Dumb question from owner new to turbos. It usually happens in 6th gear around 2500rpm-2800rpm after releasing gas then going WOT . There is slight hesitation as if there is no power then after 3k rpm, it goes. If gradually stepping on gas then flooring it around that rpm then no issues. Is this turbo lag or something else?
Turbo lag in MS3?
- Thread starter hyperpm
- Start date
thats because your revs are too low to build boost.
As you know, turbo's spool with the exhaust gases. So if your only running 2,500-2,800 RPMs; then you are in the very beginning of the turbo's power. This is the point in the RPM band where the turbo is supposed to spool up. Hense your lag.
If I was you, i'd try to limit yourself from going WOT when your tach is below 3,500 RPM. Alot of guys have blown their mod'd motors over boosting in low RPMS like that.
You have 6 gears... use them.
6
60181
I agree....although I use 3k as the minimum limit for WOT. If I'm in need of quick strong burst of power, I downshift.
Your driving habits may vary, but when I'm about to pass, I tend to down shift when needed to hit the 3000-3500 rpm range, look to insure things are clear/safe, and then go. I tend to squeeze into the throttle too. Habit from my past V8 car but it applies well to the Speed too.
mazdaspeedster3
Member
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- Mazdaspeed3. 2008
You can wait a long time going WOT at 2500 RPM's in 6th gear. It is not an automatic, you need to kick it down yourself and put it in 4th.
TheRealDefman
Member
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- 2008 MS3
Just thought I'd add that I have nothing to add... all good advice.
john blutarski
Member
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- 2004 Subaru WRX STI
+1
The load you are putting on the engine by WOT'ing at this RPM in a gear that high is huge. You are begging for knock and your motor hates you.
I agree this is turbo lag, just look at dyno runs showing the boost hitting at about 3k and it's pretty obvious, but some of what you guys are saying doesn't make a lot of sense to me.
Engineers at Mazda have to know these cars will see any throttle position at any gear and program the ECU accordingly. It has to be idiot proof. If they can program it idiot proof for first and second gear by limiting throttle and therefore HP they can certainly handle a WOT at 2500rpm in sixth. What about KR and all the other sophisticated features in the ECU?
I can understand there being some risk if the car is modified and taking parameters beyond the factory ECU or fooling it, but otherwise I don't see how WOT at 2500rpm in Sixth is a problem, other than you won't accelerate as quickly as you would in 5th.
Engineers at Mazda have to know these cars will see any throttle position at any gear and program the ECU accordingly. It has to be idiot proof. If they can program it idiot proof for first and second gear by limiting throttle and therefore HP they can certainly handle a WOT at 2500rpm in sixth. What about KR and all the other sophisticated features in the ECU?
I can understand there being some risk if the car is modified and taking parameters beyond the factory ECU or fooling it, but otherwise I don't see how WOT at 2500rpm in Sixth is a problem, other than you won't accelerate as quickly as you would in 5th.
You can't just reprogram the ECU to spool the turbo, guy. Not quite how it works 
EDIT: The problem arose from him expecting the same turbo response in 6th at 2500rpm, as you get in 3rd at 4000rpm. My guess is that this car is his first turbo car and he really doesn't understand how a turbo works or even what "turbo lag" means. Just my 2c.
EDIT: The problem arose from him expecting the same turbo response in 6th at 2500rpm, as you get in 3rd at 4000rpm. My guess is that this car is his first turbo car and he really doesn't understand how a turbo works or even what "turbo lag" means. Just my 2c.
I tuned my ecu to shift gears for me too... :dodgy:
Hah!
Yeah well mine makes pizza for me and wipes my ass too.
I think you guys are confusing what I'm saying, but whatever. I'm not talking about the ECU increasing boost and eliminating turbo lag. I know how a turbo works. I think OP might be learning a bit.
I'm talking specifically about it being bad for the motor go WOT below the point the turbo starts to spool in 5th or 6th gear and make any boost.
All issues of the OP topic and turbo lag aside, mashing the throttle at 2500rpm in 6th should not hurt the motor. If somebody tells me it's bad for the motor, I would like them to show me some documentation or an email from some Mazda authority.
It doesn't make any sense, especially since throttle inputs are actually under control of the ECU. There's no throttle cable going into the engine bay, it's all drive by wire. If it were really bad to go WOT at those RPM the ECU should just not react to your throttle input and control the throttle plate accordingly just like it does in 1st and 2nd gear. It simply won't give you a kick in the pants until the engine speed is sufficient to spool up the turbo and start making boost. You're not going to get moving very quickly until that happens, but before then, what's the problem? Is this documented someplace, like the operator manual perhaps? I have not read mine as I've been busy looking at porn and watching paint dry, but perhaps it's worth a look.
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*clears throat*
A lot of people have experienced what happens when you mash the throttle at low RPMs. the effect is magnified when bolt-on's are added to the equation. The problem is the ECU can only do soo much when it comes to control the boost into your engine and the knock that said boost can cause. When you get too much boost and too much knock you get this:
Research is your friend man.
A lot of people have experienced what happens when you mash the throttle at low RPMs. the effect is magnified when bolt-on's are added to the equation. The problem is the ECU can only do soo much when it comes to control the boost into your engine and the knock that said boost can cause. When you get too much boost and too much knock you get this:
Research is your friend man.
karl hungus
Member
my first turbo rodeo (used to low end torque n/a v8s) so i was dropping the hammer w/o downshifting too. intake woosh helps remind you your spooling. shifting is fun too.
I think OP is correct in saying this shouldn't happen. However, if it does (and you don't have mods) it should then be covered by warranty.
On the other hand, there's no reason to place higher loads on the motor than is necessary. Like others said, shift! If an automatic tranny would do it, then so should you.
I believe that lower rpms plus lotsa gas equals higher loads than higher rpms but I could be wrong. Isn't it similar to lower gears creating larger loads on the drivetrain?
Someone pitch in here and help me or show my I'm wrong.
*clears throat*
A lot of people have experienced what happens when you mash the throttle at low RPMs. the effect is magnified when bolt-on's are added to the equation. The problem is the ECU can only do soo much when it comes to control the boost into your engine and the knock that said boost can cause. When you get too much boost and too much knock you get this:
Research is your friend man.
Research indeed.
I can see how this might be a problem with say a motor with a throttle cable and a distributor with mechanical advance. It simply doesn't make sense with the level of timing and engine control in the MS3. Hell even a 5.0 mustang ECU can pull timing if you go WOT at lower RPM.
What exactly is going on? Are we talking too much timing for the throttle position and the ECU just screws up? You're not making any boost at 2500 and it's just kicking in at 3K. The ECU can read that boost, so what's it doing? Does anybody have any DH data showing KR?
I would attribute that motor failure to the modifications taking the engine parameters outside the control of the ECU, not any fault of the ECU.
Otherwise you're telling me Mazda missed the boat, screwed up, and left something on the table when they designed this car. It's a great car, just don't press the gas to the floor below 3K rpm or you'll throw a rod. WTF? With mods I can believe it but STOCK..not buying it.
