroll turbos which can be had for <$650. We are still pretty new to the Subaru world, and especially the twin scroll world. Would you be willing to offer us some advice? Being as your goals are similar to ours (autocross), your engine is similar to ours (2.34L destroked), and you've already researched turbos, I can't think of a better person to ask!
...
....
...
We are hoping for fast spool, an efficient flow range around 350whp, and capable of around 400whp before it runs out of air.

Please let me know your thoughts on this.

Flattering. Thank you.

I'm not as knowledgeable on this subject as my posts appear to make me. Honestly, I try to talk to knowledgeable people, and read knowledgeable literature. I then post what I learn (or think I've learned) so that I can better understand the subject. For several reasons. 1. Writing about it helps me learn it. 2. If I forget, I can always go back and read what I posted and learn from myself. 3. If I'm wrong, people on the internet are more than willing to point it out. 4. It inflates my ego.

I went about selecting a turbo as follows:

Once you get up to speed in AutoX you never want to shift out of that gear. Do everything you can to stay in the power band in the gear you will be ultimately driving the entire course. For most that's 2nd gear.

Find out the maximum speed I would ever be able to run in a AutoX in my class. Which according to many, including the current National Champ Jeff Kiesel, is approaching 80mph. It would also help to know average running speeds and minimum running speed for the class.

Select the RPM range you want to run the motor in. For me 3500-9300. But probably more like 3800-8800 for typical courses.

Select a tire diameter, gear (transmission), and final drive to run inside the specific RPM range knowing the speed range. For me, I selected, 23.5 inches, 2nd gear 1.882:1, final drive 4.444:1 (2005-2009 Turbo Outback Transmission). In 2nd gear, that puts my speeds at 29-78 mph for 3500-9300 RPM and 32-74 mph for 3800-8800 RPM.

Now determine how much air your selected motor can pump at a reasonable boost pressure for your selected fuel. 1.5 bar (22 psi)? 2.0 bar (29psi)?

Select a turbo that's well past the Surge Line (spooled up) by your Low RPM limit, while also making sure it's got enough to not exceed the Choke Line at your high RPM limit. I am willing to dial the boost way back (e.g. 0.3 - 0.5 bar) at High RPM to stay under the Choke Line rather than selecting a larger turbo which would move the Surge Line past my Low RPM Limit. I don't want to bog in the slow, single cone, hairpin that some courses use; I'm willing to have little power at 70+mph stretching 2nd gear to the next course element.

Ultimately, I selected the BorgWarner EFR 7163 Turbo 0.80 A/R T4 Twin Scroll (Internal WG). I haven't purchased it. That's just the best one, on paper, that fits my needs that I've found so far.

Here's what the EFR 7163 looks like on BorgWarner's MatchBot with a 2.0 bar limit (E85). 575 crank horsepower, 515 ft-lb @ 5000 RPM ft-lb.

Here's what the S200SX looks like on BorgWarner's MatchBot with a 2.0 bar limit (E85). 555 crank horsepower, 540 ft-lb @ 3100RPM. But a broader RPM range. On paper it seems to spool up (passes the Surge Line) 350 RPM sooner and gasses out (exceeds the Choke Line) 500 RPM later.

That S200SX looks good. Wow. No internal waste gate though. So that means I'd have to purchase and run 2 external ones. Plus, custom weld up all the additional plumbing that comes with dual EWGs.

[Rasmus]

I love this build. no bull****. just smart removal of what you dont need.. and modding what you do need to be more reasonable.

Thanks for the compliment.

Redid the S200SX on BorgWarner's MatchBot with a more reasonable a 1.75 bar limit Spools a hint faster, but < 100 RPM faster than the 2.0 bar setting. Not surprising. Peak HP's the same at around 555 hp. Peak Torques down to 490 ft-lb @ 3100RPM

EDIT: Also redid the EFR 7163 on BorgWarner's MatchBot with a more reasonable a 1.75 bar limit Spools 100 RPM faster than the 2.0 bar setting. Not surprising. Peak HP's the same at around 575 hp. Peak Torques down to 490 ft-lb @ 3000RPM

[Rasmus]

Rebuilt the fans and installed them on the radiator. Installed the radiator, but I seem to have bit of an airflow issue. I was able to save 85 grams by shaving off some unused tabs and brackets from the the fan shrouds. Meh.


Fabbed up my own upper radiator mounting brackets out of aluminum bar stock. I imagine that saved a bit of weight from the FFR solution of cutting up Subaru's steel brackets. Those grommets once isolated NVH for a muffler heat shield on a Subaru.


Princess Bubblegum came by to inspect the routing of the coolant tube on the passenger side.


I purchased this radiator because it's reported to have the same water capacity as the Subaru one. Plus it costs about the same. Nabisco also reported it was lighter. But I've realized that most of Nabisco doesn't know how to use a scale and that just wishing something was lighter is the same as it actually being lighter. Koyorad Radiator 3.716 kg w/o cap.


I've weighed the stock one when it was new, and it was 3.426 kg with cap. Gained over 300 grams.

[Jaime]

People like to pick on the plastic end tanks, but they're hard to beat for weight.

[Pearldrummer7]

Looks good. Laughed out loud at the Princess Bubblegum reference.

So, I pose this question to all R guys, but especially you, as our resident weight-loss expert.


Why did you panel both the inside and outside of the side of the car? Seems you could've saved a little fabrication and a little weight by only paneling either the inside or the outside. Is it that big for aero to do both?

[Scargo]

Out of curiosity... what wheels and tires will you run? You mentioned 23.5 OD tires. Does that equate to a 15" rim?
If you got the 4.11 gearset you were initially wanting could you go to a bigger turbo, say a EFR 7064? The compressor efficiencies up to 6K look phenomenal on it. I have almost never seen a course where you could do 80 but, OTOH if you have a high p/w ratio car I guess you could get there fast. I remember the Corvette club in N Texas hosting a meet at an air force base and the course was very fast!

[Rasmus]

Why did you panel both the inside and outside of the side of the car? Seems you could've saved a little fabrication and a little weight by only paneling either the inside or the outside. Is it that big for aero to do both?

It's not for aero at all. In fact, If I catch your meaning, you're asking why I've double skinned the sides?


I didn't. My panels alternate. Inside. Outside. Inside. I took the panels that came in my kit, which were designed to fit the 818S tubes, and cut some of those down, then fabbed up others so everything would fit. I admit, I put those two panels on the outside for aesthetics. I wanted people to be able to see the bars when they looked in.

[xxguitarist]

S200SX looks like on BorgWarner's MatchBot with a 2.0 bar limit[/URL] (E85). 555 crank horsepower, 540 ft-lb @ 3100RPM. But a broader RPM range. On paper it seems to spool up (passes the Surge Line) 350 RPM sooner and gasses out (exceeds the Choke Line) 500 RPM later.

That S200SX looks good. Wow. No internal waste gate though. So that means I'd have to purchase and run 2 external ones. Plus, custom weld up all the additional plumbing that comes with dual EWGs.

Thanks for giving us your input on it. FWIW, I'm seeing if I can work out a deal on a twin scroll T4 header/uppipe with EWGs at a price that won't put everyone in the poorhouse.

[Pearldrummer7]

It's not for aero at all. In fact, If I catch your meaning, you're asking why I've double skinned the sides?


I didn't. My panels alternate. Inside. Outside. Inside. I took the panels that came in my kit, which were designed to fit the 818S tubes, and cut some of those down, then fabbed up others so everything would fit. I admit, I put those two panels on the outside for aesthetics. I wanted people to be able to see the bars when they looked in.

Fantastic. That makes it all much clearer to me. Sorry to bug you with that! I think it looks great as you did it.

[longislandwrx]

If you choose not to do what rasmus did, and want the doors to be open, at the minimum you need a little triangular piece of metal at the bottom to enclose the coolant tube.

[Rasmus]

Because I'm currently obsessed with it:

Here's the EFR 7163 at a nice 1.5 bar (22psi). Spools up even faster than 1.75, which again, is not surprising; achieving full boost at 2700 RPM (232 hp/454 ft-lb). Peak power is still 575 hp but moves up 300 RPM to 7300. Peak torques at 2700 RPM: 454 ft-lb.

Here's the S200SX at 1.5 bar (22psi). Spools up a hint faster. Full boost @ 3000 RPM (255 hp/450 lb-ft). Peak powers still at 7000 RPM, 555 hp. Peak torques at down at 3000 RPM, 450 ft-lb.

Looking at those two plots the EFR 7163 must be rocking some really nice Anti-Surge ports to get it to work like that down low. The S200SX probably doesn't have the Anti-Surge ports which is why it's Choke Line is pushed out a bit further but can't spool up as quick.

Hmmm. I wonder if you could get a S200SX compressor housing with Anti Surge Ports?

[Rasmus]

I was almost ready to jump to the S200SX but I just read that the EFR Line has
An integrated Internal Wastegate for it's twin-scroll offering. I knew this.
An integrated BPV/BOV (100% recirculating type). No need to source an aftermarket one or run the OEM one.
An integrated EBCS (Electronic Boost Control Solenoid).
Plus it comes standard with Anti-Surge Ports on the compressor housing
It's center section runs ball bearings vs the S200SX's oil bearings
It's water cooled so you don't have to run a turbo-timer on shut down, or run lighter weight oil to keep the turbo from burning it's shaft up

On the surface the S200SX seems like a great value. But when you factor in all the extra's you have to get to run it properly it might be a wash money-wise.

[xxguitarist]

While I knew about the EFRs IWG too, I wasn't aware of the built in BPV. Interesting. Makes plumbing for the AWIC much cleaner, easier.
Wasn't aware of the integrated EBCS either. Between selling the grimmspeed EBCS & forge BPV that came on the car, we'd be getting closer to break-even with the S200SX.

Personally.. I was looking forward to ditching the water cooling.. No need for the aux tank next to the engine! Easy enough to idle the car for a bit if you've boosted recently.

Seems like the drivers seat experience would be vaguely similar for both turbos though?

[Rasmus]

Seems like the drivers seat experience would be vaguely similar for both turbos though?

Seems that way. Once you got up to target boost, I think the ***-dyno would think you were running the same turbo. However...

The EFR will come on quicker while under target boost at low RPM's. That is as it rides along the Surge Line up to target boost. For example:

The EFR will hit 0.75 bar (11 psi) at 1600 RPM making 95 hp. Then 1.0 bar (14.5 psi) at 1700 RPM making 105 hp; then 1.25 bar (18 psi) at 1950 RPM making 150 hp.

The S200SX will hit 0.75 bar (11 psi) at 2450 RPM making 145 hp. Then 1.0 bar (14.5 psi) at 2700 RPM making 180 hp; then 1.25 bar (18 psi) at 2850 RPM making 215 hp.

That's probably mostly due the the Anti-Surge Housing on the EFR. The power comes on much quicker and smooths you into your target boost and higher horse power. The S200SX without Anti-Surge (it's the only graph BorgWarner has for me) is your "VTEC, YO!", old-school-turbo-lag, turbo. When it finally gets pass the Surge Line the power comes on HARD and Fast. Bear in mind that the EFR is hitting ~150 hp, 500 RPM sooner than the S200 hits 150 hp.

With anti-surge ports on the S200SX's compressor housing I'd guess the two turbo's would drive very close to the same on the assdyno. A real dyno could tell them apart, but seat of the pants? I doubt it.

[Rasmus]

On a different note:

Happy day! I finally acquired all the parts for the rotating assembly to get balanced. Dropped it all off at the machine shop.

Crankshaft
Rods
Rod bearings
Pistons
Piston Rings
Wrist Pins
Timing gear/teeth
Flywheel
Pressure Plate
Bolts for the lot

Told 'em to balance it for up to 9300 RPM. That's the most it'll ever see, but a little more head room would be nice and bring peace of mind.

[fzust]

Cool build! Look forward to seeing you out there!

#196 XP FrankenLotus

[Rasmus]

Cool build! Look forward to seeing you out there!

See you on course Fred.


While my parts are at the machine shop I pulled my valve covers out of the shed...


Cleaned 'em up.

[longislandwrx]

so fresh! technique? mineral spirits? mastercard?

[Rasmus]

so fresh! technique? mineral spirits? mastercard?

Oven Cleaner to take off the baked on oil (Yes, yes, I know.) Mostly so the baked on oil doesn't contaminate and clog my...
Media Blasting Cabinet, Baking Soda, 60 psi
220 grit wet/dry
400 grit wet/dry
Take photo
Delete that
Take photo with flash so it looks even better
Post on Internet

[MrDude_1]

You should have weighed them before and after. lol.

[Displaced]

Nice build, will be interesting to see what it does once finished.

That said, I'd take some of those Matchbot numbers with a grain of salt.

Putting in values for VE, intercooler efficiency, muffler backpressure etc like you've done I'm showing way over 800 horsepower on matchbot with a EFR8374.

On the dyno it put down 685hp @ 8000rpm and 30psi, which is basically in line with other shops dyno's and those around the web. (32psi = 700hp)

Playing around with Matchbot I was able to getit's outputs to match dyno numbers by upping parasitic losses, wether or not those hold true are another matter. (haven't measured EGBP, or intercooler pressure loss etc.)

http://www.3k-warner.de/aftermarket/...6_wrsin=92044&

Just food for though, but I'd still suspect you to be in the high 400hp to low 500hp range with a 7163

[Rasmus]

You should have weighed them before and after. lol.

That'd be hilarious! "Cleaned Valve Covers. Saved 6 grams."

[Pearldrummer7]

Oven Cleaner to take off the baked on oil (Yes, yes, I know.) Mostly so the baked on oil doesn't contaminate and clog my...
Media Blasting Cabinet, Baking Soda, 60 psi

That was such a smooth sentence transition.

[Rasmus]

Out of curiosity... what wheels and tires will you run? You mentioned 23.5 OD tires. Does that equate to a 15" rim?

I haven't forgotten or missed your questions Glyn. I just needed to think a bit before answering.

Street Use (i.e. Cars & Coffee, Show-n-Shines, Can Kicker Shoot the **** Nights, Group Drives)
Front: 215/40-r17 on 17x8's +40mm offset. O.D.: 23.8". A little under the maximum recommended O.D. from FFR and Wayne (24.0" Max).
Rear: 255/40-r17 on 17x9.5's +30mm offset. O.D.: 25.0". +30 offset because I'm running "Wagon Width" rear lateral links: 10 mm shorter per side. So I can push the wheel out 10 mm and it'll sit exactly where FFR and Wayne recommend. Plus, DAMN SON! It look cool, all deep dish, like dat!

Wheel Brand and Model:

Dunlop Direzza ZII Star Spec. I like the tread pattern and it comes in both sizes.

CCA Solo/AutoX
Front: 8.7/21.5-15 on 15x8 +40mm offset (O.D: 22.10")
Rear: 10.5/23.0-15 on 15x11 +5mm offset/6.2" backspace (O.D.: 23.55"). I'm not even sure If I could get this to fit. It sticks out 2 inches more than the street set.
Rear Alt: 9.0/23.5-15 on 15x9 +30mm offset/6.2" backspace (O.D.: 23.60")

Wheel Brand and Model

Avon 15" Crossply slicks. I like the tread pattern and it comes in both sizes.

[Jaime]

...I like the tread pattern...

Nice

[Hindsight]

Rasmus, I thought the recommended front size was 214/40/17 due to the <= 24" OD? I believe Wayne said anything with a larger OD will rub? I am asking because I would much prefer to go larger than 24 myself but have been limiting my choices due to Wayne's findings.

Are the rear lower control arms the same on the wagon vs sedan? So its just the lateral links that are different?

[MrDude_1]

Avon 15" Crossply slicks. I like the tread pattern and it comes in both sizes.

I also like that tread pattern... but do slicks like this get hot enough to stick in autocross on such a light car? I thought the higher end DOT tires worked better cold, but I know tires have changed since I last autocrossed seriously.. (5 years ago)

[Rasmus]

Rasmus, I thought the recommended front size was 214/40/17 due to the <= 24" OD? I believe Wayne said anything with a larger OD will rub?

I'm so glad you wrote something and stopped me. You're right. The size has been change from 215/45-r17 to 215/40-r17. I would have been cursing myself.

[xxguitarist]

Rasmus,
I'm sure you know already, but EM rules specify a couple differences for a DOT-R tire vs full race compound. IE, external battery switch & trans shatter shield.

We're probably going for V710 to get the car dialed in, to avoid wasting the A6 or A7 that we'll switch to once we're set up.

[Rasmus]

Rasmus,
I'm sure you know already, but EM rules specify a couple differences for a DOT-R tire vs full race compound. IE, external battery switch & trans shatter shield.

First thing, I hate the Modifed Classes ruleset in the SCCA Solo Rules. I have to skip around to four different sections to get the full set of rules. Hate it!

They way I read it:

18.0.D. Tires
Any tire (including recaps) meeting the applicable portions of Section
3.3 is allowed.

As long as it's safe you can run any tire you want. I don't see where the rules have conditions on DOT-R vs full race compounds.

18.0.E. Safety Requirements
1. Scattershields/Chain Guard:The installation of scattershields or
explosion-proof bell housings shall be required on all cars where
the failure of the clutch, flywheel, or torque converter could create
a hazard to the driver or passengers.

The orientation of the flywheel and clutch in the 818 would not create a hazard to the driver or passengers in the event of a catastrophic explosion. Sure it'd shred the rear wheels, tires, intercooler, turbo, and a fair amount of bodywork but the humans are not in the direct line of fire from such an event. So the 818 in E Modified Class doesn't have to run a scattershield. That stated, based on my totally inaccurate finger pinch measurements the phase 2 5-speed case I'm running appears to meet the requirements of rules if I did need to run an explosion-proof bell housing"¼ inch (0.250”; 6.35mm) aluminum alloy".

18.0.E. Safety Requirements
2. Master Switch: All cars shall be equipped with a master switch
easily accessible from outside the car.

You have to run a master switch no matter what.

Let me know what I've interpreted wrong. That rule sets hard to follow some times.