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RX8 Faster at night? Cooling?

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Old 07-06-2015 | 04:12 PM
  #26  
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The OEM intake tray will work with the Mazdaspeed intake but you would be better off selling the useless Mazdaspeed intake and just installing the OEM intake system.
Old 07-06-2015 | 04:20 PM
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Originally Posted by 9krpmrx8
The OEM intake tray will work with the Mazdaspeed intake but you would be better off selling the useless Mazdaspeed intake and just installing the OEM intake system.
wut?
Old 07-06-2015 | 05:11 PM
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TX

Originally Posted by TeamRX8
wut?
As far as I am concerned it is nothing but an expensive noise maker that occasionally gets wet. But sure it is worth it in a track car that is maximized and looking for every pony.
Old 07-07-2015 | 01:23 AM
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you forgot the all important reason to change it though

https://www.rx8club.com/series-i-aft...2/#post4703281
Old 07-20-2015 | 12:14 PM
  #30  
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been logging my trips. sluggishness starts around 210F - the hottest i've seen the coollant get is 214F.

Nighttime coolant temps are always below 195F and the car feels great then.

Car feels the most powerful around 185F. I want it at this temp just not sure how to get there.

Thermostat was replaced in Jan 2015

Going to start with coolant flush first as I don't know when the last time the flush was done.

Driver's side oil cooler is pretty banged up, might as well straighten the metal out, get steel oil lines, cover it with mesh to prevent future damage.

Any info about fans? I've been trying to search but can only find arguing on these forums. I'd really like a faster set of fans like in the S2.
Old 07-20-2015 | 03:49 PM
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I'm probably lacking the MSP16 update as well, which could contribute to my issues. upon calling the local mazda stealer they told me they'd update my ecu for $118. They can't tell me if I've got the newest update without me coming in.

My warranty expired in May, I thought MSP16 was supposed to be free - mentioning MSP16 on the phone didn't help - Mazda Canada has no idea what it is.

Should the update be free considering it's a TSB?
Old 07-20-2015 | 03:51 PM
  #32  
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There is no argument, the S2 fans are upgraded (bigger motors) from the S1 or you can go with a FAL dual fan setup in either 2500CFM or 3000CFM. You could also go with an S2 radiator while you are at it. Oil temps don't have a huge effect on coolant temps. with my larger secondary BEHr oil cooler I am having oil overcooling, My oil can be 20-30F lesser than my coolant when beating on it extreme temps. I am also turbocharged.


But straightening the fins would be a good thing.
Old 07-20-2015 | 04:01 PM
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You can see here where I fixed some pretty badly damaged fins. Just use a pair of flat tweezers, they sell a decent set at Harbor Freight.


Old 07-21-2015 | 03:16 PM
  #34  
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Is 185F too soon for the fans to turn on? I think they are turning on at 200 currently.

In a phone battle with Mazda Canada about getting MSP16 done for free as my car has been out of warranty since may 2015 - I had never been offered MSP16 even though the car has been in Mazda's garage multiple times 2008-2015.

They're saying the Canadian TSB is 1.7h rather than the .3 in the USA TSB, corporate relations advisor told me he couldn't find a Canadian MSP16 TSB. I feel like I'm just getting thrown around from dealership to corporate over and over; with the dealership refusing to do the update for free...

Last edited by Kim Jong Illest; 07-21-2015 at 03:53 PM.
Old 07-23-2015 | 09:41 AM
  #35  
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update: ended up paying for the PCM update - car definitely feels more streetable but I seem to have lost some low end power (<5k rpm).

coolant temps have gone down by 10 degrees on average but I'm still feeling a lag in the throttle response when ambient temps are hot. it's better than before but still not feeling the same pull as I do at night with the same coolant temps.

if I'm in 3rd gear @ 3.5k RPM it takes a whole 1.5 secs to reach 6k rpm with heavy throttle.

is there any other component that ***** itself at high ambient temps? I'm leaning towards fuel pump but not sure how to diagnose it.
Old 07-23-2015 | 12:07 PM
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It is normal for power to drop off a little bit when it is hotter. There are 2 reasons I know of for this:

1. Warmer air is less dense, so less power
2. I strongly suspect (but have not confirmed) that the ECU pulls timing at hotter temps (presumably to avoid knock and/or lower EGT).

I can see the effect in my data at the track. However, it is very small - not something easy to notice just driving the car. We are talking 1 or 2 mph out of 100 down a straight.

There is a psychological effect driving at night. Less visibility and a slower brain (tiredness) both make things feel faster.

If the speed difference is more than this, i.e. you can measure 0.5s or 5-10 mph, then that implies something is not working properly.

First 2 things I would check:
1. Is your intake drawing cold air, or air from inside the engine bay?
2. Is your ignition working well?

Unless your car is overheating (going over 230F coolant temps), I would not expect any significant gain by lowering coolant temps.
Old 07-23-2015 | 12:09 PM
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Originally Posted by Kim Jong Illest
Is 185F too soon for the fans to turn on? I think they are turning on at 200 currently.
IMO 200F is fine. 185 is too early since the thermostat is fully open at just about 185, which will result in you basically running the fans all the time. 185F to 200F coolant temp should not really make any difference to power (I think the engine starts to pull timing over 210F).
Old 07-23-2015 | 12:40 PM
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^^ re: "think it does"

so you don't really understand the software maps you're tinkering with?
Old 07-23-2015 | 12:42 PM
  #39  
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Originally Posted by blu3dragon
It is normal for power to drop off a little bit when it is hotter. There are 2 reasons I know of for this:

1. Warmer air is less dense, so less power
2. I strongly suspect (but have not confirmed) that the ECU pulls timing at hotter temps (presumably to avoid knock and/or lower EGT).

I can see the effect in my data at the track. However, it is very small - not something easy to notice just driving the car. We are talking 1 or 2 mph out of 100 down a straight.

There is a psychological effect driving at night. Less visibility and a slower brain (tiredness) both make things feel faster.

If the speed difference is more than this, i.e. you can measure 0.5s or 5-10 mph, then that implies something is not working properly.

First 2 things I would check:
1. Is your intake drawing cold air, or air from inside the engine bay?
2. Is your ignition working well?

Unless your car is overheating (going over 230F coolant temps), I would not expect any significant gain by lowering coolant temps.
I'm quite certain that the effect I'm feeling is not psychological.

There's a clear difference in how the car feels especially after sitting in the sun while I'm at work - my trip back home isn't the most comfortable. When I get home I park it in my underground garage and laze around for about 4 hours before going off to the gym. Upon taking it out of the garage and getting it to operating temp I can feel the difference in the pull; it feels as though the clutch grabs more evenly and feels faster and smoother.

I have a MS CAI, so intake draws from the front bumper; filter is clean; although as I mentioned earlier in the post my radiator/fans are not blocked off from the engine bay due to a missing air box tray.
D585 have less than 7k miles on them while the plugs have less than 15k miles, I've never seen a blinking CEL nor a stored misfire in torque.
Old 07-23-2015 | 12:46 PM
  #40  
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Originally Posted by TeamRX8
^^ re: "think it does"

so you don't really understand the software maps you're tinkering with?
are you talking to me? I don't have the software to even change the fuel maps.
Old 07-24-2015 | 10:22 AM
  #41  
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not quite sure what to look at next.

I've got 2 logs @ operating temp for 2 trips (1 during the day, 1 at night)

I can't seem to find any differences other than slight changes in the MAF flow rate at idle between the 2 temps.

maf flow rate is 4-4.8 at idle -> is this indicative of a vacuum leak?

https://dl.dropboxusercontent.com/u/...ataloghvc.xlsx
Old 07-24-2015 | 12:07 PM
  #42  
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Originally Posted by TeamRX8
^^ re: "think it does"

so you don't really understand the software maps you're tinkering with?
Perhaps I should have written something like "according to the tables in Mazdaedit".

I did not want to state it as fact as I have not verified this myself. I've also not come across anything online other than some vague posts about the ECU reducing power at high temps.

Old 07-24-2015 | 04:01 PM
  #43  
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MAF flow 3.9g/s indicative of vacuum leak? Bad MAF?

my idle feels good.
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