[Inn-Tune]

Originally Posted by ride5000

i have never seen a compressor map for a 16g series turbo with a 50% island on it.

you want to post it up and help the community out?



i know you're talking out your ass, but i'll play along anyway; i do enjoy watching people hang themselves, bit by bit.

If you read my post it says:
"At 7000 rpm you're under 50% efficiency, but even if it was as high as 50% efficient, outlet temp from that calculator says 423 F"

In case you didn't notice those numbers are all approximations used solely for the purpose of explaining the concept of a decrease in compressor efficiency resulting in an increase in compressor outlet temp (other things being equal).

The last island on my compressor map is 60% and at 7000 rpm the data point is far enough off the map that it's safe to assume that efficiency is around or under 50% in this case BECAUSE the number doesn't need to be accurate at all to illustrate the relationship between efficiency and temperature.

It's people like you that make me wonder why I bother making tech posts. Armchair tuners like yourself like to try and show they know "better" by trying to nitpick rather than contributing something positive. If you have some knowledge in this area why not share something that can benefit the board? If you want to go take airflow readings from a small 16g STi so you can post exact compressor efficiencies at each RPM and pressure ratio my guest.

[fullerton]

i think this discussion is missing an important piece.

Just because an IC is placed somewhere, does not mean it will heatsoak.

For example, if one were to run a larger then stock TMIC on a car with a smaller turbo, they could easily prevent heat soak in three easy steps.
1: Wrap the turbo in an insulating layer and a heat reflective layer.
2: Cover either the stock or an aftermarket heat shield with a heat reflective barrier.
3: Cover all non-air exchange parts of the TMIC with a heat reflective barrier.

And if you want to be super careful:
• Source all air for outside the engine bay.
• Be sure that air is forced through the TMIC.
• Utilize the I/C Sprayer more efficiently with a boost referenced switch.
• Wrap any air paths with heat-reflective barriers, both pre- and post-turbo.
• Wrap the entire exhaust path with a heat resistant barrier.



By doing this simple and inexpensive work, I am able to run for 20 minutes at the track and come in with a COLD TMIC.

[modaddict]

Originally Posted by fullerton

By doing this simple and inexpensive work, I am able to run for 20 minutes at the track and come in with a COLD TMIC.

However it won't work for everyone.

I live in the dessert. 100+ degree heat and ANY stoplight would make my sti tmic heatsoak BADLY!!!

There was no cure, no solution, no inexpensive work to keeping the tmic cold.

the absolute solution was a fmic, period.

[fullerton]

Well, I can not say that I experience that heat often, but the track time I do is always during the hot Illinois summers. 85°-95° is not uncommon here.

At least this solution is fairly inexpensive and a bit easier to try before going $$$ on a FMIC as that would necessitate a new tune. (assuming you keep the stock TMIC)

Perhaps the heat shielding could have helped, but too late to find out.

[fullerton]

Originally Posted by fourseasonsandles

How does the math work for this with DEI?!



On that note.. Great write up Mike!

Has that been patented yet? He better get going on it before some takes it and uses it.

[Flycaster]

Additonally, you can do all that trick stuff and there is still nothing you can do about the fact that a TMIC sits smack on top of a 200Lb chunk of HOT alumininum.

[modaddict]

Originally Posted by fullerton

Perhaps the heat shielding could have helped, but too late to find out.

true.

However, the consistency of a fmic is what I wanted. And i don't have to spend $200 on heat wrap (although I spent 150 on a turbo blanket)

It was amazing how hot the stock vf39 would make my fmic....then touch the other side of the core....nice and ambient temp. that vf39 is a hairdryer at 21psi. (in my experience)

[fullerton]

Originally Posted by Flycaster

Additonally, you can do all that trick stuff and there is still nothing you can do about the fact that a TMIC sits smack on top of a 200Lb chunk of HOT alumininum.

Its all about where you let that heat go.

[fullerton]

Originally Posted by modaddict

true.

However, the consistency of a fmic is what I wanted. And i don't have to spend $200 on heat wrap (although I spent 150 on a turbo blanket)

It was amazing how hot the stock vf39 would make my fmic....then touch the other side of the core....nice and ambient temp. that vf39 is a hairdryer at 21psi. (in my experience)

Forgot to mention. Mine must throw flames at 25psi on 100, but it the IC is still COLD to the touch.

[Flycaster]

Originally Posted by fullerton

Its all about where you let that heat go.

Unless I failed grade school, heat rises amigo - it's going straight up thru the TMIC, and if you block it off going up, you'll kill the downflow at speed. You can't have it both ways.

[jasv11]

Originally Posted by fullerton

Forgot to mention. Mine must throw flames at 25psi on 100, but it the IC is still COLD to the touch.

My vf39 with meth injection and peaking at 23lbs tapering to 16.5 runs cool on the drag strip and on the highway (beating on it mucho) but when I autox the car doesnt get going fast enough to cool the top mount and after 60 seconds of relatively slow speed pounding my top mount gets real hot and I can feel the loss in power during a second autox run without cooling the car down enough between runs.

just my observations

[modaddict]

Originally Posted by fullerton

Forgot to mention. Mine must throw flames at 25psi on 100, but it the IC is still COLD to the touch.

your definition of cold must be different than mine

Do you have any fingerprints left?

just pokin' man. Have a Merry New Year.

[fullerton]

Originally Posted by Flycaster

Unless I failed grade school, heat rises amigo - it's going straight up thru the TMIC, and if you block it off going up, you'll kill the downflow at speed. You can't have it both ways.

I agree, hence my large use of heat reflective shielding.

Also, I think it is necessary to state that I am more interested in everything working at the track and less interested in DD performance, though I do tend to touch it after hard DDing and it is never hot to the touch though it can get warm depending on weather.

[n2oiroc]

front mounts arent immune to heat soak either. my old supra got heat soaked a lot worse than my sti with a spearco tmic ever did. radiators and condensors arent exactly chunks of ice.

[ride5000]

Originally Posted by Inn-Tune

If you read my post it says:
"At 7000 rpm you're under 50% efficiency, but even if it was as high as 50% efficient, outlet temp from that calculator says 423 F"

In case you didn't notice those numbers are all approximations used solely for the purpose of explaining the concept of a decrease in compressor efficiency resulting in an increase in compressor outlet temp (other things being equal).

gee, that IS some rocket science right there, isn't it? sure glad you demonstrated that...

look, here's the bottom line: when you first started posting on nabisco, i thought you had a lot to offer. you had some good information and experiences to discuss. i still think you do, fwiw.

HOWEVER--be careful about what you say.

there are a lot of neophytes around that don't know enough to separate the wheat from the chaff. i am not one of them. i WILL call you on your suspicious statements and ask you to clarify them. there is a very long list of vendors that i've met head on. in the end i guarantee you that i look no more stupid than they do. just ask david buschur or full race. they are both people/companies i had the utmost respect for until they started pawning off their assumptions or theories as "facts." i am not so stupid as to blow them off entirely--they both still have a lot to offer--but they have fallen down a few notches in terms of reliability of information. i don't give a crap how many fanboys disagree with me; i know what i know, and i don't need to be popular OR sell a product.

the FACT of the matter is that the hotter the turbo discharge temp is, the better the intercooler works. if you want to make an intercooler appear to work superlatively, you pump in ridiculously hot air.

so i'll ask once more, where did your number come from?

you first said, "That is the actual reading on a real STi."

then you said, "Th numbers used were with the APS TR70 rotated turbo kit iirc."

still never answered the question of WHO read the number and HOW it was measured, but whatever. i still say it's stupid hot, and it paints the IC performance in the best possible light.

The last island on my compressor map is 60% and at 7000 rpm the data point is far enough off the map that it's safe to assume that efficiency is around or under 50% in this case BECAUSE the number doesn't need to be accurate at all to illustrate the relationship between efficiency and temperature.

first of all, congratulations for admitting you assumed something. extrapolation of a value off of a charted characteristic is fine but you'd damn well better acknowledge it as such.

second of all, that's not what you're "illustrating" in your first post example. you don't have to pick a ludicrously low compressor efficiency to demonstrate that outlet temp and efficiency are inversely proportional.

look at the post title: "how an ic makes you power." you attempted to demonstrate how much power is lost/gained by intercooling, and you picked a number for turbo efficiency that was very low to inflate that power loss/gain. that's fine too, but expect to have someone like myself point that out.

third, if we want to crack this nut open, let's talk about the midrange rpms, where compressor eff. is still quite high. how much time is spent at redline and peak boost vs. elsewhere in the powerband? what if the driver is shortshifting because of the power characteristic of the car?

It's people like you that make me wonder why I bother making tech posts. Armchair tuners like yourself like to try and show they know "better" by trying to nitpick rather than contributing something positive. If you have some knowledge in this area why not share something that can benefit the board? If you want to go take airflow readings from a small 16g STi so you can post exact compressor efficiencies at each RPM and pressure ratio my guest.

ahh, the good old, "if you don't stop picking on me, i'll take my ball and go home."

don't patronize me or any other reader of this board and tell me you're posting JUST to share knowledge. if that were the case you wouldn't have a vendor account and you wouldn't be pushing your company. both of those things are perfectly fine and should be encouraged, but understand they also reveal a vested interest, and you WILL be held to a higher standard of fact checking and research as a result.

as far as what i have to contribute, i've already made people aware of the scale and scope of typical compressor outlet temps, which was conspicuously absent in your posts. no need to thank me for that. i threw in a nice link to an online calculator, too, so people can plug and chug numbers of their OWN choice to see how things relate.

i've also hinted at the performance tradeoffs associated with typical usage, such as the necessity of detuning for a road course (where average engine power dissipation per unit time is higher than anywhere else) vs. tuning for pure street use (where triple digit pulls are typically few and far between).

i'd also like to point out for those of us who have and use launch control, every effort should be made to limit the amount of time building boost while stationary because of the rapid rise in IC core temps. you can check this out while parked with your hood open and your friend behind the wheel.

ken