Which Top Mount

You can get a 20g to hit fast enough to make it usable for HPDE, but at the cost of excessive exhaust gas temps. I am not a fan of the combo.

The idea behind an intercooler is to attempt to bring the compressed intake charge back down to as close to ambient temp as possible. Especially in a track car, why would you not use a FMIC? This is where the power is at:

https://www.extremeturbosystems.com/collections/legacy-gt-intercoolers

I like the 8cm 1.5XTR for the faster spool, never saw a loss up top.

What size injectors are you running for flex fuel? What intake and turbo inlet? Headers?

With enough info on the supporting mods I can make an educated comparison once the tune is complete and you have the dyno data.

Perrin EL coated header

GS coated up

Perrin inlet

Cobb SF with box

ID1300xds

New OEM MAF

Also to note, this is a street sleeper, still has factory wheels and don't need a huge FMIC showing off the goods!

The intake is far too small for the set up. You need air to mix with the fuel. You need a 73mm intake. KSTech makes a nice one that works great, and is easy to scale and tune as the MAF location is proper. You need air to mix with the fuel.

http://www.kstech.biz/legacy-gt-megamaf-73mm-big-maf-cold-air-intake-type-2/

You can get a 20g to hit fast enough to make it usable for HPDE, but at the cost of excessive exhaust gas temps. I am not a fan of the combo.

 

 

 

The idea behind an intercooler is to attempt to bring the compressed intake charge back down to as close to ambient temp as possible. Especially in a track car, why would you not use a FMIC? This is where the power is at:

https://www.extremeturbosystems.com/collections/legacy-gt-intercoolers

 

 

 

I like the 8cm 1.5XTR for the faster spool, never saw a loss up top.

 

 

 

What size injectors are you running for flex fuel? What intake and turbo inlet? Headers?

 

 

With enough info on the supporting mods I can make an educated comparison once the tune is complete and you have the dyno data.

Definitely agree that FMIC is the optimal choice and if I went that direction I'd definitely go with ETS since they're local and the quality is top notch. That said, if I'm sticking with TMIC for the foreseeable future, seems like you feel 18G 'ish size is the largest I'd want to go? Currently running EVO 16G, top Feed ID1000cc, Cobb DP / UP, Cobb intake, Perrin Inlet and (gasp!), stock exhaust manifolds. Swaintech coated Killer B Holy Header is probably on the docket for an off season upgrade. Thoughts on Blouch's 18G-XT w/ 7,8,or 10cm housing or their 18G XT-R?

Saw this setup a few years ago, and thought it would be about perfect.

https://www.rallysportdirect.com/part/intercoolers/prw-pwvmnt01-process-west-v-mount-intercooler-kit

Holy shit! That about sums it up!

Saw this setup a few years ago, and thought it would be about perfect.

https://www.rallysportdirect.com/part/intercoolers/prw-pwvmnt01-process-west-v-mount-intercooler-kit

The Cobb post MAF hose is 3", however the Cobb MAF housing is 2.5". There is the bottle neck. You are going to max out the maf scaling and run out of intake.

I have had great success with the 18gXTR. Still a fan of the 8cm. 10cm works better with e85 and a slight bump in engine compression.

I actually measured the Cobb MAF housing, it is 2.75" ID (69.85mm). I also measured the GS and it is also 2.75". The factory MAF is 2.5" (65mm), only good to about 300~ (hit MAF limit on dyno with my other legacy, hence the GS intake).

If the Cobb MAF housing was the same diameter as stock, why would it require a tune? Not sure what the 70mm is good up to, maybe someone else can chime in. PRE's turbo shootout test car (05 legacy GT) that saw almost 500whp was running a 2.75" MAF.

My bad. Its been years since I measured a Cobb, but my notes say 2.5"???

I have no knowledge of PRE test car, but 500whp can not be made with a Cobb intake. I doubt 500whp could be made with a 73mm intake. Not true 500whp. But I can make a dyno say a 1984 Yugo makes 500whp so dyno numbers used in marketing are worthless.

I can tell you from experience testing on a dyno that the Cobb intake is not large enough to take full advantage of a dom1.5xtr. We had a package at my shop that we offered using the dom1 5xtr and I guarenteed over 400whp (e85) with the set up and the customer was allowed to video the dyno session and was given printed and digital copies of the dyno reports.

Just trying to assist, not muddy the waters.

If the Cobb MAF housing was the same diameter as stock, why would it require a tune?

Turbulence/flow changes compared to the stock intake can lead to different MAF scalings, but mostly I agree with you that it certainly does make sense the SF intake has a larger diameter housing to require (from my memory) about a 15% increase in MAF scaling compared to stock. I doubt turbulence would cause a 15% error across the board. The numbers come out reasonably close too (2.75" diameter is about a 20% increase in area from a 2.5" diameter).

 

I can tell you from experience testing on a dyno that the Cobb intake is not large enough to take full advantage of a dom1.5xtr. We had a package at my shop that we offered using the dom1 5xtr and I guarenteed over 400whp (e85) with the set up and the customer was allowed to video the dyno session and was given printed and digital copies of the dyno reports.

 

Just trying to assist, not muddy the waters.

can confirm, my tuner said the cobb intake wouldn't run out of room on my 440xt and told me to get the KS tech 73mm.

Msprank can you elaborate on this comment a bit? I ask because not only do I know a few forum members locally that are running a 1.5xtr with good success and making good power (on Grimmspeed topmounts), but my next upgrade for the track car was going to be this turbo or maybe even a 2.5xtr. I’d prefer to stay top mount thru this process and this is the first time anyone has ever mentioned that these Turbos are not suited well to TMIC’s

Pretty sure that I’m one of those local forum members.

I’m running the Cobb SF intake, Perrin turbo inlet, 8cm DOM 1.5XTR w/2.4” inlet, GS TMIC, Company23 EBCS, ID1000’s, Cobb Flex Fuel, Holy Header, external wastegate replumbed into downpipe.

Two variables that I also have, hybrid speed density tune (because of issues mentioned about MAF) and a built block with cams and upgraded valve train (because stock motor blew at 135K and why rebuild to stock?).

Pretty sure that I’m one of those local forum members.

 

I’m running the Cobb SF intake, Perrin turbo inlet, 8cm DOM 1.5XTR w/2.4” inlet, GS TMIC, Company23 EBCS, ID1000’s, Cobb Flex Fuel, Holy Header, external wastegate replumbed into downpipe.

 

Two variables that I also have, hybrid speed density tune (because of issues mentioned about MAF) and a built block with cams and upgraded valve train (because stock motor blew at 135K and why rebuild to stock?).

 

Do you have a 92 pump gas plot, there are both flex fuel yeah?

Do you have a 92 pump gas plot, there are both flex fuel yeah?

#2 is 92 pump.

E10 is in reference to the ethanol blend which is standard in Oregon on pump (https://www.oregonlive.com/environment/2008/05/oregons_ethanol_requirement_lo.html).

All this has me dreaming of how to do a mild autox/street build when the turbo needs replacing in my wagon. My wallet is already screaming in terror.

A mild autox is more mild than you think. Changing engine components pretty much moves you to much faster class. But it is damn fun to autox a wagon.

A mild autox is more mild than you think. Changing engine components pretty much moves you to much faster class. But it is damn fun to autox a wagon.

Mild might have been the wrong word. Mild for SM/XSA, no chance for a trophy at a National Tour, but fun locally.

Not enough data logged with the graph to tell exactly what they do. But.. those numbers are highly inflated for the intake, injectors and boost levels noted. Recording at a supposed 40deg F helps too. But they did not log the weather station, they manyally typed it into the description.

Only way to have better info is if there were before and after graphs and maybe a stock/stg 1/stg 2 graph for baseline comparisons.

Not too many Subies broke 400whp on my Mustang. I was brutally honest and admit MANY owners left a bit butt hurt by the numbers. But none ever complained after a drive. Those that dropped the car off making under 400 and left with it making more than 400 normally returned within a few days with stories of life flashing before their eyes.

I suppose if you want positive marketing, big numbers catch attention.

JMP VF52.PDF

Not enough data logged with the graph to tell exactly what they do. But.. those numbers are highly inflated for the intake, injectors and boost levels noted. Recording at a supposed 40deg F helps too. But they did not log the weather station, they manyally typed it into the description.

 

Only way to have better info is if there were before and after graphs and maybe a stock/stg 1/stg 2 graph for baseline comparisons.

 

Not too many Subies broke 400whp on my Mustang. I was brutally honest and admit MANY owners left a bit butt hurt by the numbers. But none ever complained after a drive. Those that dropped the car off making under 400 and left with it making more than 400 normally returned within a few days with stories of life flashing before their eyes.

 

I suppose if you want positive marketing, big numbers catch attention.

You are right, before I switched to a hybrid speed density tune, I was “limited” to 402whp.

Here is the rest of my build:

-IAG Stage 2 Tuff (#2476)

- new OEM block

- new OEM nitride coated crank

- Cosworth 1431 pistons

- IAG Spec H beam rods

- ACL “H” STD HX main bearings

- ACL “H” STD rod bearings

- Manley piston rings

ARP Head Stud Kit

Blouch DOM1.5xtr 2.4” inlet and 8cm hotside

Cobb SF intake and box

Cobb Flex Fuel Kit with Fuel Pressure Monitoring kit

Company 23 Anti-Surge EBCS

AEM 340lph fuel pump relayed to 12v source

-4 Fuel Return line

Fluidampr crank pulley

Fuelab Mini fuel pressure regulator 25-90psi

Grimmspeed TMIC w/ black thermal dispersant coating

Grimmspeed STi style hose for TMIC

GSC Beehive Valve Springs w/ Titanium Retainer Valvetrain Kit

GSC Power-Division Stainless Steel Exhaust Valves, 32mm

GSC Power-Division Stainless Steel Intake Valves, 36mm

IAG TGV Deletes (black)

IAG fuel rails anodized black

IAG fuel lines with STi FPR

IAG AOS in black

IAG air pump delete

ID1000's

IP&T V1 Filtered Oil Feed Kit

Killer B Motorsport High Flow Water Pump Housing (WPH)

Killer B Motorsport High Performance Oil Pan (EJ25Pan)

Killer B Motorsport Ultimate Oil Pickup (070-110)

Killer B Motorsport Oil Baffle Windage Tray (EJWT)

Killer B Holy Header with EWG V-Band Uppipe, Swaintech Coated

Koyo aluminum radiator

Perrin 2.4" black silicone turbo inlet

Prova Air Intake Guide

Samco ancillary, radiator and oil cooler lines

STi 11mm Oil pump

Subaru OEM water pump

Tial MV-S 38mm EWG in Black rerouted into downpipe

Tomei Poncams

Tomei Timing Belt Guide

TurboSmart BPV

Maddad Catted Downpipe

Nameless Performance mid-pipe

JDM Prodrive wagon-specific mufflers

Not sure if this helps for comparison but here is my Stg.2 dyno from the same tuner on the same dyno. JMP 11 blade billet VF52 on stock fueling, Cobb DP / UP. Everything else OEM. 2008 Outback XT 5MT

Based on this, I’d love to see your response.

there's always this option. buy now

https://legacygt.com/forums/showthread.php/me-gt3076r-turbo-supporting-mods-283908.html?t=283908

Jrae2424, he didn't say it would be choked out up top, he said it wasn't ideal or recommended. He said there will be power left on the table without using a FMIC.

That being said, there are plenty of cars over 400 and even 500hp with the GS tmic, E85 is one hell of a drug! (Charlie Murphy)

If I didn't want sleeper status, I would definitely have a FMIC, have had them on all of my turbo cars. (Go ahead and take a rock or a piece of metal to the FMIC and see how that hurts the wallet!) Been there and done that almost 50 times at this point (no, the wife is NOT happy about this number and never will be )

The only way to prove anything would be to have logs, I will have a hybrid SD setup as well. We need another legacy owner with similar setup except FMIC that has an IAT before the throttle body to make a comparison.

That being said, the auto trans you have right now might not live to see the difference. Good luck brother!