After the turbo conversion, I have finally got a chance to attend a track day to see how the car would behave. Basically, the RX-8 handles like a dream and the turbo power would be enough to hook up with those not turbo 997. However, the weather is hot and sunny, 34C with 85% humidity, the water temperature overheats to 120C with 2 laps with using 102 octane race fuel running 8k rpm gear change!! Oil and exhaust temperature seems OK.

I have installed a large Koyo radiator and made an air scoop to duct direct air but still not helping very much. Any good idea to cool the water temperature down? Any good recommendation on radiator fan??

The other problem is 180km/h cut off as my car is JDM version. I have tried the HKS SLD but no go as it will stop me to get readings from the OBDII port, so I ditched it. But I was the slowest on the main straight during the weekend. Any good suggestion for this??

Otherwise, the car can surprise many Porsche owners!! I can't wait to have the problem fixed and give the 997 a real fight!

 

I see it time and time again at the road courses. Aftermarket Forced Induction overheating on cars designed to be NA from the factory. S2000s, Mustangs, Corvette's, all spilling their coolant in the paddocks.

An FI S2000 owner I spoke with had his blower kit on for 2 years of flawless street use to see it cause major cooling issues at his first track event (Sebring).
R&D for these systems may not take into account track use for proper cooling.

 

As far as ducting air to the radiator, make sure you have a nice "tunnel" for the air to move towards the radiator without allowing air to escape through the top or bottom. I've seen turbo Miata guys run at the track cover up "leakage" areas and they say that it helps to reduce coolant temperatures.

 

koyo radiator=good,stock water pump=bad.
you didn't mention coolant---but make sure it is at least 70% water 30% coolant. bottle of reline water wetter will not hurt. You have the mazdaspeed front clip? Need all the airflow you can get.
make sure the back part of the radiator is not "blocked" by the battery box etc. move it.
if the water temp is that hot and the oil temp isnt even close the cooling system is really in need of help. Contact Mazmart --they have a new pump out--will also need to do something to make the thermostat flow better.
lets us know
olddragger

 

Whats the OBDII port does it effect a non turbo car running standard ecu ?
As I was going to get the SLD.

I have installed the SLD once and it blocks my reading from OBDII which needs for get readings from the engine and clear engine codes. Now I am looking for other solutions!

 

koyo radiator=good, stock water pump=bad

I will custom build an even bigger radiator for my next track event in October. I shall post picture once completed!

you didn't mention coolant---but make sure it is at least 70% water 30% coolant. bottle of reline water wetter will not hurt.

Yes, I did exactly that...except the wetting agent. I will add that in next round!

You have the mazdaspeed front clip? Need all the airflow you can get.
make sure the back part of the radiator is not "blocked" by the battery box etc. move it.

Yes, I have full Mazdaspeed kit and the battery moved to the rear already. However, the turbo is sitting close to the radiator. I shall need to wrap up the exhaust side next time.

if the water temp is that hot and the oil temp isnt even close the cooling system is really in need of help. Contact Mazmart --they have a new pump out--will also need to do something to make the thermostat flow better.

Do I contact Paul from Mazmart? How much is the unit? Can I have the contact detail? I wish I know this earlier!! Thanks, this will be a great help. As for thermostat, I have taken that out during track day! Any better suggestion?

 

what you need is a vented hood. Inlets for air are only half the solution. You also need a very restriction free exit path.

Also look into another oil cooler. Fluidyne makes a very efficient bar shaped one that wont take up much space.

 

I have ordered i-Feeling vented hood from Japan, it should arrive within 2 weeks. As for oil cooler, I have installed 2 Mazdaspeed cooler, which should be adequate.

 

The vented hood it's help a lot,My friend has a turbo 8,He used to hav the same problem as u,But after he install the Vented hood.It's improve a lot.......
Nice car man...I'm org from HK too.but now in United State,I havn't seen any 8 like urs in HK...Good job man

 

Thanks mate. Let see whether the boonet will help! I have got in contact with Paul of Mazmart for the water pump. He is working out the shipping cost for me.

 

do you still have the air conditioning condenser installed? I'm removing mine to create less restriction for airflow to the radiator. I'm watching this closely. It will be rare that I deal with ambient temps at 93F on track days, but still concerning.

 

Bummer - I was going to get the SLD also but did not realise this problem would occur .
I have run the car without the rear wheel sensors - this does work but be warned
you will lose :
ABS
TCS
power sterring will default to high speed setting .

Of these the only one which affects your track driving (on a dry day) is loss of ABS . Some drivers don't mind this - I managed to flat spot a tyre & go off the track however

 

I am still solving the SLD problem. As for removing the A/C condenser, no!! I need my A/C to drive to the track. Also, the FMIC block most of the airflow anyway. I have made an air scoop going from the undertray!

 

SE3P - I see you have the Okada plasma coils . Can you comment on how effective these have been for you ?

 

I hear ya, but the way the A/C condenser fits onto the radiator doesn't leave much room to get air on there does it? When I was discussing this with my installer, he nicely stated the air is getting superheated twice before it gets to the radiator, once by the intercooler, and once by the a/c condenser. I know its hot out, but that will def help on the track. Now on the street, different story. If its hot out, I drive my Speed3

 

SE3P - I'm not 100 % positive on this but I think if you ran the Interceptor x EMS that you would get over the speed limiter problem . Also I believe that it is a better EMS than the Haltech you currently run so you may pick up a few hp as well .

 

vented hood will be very good ! Dont remove the thermostat --that alone has made cars run hotter. At least in some recip engines. SOme have drilled a 1/16 hole into the thermostat to help just a little with flow. remember a thermostat will not control how hot an engine runs, it only keeps the engine from running to cool. I have even seen a pressure regulator for radiator. You can always go with Evans coolant if you really need it---but watch oil temps closely. Wraps for the turbo heat is good also,
what temp does your fan/fans come on? get them turned on at 180F--makes a difference. even at speed.
tell Paul at Mazsport olddragger sent ya!
olddragger

 

Brettus, thanks for your advice. However, my RX-8 is JDM version, therefore the speed limiter is built in to the ECU, the only way available to cancel such function is either by installing a HKS SLD (which I failed) or flash the ROM inside the ECU (which I am talking to RE-A for help). As for the ECU, the Haltech Interceptor works out fine so far. I was planning to use EMS but my turbo dealer couldn't send me the ECU for over 12 months, so I took Haltech Interceptor as alternative, now I am happy with the result.

 

oldagger, I will take you advise and try not to remove the thermostat and and wrap up the exhaust side of the turbo. Last time I have tried and it didn't make much difference to the temperature. The fan switch I have used the item from Mazsport, which will kick the fans on at 90C, but the factory fan are too week for the car, which I will change next time round with thicker radiator. Also, I have ordered the water pump from Mazparts, which should help the flow of the water.

 

The Interceptor x controls fuel & spark independent of the ECU so i'm pretty sure it will cancel out the speed limiter . PM Scott at Mazsport to be sure . This approach could well be cheaper (and better) than RE-A solution . I'm sure you could sell the Haltec and recover some of what you have already spent.

If you manage to reflash the ROM make sure you let me know because I'll be wanting to do that as well .

 

if you get new fans--dont forget to get a better shroud made at the same time. the stock one has some leaks.
OD

 

Ealier in the season I experienced high water temps on the track (110 C)
I have purchased a ventilated hood and will post the results from my next event at the end of the month. I replaced the antifreeze with water and water wetter previously and did not see any significant difference.
I do not think that different fans will make a different because above 30 mph the fans do not move any more air than the ram effect alone.

 

Thanks for the advice, I will make sure there is no air leak!

 

Yes, plese keep us posted with result. As for the fan, it will be great use for turbo car, as the intercooler block a lot of air flow.

 

beg to differ on the fans do not offer anything above 30mph. How did you come across that figure?
While I am on it--what some people may not realize is that while on the track there are many times your speeds are not that high---it all adds up.
olddragger