a vented hood works wonders with heat soak. If you wanna take it a step further: add a fan behind the IC = sweetness.

 

Ok the point I was tryn to make with the air dam goes like this. look at the way any vette routes its air to the rad. It uses an air dam( that thing that hangs down off the bottom of the radiator) to route the air going under the car to the rad. Did you look at the mustangs and f-bodies that you saw over heating at the track to c if they still had it cause if it is removed they have been know to over heat. happened to a buddy of mine(parking curbs and driveways claim many). I dont have any pics of this, wish I could find some on this form that I have seen. Anyway, you remove the under tray and do about the same thing as the vett. You must also block any air from escaping from around the radiator into the engine bay. If you block everything off to were there air no "leaks" and all air must go through the radiator it should work. Run the fans on high for low speed and stoped traffic. shouldn't matter too much at high speed.

some have used radiators not made for the rx7 wich are bigger, I.E. more cooling surface. but the more mods. again look though the fourms its there.

vettes have been doing this for a long time now. even the z06 does this air damn thing. If you look at most any car there is some form of blocker that routes air through the cores, what ever they be.

It seems so many have problems cause they over look this and then go wright on this fourm how there fmic caused their engine to run hot, when they don't understand how to duct air.

One thing I don't like about fmic is you intake becomes a problem. where the hell do you get cool air?? Anyone solved this?? most I have seen put a small filter behind the radiator cause u can't fit a big one sucking in the hot air from the radiator which in turn is compressed(heated more) and pushed through the ic, then the cooling out side air (not from the turbo) that flows through the ic to cool it is also having to cool the hot air from the radiator that the turbo sucked up. which in turn is run back through the radiator. Sounds kinda like the problem that stock fd's had when the intake sucked hot engine bay air through the stock ic duct heat soakin the ic, just a little different. If I remeber correctly that killed a couple of motors during testing, and at some point was changed, after 95.

Thanks for letting me speak. I hope I didn't put my foot further up my own ***.

 

Unless you've got a picture/diagram of what you're talking about ON AN RX7, I don't think you can make any claims. You're talking to people who've owned these cars since the early-mid 90's, and have seen everything there is to see, and we don't know what the hell you're talking about.

RX7's are configured differently up front from F-bodies and vette's... there's really no other place to draw air except for the nose opening, which is blocked with the use of a properly-sized FMIC.

 

you are certainly comparing apples to oranges.

Regarding the vette: Keep in mind that it was designed to have air ducted through. Meaning that there are other components that have to compensate for the lack of direct fresh air coming in.

Questions that you need to ask yourself before you decide that ducting is all the we need.

1) is the Vette radiator thicker?
2) Thermal conductivity of the radiator: is it better?
3) are fans more effective?
4) what about the oil coolers? more effective as well?
5) Water pump... Higher flow as well?

 

If he does any SCCA Racing he might get bumped up a class based on his hood alone and therefore not be competitive. I know that's the case in Auto-X. He should read the rules for whatever racing he wants to do before doing anything to the car.

I've got the PFS SMIC and I really like it. It's got a duct and my intake temps are pretty stable. It does warm up a little but the difference between the temps on the hot side and the cool side are dramatic. It's a great IC.

 

Why would I do that when this is an FD??? Read Ptrhahn's reply above.....show us the pictures or the links. Otherwise I don't think you understand what you have read or seen before IN REGARDS TO FDs.

Stick with the SMIC as we have recommended. BTW, you can save a bundle by picking up a used setup.....I picked up my PFS intake and SMIC years back for ~$900, it's $1600-1700 from PFS for a new setup.

 

seandizzie, let's assume I duct fresh air around an FMIC to feed my radiator properly. Where does the air cooling the FMIC exit?

 

My well-ducted Greddy SMIC will heat-soak when the radiator fans come on because air is driven backwards through the IC. I suspect any well-ducted SMIC will also have this problem unless it has a well-designed (with its own duct) fan system that comes on at the same time as the radiators. Seems like a vented hood (or any other additional exit for radiator fan air) would also help.

It is not popular on this forum (so many will probably freak-out at the mere mention) but if you want to save some money (say, for a future V-mount) the XS-Power ebay IC and a Petitt duct almost certainly provides the most performance for least dollars. Most of the performance of an SMIC will come from the ducting design, not the IC itself. I have an XSPower in the basement, and the fin design appears more or less the same as the Greddy. Not the most recent technology, but very good for the price (and improvement in the fin design isn't going to convert to much performance difference anyway - certainly not when compared to careful attention to duct design).

 

I am very interested to see reports of overheating issues on FMIC equipped street cars. I imagine they could all be remedied by preparing the car differently- though i never will claim to be an expert.

generally SMIC means side IMHE- however considering that the stock mount intercooler is to the side (above) related to the radiator or support. It's purely semantics.

Intercooling is free horsepower, it's been mentioned before that it's the size of the core primarily that determines cooling efficiency and anything is better than the stock plastic heat sink. The aquamist system won't hurt either- have a visit to the AI forum!

No one has yet produced *salient data* (that i've seen) on the effects of vented hoods although you can't deny that they help when the car is not moving and esp. when it is turned off.

 

All I can tell you is that I saw vasts diferences in both water temps and intake temps when I switched over to a vented hood.

 

If he's gonna race through, he needs to check the rules on hood swaps. SCCA puts you in a different class just because of your hood.

 

^^^ he said 95% street use, w/ occasional track use. SCCA rules don't really apply.

I think Mazda pretty much acknowledged that the car would've benefitted from a vented hood, but they didn't want to use one because it destroyed the lines of the car. That's probably why they offered one through Mazdaspeed, and every racing RX7 I've seen, where allowable, has used a vented hood.

As far as an FMIC, annecdotally, I can drive my car to work in DC on a fairly hot day, and not hear the fans come on even in traffic. As soon as I hit my parking garage though, within 1 or 2 floors, the temps are climbing and the fans are on, even though I'm still moving. Why? The stale, dead, non-moving air in the garage (it's not even really hot in there) is all I can figure, but it's dramatic... You can only imagine the relative effect after you've slowed down and heated the incoming air with another heat exchanger.

I know they are usable for the street, because the cooling system isn't at the end of it's envelope in most cases, the fans can control the temps... but on track, where the system is running wide open and is only marginal, no thanks.