cr-rex

iTrader: (114)

shortly, i will be starting my first real build on a car that will be done 98% by me and me alone. the bigest part of this is the vmount set up i want. i will be running the stock twins with the full non-seq mod. most will say that vmount is overkill or not needed but its what i want so its what i am going to do.

the car will see SUPER occasional street use and be used mainly for autox/track days. i will be de-registering soon and i will get temp tags for it every event.

i have a few questions about actually DOING the set up...

1. is there a certain angle the radiator and intercooler are supposed to be at? i noticed some people lay them down completely, some do a ~45degree, some go higher than that. i will be using the cwest front bumper so i would like to maximize the openness of the "mouth".

2. are there people that dont use fans on their radiator when they go vmount? for those that do, does it matter if they are on the top or bottom of the radiator? the rotary-works ( rotary-works.com: V-Mount Aluminum Racing Radiator for RX7 FD ) radiator has mounts for it to go on top. i would think that bottom mount fans would be better.

3. for the ducting, does it matter if i make 2 separate ducts for the intercooler and radiator or will 1 suffice? i've been looking at a lot of pictures of other peoples vmount set ups and there are soooo many different ways to go about this. i just dont know what is best for me.

4. when routing the radiator hoses, should i use pipes or will rubber lines do just fine? or does it even matter....

is there anything else i should be considering that i may not be aware of?

Tem120

iTrader: (5)

Just the opposite , the small stock twins start to shoot out super heated air at anything over 14 psi. so specially with turbos that are as inefficient the stock twins a good intercooler setup is more important.

cr-rex

iTrader: (114)

i will be running the stock twins with the boost set to .55 bar.

Tem120

iTrader: (5)

heh thats to low . stock is 10 PSI which is .69 bar Most people raise it to 12 -14 psi , .83 - .96 Bar

you can set it to what ever you want of course . its your car . BUT you wont be gaining anything at that setting .

cr-rex

iTrader: (114)

at .55 the car has more than enough power for me and on the little track we have here, it seems as though it could be too much. i dont care for super high power. i just want something with some get and go and the turbos set at .55 fills that need. at least i know i'm gonna be getting some longevity from my set up. brand new motor with good twins on a lower than stock boost setting driven rarely. definitley gonna be around a while =]

Tem120

iTrader: (5)

you say that now.. I remember when i was happy running 7 psi ... then I got used to it.. haha

also if you are running the stock ECU , you must remove teh restrictor pills in order to run lower then stock PSI .

cr-rex

iTrader: (114)

ive been happy with this set up for quite some time now. i dont see me changing my mind. im on a power fc with profec b2. none of the stock vacuum lines are in the engine bay. so no pills for me. i think since i've had my car running the boost spiked twice. once to .58 and another time to a hazderdous .65.

otherwise, i peak at .55 all day.

John Huijben

iTrader: (1)

I agree with TEM120, A V-mount definitely makes sence with stock twins. I'm running stock twins at 7 psi non sequential just like you are, and the temperatures are way too high during trackdays, even with a thick koyo rad, dual oil coolers, and switching the fans on at a lower temperature.

As for your other questions, as for the radiator angle, you have to see what fits and works. I would think having the radiator perfectly horizontal would work but having it a an angle is a bit better, doesn't need anywhere nere a 45 degree angle for it to work though.

As for fans, pulling fans are better than pushing fans, and if you have a proper radiator shroud like you should the position doesn't really matter that much.

As for ducting I think one duct would suffice, maybe in a situation where the radiator is perfectly flat and the intercooler is at an angle having split ducting makes sense.

Rubber can be used for radiator hose, it's that way stock from the factory. Sure, people will say that fancy welded aluminium tubing is better, but both will work just fine.

Tem120

iTrader: (5)

lol I wouldn't call .65 hazardous But hey if thats good for you then all for it.

cr-rex

iTrader: (114)

thanks for the advice. looking at the picture of the rotary works radiator, i noticed that the fans DO mount on the bottom. the location of the drain plug only makes sense 1 way... damn, i cant believe i didnt notice that before... oops...

that was the joke i was making....

Speed of light

iTrader: (8)

Welcome to the v-mount world. A well thought out and implemented v-mount will be a nice transformation to the car and engine bay. You will be able to move enough air though the radiator that cooling should never be an issue, and you wont need a humungous radiator either.

The op raises some interesting questions, so I'll offer my thoughts with respect those original questions:

1.) Fwiw, I put my radiator in a 22deg. angle. I don't think this is particularly critical, so you have some room to work in terms of getting your setup to fit and achieve your objective--no need to get caught up worrying about the angle vs. airflow. It's far more important to have a robust installation if you want it to last. I suggest that you mount the radiator resiliently for maximum reliability.

2.) I used stock fans mounted below. I would imagine top mounted fans would work; however, good shrouded fans mounted below will likely be more effective.

And speaking of fans, if you're relying on the radiator fans a lot, you may want to put fan(s) on the intercooler as well that switch on simultaneously with the radiator fans. This is to prevent recirculation of warm air from the engine bay though the IC when the radiator fans are on--effectively preheating it for you. This may not be a big deal for a track car, but for a street car, especially with a/c, fans on the IC can really help the IC heatsoak problem.

3.) Probably one of the most important points for maximum effectiveness is to make a duct that completely seals the "v" plenum and duct to the bumper. Don't forget to seal the V all the way around. One single common duct/plenum works fine. I have played with and have some evidence that a splitter might help a bit--I'll take an educated guess that this is because it probably reduces turbulence in the common plenum area somewhat, but it is by no means essential.

4.) As to the hoses, any number of solutions will work; however, I would approach this problem specific to your install and with reliability in mind.

Hope this helps.

cr-rex

iTrader: (114)

Thanks for the info, it helps a lot. With the radiator mounting, i think whatever angle i set the intercooler too, i will match with the radiator. Does the gap between the top of the radiator and the bottom of the intercooler matter? Would it be ideal to have them close? If it doesn't matter then i was thinking about filling that space with a single intake filter for the twins.

Im not running a/c btw. My fd is not and will never be a dd or any kind of regular driven car so i dont see the need. It just takes up space anyway.

I will be attaching the ducts TO the bumper to get a nice seal. I have .04 and .03 sheets of aluminum to play with. It will be a nice rectangle to fill the mouth of my cwest bumper.

I was thinking about putting a slim fan or 2 on the intercooler. I got a treadstone so i would need some pretty small fans. How would i go about wiring in something with the stock fans?

ALPSTA

iTrader: (3)

Watch out for the air conditioning if you are planning to keep it. I had it re-gased but it doesn't perform like it used to before the v-mount.

When I connect the fans blowing to the radiator the aircon works but water temp rises, when I connect the fans to suck air from the radiator (which is how they are supposed to be connected) then it sometimes cools sometimes doesn't. I didn't get around to looking at it detail and solving it. But since haven't started doing this you might want to look into it.

cr-rex

iTrader: (114)

Thanks for the input but next time, it may help to read the thread BEFORE you post.

RENESISFD

iTrader: (13)

When designing a V-mount it is also important to consider where the air will go after it passes through the cores. Once you make this determination you will then realize that the angle of the cores is dictated by your choice.

Example, if you will vent the IC core out the hood then you will obviously want it to be more flat, if you want it to vent into the engine bay then you will want to angle it more.

Good ducting and a through consideration of where the air will go after it goes through the cores is more important than the actual core angle.

cr-rex

iTrader: (114)

well i have a vented hood that i'm not sure i want to use or not. its a carbon fiber mazdaspeed style hood. if i dont use it then i will be sticking with the stock hood. does it really make a big change to not vent the passing air through the hood instead of ramming it all in the engine bay?

ALPSTA

iTrader: (3)

You're right I read the first few posts and missed your last post about the a/c. I wouldn't have posted trying to help if I had known it'd cause such a drama

Speed of light

iTrader: (8)

The width of the gap [at the closed end of the V] does not matter so long as it's filled to maintain pressure in front of the heat exchangers. Yes to the filter, if I understand you--I source a cool air intake from the v's plenum area as well.

Someone else has already mentioned leaving adequate space above the IC for exit air. With a stock or solid hood, air will exit around the engine and under the car, which works fine. Some use vented hoods for maximum affect, but it's not necessary.

I also run a slightly modified stock undertray, which I recommend.



Air conditioning should work as good or better than a stock mount if everything's right.

Condenser orientation is important. How did you install the condenser? Is the liquid line that feeds the receiver/dryer (smaller of the two) located at the bottom edge? This is essential for proper a/c function; however, it is a common mistake to have the condenser tilted the wrong way.

If everything's correct (and you're running with an engine thermostat), engine operating temps should be very stable--just short of rock solid--with a v mount.

cr-rex

iTrader: (114)

Yes, you understood correctly. That is where i am intending to pull my air from for the twins. I will experiment with the stock and vented hood. Im worried about the vented hood because i dont have any type of covered parking and a car cover just doesnt cut it. My engine bay suffered greatly when i had the vented hood on. After my ''rebuild'' i dont want that to happen again so i may just use it for track days.

Whats different about your undertray? I was planning on making one out of some .03 aluminum sheets. I was going to put some scoops in it so that the air would flow into the bay. I think the ''scoops'' would work better than just poking holes in the bottom of it.

RCCAZ 1

iTrader: (10)

Sorry to resurrect this thread from the dead, but I wanted to ping the forum to see if anyone has ever tried converting their bone stock FD (albiet, maybe aftermarket DP) to a Vmount configuration. Could the stock ECU handle it with stock cat and catback in place if you kept the boost levels stock?

I feel the design provides superior intake charge cooling for summertime track events, so was wondering if anyone has successfully tried it. Can't recall ever seeing a post or thread that addressed the question.

Thx

cr-rex

iTrader: (114)

good question. i would go ahead and say yes. in all reality though, it would be a waste. not so much because you wont be getting the most out of on the stock ecu but going through the trouble and cost of a vmount, not going power fc or some other ecu would be a little confusing and wasteful.

RCCAZ 1

iTrader: (10)

Thanks for the reply. Yes, I'm asking for a friend who will eventually move to the Power FC or some other aftermarket ECU. It's just that he's currently tracking it in stock configuration, albiet a DP, and the other day he hit 230F on the track. I'm trying to help him find a solution to lower his track temps most efficiently before investing a ton of cash. I know we could rig up a V-mount with his aftermarket Koyo rad for less than $1000.

cr-rex

iTrader: (114)

My suggestion is that he stops immediately. If hes pushing the car to its limits like that then a v mount wont even be a concern soon. I advise he hold off and get his set up correct then get back to the track. Playing it safe is typically the best way to make these finicky cars/motors last.

Mrmatt3465

iTrader: (10)

Hey there.

I am the one having the heat issues at the track. This was measured at my throttle body coolant line with my Defi water temp gauge. As soon as I saw it begin to get warm like that I eased up. It was just under 100*F that morning. My current set up is a stock base model with refurbished R1 oil coolers, Koyo radiator running 50/50, and an FC thermo switch. All of my ducting is in order as well. The r1 coolers have new flaps in place and I placed sealing foam on either sides of the Koyo during the install. I was advised to try going 70/30 on my coolant ratio and possibly V mount. While I'm still fairly new to tracking the RX7, I was hoping to keep things mostly stock. I don't think a V mount would alter flow and boost as much as say an intake or exhaust (which are stock for me minus a heat coated downpipe). So I'm considering a setup as long as one can be obtained at a reasonable price.

Matt

lOOkatme

iTrader: (19)

If you are going to do a set up change, I recommend figuring out how to get cold air to the intake and radiator as top priorities. fit the intercooler where you have left over room. it doesn't have to be very large.

duct everything very well.

A major cooling load is done by the oil system, ensure your oil system is cooling well and all heat exchangers are ducted as best as you can.

The inlet ducts of the heat exchanges can be smaller than the heat exchanger surface area.

remember that all this work only works if you are moving, and usually at higher speeds.