[pt518sti]

Is there really any benifit of upgrading to a better TMIC with the stock turbo?

Please help clear this up once and for all

[BoostJunkie]

you might see some gains, especially in warmer weather. it would also allow you to tune more aggressively if you were to get a protune.

[0700]

A "better" TMIC would have better cooling...... Cooling is a function of cool mass and time in contact with said mass. Most of the aftermarket TMIC have more cool mass but do NOT have more time in conact with said mass, I.E., all the hot side tubes are in the 7-8" lenght range just like stock, so why would they work better than stock. I read that the APS tmic jousted with the STi tmic and straight lost....not surprising...

On the other hand, most fmic's have more cool mass AND more time in contact with said mass, I.E., 20-28" hot side tubes compared to 7" tube, 3-4 times more! This would decrease charge air temp, but at the expense of greater charge volume and slower pressure rise time, oh and you get to hack the crap out of your car, and decrease main radiator efficency.....

[jgheels2003]

Originally Posted by 0700

A "better" TMIC would have better cooling...... Cooling is a function of cool mass and time in contact with said mass. Most of the aftermarket TMIC have more cool mass but do NOT have more time in conact with said mass, I.E., all the hot side tubes are in the 7-8" lenght range just like stock, so why would they work better than stock. I read that the APS tmic jousted with the STi tmic and straight lost....not surprising...

On the other hand, most fmic's have more cool mass AND more time in contact with said mass, I.E., 20-28" hot side tubes compared to 7" tube, 3-4 times more! This would decrease charge air temp, but at the expense of greater charge volume and slower pressure rise time, oh and you get to hack the crap out of your car, and decrease main radiator efficency.....

The first paragraph of this should be copied and stuck. Thats the best way to answer the question, and a great way to explain why its either the stock TMIC or FMIC. Aftermarket TMIC's flow as fast or if not faster (what happened with me) than the stocker and there is less cooling as a result with a larger mass that is soaking heat. It concurs with my own experiences as well.

[Rdrcr]

Originally Posted by 0700

A "better" TMIC would have better cooling...... Cooling is a function of cool mass and time in contact with said mass. Most of the aftermarket TMIC have more cool mass but do NOT have more time in conact with said mass, I.E., all the hot side tubes are in the 7-8" lenght range just like stock, so why would they work better than stock. I read that the APS tmic jousted with the STi tmic and straight lost....not surprising...

On the other hand, most fmic's have more cool mass AND more time in contact with said mass, I.E., 20-28" hot side tubes compared to 7" tube, 3-4 times more! This would decrease charge air temp, but at the expense of greater charge volume and slower pressure rise time, oh and you get to hack the crap out of your car, and decrease main radiator efficency.....

Mike

[stretch]

Originally Posted by 0700

A "better" TMIC would have better cooling...... Cooling is a function of cool mass and time in contact with said mass. Most of the aftermarket TMIC have more cool mass but do NOT have more time in conact with said mass, I.E., all the hot side tubes are in the 7-8" lenght range just like stock, so why would they work better than stock. I read that the APS tmic jousted with the STi tmic and straight lost....not surprising...

On the other hand, most fmic's have more cool mass AND more time in contact with said mass, I.E., 20-28" hot side tubes compared to 7" tube, 3-4 times more! This would decrease charge air temp, but at the expense of greater charge volume and slower pressure rise time, oh and you get to hack the crap out of your car, and decrease main radiator efficency.....

I'll tell you why it's better since you asked.

The TMIC's may have nearly the same length, but the air moving through them will be going much slower, so it still has much more time to cool. It will be going slower because the core is thicker and thus the air has a far greater area through which to flow.

A FMIC may have longer tubes, but the air will have to flow very quickly through those fins. I believe Corky Bell says that it is more beneficial to have many short fins than fewer long fins, making the the TMIC shape more efficient for its size. A member here reported measuring 35 degree lower temperatures in actual use with a newer TMIC.

However, it's the smaller pressure drop (compared to stock) of the larger TMIC that really makes it worth its weight. DaveNow has measured the pressure drop of the stock intercooler to be near 3psi, but the aftermarket TMIC's are closer to 0.3psi. What a huge difference! That's 2.7psi less that the turbo has to make, meaning that's 2.7psi worth of heat that the already-too-small turbo has to work to create. As you probably know, the more work the turbo has to do, the hotter the intake charge will be exiting the turbo. Even ignoring cooling capacity of the intercooler, the lower pressure drop alone should prove to be an impressive gain. It's no surprise that DaveNow also reported seeing 20whp gains.

As far as heat soak- yes, a TMIC isn't the most optimal location. It can be more of an interwarmer without proper precautions. Wrap the turbo, use a heat shield, and coat the downpipe. Engine temperatures can stay reasonable. You may notice part of the hood scoop blows air onto the turbo to force air to flow down off of it rather than up. User-reported surface temperatures of the TMIC's have been extremely encouraging, and I don't think heat soak is an issue.

[billg]

Originally Posted by stretch

I'll tell you why it's better since you asked.

The TMIC's may have nearly the same length, but the air moving through them will be going much slower, so it still has much more time to cool. It will be going slower because the core is thicker and thus the air has a far greater area through which to flow.

A FMIC may have longer tubes, but the air will have to flow very quickly through those fins. I believe Corky Bell says that it is more beneficial to have many short fins than fewer long fins, making the the TMIC shape more efficient for its size. A member here reported measuring 35 degree lower temperatures in actual use with a newer TMIC.

However, it's the smaller pressure drop (compared to stock) of the larger TMIC that really makes it worth its weight. DaveNow has measured the pressure drop of the stock intercooler to be near 3psi, but the aftermarket TMIC's are closer to 0.3psi. What a huge difference! That's 2.7psi less that the turbo has to make, meaning that's 2.7psi worth of heat that the already-too-small turbo has to work to create. As you probably know, the more work the turbo has to do, the hotter the intake charge will be exiting the turbo. Even ignoring cooling capacity of the intercooler, the lower pressure drop alone should prove to be an impressive gain. It's no surprise that DaveNow also reported seeing 20whp gains.

As far as heat soak- yes, a TMIC isn't the most optimal location. It can be more of an interwarmer without proper precautions. Wrap the turbo, use a heat shield, and coat the downpipe. Engine temperatures can stay reasonable. You may notice part of the hood scoop blows air onto the turbo to force air to flow down off of it rather than up. User-reported surface temperatures of the TMIC's have been extremely encouraging, and I don't think heat soak is an issue.

This is the real answer. This is why I bought the Spearco TMIC. Also, I didn't want the greater expense of the FMIC, not to mention blatant advertising of the FMIC to the police to pull me over and check my other components. Look stock! Having said that, one could get better whp and less heat soak from an FMIC.

[stretch]

I'm glad someone agrees. I can't believe how many people talk poorly of TMIC's, nor how many plunk down over a grand on a FMIC when there are cheap top-mounts on ebay for under $200. Now that they've been through a revision or two, they seem to work well.

Most puzzling to me is that some here have switched to a short ram intake with no heat shield so that they can fit a FMIC. I personally think this is silly- I'd bet that a proper cold air source and a good top-mount would produce a lower intake charge temperature than a short ram and a front-mount. Switching to a short ram could boost intake temperatures by 30 degrees depending on your driving, and that isn't going to be easily compensated for. A TMIC also keeps air flowing to the radiator and, as you said, keeps the car looking stealth.

I realize some larger turbos may necessitate a bigger, higher-flowing intercooler, but only the really big ones. IIRC, the pressure drop of most aftermarket TMIC's doesn't begin to sharply rise until the 400whp range. Beneath that, I think they're the way to go, especially for the price.

[Neanderthal Racing]

a properly sized fmic for a larger than stock turbo makes the most sense to me. personally, i wouldn't bother with an aftermarket top mount but there is plenty of room for disagreement.

[Islandboy630]

Originally Posted by stretch

I'll tell you why it's better since you asked.

The TMIC's may have nearly the same length, but the air moving through them will be going much slower, so it still has much more time to cool. It will be going slower because the core is thicker and thus the air has a far greater area through which to flow.

A FMIC may have longer tubes, but the air will have to flow very quickly through those fins. I believe Corky Bell says that it is more beneficial to have many short fins than fewer long fins, making the the TMIC shape more efficient for its size. A member here reported measuring 35 degree lower temperatures in actual use with a newer TMIC.

However, it's the smaller pressure drop (compared to stock) of the larger TMIC that really makes it worth its weight. DaveNow has measured the pressure drop of the stock intercooler to be near 3psi, but the aftermarket TMIC's are closer to 0.3psi. What a huge difference! That's 2.7psi less that the turbo has to make, meaning that's 2.7psi worth of heat that the already-too-small turbo has to work to create. As you probably know, the more work the turbo has to do, the hotter the intake charge will be exiting the turbo. Even ignoring cooling capacity of the intercooler, the lower pressure drop alone should prove to be an impressive gain. It's no surprise that DaveNow also reported seeing 20whp gains.

As far as heat soak- yes, a TMIC isn't the most optimal location. It can be more of an interwarmer without proper precautions. Wrap the turbo, use a heat shield, and coat the downpipe. Engine temperatures can stay reasonable. You may notice part of the hood scoop blows air onto the turbo to force air to flow down off of it rather than up. User-reported surface temperatures of the TMIC's have been extremely encouraging, and I don't think heat soak is an issue.