Ok so long story short, I'm about to start building my first race car from a bare shell (FD) and through my own track experience in my current FD is that it tends to start getting too hot after two laps (lapping at around 1.05) of hard driving with my current Greddy front mount intercooler set up so the obvious and proven way is to V-Mount the radiator and intercooler.

My question's are:

Is there a formula i need to consider before I launch into a V-mount set up ie the angle that both need to be on to maximise the cooling ability of each cooler?

Do i need to separate the airflow from radiator and intercooler by making separate airdams for each to direct the air?

Do I need to make provisions for the air to exit once it passes through the intercooler and radiator ie do i need to make a duct in the bonnet for the air to escape, see attached photo.

The reason I am curious is that i have seen and made numerous vmount set ups and without knowing any real information as to how they should be set up, they are all made differently (often due to different intercoolers supplied), with some the intercoolers are sitting almost flat, some are at an angle, some meet in a wedge with the radiator and some have a separation channel etc etc. I just dont see any uniformity when it comes to the setups.. I am also wondering if i duct both my radiator and intercooler for better airflow, will it effect my down-force and or lift and as a result, my handling?

 

wow I was hoping that someone would know....

 

You should talk to Damian. He has a very proven setup. It's not technically a v-mount, it has a diverting duct to pull about 20% of the air coming in the main front opening into the intercooler. The rest goes through the radiator.

Yes you found out the hard way that front mount intercoolers is just about the worst possible setup for a turbo rotary on a road course. The FC guys that run them really get me head scratchy, because not only do they block the radiator but the oil cooler too. Heck the silly little stock Top mount on the FC is infinitely better for engine longevity than a front mount.

 

Thanks man, so who is damian??

 

No real formula but you want to try and get some forward facing angle on both. More important for the rad to get direct air than the IC so if you have to compromise, compromise on the ic. On my custom V-mount setup, the angle on the radiator is about the same as the angle of the stock radiator mounting and the top of the radiator is supported by the 2 tabs and the cross brace. Nice and sturdy.

No, you don't *have to* for race use but it may help to have a "splitter" between the two to help direct and split the air flow. It will make more of a difference on a street car from my experience since at slow speeds the fans are so strong that they will suck hot engine bay air through the IC which will increase heat soak on the IC and Intake Air Temps until you start moving again.

Summary - not the most important thing for a race car. Will make a difference if you spend a lot of time commuting in stop/go traffic.

You don't *have to* but it can help. I would definitely do something on the bonnet (hood to us US people) as it will help get air out and through the heat exchanges and underhood. I suspect it will help aero a little by decreasing lift.

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You are welcome to search on my old posts on the topic as well as those made by Speed of light who is an old engineer and built my setup. See if you can find pics of the "subframe" he built for me. It would be quite useful on a race or track car since it would protect the radiator in the event of an off and overall provide a very robust mounting option. He might be willing to build you one if you ask nicely.

 

I dont really agree that a FMIC is the worst setup for a road course FD, it might not be as good as a V mount, but it can be made to work just as well. Over here in New Zealand, we dont get hugely high temps, even in summer, so with a well built FMIC setup you can keep the car well cool enough.

I have a 450-500hp (depending on boost) FD that I track mainly, and after about 9 hard laps at the last test day, I was seeing solid 96-98*C water temps.

I was having overheating issue before with the FMIC, but as soon as I built the ducts for it, the problem went away. See my build thread for pics:
https://www.rx7club.com/build-threads-292/my-black-fd-track-spec-build-up-56k-stay-away-%3Dp-895769/page6/
You need to make sure the duct seals to the radiator and I opted to let some of the air pass around the intercooler and hit the radiator fresh. I also moved the intercooler forward as far as I could and put the radiator on a lean so there was airspace between it and the motor for the air to exit up and out the bonnet/hood.

I too am interested in peoples throughs on V mounts and the effect they have on positive undercar pressure with the air traveling through the radiator exiting under the car. Would it undo the effect a front splitter/undertray would have??

 

Thanks for your input guys!

I have made an airdam for my current set up but it didnt make much difference on the track at Pukekohe raceway, 2 laps and its getting too hot. I do have a different cooler to you though Tursty, i have the Greddy style cooler which is wider then the opening on the front bumper..

My other limiting factor is that my surge tank and fuel pump are in my engine bay between the engine and the radiator so space is an issue but I think at this point i am going to rip out my intercooler and radiator and start from scratch and see what i can do to make up a v mount system... I think this is really my only option at this stage given what i have, the IC and rad are already sealed in together.. maybe your intercooler is more efficient than mine....

I will either set it up on my road car or mock it up on the front cut I have as this set up is for the track car that I am building in the coming months, I am aiming for 600hp so I want it to be as efficient as possible. Sadly there arent too many v mount options in nz, esp if you have over 400hp!

 

The Greddy style FMIC that completely covers the bumper opening can not be made to work well IMO. Some people can get a FMIC to work but more in the style of the Blitz FMIC.

SHPNOUT and fingerlock both use FMIC based on a Pettit Racing setup successfully on their RACE cars. Fully ducted, vented hoods, proper radiator, no street accessories, single turbo, probably some other cooling mods that I don't know about... They are in the 400 rwhp area.

 

I too thought about building a V-mount set up last year, but ended up going to the FMIC route similarly to Shpnout's car. His setup worked and why reinvent the wheel? Also the V-mount was going to be way more complicated to build. Basically what I did was get the largest radiator that would fit in the hole and modify my Pettit intercooler (Originally SMIC) to FMIC. I have since ducted all sides of the "radiator box". This setup works at 105F, 50C... in the 415RWHP range.

Here are a few crappy photos of my setup...







Guy

 

I have 410rwhp and even tho i have made an airdam it still has cooling issues... I am going to pull it all out and reconfigure it with trying to make my Greddy fmic into a V-mount set up..

Here are some pics of my current set up... on that note, i have just spent 30 mins trying to get my pics on here via flickr but it was a complete waste of time and cant figure it out.... can someone please suggest a good site that will let me share a nice and easy URL of my images on here?.... i will just use the old fashioned way for now till i figure it out....

 

photobucket. Best of luck with the new configuration.

 

Yeah photobucket.com is what I find easiest to use.

I think the problem you have is lack of airflow. To combat that problem, I cut out that support ....thing, that runs between the two chassis rails at the frront and moved the intercooler as far forward as I could. I then put the radiator on a big lean forward so that there was plenty of room between it and the motor for the air to exit. I think it you did this, and moved the surge tank to the back (this will help with the quest to move weight rearward as well) you should be sweet. And would be a lot less work then building a v mount.

Im still really curious with how people get around the positive under car pressure with a v mount??

 

Thanks tursty, this set up is going to be for my track car so things will be different for that car but in saying that I want to change the set up on my road car too. I will pull the rad and the ic and see how much trouble it will be to v mount what I already have. Just have to wait a couple of weeks for my flatmate to move out so I can get to my car and work on it cause her **** is in the way!