TMIC in a GC8, How much power? What fits?

[Stoffa]

Just info gathering, wondering how much power people have got out of top mount intercoolers? also if people have been datalogging, what intake temps have you been getting on the street and on the track?

Toying with the idea of ditching my front mount and going back to a top mount and getting more response, Ive got a v5 so I could easily get a version 7/8 factory one in there, but probably not an after market v7/8 would love a Process West V7/8 one but I dont think it'll fit. I want to keep a strut brace, but if need be I could get a custom one made.

Im currently running 240kw with my fmic so it shouldn't be too much of a hard ask for a TMIC, and the car is plenty fast enough at that power.

[pl0x]

 pl0x said:

Legacy B4, single turbo vf22 @ 15psi with V5 wrx topmount, car was making about 190wkw on this tune

High temps could be due to small scoop, wrx Y pipe etc etc.

my intake temps with the factory top mount were hitting 70c+ (18c ambient) from just a 1st-4th pull. below data log:

Now with front mount in its sitting at a lot more constant temp, 34c was the highest it saw after a few pulls (16c ambient). below data log:

That was only with the small legacy scoop and only a wrx Y pipe. So your scoop would provide more airflow

[Bazza-NZ]

Talk to Rick about this. He had his putting out 300kw with a top mount

[Stoffa]

Yeah but his was way oversized, he moved the engine forward to make it fit

[Bazza-NZ]

 Stoffa said:

Yeah but his was way oversized, he moved the engine forward to make it fit

That is true... but shows that high KW figures are possible if you are prepared to do the work.

[boon]

FWIW I have a Process West one on my V7, getting 231kw on STM's dyno (no idea what that translates to on Shred but I'm guessing around 240)

Never done a datalogging run on my IAT, as my laptops battery lasts about 3 minutes. You're welcome to jump in some time and see what I get if you have a laptop set up for it?

[Stoffa]

I would love to check out your engine bay just to see if a v7 one will actually fit in my v5, I'm running a v8 manifold so should be ok

[Eight_dollar]

Speak to Rick, he moved the engine slightly as the IC was to suit V8

His V5 manifold was the prob - if your running V8 then your fine

from memory (check with him tho ) his intake temp was 38-42 (something like that) at 300kw

One bonus was handling too, the moved engine gave it much better turn in on the track

He mentioned about weight %'s etc - but lost me lol

[sultan]

I would have thought moving weight forward would promote understeer

[GC82GO]

http://rusubaru.com/intercooler-efficiency/ READ THIS, BASED ON SUBARU being TMIC vs FMIC

[GC82GO]

Subaru TMIC info, ver 3-4 STi best for flow., Cooling Mist + v3-4 STi IC, 270kw. No extra lag. been done. FMIC is for big power. Dont waste your money, Unless you wanna look like a rice boy.

Version 2 (MY94-96) WRX Intercooler

Flow 282.7 cfm

143.9 cfm with standard WRX feed pipe attached

Mass 2.8kg

Core Measurements 40 x 11.5 x 6.2cm (2852cm2)

The Version 2 intercooler is immediately recognisable as the poor cousin in the WRX range. It's the smallest and lightest of the bunch, its end tanks and core section are oddly arranged and its core volume isn't particularly large. The plastic intercooler feed pipe (which is notorious for splitting at high boost) also flowed appallingly - installing it reduced flow bench figures by 50 percent!

Version 2 (MY94-96) STi Intercooler

Flow 285 cfm

224.2 cfm with standard STi feed pipe attached

Mass 2.8kg

Core Measurements 40 x 11.5 x 6.2cm (2852cm2)

This imported Version 2 STi intercooler is a rare find. Visually, only the silver finish and a different rear end-tank shape distinguish it from the contemporary WRX part. So how much better does the STi intercooler perform? Well, not much. A slightly larger charge-air entry into the rear end-tank allows a tad more flow than the standard WRX 'cooler - 285 cfm versus 282.7. Thermal mass and core volume, meanwhile, is identical to the stock WRX - pretty minimal.

While the STi intercooler holds a slim flow advantage over the base product, its cast alloy/silicone hose feed pipe flows considerably better than the standard plastic part; the absence of a convoluted section (which causes massive in-pipe turbulence) is the major reason for this improvement. Once bolted together, the STi intercooler and feed pipe assembly outflows the standard WRX combo by more than 50 percent - a good net gain. Note that the Version 2 STi feed pipe won't bolt onto the conventional WRX intercooler (damn!).

Version 3-4 (MY97-98) WRX Intercooler

Flow 309.8 cfm

159 cfm with standard Y-shape feed pipe attached

Mass 3.150kg

Core Measurements 37.5 x 14.5 x 6.2cm (3371cm2)

Subaru took a major step up in the size of the Version 3 core - and the benefits show. Compared to the earlier Version 2 WRX intercooler, airflow is up 10 percent, thermal mass is around 12 percent greater and the heat exchange volume is 18 percent larger. While this is certainly an impressive upgrade (for an OE part), bear in mind the aftermarket Version 2 core still performs better in every aspect.

Interestingly, bolting on the standard Version 3-4 WRX Y-shaped feed pipe (which is a combination of cast alloy and plastic) caused nearly a 50 percent flow loss - similar to that seen on the Version 2. Again, we can blame a portion of this restriction on the convoluted section of the plastic feed pipe.

Version 3-4 (MY97-98) STi Intercooler

Flow 315.7 cfm

Standard STi Y-shape feed pipe unavailable

Mass 3.150kg

Core Measurements 37.5 x 14.5 x 6.2cm (3371cm2)

Ah-ha - here's an intercooler that many WRX owners are prepared to spend big money on. But is it worth it? On the scales, the imported STi 'cooler is virtually the same weight as the WRX equivalent and the core dimensions are identical. In short, there's no heat exchange advantage to be seen.

And what about airflow?

Well, the STi intercooler flows 315.7 cfm at 28-inches of water - about 2 percent better than the basic WRX core. Again, we're talking about a minimal gain. The reason for this slightly superior flow appears to be linked to the fact the STi intercooler doesn't have the recess found on the left side of the conventional Version 3-4 WRX rear end-tank.

While the Version 3-4 STi 'cooler is barely any better than the WRX part, once again we'd expect its associated silicone feed pipe to out-flow the normal plastic one. Unfortunately, though, the STi Y-shape feed pipe was unavailable for our tests.

Version 5-6 (MY99-00) WRX Intercooler

Flow 286.3 cfm

134.8 cfm with standard Y-shape feed pipe attached

Mass 3.8kg

Core Measurements 37.5 x 14.5 x 6.2cm (3371cm2)

As mentioned in Part One, the Version 5-6 intercooler has the same core dimensions as the previous model but has much denser external cooling fins and revised internal fins. This contributes to a big 21 percent increase in mass over the Version 4-5; we can only guess Subaru suddenly decided to get very serious with charge-air cooling.

This focus on improved cooling has come with a trade-off, however. On the flow bench, the Version 5-6 WRX intercooler dropped to nearly to the performance of the Version 2 WRX intercooler. With just 286.3 cfm flowing at 28-inches of water, this is certainly one of the most restrictive Subaru top-mount cores.

Airflow continues to decline when the standard Y-shape feed pipe is bolted on; this part is identical to that used on the Version 3-4 and caused a similarly massive flow loss. The result - at 134.8 cfm - is the worst flow figure of all the 'cooler/feed pipe assemblies.

Version 7 (MY01-02) WRX Intercooler

Flow 293.1 cfm

134.8 cfm with standard Y-shape feed pipe attached

Mass 3.5kg

Core Measurements 41.5 x 15 x 6.2cm (3860cm2)

Surprisingly - despite its larger dimensions - the current Version 7 WRX intercooler has 9 percent less thermal mass than the unit before. On the other hand, its 15 percent larger core volume - with a completely different cooling fin design - redeems its overall charge-air heat exchange potential. Airflow through the Version 7 intercooler is only slightly improved over the previous Version 5-6 - at 293.1 cfm, though, it's still a fair way behind the flow of the Version 3-4.

The Y-shaped cast alloy/plastic feed pipe is slightly different to those used in previous models and its restriction isn't quite as severe - adding the Version 7 feed pipe reduced airflow by 37 percent (down from about 50 percent in the Version 3-4 and 5-6 WRX).

Aftermarket Version 7 (MY01-MY02) Intercooler

Flow 349.5 cfm

231.7 cfm with silicone aftermarket Y-shape feed pipe attached

Mass 8.3kg

Core Measurements 48.8 x 17.5 x 11.2cm (9565cm2)

Boy is this thing heavy! The MRT bar-and-plate replacement for the Version 7 WRX 'cooler is well over double the mass of the original part; it's so heavy, in fact, we reckon you might need to strengthen your intercooler mounting brackets! Much of this extra weight comes from an 80 percent thicker core, which - in addition to contributing to a massive 147 percent larger core volume - also enables air to flow more freely. The airflow through the MRT Version 7 core is exceptional - its 349.5 cfm result equates to 19 percent more flow the stock unit.

As part of the MRT upgrade a two-piece silicone Y-shaped feed pipe is supplied. Thanks to its smooth internal surface, this pipe gives minimal restriction - adding it to the intercooler reduces airflow by a relatively low 33 percent. Note that this particular feed pipe won't mate to your factory Version 7 intercooler (again, damn!).

BG (MY97-98) Legacy Twin-Turbo Intercooler

Flow 314.3 cfm

255.7 cfm with twin cast alloy feed pipes attached (not including plastic pipes to turbochargers)

Mass 3.6kg

Core Measurements 37.5 x 14.5 x 6.2cm (3371cm2)

Hmmm, these figures look familiar. It seems the imported BG Legacy twin-turbo intercooler core is the same as used in the Version 3-4 STi - that's not surprising considering they're from the same timeframe and are used on engines making similar power. On the flow bench, the TT intercooler flowed around only half a percent less than the Version 3-4 STi job - this margin is so miniscule, however, it's likely to be variation of the flow bench.

In terms of heat exchange performance, the Twin-Turbo intercooler is around half a kilogram heavier than the Version 3-4 STi - though we suspect this is only because of some extra brackets and a metal core garnish. The core volume is identical to the Version 3-4 STi and WRX; that means, amongst the OE intercoolers, its core volume is beaten only by the Version 7 part.

BF (MY92-93) Liberty RS Water-to-Air Intercooler

Flow 221.1 cfm

211 cfm with standard RS feed pipe attached

Mass 3.9kg

Core Measurements Unable to measure, but smaller than Version 2 WRX (at 2852cm2)

First, we must point out that the 3.9-kilogram thermal mass quoted for the RS water-to-air heat exchanger is a little misleading in the context of air-to-air intercoolers. Some of this mass can be attributed to the external water jacket with two water necks and the alloy feed pipe that's cast as part of the intercooler body. Oh, and - since it's contained within the water jacket - we were unable to measure the volume of the water-to-air heat exchanger core.

And how did the RS intercooler flow? Well, we recorded 221.1 cfm but - again - this figure is misleading. As mentioned, the RS intercooler body integrates a large section of the feed pipe; this inevitably causes extra flow restriction compared to the rest of the 'coolers, whose feed pipe connect at the base of the rear end-tank. In other words, the flow figure for the bare RS intercooler is at a disadvantage.

On the other hand, only a short length of plastic pipe (which incorporates a blow-off valve fitting) is required to link the beginning of the alloy feed pipe to the turbocharger. Adding this to the intercooler saw just a 5 percent flow loss; the relatively small loss from fitting this part helped bolster the flow of the complete RS intercooler assembly beyond that of the Version 2, 3-4 and 7 WRX!

[GC82GO]

Sorry for so much reading.. But read it. !

I also see no point in installing a V7-9 IC in a GC8/Any suby. specially after reading this factual write up by autospeed.

[Stoffa]

yeah after quite a bit of research if I do it i'll probably go with a Process West V7+ one.

[marc]

If I get some time can post some pics of my Process West one on my ver8 sti if that helps u..

[Stoffa]

Yes please. trying to figure out if i'll have enough room. im guessing ill have to use a v7 remote clutch resivour

[dzk]

Subscribed to this, are you going for v7+ type intercooler due to running the v8 manifold?

Subout on here can get the kits

http://www.processwest.com.au/index.php/products/subaru/wrx-sti-gc8/my99-00-top-mount-intercooler-kit

Price list

http://www.processwest.com.au/index.php/price-lists/subaru-price-list

Don't know how true this video is but maybe worth a watch with just process west top mount kit

[Stoffa]

I v7 ones are alot bigger and I've already got a v7 bov now. After talking to Chris at STM he said boons one was the most efficient tmic he's seen on a Subaru. Still undecided