I'm in the market for an upgraded top mount intercooler for my 2006 USDM GD STI ej25. I'm in between choosing the ETS and the Grimmspeed top mount intercoolers.

Is the ETS really recommended due to fitment issues with the Grimmspeed?

I have one buddy who had the ETS top mount and noted "it's easy to take in and out" but he never had the Grimmspeed. I see ETS notes a different intercooler for 02-07 than 08+, and the 02-07 model states "clears the AC line".

Grimmspeed is $620, ETS is $700, both prices shipped. There are alot of used Grimmspeed intercoolers local for ~$500. I'd rather save the $200 and get a used Grimmspeed intercooler, unless the fitment/install is really that much more difficult.

I don't mind doing minimal modifications to bend the A/C line and add some protective rubber to it to prevent rubbing through the A/C line.

I'm just curious to hear from people with a GD STI with a Grimmspeed and/or ETS top mount intercooler and their experiences/regrets.

Thanks.

You'd really need to dig into the core specs. Size isn't always king but can help if it's a cheap core. Search for any posts that may be comparing them both. Fin density, design, etc., all come into play. Cores are a get what you pay for product.

I don't know what your target power level is, or what the car is used for, but from our testing, I would without a doubt recommend using an OEM 2017+ STi TMIC. Form our testing, it beat both of them, by a lot. As far as fitment on an 06 STi, you may need to tweak the A/C line (maybe not), likely buy a GR or VA passenger side mounting bracket, and you'd be good.

https://forums.nasioc.com/forums/sho...d.php?t=529972 still slaps for info as you haven't said why you are swapping. Many assume they need to swap when they don't. If you are are going to be under 400WHP, there's no need. Now if you want to get a new one because you are a free American, then pick one and go about your day.

Mr the killer bee, I understand in your testing you saw the type RA TMIC was superior to all but one currently available model, so as not to hijack this persons thread, is there a link to another thread where you have a writeup or some more info such as what is reasonable max hp to expect out of type RA TMIC, what are the inferior (and superior) competitors good to?

Heck this might not be a thread hijack, i think all this info is perfectly applicable here!

Let us know thank you.

Thanks. My plan is a 20g on a IAG, ~22 psi, stage 2 block, 91 pump gas for now, may switch to e85 later. Drivability is to do full track day sessions at full send.

I have read on the “20G, post your hp and setup” thread and did some some people are using the stock 08+ sti tmic.

I did see the possible fitment of the new stock sti tmic. I figured if I’m already switching to one of those by throwing money at it, might as well be an American and go big.

Still curious to hear people’s fitment woes if any with the Grimmspeed TMIC on a gd sti.

Thanks all.

The more, the merrier. I did read a thread where someone tested the latest sti stock TMIC vs the Grimmspeed and the stock TMIC outperformed it. I need to double check the datalogged values to confirm that statement.

Maybe the key is to use the latest sti stock TMIC with a Grimmspeed splitter…

My EJ20 20G setup right now is using a VA STi TMIC, and so is my buddy's built 2.5L 1.5XTR setup.

Both make good power on E85 without being majorly limited by the TMIC. IATs were a tad warm on his 1.5XTR setup up top, but going even larger than these turbos can actually be more efficient and produce less heat depending on the configuration, requiring less or similar intercooling despite making more power.

Part of the reason JR and Killer B were able to get close to 600WHP on the VA STi TMIC:






I have another friend making more power with a larger turbine housing on his Dom 1.5 using the ETS TMIC and his IATs were hot on the dyno as well. Both the VA TMIC and the performance bar and plate intercoolers on the market like ETS and Grimmspeed will heat soak on the dyno somewhat, the bar and plate typically moreso due to the larger mass. With that larger mass will also requiring significantly more time to cool off, whereas the tube and fin setups are pretty quick to warmup and cool down.

I linked my setup above but I am making 360 wheel on E85 with a 20G on a very low reading dynos. I measure IATs at the Spec C intake manifold location and I never have IAT problems even in downtown traffic or between pulls. It is currently a street car but considering it's making fairly close to double what an STi makes on my tuner's dyno, I am satisfied with the results. His dyno measures a stock STi at 200 wheel. This setup is more than adequate for now, plus I have a treadstone kit in my garage ready to go when my car is ready for the 2.5L 600WHP setup

It also depends heavily on how tests are performed. OEM tube and fin and aftermarket bar and plate TMICs will perform differently compared to one another in testing scenarios, vs the real world with actual airflow.

It is certainly important to use a good quality and well fitting splitter.

If you go the VA TMIC route (which I suggest due to their availability and price) I advise you to look into the shroud that Got It Rex makes over in Australia, it's specifically for getting optimal airflow for the GR/VA TMIC on the old platforms. They don't have it listed on their website, only the GC model is listed. But if you email them they will ship you one (shipping to the US aint cheap). They did for me and it fits perfectly.

Also look for TMICs that are 2017+. The VA TMIC differs from the GR, and the 2017 VA differs from the 2015-2016. IIRC the code on the side is TM0250.

This thread has me considering switching out my GS TMIC for the VA TMIC.

The splitter is a fascinating point, i bet very little flow occurring THROUGH front portion of TMIC.

There's alot to chew on here. I'm currently tracking down a pretty good condition 2020 OEM STI top mount for $100. I figured I could get my hands on it for a deal, and then visually see the differences between stock GD and the type VA, or just sell it later.

How much mass does the type VA OEM IC have?

Will the Grimmspeed splitter for 04-05 STI hood scoop perfectly fit the type VA intercooler? I ask since it looks like the Grimmspeed splitter fits their own intercooler on a VA STI, or is the type VA oem intercooler have a larger footprint than the Grimmspeed IC?

Ironically, I do thermal analysis for a living and I see merit on what's being said here.

On Grimmspeed's datalogs, their graphs using a 2.0L with TD04 even show cooler temps at lower rpm's with the factory IC, with the real only benefit being in the upper region where the GS shows lower temps. But maybe this "could've" been solved using a STI TMIC, potentially the VA IC. I do see the GS graphs indicating a more stable temperature throughout the rev range, which could be a blessing or a curse based on what the starting temp is.

Plus, I can see the "potential" for the GS (and others) to restrict ambient air flow through the intercooler compared to the stock IC, which could reduce the amount of cooling. Couple that with a 20 pound mass that's been heat soaked and constantly absorbing heat energy from the engine, and it would take way more time to reduce IAT's compared to a better "ambient air" flowing, lighter IC.

Alot of variables.

Like I said, a lot to chew on. I'm going to keep looking for those other threads I read where people posted their datalogs.

I'd like to hear input from those who've run grip driving track sessions, where the engine is at a load for long periods of times to see where the "steady state" conditions lie with the OEM type VA vs an aftermarket TMIC.

And honestly, I'm thinking way too much about this. I "think" for my goal of 320-350hp on 91 pump, I'd shell out the $500 for a GS or ETS TMIC and I wouldn't run into issues.

But as a California smoggable car, I do like the option to run the bigger stock IC and not deal with any of the law (even though IC upgrades are legal, but the law doesn't know that).

Thanks mates.

Look at Grimmspeed's site again.



They have like 6 different splitters for the GD based on hood scoop, TMIC, and chassis. There is room to mix and match. The GD STi scoop/splitter will NOT provide full coverage to the VA/GR sized TMICs.

This was why I mentioned the Got It Rex GR/VA splitter made for the GD platform. It fits perfectly on the GR/VA TMIC and bolts right up to the GD hoods. It doesn't have the chassis/scoop specific louvers like the Grimmspeed ones, but how much those help vs obstruct flow is anyone's guess.

You have to remember the graphs Grimmspeed is giving you are likely from either dyno or cherry picked situations that are unrealistic to real world use case. Tube and fin setups shed heat fast. Bar and plate setups tend to retain a lot more of that heat soak in exchange for their raw size.

Well for somewhat of closure….

Bought a 18-21 sti oem TMIC from someone. Got home, put water through the intercooler and noticed both ends of the endtank on the y-pipe side leaked….. yup we have to think about the fact the oem sti tmic’s can leak from the crimps. Was the previous owner at fault? Probably… maybe he didn’t know, but I should’ve at least have the endtank seals tested before purchase so lesson learned.

I was hoping to use that 18-21 tm250 sti intercooler as it has 13% more rows, 3-4 inches longer. But even if I got another one, the risk of leaking end tanks still exists.

I’m probably going with a Grimmspeed or ETS TMIC. I’d go with another brand tube fin TMIC if it had welded end tanks for a comparable price.

I just don’t want a boost leak developing from an endtank, the turbo working harder resulting in hotter intake temps than real problems happen.

I “think” the aftermarket bar-plate options will suffice my needs. I’ll keep an eye on intake temps to verify this, and at least now I understand the bar-plate tmic’s will store my heat soak energy and will need more time to cool off which I can monitor with my intake temps to understand the time & speed cruising vs intake temps.

Bummer.

Charge it back and buy another

You got scammed

If you goal is full track day sesssions at full send, buy a front Mount intercooler.

Have you seen KillerB's TMIC? If you are going full send at the track, most people would go front mount, but it looks like you may be able to use their TMIC and avoid all of the hassle.

I ran a Grimmspeed TMIC on my 06 STI with the Grimmspeed splitter. Gtx2867r, 365whp, 7000rpm and running hybrid maf/sd had no iat issues and pressure drop was low. Had to tweak the Ac line a little bit and was also able to use the STI strut tower bar with some adapters to raise it up a few mm

I'd do it again, but the ets cores are a bit more efficient so while the Grimmspeed is good the ets is a touch better. I'd use either.

I never tested the newer STI TMIC but that was initially a part of my plans to test it out when i was swapping intake manifolds but that didn't happen unfortunately.


You can check my build thread for some pics and more details

I ended up finishing collecting my parts for my 20g setup, just been lazy to do the install but I will in a few weeks. So I ended up buying a used Grimmspeed TMIC for a deal. I got it, and was stunned by how heavy the thing was. It just seemed like it’s going to heat soak like crazy and I’d have to be mindful of not going full send after letting it sit for so long.


Since I took so long to obtain parts, I found another 19-21 sti TMIC for cheap but in perfect condition. So I’m sitting on both intercoolers.

My gut reaction is to use the 19-21 sti TMIC. I still need to either reach out to that vendor for the fd blob eye scoop to 19-21 sti TMIC splitter, or just make one myself. It’s payday next week so I’ll make my decision then. But now that I have both intercooler a, I can start with one and switch to the other if need be, maybe even just for science.

Again, I think either decision will work for my needs, but I’m more interested in getting the 19-21 sti TMIC working to reduce the effect of heat soak.

And to the comment about running a fmic, I have a fmic on my rx7 drift car, and one thing that turned me off of using a fmic on my sti is the need to removal of the bumper crash structure, and if there is front contact where the intercooler gets crushed, there’s chance of the aluminum bits being sucked into the engine. Plus, my sti is full cali legal with the Cobb 20g, I’d need a Cobb fmic for a carb sticker, but I don’t think it’s worth the 2k price tag.