RX8 Faster at night? Cooling?
 

Hi all, I bought my 07 Manual MazdaSpeed 8 in November, it had 50,000kms - it's at 64,500 now.

I've done a bit of work to it - replaced all fluids (Except coolant), D585 ignition, removed CAT, new coolant temp sensor, new brakes & rotors, lowered the car. I used to have poor MPG but am now stably getting 16 in the city. I only use 91 gas from PetroCanada or Shell.

My issue is that in hot temperatures the car does not feel as swift - I don't get the same feeling of being pushed back into my seat when I accelerate. It also hesitates/bucks/jerks when in low gear with with my foot off the throttle. These symptoms never happen late at night for me and the engine braking feels very smooth and runs down to 800rpm without any bucking/jerking/hesitation.

I have a weird starting issue it's hard to describe and it only happens when the engine is turned off hot & has had about 45 minutes to cool down. Normally my starts are like: tick, tick, boom - the car starts and the rpms shoot up immediately to 1300-1500 at this temp range. Sometimes however, I just get a tick, boom and the rpms gradually increase to 1300-1500 from 0. Very weird seeing this.

Not sure if it's related but I wanted to include it just so I don't miss anything.
I red-line the car every day, multiple times, 1st and second. Whenever I get a chance on the highway I red-line in 3rd.

My idle at night is spot on.... 800 rpm no deviation @ operating temp, no shaking, but during a hot day I see it dip and bounce around with a variance of +-50; if the AC is on I see it dip down to 750 sometimes.

I used to use Royal Purple but GTX feels smoother (10W40) and is half the price so I'd rather just change it more often.

Is it cooling? My ignition has less than 10,000KM on it. I really don't think it's compression the car is pretty well-maintained. Not sure where to start troubleshooting.

I have a OBDII unit, I could take logs of when it's sluggish and compare it to night values but I'm unsure of which values to log.

Any help would be appreciated.

right,
first there is no "mazdaspeed" rx8
second all cars run better in cooler temps
third hot start issues are usually related to bad compression (get a comp test to be sure)

It came with MAZDASPEED CAI from the dealer. I believe that only '07 RX8s had this option.

and I've read posts by users on this forum in Memphis, TN that have no performance loss in the summers and the heat there reaches 40C, I live in Toronto and the hottest it's gotten here is 30C.

if you read my post - my hot start issue is that the car starts FASTER than when cold. My car never takes extra time to crank.

The Mazdaspeed intake and all Mazdaspeed parts were available long before 07' and unless the dealer installed it, it was an option. I do know in Canada ya'll had some lame "Mazdaspeed" dealer package that came with 18 x 7" wheels with a mazdaspeed decal on them. But by no means was this a "Mazdaspeed" RX-8. We did have a local guy who has almost every Mazdaspeed part, right down to the rare Magnesium Mazdaspeed wheels and his car is the only 8 I have ever seen that I would consider a Mazdaspeed RX-8.

All engines run more efficiently in cooler weather.

Starting faster when the engine is cold is also normal for a rotary due to the affects of heat expansion on the seals. Starting faster when hot may indicate a fuel system issue, but it depends what you consider faster.

I believe that the CAI was installed in the factory in Japan as the YUL# which is on my windshields, headlights, tailights, ecu box is burned in on the intake.

I've seen them called mazdaspeed editions on autotrader, my mistake.

Fuel system issue now we're talking - I always had a feeling that the car was a bit more responsive right after I filled up, but I had thwird from RX7club.com drive mine to the gas station & back he said that the car felt fine on both trips - of course he's used to driving turbo'd 8's/7's with lightweight flywheels and his 20B so he may not have caught the minute difference.

As for what I consider faster - let's say a normal hot & cold start take .5 seconds (the duration of which the key is turned to crank the engine) - normally I hear 2 clicks, then ignition.

In my case hotstarts @ operating temp always start the same, and consistently - it's only when the car has been given time to cool down to the 3rd notch on the temp meter, and then started up it will fire up quicker, we'll say .4 secs. 1 click, then ignition

.5 vs .4 sec? sounds like you are more paranoid then anything, how about posting a video of starting up

I'm just trying to troubleshoot my hot weather sluggishness - I'm not sure if it's related I just figure I'd mention it.

When you crank your car every day for .5s you'll notice when you get a .4s crank - it's obviously different. and sure I can post a video I'll try to record it after I come back from lunch.

I think it's all in your head. And no Mazdaspeed intakes were installed at the factory, Mazdaspeed parts are a dealer option or are sold thru the Mazda Motorsports Program.

the gas station thing? Maybe....

the hot weather sluggishness is definitely not in my head though, I can see and feel a clear difference going up hills.

Would love for it to run consistently well, even if it involves spending some money on cooling mods.

Well without seeing a data logs from a run up the hill we can't really tell you much. you don't need cooling mods, the rotary just naturally runs hot and thermodynamics dictates that an a cooler engine runs better, for many reasons.

When is the last time the car had a tune up? Coils, plugs, wires, is the cat original? Do you use 93 octane fuel? Is your air filter clean? Is your ESS clean? MAF clean?

I got the car with bad coils as it was at 50,000 km so I bought some from ebay, they ended up being fake - so I bought d585's from Justin Hesselrode, coils, wires have less than 5k. plugs have less than 10k.

I don't run 93 - it seems a bit overkill without a turbo as per thwird but I do run 91 all the time - sometimes with ethanol sometimes without.

cleaned MAF and ESS back in Jan (winter); it was running fine then.

I cleaned the air filter with a vaccum but it could use a change, it's not too bad.

Tell me which PIDs to monitor and i will do some uphill pulls at different times of the day. I'm an analyst by trade so I can provide graphs and averages without problem & I have a high frequency OBDII dongle.

edit: car is running a straight pipe now with a stock muffler. kikkoman edition rx8

He's a nice guy but I would not follow his advice on this issue. I'd also be pickier on where you fill up.

93 is Overkill? Octane isn't magic. Although I am not surprised that advice came from thewird. And if hesselrode can't even put together a decent looking RX-8 (see picbelow), I sure as hell wouldn't trust an ignition "kit" put together by him. Might want to give that "kit" a good once over, make sure it is grounded correctly, etc. Who knows what Ebay coils and Ebay harnesses were used in putting together that thing.


https://cimg6.ibsrv.net/gimg/www.rx8...754eea8d38.jpg

That's your anti-theft embossing, like Sherlock. It was applied when the car was purchased, so the PO must have bought it at the dealer with the intake. Perhaps the dealer threw it in the sweeten the deal?

You could get a discount on insurance if you mention that the car has this.

Also YUL would mean it was originally sold in Montreal.

LOL! I'm not too worried about the kit; I'm sure the coils he gave me are Herkos but they're much better than oem and much better than the fake ones I got on eBay as well. I inspected the kit - it looked fine and performs great, in comparison - considering how I paid just a bit over what OEM coils cost I'm pretty happy with what I received. It's grounded to a clean point on my chassis.

The only problem I had with his kit was that he forgot to drill some holes in the metal bracket I ended up having to hack it in there, and the plug wires don't cover the plugs fully!

Yes the car is from Montreal, I had made the trip in November to buy it price was very good. Insurance on the 8 is lower than my corolla. 230$ a month full coverage 500$ deduct

:crazy::scared::yelrotflm:yelrotflm

really though it aint a biggie, just a bit of ceramic exposed

as I mentioned in the first post I only fill up at petro and shell, I should be pickier I thought those 2 were the best?

:lol: No biggie, it works fine but yet you are having problems with the way your car runs?

Are you reading what you type? On second thought, you sound just like Hesselrode so you deserve anything he is selling.

Maybe you should go comment on his "body roll and tire spin" thread, he can tell you all about his theory on how the roads in Louisiana are more slippery than other roads across the country, :lol:

the car runs real nice at night so unless Hesselrode bought his wires off batman I don't see how that can be a problem considering I don't get misfires. I'm just trying to be logical here. You want me to put some high temp rubber on the plug ends just to show you nothing changes? I'll do it...:anger:

edit: before installing the kit hesselrode sold me I did a continuity test on all the wires and they were greeeeeeeeeeeat

Have you done a deepscan? I highly doubt it. When you say no misifires you mean no check engine light which doesn't mean you don't have misfires or other issues. I am not saying it is the ignition solution but judging by your description of it and who put it together it surely could be an issue.

That is if you even have an issue since generally yes the RX-8 runs better in cool weather.

No idea what a deepscan is even; I tried googling to no avail.

but from taking in what you said: I'm pretty much understanding that RX8 runs like shit in hot temps; that's normal. Ok, I get that...

Best bang for the buck cooling mods? Oil coolers, oil cooler hoses, radiator? Any particular brand?

I also don't have this part in my engine bay, I believe it could have something to do with my issues. https://cimg9.ibsrv.net/gimg/www.rx8...9678596050.jpg

You ECU can have stored codes showing just how many misfires and other events that happened. The normal store bought OBD scanner will not have this ability.

I didn't say the RX-8 ran like shit in hot temps, just better in cooler weather.

And that piece you identified is the scumbagmazsport intake system for the Greddy turbo kit so I have no clue what you are talking about. Or are you meaning the plastic tray below the intake? If so then that will definitely cause excessive intake temps at low speed/idle. But that won't be an issue at speed. Excessive intake temps on a MAF based car can cause some weird issues.

the OBD tool I have is this 1:

https://www.scantool.net/scan-tools/obdlink-lx.html

what do I need to see the ECU event log? mazda edit?

yeah I meant the plastic tray below the intake, I don't have 1 so I'm not sure what it looks like & I'm not sure if it will fit with the MS CAI (maybe that's why it's not there in the first place).

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?

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.

you forgot the all important reason to change it though

https://www.rx8club.com/series-i-aft...2/#post4703281

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.

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?

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.

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.


https://cimg7.ibsrv.net/gimg/www.rx8...5f23498b8c.jpg

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...

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 shits itself at high ambient temps? I'm leaning towards fuel pump but not sure how to diagnose it.

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.

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).

^^ re: "think it does"

so you don't really understand the software maps you're tinkering with?

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.

are you talking to me? I don't have the software to even change the fuel maps.

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

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.

:beer:

MAF flow 3.9g/s indicative of vacuum leak? Bad MAF?

my idle feels good.