eage8

iTrader: (9)

hrmm... interesting, I might have to try this...

prof

I will indeed - I'm at work at the mo - so I will get the figures up when I get home - I took the readings on the Emanage using the Engine Intake temp sensor, I will try and translate into Faranheit (apparently we went metric).

One thing I did notice - with the stock intercooler - If I'd been running the car and park up, and then came back to it after say 20-30 minutes on a warmish day 70-80F - the intake temp sensor was reading a wapping 70 C (158 F), and would take over 5 minutes of driving at 30 mph to come down to 58 C (136 F).

With the sensor mounted in the Greddy tube, and using the ARC intercooler - the same peak temperature is now only 65C (149 F) and drops to 45 C (113 F) within 3 to 4 minutes.

It's the same exact sensor, I moved it from the old throttle inlet to the Greddy tube, same wiring and same measuring tool.

I do wonder how much of the heat registered by that thermistor is just off the engine block - either radiated heat or conducted through the throttle body. I still have all my cold start stuff on the throttle - so there is hot water being piped around that.

I am toying with the idea of using an isolating plate between Greddy tube and throttle body - like the one between throttle and upper inlet manifold (although not so thick) , and heat wrapping the tube as well. I'm waiting for some hot days again now to see how it copes in the summer time.

gxl90rx7

iTrader: (1)

thanks, prof im very interested in your numbers. im using a haltech sensor in the stock location, stock TB elbow

the ARC does not come with a heat shield, correct? I have an extra tmic laying around, Ill take the shield off tonight and try to get some numbers

prof

Yep - No heatshield on the ARC unit Looking at the heatshield on the stock unit, it does seem to sit quite close to the underface of the intercooler - but it's angled down and away so presumably Mazda engineers designed it to carry the air through. Oddly it's painted black, which means it absorbs all the heat radiated from the top of the engine - which might explain part of the heatsoak problem.

Ok - some figures I have - these are the range of temperatures I took from the engine Intake temp sensor. In the first 2 cases, the car had been on idle for some time prior to the runs - so there is a lot of heat already in the system. Ambient temperature was high 20's (80+ Farenheit).

I took readings from the car with the stock intercooler and Rad:

The temp range for the engine inlet sensor 52.2 - 63.6 (125 F - 146F), temp at max boost (11.7 psi) was 54 C (129F). The inlet temps drop on higher boost because of the airflow, but after coming off boost and into trafic they went up to the max figure !!

With the ARC intercooler and stock Rad:

Almost identical conditions to the last run - e.g. idling for a long time, followed by the same run on the same bit of road :

Temp range was 47.6 - 54.1 (117 F - 129 F), temp at max boost (8.6 psi) was 50.9 (123 F).

Then I took some runs with the rad changed as well, these runs were from 'cold'

Temp range was 30 - 46.2 (86 F - 115 F), temp at max boost (10.4 PSI) was 43.8 (110 F).

The ambient temperatures were give or take 1-2 degrees C on all these runs, the difference in the last run was it was from engine cold, with boost being built after 10 mins of running - water temps upto 80's ( >176 F )

I'm in no doubt the ARC intercooler is more resistant to heat soak, brings temps down much quicker from standing heat, and is returning running temps at least 10 degrees C lower than the stock intercooler. Changing the rad also helped with heatsoak.

Gene

iTrader: (1)

What are the dimensions on the ARC? I bet we could get custom ones just like it from bell intercoolers or whoever...

rotarygod

iTrader: (1)

260 mm tall x 70mm thick x 235 mm wide and good for up to 350 hp according to arc.

gxl90rx7

iTrader: (1)

ok i tried the stock IC with the heat shield removed.. intake temps were lower but not by much. ambient temps were 60F, cruise IAT were around 75-80F. after 15psi run to redline, temps were in the 120-130F range. but on my original intercooler, i had cut some of the rear of the shield off, up to the first set of rivets. so not a perfect comparison, but it does seem to help

i will say at 6psi, the intercooler works great. the temps dont even get above 110F

RotaryWeaponSE7EN

iTrader: (6)

move what?

Gene

iTrader: (1)

Have you got any pictures of this installed? How does it line up to the hood duct compared to the stock one?

prof

I put a pic up on post 21 of this thread - the line up with the hood scoop is spot on, but you may have to cut the rubber grommet thingy if your bonnet doesn't shut properly - it's thicker than the stock unit !

FC-Dan

Is that 350 to the wheels or to the crank? It is kind of expensive tho, compared to the corksport fmic kit. Not to hijack the thread, but does anyone have any thoughts about the corksport fmic?

SirCygnus

iTrader: (1)

thats usually at the crank.

rotarygod

iTrader: (1)

Most people never hit 350 anyways although they'd like to think they do.

gxl90rx7

iTrader: (1)

the opening in the hood is 12" x 9", yet the stock intercooler only uses 12" x 6" of that. I was thinking of making a custom 12x9" IC, but the front end tank will hit the alternator. and you also have no room for a thicker core either.

I was also looking at the hood opening, if you look closely, the inside of the opening is not sealed at all, it looks like a lot of airflow is lost to inside the hood itself. I bet if you took some alminum or something to block off this space so teh air had nowhere to go but down into the intercooler you would get a lot better flow to it. anybody try something like this?

Hypertek

iTrader: (3)

my car came with hks tmic
http://i41.tinypic.com/2r2ozra.jpg
full racing beat exhaust/no cat and fuel cut defenser... evo9 fuel pump
stock turbo, i ported the throttle body tho.

hits under 1 bar.. probably about 12psi or so.. no probs.
Id think thats the limit. Any more mods and will def. need some additional management.
i couldnt compare it to stock because ive never driven stock.

FC-Dan

I was just wondering about the hp because isn't 275 to the wheels just slightly less than 350 to the crank? Considering 15 to 20 percent driveline loss. My goal was 350 whp MAX, and I doubt that I'll even want that once I start hovering around 300, I was just wondering because the ARC tmic, imo makes for a cleaner engine bay.

rotarygod

iTrader: (1)

I'd be willing to bet you could do it. There's so much more to a power number than just an intercooler. Your turbo and tunign play huge roles. I'd like to see someone hit 350 rwhp with a top mount. I don't see why it couldn't be done. WRX's can do it. When it comes to the intercooler it's all about airflow to it. As someone suggested, you could probably increase this quite a bit by paying attention to some well placed hood mods and they could probably be done without visually altering the opening.

I like a cleaner look personally which is why I'd like to see more top mounts pursued. I personally feel that long pipe snaking through the engine bay to a front mount looks sloppy and unimpressive. I just don't like the added distance either.

eage8

iTrader: (9)

If I could find one for relatively cheap I would definitely get one... the stock IC is really the bottle neck of my system at the moment, and I really don't want to remove my bumper support. I was planning on getting a custom front mount made, but this might be a better option.

If only they weren't so pricey... rhdjapan is the only site I can find them at and they're charging like $1100 which is the price of a full front mount kit.

rotarygod

iTrader: (1)

As much as I like the simplicity of the top mount, a front mount is a fraction of the price. The other option is of course to have one made which isn't really all that expensive anymore.

Trots*88TII-AE*

iTrader: (11)

If shorter piping is the main factor in choosing an upgraded topmount, why not go Vmount? You can have it setup with similar lengths of piping, but if you have a reverse vent hood, you get MUCH more airflow then a topmount could ever provide. The only downside obviously is cost and/or fabrication.

Jturbo

iTrader: (9)

I have owned one of these intercoolers in the past. I did notice that I had a little pressure drop, around .2 BAR, probably from the larger core. I was planning on using it with a small hybrid, but had to sell it before I could finish my car. It may work well for a stock turbo with increased boost, or a small hybrid turbo. However, I would still use a front mount if going with a big turbo.

HOZZMANRX7

iTrader: (43)

"Most people don't realize that you can drastically increase flow on a stock TII by modifying the intercooler outlet and tb inlet piece. The stock intercooler actually stays decently cool when there is airflow. Of course I'm talking about sub 250 hp levels. When sitting still it's a huge microwave though."

Question and a thought.

Please describe the modifications to the stock outlet and TB inlet piece you have in mind?

Related, what stock pieces all would you suggest ceramic coating might improve effectiveness?

sim_rx3

very interesting reading..

im in the same boat, well sort of..

ive got a 1990 HC Luce with Factory 13bt (the 13b turbo engine is the 86 to 89 rx7 version engine with a few differences.)

so basically with my car only being 1 of 18 rotary version Luce of my model in australia (only about 500 produced for the domestic market by mazda between 1986 to 1991). im looking to get it nice and slightly quick.
but keep it as original as possible as well.

basically my car doesnt run a bonnet scoop. it uses a ducting system through the bonnet to get air through to the intercooler. so im at an added disadvantage with charge air heat soak befor the frontal air gets to the cooler.

so this is what im doing to combat it and get temps down -

im going to run water injection. but a very simple one that has been proven to work well.
using a spray nozzle they use in chook sheds mounted in the intercooler bowl near the outlet to the throttle body hat under neath so it cant be seen.

the charge air from the turbo is taped into the top of a sealable alloy canister.
the bottom of the bottle runs to the solenoid then the hose runs from the solenoid to the mounted spray.

the solenoid is programed by the aftermarket ecu (haltech e8) that switches it on at 8psi. it uses 2-3ltrs per about 3-4 tank fulls of fuel.

will keep you guys posted on how it goes..

my set up

13b ports cleaned up
stage 4 BNR turbo (cause it is auto i didnt want a back cut rear wheel)
ARC top mount for aided air flow (although looking at a custom top core so i can put the factory intercooler guards back onto the custom cooler to keep that "factory look")


although one thing i have read up on, the dual nozzle coolmister kits on ebay (1st nozzle after turbo outlet, second nozzle at intercooler outlet), anyone used one yet?? with any sucess??

ps anyone going WTF is a 1990 Luce look here - https://www.rx7club.com/old-school-other-rotary-63/my-daily-driver-1990-hc-royal-classic-luce-factory-13bt-auto-508087/ haha

SirCygnus

iTrader: (1)

the general rule of thumb is never spray before the inter cooler.

classicauto

iTrader: (3)

Thats a pretty **** rule of thumb then

Lots of people spray pre intercooler, with most of those being people who spray pre-turbo. I've yet to personally experiment with that spot but lots of gains are to be had since you're cooling the charge as it being heated up....but that discussion will take us off the TMIC topic