Morning all (well, it's morning here)
I currently have a fully ducted modified eBay special IC in a V configuration:



During mapping, IATs were skyrocketing, as they do on the road and track, even at modest boost.

So I have at my disposals two IC cores to replace it with - an HKS Bar/Plate type one, with a similar frontal area to the current one, or a Trust/Greddy one which is smaller but thicker:


So I need to choose between them.

I've been under the impression that the frontal area is one of the key things (as well as internal design) that helps eficiency and pressure drop. I'd quite like to keep VMIC, and avoid buggering about too much with the radiator if possible.

Anybody got any experienced of using these coolers in a similar setup? Outlets aren't too much of a worry as I know a good fab guy!
Cheers
Si

EDIT: FWIW, setup is a divided T4 GT35r w/ported shroud, and a fair bit of work on engine, inlet and exhaust, no WI (Please don't turn this into another WI thread )

 

Those Greddy cores are supposed to be quite good. Would be a tidier install with minimal modifications, I'd go for that out of those two.

 

**** i have always loved your engine bay bro, keep it the same just grab a vented hood and some water meth and completely forget about IATs all together

Brad.

 

I think Garrett makes the best intercooler cores in the market. Search for your choice of core size and have custom endtanks made or buy a pre made one. They are expensive.

 

your problem likely has nothing to do with your intercooler at all but the airflow outside it. even the cheapest radiators and intercoolers usually work just fine, if you duct them properly.

 

I think it might be harder with some of my routing - the thing that stops me going witht he greddy is actually packaging tbh - smaller is fine, but the thickness means an awful lot of re-jigging.

Cheers man I'm trying to go for the simplest solution though - don't want a vented hood, I've played with one and it made no differnce to the IATs. I have WI but I think that may mask the problem - I'd like to get the best out of the IC's before exploring other avenues

It's a choice of these ones really - I'm not buying yet another one!

Care to expand? By 'duct properly' what exactly do you mean? Everything I've read indicates that these cheapo cores really aren't that great. The core is fully sealed in at the front, sides, and rear. The car has a MazdaSpeed undertray, and minimal stuff to get in the way of air evacuating down the tunnel. Other than a horizontal divider, I don't really see what else I can do with the ducting.

 

Just looking at that pic, I don't see anything preventing air from just going around the intercooler. Make some ducts that trap the air so it is literally being forced through the heat exchangers. A properly ducted setup should NEVER have problems keeping cool regardless of where you bought your IC.

However, if you want to use a different IC, from what I have read the bar/plate type exchangers are better at cooling than the tube/fin. They have some minor drawbacks but in the end have a greater cooling capacity. However I did not know hks or any jap company really made bar and plate ICs.

 

As said, the cooler is fully ducted and enclosed:


There are some more bits to seal some of the gaps that you aren't on in that pic. Foam tape is used to seal/cushion.

The only 2 options are the ones I've got unfortunately - it's not a 'what other cooler should I use' question, it's a 'which one of these'

 

The cheap inter coolers seems to be mixed aluminum and alloy. Also, good inter coolers have have mini louvers on the fins. And even inside there are little louvers on the fins.

 

I Used to run the hks front mount and loved it. I sold it to get the rx7 store v mount which I regret to this day. It had extremely low temps. Wouldn't go much over ambient. I needed to duct the radiator well which helped the water temps. I didn't care for having to fix bent fins all the time tho.

I now have a custom v mount so all is ok.

 

V mounts are meant to have constant air moving through(race setup) and will heat soak way before a front mount. But not as easy as a top mount. An e fan puller on the inter cooler might be a good option a long with a vented hood. Vented hood is a must.

 

Wow that is actually a nice looking setup. I'm surprise you're having temp problems. I'm assuming water temp is okay?

And you said the hks one you had was bar and plate so when I said that I was talking about an ic you already had. Likewise with the tube and fin which would be the greddy.

Honestly just use which ever is easier to fab up to your current setup. I can almost guarantee that either will give you the cooling you want especially with that duct work.

Sorry, I didn't see those ducts in the first pic

 

sure

i've dyno tuned cars with similar intercooler setups as yours and they heat soaked and ran higher IATs than even those with stock mount intercoolers.

divide the airflow to the radiator and intercooler. the divider also prevents the radiator heat from just rising and moving through the intercooler. make sure air doesn't simply move around either of them. i would bet if you used that same core as a front mount just for testing purposes you would see a completely different result, people who blame core efficiency just need something to point a finger at for careless setup procedures.

also make sure the bay is evacuating, monitor temps on the dyno and on the street and compare the difference with air moving through the car with the hood closed and open.

 

Now wait a minute. You say temps are skyrocketing. Under what conditions exactly (please be more specific)? What are you measuring with, the stock sensor? What temp are they starting with and what are they ending with? Do you have any datalogs?

Are we talking 20C over ambient or 50C over ambient just driving around? Also the stock IAT sensor is slow responding so it will stay heatsoaked.

 

The more horizontal the cooler, the less efficiency...looks fairly flat in your pic? Is there any shrouding around the top front, there's a rather large leakage path through the box section otherwise - likewise between that and the reo, if the stock plastic piece is removed and nothing done to compensate.

Never understood the large-**** IC with the intake whacked directly behind the discharge either, but it seems to have been the fashion for a long time now, so unlikely anything will change there.

 

+1 for
better angle of the intercooler
Need a shroud for improved airflow to the intercooler
A vented hood would make a big difference

and like Arghx said the stock temp sensor sucks!

 

What he said. Best post on this thread. Tell us more of how your temps are increasing.

 

To answer questions:
The intake has a fresh air feed to it from the front of the car.
Temps are measured using a Triumph IAT sensor mounted in the Greddy elbow.
I've actually done some testing with the stock bonnet and with an AD9. There was barely any difference between the temps, so I stayed with stock, as I didn't want to ruin the clean lines of my stock bodied car. This has been discussed in great length elsewhere(Including long conversations with two personal acquaintances who work in wind tunnels for F1 teams and GT teams) and I'm happy with it.

When I say 'skyrocketed', I'm talking hitting low 60's on the dyno on a 25 degree day after successive pulls. I've seen just under 60 on the road and track in similar temps as well.
(these are degrees C, so what, 140 on a 75 degree day in F?)

It's unfortunately not possible to change the angle of the IC as lifting the front would cause problems with impacting the bonnet, and dropping the rear isn't possible due to face I still run the stock oil cooler pipes - replumbing that isn't something I have the time or money for at the mo.

Engine is in good health, a couple of thousand K on a fresh build. Water temps are rock solid. Heat soak has never been an issue when moving along, I don't use the car in heavy traffic. It's used for track days and country roads.

This was basically a cooler efficiency question, but seems to have derailed a tad! I think I'm just going to go with the HKS and see where it gets me. Cheers for the help.

 

Install a thermocouple in your inter cooler inlet and outlet. Calculate the temperature change and efficiency. 60C in the conditions you described isn't that high... Air to air inter coolers heat up fast and your compressor outlet temps are probably close to 150C.