[TimM]

IAG Deletes-impressive machine work...~$300 I suppose they should be. Compared to OEM, definitely some power gained.

Bottom:

Mocked up:

Down the throat:

They match up very nicely with the ported heads-can't complain whatsoever.

 

[TimM]

Bought a hopefully accurate digital scale to weight the engine pieces:

Scat Rods:

The lightest @ 512.0 grams:

Cosworth Piston (lightest @ 387.6 grams):

Cosworth Piston Pin (beefy / lightest @ 120.7 grams)

I was a bit surprised at the Cosworth piston weight spread of .5 grams from lightest to heaviest.

The pins were only .1 spread.

The rods were slightly more @ .7 gram spread.

I could have these all balanced at an extra $225 by the somewhat reputable machine shop (hey, they have a EJ257 torque plate!)...

Or just move the parts around to come out with a spread of .3 gram. A true balance would equalize the small end / large end of the rods as well as each individual part. I'm not sure I'm to that level of detail.

I always wonder how one explains the oil splash with an operating engine...that oil weighs something and likely no one can quite compute it yet nor at all rpms which it is different. I'm leaning toward-close enough for government work...and let it fly (NOT apart!).

 

[TimM]

Came across a couple more images of it new...these and the previous were actually the day we brought it home.

Nice Subaru provided floor mats...oh that wasn't an option:

Nor was a radio...how many cars in the last 30 years came with radio delete plates???

 

[TimM]

With some recommendations of forum members...

I'm preparing to fine tune the exhaust side by eliminating the Cobb ~2.5 inch connection between the downpipe and cat back portion by installing a full 3 inch flex connection and v band clamp.

The two items from Summit ran ~$140. The pro shop estimates the install to be about $150 using SS TIG welding. Hopefully this coming week will be the appt.

I don't expect it to provide a tremendous increase, but witnessing the exhaust flow at the dyno, it certainly can't hurt even at my conservative HP goal.

 

[yamahaSHO]

I will be doing this as well. It infuriates me that Cobb can't get this right and make it a full 3" and provide/sell an adapter to make it bolt to a stock cat-back, especially since 99% of people putting a downpipe on the car are also doing a full exhaust.

 

[TimM]

Agreed.

Although I do like an OEM connection for reliable sealing. We will see how the V-band pans out. All told, it will cost me ~$300 to correct the neck down. I do think it will be worth it.

Thanks.

 

[TimM]

Changed the plan for the dyno location...worked a deal for a closer dyno shop so another baseline will be done this week.

They use a different dyno than the previous visit/location. Far closer and much more reasonable for my 3 visit plan.

I suppose it will be interesting for the back to back comparisons, but was not my intent although the extra $75 will save me several hundred.

Sounds like my 262 WHP will grow to ~280 or so...that sounds much more impressive!



Additionally, reconsidered my plan for using my familiar SCAT rods...knowing this engine will be twice the HP per cylinder than I'm used to...elected a set of Manley rods with 625 bolts as more than one person on this forum suggested.

 

[TimM]

Well, the dyno visit was interesting.

Different dyno and location and day...so the numbers are different.

Shot of the odometer...172,023 miles...

Land and Sea dyno with dual 13 inch rollers.

Uncorrected WHP is 303 and WTQ is about 320. I say about as I'm still waiting on a chart with the specific numbers.

Camera image:

Up 41 WHP from the visit 30 days prior with absolutely no changes except another ~1000 miles.

So lesson is...as we all have heard and seen...if you the numbers aren't big enough...go to another dyno!

Video to follow...unlikely as it is boring.

 

[yamahaSHO]

Use a DynoJet every time and your numbers will be more consistent, regardless of location.

 

[TimM]

The Manley H-Tuff rods are on the way-thanks Outfront Motorsports (15024R6). I will have to say the Manley information on what name refers to what rod is confusing. These are the bigger H-beam with the 625 ARP rod bolt. Yes overkill for my application, but figure once I replace the heart of this car...it will happen again down the road for more HP.

I also disassembled my new OEM shortblock fully. Neat little engine. Sharp edges on that case for sure!

I bolted the case back together minus crank to drop off at the engine shop for main bearing oil clearance confirmation this week. Odd to do the work on the card board covered floor rather than an engine stand.

Crank weighed in at 20.6 pounds.
Empty case weighed in at 53 pounds.
OEM STI rod weighed in at 596.9 grams.
OEM STI piston pin weighed in at 152.2 grams!
OEM STI piston with rings weighed in at 439.9 grams.

 

[TimM]

yamahaSHO: Of course, I'm attempting to use the same facility for the three visits...minimizing the variables.

Possibly Dynojets haven't gotten a bad rap with their more basic inertia setup. I've never used one...almost always a Mustang until this last visit on a Land and Sea.

 

[yamahaSHO]

The beauty of a DynoJet is that turning a 3,000 lbs drum doesn't change from one dyno to the next.

 

[TimM]

Agreed...additionally it is known there are always 'knobs' one can adjust to come up with different numbers on identical dyno installs.

 

[TimM]

Machine shop called about the shortblock I dropped off yesterday...quick!

Bores: New OEM standard bore allows right at .0025 on the Cosworth pistons (99.5) with no machine work. Taper of the bores is only very slight from the factory-certainly some money saved there.

Main oil clearance: I was hoping for tight...what Subaru has as delivered...

#1: .001
#2: .0012
#3: .0012
#4: .0011
#5: .001

This shows to be on the loose side according to the OEM manual (.0012 in) is normal limit with maximum limit is .0016-.0018)

I will probably leave as is...otherwise my options are try aftermarket bearings or machine work to the case...

We will see how the rods come out upon their receipt.

 

[got2boostit2]

I thought the mains are tight? At 0.0012 and 0.001 and 0.0011. Even though on spec.

 

[TimM]

Got2Boostit2: Are you saying they should be looser?

Typically, higher HP builds are indeed looser for domestic V-8's-my only experience.

This is as Subaru assembled, but I'm expecting to increase the HP by ~125 or so...I could understand that OEM spec may not be applicable.

Again, likely I will leave as is...I'm more comfortable with Subaru's work than most.

I may balance the engine though...the honing/bearing savings offset the cost.

 

[got2boostit2]

No sir, just biased to the tight end if the spec. And I'm all for balancing.

 

[TimM]

Got2Boostit2: Pulled from the OEM manual:

#1: .00012 to .0012 (max limit of .0016)
#2: .0004 to .0012 (max limit of .0018)
#3: .00012 to .0012 (max limit of .0016)
#4: .0004 to .0012 (max limit of .0018)
#5: .0004 to .0012 (max limit of .0016)

So actually my case is at the loose end of the OEM spec. I'm guessing you are saying that is on the tight end of the typical built engine...which makes sense for a higher performance than stock engine.

I'm going to let it ride...I'm pretty easy on my engines apparently so...

I did pick up the block from the machine shop-it is so light. Amazing.

Then the rods came this afternoon...so another trip to the shop is required.

Did a quick look see at these big bolt Manley Rods...H-beams always looks so slick. Weigh in was right around 578 grams for one. This is ~20 grams lighter than the OEM STI rod-this is great. I will do a piston comparison as well. 20 grams less stress on the rotating assembly...

I also met face to face with the tuner (M-tuned). He is ok with my plan and will provide a limp map for the larger injectors/pump/TGV deletes. We will shoot for 3.5 weeks until pull the OEM turbo off.

Autocross this Saturday...see if I can make up for my poor performance last month!

 

[TimM]

Autocross was a blast...6th overall of 72 cars. Mainly a slalom which I do not prefer.

Setting the Ohlins FPS on #30 (stiffest) was a nice improvement. I do think my 8000 mile Rivals are cycled out...but have another 4000 miles of tread.

Some images I did not take, but are very nice:

Great to see one's car at speed...hard left turn...AWD is easy!:

 

[TimM]

Had some time to examine the Manley H Beams with ARP 625 bolt. Pretty nice and beefy. They weigh 66 grams more than the SCATs I originally purchased (and returned).

Some numbers:
Manley H Beam........578 grams
SCAT H Beam..........512 grams
OEM STI rod............597 grams

OEM STI piston with rings.........440 grams
Cosworth piston with rings........413 grams

OEM piston pin..........152 grams
Cosworth piston pin...121 grams

In the end, piston, pin, and rod reduce the 'bob' weight by ~78 grams. All good for increased durability at higher revs.

Cosworth Piston:

Fun stuff!