Legot

iTrader: (1)

Fuel pump and VDI?

RIWWP

iTrader: (2)

There are ECU safeties built in to try to save the motor and the car when someone does something as ill advised as trying to redline it in neutral while stopped.

Legot

iTrader: (1)

Oh yeah! I read something about that when I first got started. Something about keeping the cat temp under a few thousand degrees via air cooling.

Aston177

Cat temp was around 1300F. Reading through Torque using an OBD2 adapter. What's wrong with revving it a few times in neutral? I'm not holding it at redline. Just a few pumps of the accelerator to hear the beep

Legot it really didn't sound like I wasn't getting fuel. It was as if the car's rev limiter was set to 6500rpm instead of 7800rpm. Like you said, it did sound like a cold rev limit. I would've understood if it wasn't warmed up, but it was. Coolant temp was reading 208F. And how it revved all the way to 7800rpm on the 3rd time I floored it kinda got me worried. Why didn't it rev all the way when I first revved it?

Thanks RIWWP. Didn't know it was a safety feature. But then why was I able to rev it all the way to 7800rpm on the 3rd try? ECU gave up? :D

ShellDude

iTrader: (12)

Yup

ShellDude

iTrader: (12)

Please stop redlining no load. I cringe with each of your posts.

bishop1950

Mazda Shop manuel shows torque Values for the fuel rails at 225 ft lbs ??? I think that is wrong and remember some where seeing that , What is the correct value ?

bishop1950

I found the correct value 18.9 ft lbs max

Aston177

I thought it goes "a redline a day keeps the carbon away". How can redlining with no load be more harmful than redlining under load?

ShellDude

iTrader: (12)

That claim is highly overrated.

RIWWP

iTrader: (2)

Redlining = lots of heat. Redlining with no load does nothing to clear carbon, because it is just heat without the airflow through the engine OR through the cooling system OR along the exhaust system. So you are just adding lots of heat to the whole for no reason, no benefit. And this heat can't be shed by ANYTHING on the car, because you aren't moving.


The redline references are all IN GEAR AT FULL THROTTLE. Full throttle from 4,000rpm to redline, then shift. Don't hang it in redline either. Shift when you get there.

This is covered in numerous places across the forum, including the new owner's thread.

Aston177

Right. So heat is bad for the engine. I knew that. I never hold it at redline, and I never let the temp go up. I just rev it for maybe 3 seconds and start moving again. You guys sounded like I was killing my engine. That's why I asked

RIWWP

iTrader: (2)

Nevermind.

Steve Dallas

You certainly are not helping anything by redlining the engine with no load and with a coolant temp that is already 208F with nowhere for the additional heat you are generating to go. RX-8s get hottest at idle, and the cooling system is barely equipped to handle it without redlining the engine on top of it.

Last weekend at the track during the hottest session of the day, my max coolant temp was 205F, and my average RPM was 7,100. So, for 20 minutes, I was running the **** out my car, and it stayed cooler than yours at idle. Did I then park it and heat it up more by gunning the engine? No! I drove straight off the track onto the highway so I could put 4 miles worth of 70MPH air through the radiator and oil coolers at 3,000 RPM to bring the coolant down to 180F before parking it.

If it is really important to you to do the redline thing, do it on an on-ramp to a highway with the engine under load and air flowing through the cooling systems. What you are doing is counterproductive and borderline insane.

Aston177

I know revving it does nothing good. I just do it for the thrill of it lol. I ALWAYS keep an eye on my coolant temp when redlining. And it’s not like I hold it there. It’s just 2-3 times to 7800rpm. I don't even do it often. My coolant temp was 208F because I was flooring it before I revved it in neutral. My car normally idles at around 200F, and that's in 85-90F ambient temp.

Btw, those are amazing temps. What was your ambient temp and how did you monitor your coolant temp?

Signal 2

OK, let me try...it's dumb. Doesn't do anything but add stress to your engine. More harm than good. You should not do that. Cease. Stop.


And I recommend you never post outside this thread.

Steve Dallas

Sigh. I'm going to just ignore hat 1st paragraph so as to stay within the rules.

The ambient temp was 82. I monitor my temps using either Torque or Harry's Lap Timer paired to a OBDLink MX.

About 180F (176.9) is normal cruising temp for an RX-8--at least it is for mine. Stop and go traffic will bring it up to about 205F with the AC on. If you are already sitting at 208F, you don't want to intentionally take it higher just so you can hear your exhaust or impress your friends or whatever. Heat is one of the things that kills rotaries.

The hottest I have ever seen my car get was a brief blip up to 215F in 90 degree weather on a much more demanding track. When I saw that, I took two cool-down laps to bring it back under control.

Aston177

The only confirmed "stress" is heat. If I'm keeping the temps under control, I don't see a problem with revving it in neutral. According to you, even blipping the throttle when downshifting is bad, because that's revving in neutral as well. What about checking for flames? Testing the sound of the exhaust? Every time you rev the engine in neutral, it's bad? Unless there's some decent evidence to prove that it's bad to rev rotaries in neutral...

I'm just a curious guy :D


Those are great temps. Do you have the rx8 performance fan mod? I took my car out tonight and was flooring it constantly from like 15 to 60mph and my temp stayed below 198F in 80F weather So I'm not too far off. However, when I'm idling in 95F weather with the AC, the temp slowly creeps up past 215F. If I turn the AC off it would drop down to say 206F. I'm gonna get the fans checked and go from there. Does your car idle at 206F in traffic with the AC on or off?

Thanks for keeping your word and posting up the summer track temps. Really appreciate that

RIWWP

iTrader: (2)

One more try... because I'm a glutton for punishment.


Aston... you consistently need to be told the very precise reasons for this thing or that thing. You seem to have a complete inability to apply general concepts correctly.

In this case:

You have a coolant temp sensor, fine...

Are you also monitoring the oil temperature? the temperature of the exhaust? The temperature of the radiant heat baking into your fuel lines and other flamable underbody bits? Do you have a transmission fluid temperature sensor?

Airflow is needed to cool these things.


Blipping is a fraction of a second throttle, AND it's when you have lots of airflow through the radiator, through the oil cooler, through the transmission cooler, around the transmission, along the exhaust. Thinking that this is the "same thing" as your "sitting still and revving it to redline in neutral" is just terribly flawed.

Add on top of that ... reving in neutral does NOTHING for any carbon buildup.

So yes, reving to redline in neutral while stopped is not smart. Period. Will you do instantaneous damage? Probably not. However you aren't doing any good to your car, and possibly some harm. There isn't a need to try to quibble about specifically how long, because that isn't the damn point. You are taking risks with your hardware that are completely unnecessary based on trying to achieve a goal that is impossible to achieve the way you are doing it.

Steve Dallas

[Ignoring first paragraph again--this time for my own sanity. ]

My cooling system is stock, but I have an S2 car, which has a larger radiator core, 3 speed fans, larger fan motors, etc. It reaches 110F+ here in the summer, and my car never goes above 210F while stuck in traffic with the AC on. Sitting right at 205F when the ambient temperature is in the 90s or higher is the norm. Admittedly, I pretty much just leave it in the garage in July and August.

Aston177

Punishment? Because I’m a guy asking dumb questions on the “dumb question” thread? Because I wanna know exactly WHY it’s bad to redline in neutral? So, my curiosity is what gets me punished? That’s not very fair...

Sorry if I’m being a pain RIWWP. I’m just trying to learn something here.

I know that It’s just 3 blips within 3 seconds. That’s not gonna overheat the engine or make the flammable underbody catch fire. Although I do not have an oil temp gauge, I’m always constantly checking my exhaust and transmission temps. Exhaust stays around 1100F and transmission stays around 197F, and that’s after my revving in idle (which is nothing, really. Just 3 blips). Well within the limits. I’m not an idiot to keep on revving it in neutral for minutes, or even 10-20 seconds. It’s just 2-3 blips. That’s it.

As long as I keep all my temps in check while revving in neutral for 2 seconds, I don’t see how this is a whole lot different from blipping when downshifting.


Yes, I stand corrected. I thought that just revving it helps clear carbon. I didn’t know it HAS to be in gear. Guess I missed that in the new owners thread. That’s for clearing that up

I agree, it’s not smart, and I’m not doing any good. I only did that because I THOUGHT it did good, and as I said above, I stand corrected. BUT, it appears that you, or anyone on this thread don’t really know what harm revving in neutral does to our engines, apart from overheating. I know that it’s bad to rev a piston engine. But it’s not like our pistons touch the valves, like in piston engines. I wanted to know exactly why it’s bad to rev a rotary in neutral. That’s why I kept asking.

That said, I’m not going to find out what harm it does lol. But I agree that it doesn’t do any good, and therefore I’m gonna stop doing that from now on

Sorry for being a royal pain. I’m just trying to lean something new here.
Thanks and sorry again

gwilliams6

It took several posts but at last you got it, whew!!!

Signal 2

If you regard the engine as something that has a finite life-span from new, and that life-span can be lengthened or shortened as a result of it's maintenance and use, then it does do "harm". Running an engine up to red-line with no load for 2 or 3 seconds makes a lot of things happen, but reducing carbon deposits probably isn't one of them. And 2 or 3 seconds is a LONG time. Just because you don't see your temperature gauge move doesn't mean unnecessary heat wasn't created and unnecessary wear on things like hard seals and bearings didn't take place. After-market temp gauges rarely have the resolution to see momentary spikes like that. Stock gauges never do.
Even though we won't be able to quantify it, rev'ing your engine to redline repeatedly as you have described has shortened the life-span of your engine. Doing it more will shorten it more. So stopping it is good.

RIWWP

iTrader: (2)

I was referring to my own punishment, not yours. You clearly aren't suffering any.

UHATEIT

I was referred to this thread for my DUMB question so I can see if anyone can help me out:

When I bought my car it did not come with a fob for the alarm, I bought one and during the programming process the alarm sounded and I did not kmnow how to turn it off (turns out all you need to do is put the key in the door hole and turn it and the alarm turns off). Instead I popped the hood and pulled the negative cable on the battery which shut everything off. But when i put the cable back on the alarm kept going off, so while trying to figure out how to turn it off, I decided just to yank the fuse to the horn so the horn would stop but the lights would keep going. I found a thread about using the key in the door and the alarm stopped and I put the horn fuse back in.

The issue I now have is that the horn does not work. It will now bip when I press the keyfob buttons and it will not go off when I push the steering wheel. I have tried swapping fuses with the fog light fuse and it is not the fuse as it works for the fog lights. So I guess I'm trying to figure out what the hell happened to the horn, did the horn itself die by me yanking the fuse on it or did the horn burn out? Im not sure where to go with this and also, my really stupid questionm is where the horn itself is. So that if it is bad and I need to swap it that I can find it and test it while I have the front bumper off at the time for painting anyways.

Any help on the horn issue would be appreciated! So I can test it or replace it while the bumper is off for painting.