Stock Turbo VA STI top mount vs. Grimmspeed Top Mount intercooler

[@codyhendrickson7735]

I appreciate the thorough video. This is good stuff to see played out on video!

[@MattTr0n]

Very good info to know! I had been wondering this for a while when building setups for customers. I wasn't aware of the top end lacking on stock turbos. We don't have a dyno yet so we send them to Surgeline in Portland for final tuning.

[@WT4T]

You should send them to us at PREracing! Also in Portland

[@Ezio214]

Could you do a comparison video for the VB? I'd love to see the Perrin go up against the stock, Cobb or the ETS TMIC.

[@WT4T]

You really won't see a difference on the dyno

[@jpribeiro7694]

Thank you, great video as I am just about to upgrade the top mount in my 2010 Mazdaspeed 3. Not to make more HP but to maintain HP because of lower intake air temp during spirited driving. Really surprised how little HP and torque the STI is making now, even modded and tuned. I have basically the same mods, hitting 22-23psi and easily make those numbers in a 13 year old front wheel drive.

[@WT4T]

From my experience most Mazdaspeed 3's with basic boltons and a tune don't put down more than 300whp on my dyno. You also have to consider that nothing really has changed horsepower output wise on STI's since 2004.

[@robertomorffi6856]

Every dyno is different. I can also say that I had my 2020 sti tuned by circuit Motorsports in Orlando my car is mainly stock except for a grimmspeed drop in air filter and it put down 306/332 which is more than this modded sti put down. The only way to tell if it’s the car.. the dyno or the tune would be to dyno both of these cars back to back in the same place. Tough to really say. I also live in Orlando so with heat soak I’m sure this top mount would be useful.

[@mejia212]

Did you see any difference in heat soak btw pulls ? GS vs OEM Debating purchasing the GS with thermo coating or just go fm

[@WT4T]

Larger thermal mass = worse heat soaking. It's just physics.

[@woodzy575]

nice clean data. Thanks

[@doubletee4391]

happy to see a new video

[@jordandudeohs6297]

Thanks for the info, I was wondering if you would recommend me getting the Grimmspeed tmic if I’m planning on upgrading to the Cobb 20g? The car is going to be running flex fuel and it is a 2020 Sti

[@WT4T]

Yes that's a good mod, definately get the air diverter for your year as well!

[@satsun]

On NASIOC, Killer B mentioned that they tested seven TMICs and found that only one was better than the OEM 2019 TMIC (this TMIC shares P/N with 2017-2021). They didn't say which one performed better, I assume because they're doing R&D to develop their own. They did mention that the 2019 TMIC significantly outperformed other OEM TMICs.

[@WT4T]

Yeah the VA STI tmic is a beast. Past 22-23psi you'll see significant gains on an aftermarket one but stock turbos can't touch that especially at higher rpm

[@SonikJesus]

Interesting! Do you have a link to that thread?

[@satsun]

@@SonikJesus Pasted a link, not sure if those get filtered in YT comments. It's in the 2.5L Turbo Powertrain subforum, "First Reliability Mod" thread, post #16.

[@TheLastS209]

It was spearco that performed it, but the OEM unit is superior to all the other aftermarket trash

[@adidas2284]

2.1 stroker with an 18g turbo running 22 PSI on E85. All IAT were measured post TMIC 06 STI TMIC - 19* rise IATs (made most power & torque) 08+ ETS TMIC - 30*+ rise IAT 04-07 STI Side entry Mishimoto TMIC - 17* rise IAT

[@WT4T]

What were the ambient conditions?

[@adidas2284]

I kept the ETS on before that motor gave out and here is the coolest log vs hottest log I have. Coolest: 43* - 77* Warmest: 72* - 102*.

[@WT4T]

What about oem?

[@adidas2284]

@@WT4T it's the one labeled 06 STI.

[@cwojcik_rc]

Great, thorough video. Could you get that extra pound of boost and 20 wtq on the stock intercooler if you maxed out the WGDC there as well? If you are making the same power at the same boost, doesn't that prove that the Grimmspeed really isn't doing any better than the stock intercooler? If it were cooling better, then you'd be flowing more air and thus making more power at the same boost (since the temperatures exiting the intercooler would be lower, and PV=nRT). Could you compare MAF values at the same intake temps and boost readings to see which one is working better?

[@WT4T]

Probably, the most important test was the one where there were no tune changes. I don't typically like to go much above 19psi on stock tmic stock turbo so it technically wasn't maxed just "known safe"

[@robertomorffi6856]

In both tests there was no airflow over the tmic. Even a large fan blowing towards the front of the car is not the same as actual road conditions with air being physically forced through the tmic through the hood scoop. I’m sure with some back to back runs the stock tmic would heat soak much quicker than the grimmspeed

[@WT4T]

Actually there is a big fan facing down onto the tmic. I see little to no difference between hood open/ closed on this dyno fan setup and usually significantly less heatsoak than on the road with the hood closed (measured on cars with IAT sensors in the intercooler) Glad you're an expert though! 👍

[@robertomorffi6856]

@@WT4T I appreciate the recognition!

[@TheSwampDonkey]

Really good info. Thank you!

[@WT4T]

Glad you enjoyed it!

[@bbehzadi413]

2020 STI I’m running the Grimmspeed tmic with splitter. I made 352WHP and 340lb of torque with a smaller 20g on a dynojet. I haven’t had any issues so far but might wait for the Killer B tmic to come out

[@WT4T]

I wouldn't switch one for the other honestly. Very minimal gains if anything

[@dkhuggs7022]

EXXXXXCELLENT!

[@BFE08STI]

I was kinda surprised that you still had a clamp with the threads going through it... Get one thats closed on the back so it doesnt chew on the hose :)

[@WT4T]

Meh. I don't typically see an issue with it. The extra "chewing" holds them on better anyways.

[@BFE08STI]

@@WT4T it's probably worse with that clamp type on rubber hoses than silicone, and it depends on how sharp the threads on the drive screw is too 🤷

[@WT4T]

@BFE08STI I've seen them get chewed up on Silicon and usually it's only on hoses that are very old and oil impregnated. The lined back clamps love to just slide off. There are better options like Murray constant tension clamps but they are very expensive and hard to get

[@conricollins5277]

Great grandma's boy reference!

[@WT4T]

Glad you caught that!

[@vasegan]

where is the IAT sensor located ?

[@WT4T]

In the maf sadly. It can be split out and relocated but would require modifying the intercooler to install.

[@vasegan]

would logging IAT be something worth while?

[@WT4T]

Yes it whould be helpful however on these cars it's in the maf which is before the intercooler so you won't see a difference.

[@benc911]

I was able to increase boost and timing on my hawk sti, stock vs grimmspeed.

[@WT4T]

What turbo?

[@benc911]

@@WT4T sc42 (UK) basically a bloush dom 1.5 But it's also tuned on the road so gets better airflow to the intercooler. Dynos will never replicate airflow the same as driving on the road.

[@KoryBrooks]

I see no airflow across the TMIC. Any intercooler is worthless without airflow. I would set a small box fan directly on top of the TMICs to do back to back testing, and collect temperature data at the exit of the TMIC to see if a reduction in temps is all it does, which is a benefit on its own. For more fun, an external water/meth intercooler sprayer with a box fan on a stock TMIC would be interesting to see, the factory used them before.

[@WT4T]

Windspeed at the tmic is about 50mph with all my fans on.

[@KoryBrooks]

@@WT4T I guess we cant see everything through the lens of a camera. 🙈 Intercooler chiller it is! Also would love to see a fuel rail chiller as well

[@robertomorffi6856]

​@@WT4T not directly.. tmic is on an extreme angle. With your current setup in the video there's no possible way to duplicate the direct airflow the hood scoop creates in an actual real world scenario.

[@WT4T]

There's a significant amount of airflow. I've had plenty of cars do much better on this dyno than on the street with the way my fan setup is.

[@tranwrx]

Stock fuel pump?

[@WT4T]

It's been way too long since I made this video, so I have no idea.

[@tranwrx]

@WT4T same set up with aem fuel pump. at 330hp and 350hp..

[@WT4T]

@tranwrx I wasn't out of fuel. I'm pretty confident this car had an upgraded pump.

[@tranwrx]

@@WT4T run E85 more power

[@christopheredwards357]

Same results with the mishimoto top mount. Until you went on the road and tested it with real air flow, according to mishimoto. Mishimoto engineers found with real on the road air flow there was better cooling by an average 10c and an increase in 5hp. Dyno testing is useless.

[@WT4T]

Usually, my fans are better than "real airflow" but they say what they say.

[@lucian7182]

My gs tmic enabled my tuner to pull out an extra 20 ish hp out of the car. The oem unit in my experience heat soaked faster but also cooled down faster due to its design. The gs tmic was able to do a couple more pulls vs oem before heat soaking but took longer to cool down due to bar and plate design.

[@WT4T]

@lucian7182 thermal mass is a double edged sword for sure

[@lucian7182]

@@WT4T definitely, really depends on your use. If you are zipping around town from stop light to stop light the oem would probably be the best option. If you were doing a couple road racing pulls the GS unit would give a slight advantage for the couple pulls anyway. Both would be questionable for a track day.

[@jamescooper5183]

Basically keep your stock ic and not waste your money..

[@WT4T]

Or go fmic.

[@jamescooper5183]

Do you have a video between a front mount vs top mount? All your videos are great man I just subscribed, you provide great info..

[@WT4T]

@jamescooper5183 I think I made a short one a while back.. not sure what platform. I'll look around

[@lucian7182]

The stock intercooler is only rated for about 400 whp, the aftermarket units are typically rated for 500-550whp. Fmic isn’t really necessary for a dd making under 450+ whp unless you are doing drag racing.