Intercooler debate!
 

Hey,

I'm getting my mods in order for when I have the money to go gt3540 single. I'm aiming for ~450 rwhp, and obviously I need a good I/C;)

The heating problems kind of scared me away from a front mount, but anyone who thinks differently feel free to give your thoughts/opinion. What are the best ones out there?

The m2/asp large seems like a good choice, for one because it's huge, but it has relatively good specs:
ASP Race IC
Core 3.5" x 12.55" x 17" CID of core 746.7
CFM of air flowed at 1.5 psi of pressure drop 760
Pressure drop at 10 psi and 6000 RPM .35 psi
Efficiency of heat transfer at 5mph air speed through core. 76%
Efficiency of heat transfer at 20mph air speed through core. 88%

Has anyone had any experience with the rotaryextreme v-mount setup, or a similar one from one of the japanese tuners?

What kind of I/C are the "big guns" like ihor, steve kan, gmosen, etc. running??

Thanks for any/all help!
kyle

In Corky Bells Maximum Boost, I remember him saying that endtanks on the top/bottom w/ the fins running vertically induce less pressure drop. I cant remember the logic, but I do remember thinking that it made sense. Anyone care to elaborate on this?

I think the logic behind that statement is that with vertically running tubes/fins, there is less overall distance for the air to travel, thus less distance to pressurize. However, there are more tubes as well, so the same general surface area for cooling is maintained.

Did anyone have a custom IC system fabbed? How hard was it to get the piping made? How hard was the installation?

Thanks,
kyle

the m2 large kicks ass...I love it.

j

I'm currently using a Greddy 2 row, FMIC with a GT35/40 setup. My intake temps are typically 5 - 15 degree's C over ambient, 42C is about the max I've seen (85F degree day) with the GT35/40 setup, was seeing higher with my twin setup, sometimes 50C when it was 90F.

That makes me VERY happy. I'm running 16psi as my high boost which I hear is near the max of the 2 row (have read I should go 3 row beyond 15psi, but when the temps where they are now, I'm very happy with the 2 row). Eventually I may move to a 3row.

My water temps are great, set fan1 to come on at 87, fan2 at 89. Rarely see water temps > 90C.

K

Nocab, nice ride!! Thanks for the info. I was planning on running either a gt35/40 or a straight gt40 with the around town boost set @ ~1 bar, and the high boost @ 18 psi, possibly 20 psi on race gas, so if I went greddy, I whink I'd go with the 3 row. Is the install on the 3 row any harder than the 2 row?? Did you have to remove the air pump? I was planning on a mp w/ the air pump still mounted, but not being turned so I could slap a cat/belt on for emissions testing.

I'm assuming yours is a kit, have you heard about the specs on a comparitavely sized spearco core?

anyone feel free to chime in...

Thanks,
kyle

nocab, sell me your 2row if you switch to the 3 row

Stock mounts are a waste of time.



-Ted

May I ask, what do you guys pay for these I/C's in the states?

here in NZ, as an example, the FMIC for my 20B Cosmo, will be 750x300x75mm (may make it 100mm if it will fit), in bar and plate, would retail for approx $1300NZ ($615US).
600x300x100 is $1200NZ if I remember correctly.

just wandering as when my brother has another S6 RX-7 at his work for a front mount upgrade, we are going to make a jig up so we can copy the kits without having to have a car so we can have them ready to ship or fit.

Generaly here his work use 500x300x115mm (or 100mm) for FD FMIC

second that Ted...stock mounts suck!! anything sitting on top of a 200+ degree radiator makes no sense to me either!!! all of the "big guns" are running front mounts for a reason!!


MWW

definately get that damn thing OUT OF THE ENGINE BAY!!! :D

K

What is needed for the fmic if I don't get a kit?
Im assuming:
IC core
Custom piping
Mounting brackets
Anything else???

I figure that I can get the stuff fabbed by any respectable wleder, but where would I get the piping, and what kind of brackets do I need? (Pics would be great)

thanks for the help,
kyle

For the price and trouble of a custom intercooler setup, just get a proven kit that you can put on yourself with ease pretty much. If you save any money with the custom one is it worth it for the extra time and trouble, not to mention not being certain it is very efficient? Thats just how I look at it.

I see only two real downsides to a front mount. First, if you do any track work (over 1/4 mile!) airflow over the radiator WILL be an issue and overheating will result without cool-down laps. Two, FMIC's are exposed to road debris whereas stockmounts are not. With a properly designed duct, a stock mount will have virtually identical AIT's as a front mount when at speed. City driving is another matter entirely however :-) If you're drag race/street only go with a front mount. Out of curiosity, what's the easiest front mount to install?
Michel

My intake temps are right inline with FMIC, and I don't have to think about overheating. I also don't have to bend back the fins from road damage or vandalism.
Bling, Bling. :D
Michel, I believe the Apex'i or Blitz are the easiest, because they don't require cutting.

I think the whole over 15 psi 3 row, things is crap.
If it cools the intake charge, it cools the intake charge.
Now maybe I could see if you wanted to run 25 psi or something, but you wouldn't want to run more then 16 or 17 on pump gas anyway. I doubt the extra 2 psi on the 2 row or 3 row makes a difference.

what do you guys feel about HMICs?
Good for long term boosting like a stock mount?

I would agree. I planned on running more and more boost till I saw my intake temps rise, at that point I would know I need more IC. Till then I think the 2row is going to serve me fine.

K

rotaryextreme.com is making an HMIC. i think they need to change the way their ducting is going though. it comes out of the top of the ic instead of the part closest to the engine. i would think there would be less pressure drop and definately less plumbing mess. i like the HMIC and i would like to see another good one surface. . . like the srmotorsports one. that thing was nice.

paul

Me and my friends put some air intake temp sensors before and after some SMIC's and FMIC's a few years ago, and guess what?, the FMIC's had a slight advantage while standing in traffic for a while(at which point you're not beating on the car, so it really doesn't matter), and the SMIC's had an advantage while driving in motion and when road racing due to it not blocking the radiator. So either way it doesn't really matter if you drag race, but road racing the SMIC is a much better choice due to the radiator cooling advantage. I also forgot to add that since a SMIC has less piping to travel through it might also add more efficiency because of this, but this is only a theory so far because I don't have the equipment to test this. My 2 cents.

But the look of a front mount= :mspank:

Nocab: How hard was the install of the 2-row, is the 3-row any harder?

Ryde or die: I was planning on using an apexi fmic core, then getting the piping made...the piping doesn't make that much of a difference if its the correct diameter, does it??

THanks
kyle

took me 2 days, but I was dicking around most of the time... :) Got an archive and narrative written up here and here:

http://flathat.woodstream.net/RX7/Docs/Greddy_FMIC.html

http://flathat.woodstream.net/RX7/Greddy_FMIC_Install/

K

I think it's funny to read the information some are giving out.."Stock mounts suck " etc.
I know Corky Bell and talked to him extensively about IC's before purchasing mine. Front mounts have very large pressure drop which the M2 large IC doesn't have.
The M2 also has almost a 90% efficency rating according to the figures Corky ran. (He didn't like the front mount and said so after we went through the numbers.) We came to the conclusion using math that the M2 was fantastic (full race car efficient) and it wasn't worth him building me a custom IC.... There are also other issues such as the radiator cooling etc when installing a front mount.

Read this also:
http://www.scuderiaciriani.com/rx7/intercoolers.html

I had an M2 large intercooler (newer core design) for over two years. It worked pretty good at speed, but in traffic or even at low speeds it would heat soak like an oven. And once it got hot, it took along time for my intake temps to cool down. I tried to help things by atrapping on a small fan. It did very little. I blew my motor at the drag strip due to heat soak. I sat in traffic for over an hour on a 90+ degree day. Intake temps were in the high 60s, reaching 70C at times. Eventually traffic broke up and I started moving, but the dan thing wouldn't cool down much. When I got to the track I let it sit for a bit with he hood open while I waited in the lanes. I had some ice with me and had it on the intercooler for a while. My friend noticed how hot the stupid intercooler was. Unfortunatley I didn't think much of it and ran anyway. Detonated hard at the top or 3rd gear and trashed my front rotor, housing, and primary turbo. Now that I think of it, that intercooler was so hot I could have probably cooled and egg on it. Last I remember intake temps were in the nid 60's or so before I ran. With my new motor and single turbo I tossed the M2 and went with a Greddy 2 row. In my opinion the 3 row is too thick and pre-heats the air too much for the radiator. With my front mount my intake temps are always within 15 degrees of ambient, unless I am sitting for a long time. When it motion, the intake temps are always below 50C, even on a hot day. The only time I've seen 60 degrees+ is like when I shut the car off and run into a store or something and it heat soaks a bit. Soon after I start moving the temps drop like a rock. I'm convinced that the front mount is superior for street/track applications. For a strictly road race car, maybe a stock mount is better. But I am working on a duct to get air under the intercooler and to the radiator. Funny thing is M2 runs a front mount on their race car.