Be really careful running ethanol (E30, E40, etc.)

[RAAMaudio]

Might want to consider being at peak torque means more load on the rods, etc....could be the opposite of what you want in a tall gear.
With fuel, tunes, hybrid turbos, etc adding far more torque than the original engine was designed to handle it seems it would acerbate the issue, not improve it. I have never looked into the actual engineering specifically because I have a big turbo and never lug my vehicles down, I just look at it from a simple logical perspective, makes sense, easy to just downshift and not take the chance.

Until somebody with the actual engineering knowledge or takes the time to fully research this it would seem to be best to downshift.

 

[danbfree]

Might want to consider being at peak torque means more load on the rods, etc....could be the opposite of what you want in a tall gear.
With the stock and some hybrid turbos adding far more torque than the original engine was designed to handle it seems it would acerbate the issue, not improve it. I have never looked into the actual engineering specifically because I have a big turbo and never lug my vehicles down, I just look at it from a simple logical perspective, makes sense, easy to just downshift and not take the chance.

Until somebody with the actual engineering knowledge or takes the time to fully research this it would seem to be best to downshift.

Good info and healthy discussion, thanks... What you say is definitely something to consider if running an upgraded turbo to where you know you are pushing the limits of the stock block for sure, my comment applied more to LSPI but the more information the better... and hopefully someone with more knowledge can chime in... I just can't see the point of downshifting if you don't have to when the power is already on tap, just makes no sense to me to build and tune for all that just to have to keep downshifting like a 1.6 NA Honda.. LOL

 

[RAAMaudio]

I am also referring to LSPI, just forgot to mention it.

I have never researched it which surprises me because I research things to an anal level most of the time

That said, until proven safe I would use caution or just accept the fact one might break something and just live with it as I do with boosting stock engines to high levels. Used low mileage engines are cheap and easy enough to swap out so I do not bother with built engines when I can make more than enough power on stock ones. I have had highly built engines when what I was doing required it.

 

[alexrex20]

I would not be hammering down in 6th gear like that yes it has the torque to pull but it's really not healthy for the engine and can lead to LSPI (low speed pre ignition). I always try to keep revs at or above 2500 anytime I throttle it. Best to downshift for passing or driving spritedly even at 80 in 6th gear since it's overdrive (I know rpm are above 2500 but there's a much higher load in overdrive...higher the gear higher the load). That's just my .02

80mph in 6th gear is like 3600rpm. It'll be fine. Thanks.

Sent from my SM-G950U using Tapatalk

 

[alexrex20]

Until somebody with the actual engineering knowledge or takes the time to fully research this it would seem to be best to downshift.

Until somebody with the actual engineering knowledge or takes the time to fully research this and prove it's unsafe I will continue to drive in 6th gear at 80+ mph.

Sent from my SM-G950U using Tapatalk

 

[RAAMaudio]

There is a good chance it is completely safe against LSPI but is still puts more strain on the rods which is just simple physics but also it is true that the majority of the power is made in the strongest area of the rod angle so it might not matter.

There is a big difference between believing something based on blind faith and really understanding exactly what is going on but only time will tell if running on that basis and not doing the actual research.

Do as you will of course

I do knowing big turbos on stock engines can lead to failure and I can live with that so my posts are not directed at you directly, they are to help others think a bit more about such things, those that cannot afford to live with the consequences if something breaks for whatever reason when it is so simple to just downshift.

 

[LILIKE16ST]

Nobody said not to drive at 80 in 6th...just not floor it trying to pass someone...my car is barely above 3k at 80 mph not sure if you're running some kind of shorter tires or gearing or something. If you're at 3k it's fine to floor it in lower gears I just personally don't like making a habit of doing that in 6th gear...that gear is for cruising and mpg if u want power it's a flick of the wrist into 5th gear away from pulling with no worries. I am not an engineer and I don't know for a fact it will harm things...but the half second it takes to flick her up in 5th to pass on the highway is nothing just for some small piece of mind. 5th gear would probably put you at 3500 or so rpm on 5th gear going 80...just guessing btw...if it were an na Honda you'd need to downshift to 3rd and get her up to 5k to get that type of pull so I would not say it's like an na Honda lol. The higher the gear the higher the load at the same rpm. I'd say 2500-3k and above would be OK in all but 6th gear...I just wouldn't do it in 6th myself...

*edit*
I've seen issues online from FoST owners regarding LSPI haven't seen it a lot from FiST owners. It's pretty common knowledge based on what I've read stratified and other tuners warn against it. I like rev matching downshifts and taking off so to me it's fun anyways...not an issue.

 

[danbfree]

Nobody said not to drive at 80 in 6th...just not floor it trying to pass someone...my car is barely above 3k at 80 mph not sure if you're running some kind of shorter tires or gearing or something. If you're at 3k it's fine to floor it in lower gears I just personally don't like making a habit of doing that in 6th gear...that gear is for cruising and mpg if u want power it's a flick of the wrist into 5th gear away from pulling with no worries. I am not an engineer and I don't know for a fact it will harm things...but the half second it takes to flick her up in 5th to pass on the highway is nothing just for some small piece of mind. 5th gear would probably put you at 3500 or so rpm on 5th gear going 80...just guessing btw...if it were an na Honda you'd need to downshift to 3rd and get her up to 5k to get that type of pull so I would not say it's like an na Honda lol. The higher the gear the higher the load at the same rpm. I'd say 2500-3k and above would be OK in all but 6th gear...I just wouldn't do it in 6th myself...

*edit*
I've seen issues online from FoST owners regarding LSPI haven't seen it a lot from FiST owners. It's pretty common knowledge based on what I've read stratified and other tuners warn against it. I like rev matching downshifts and taking off so to me it's fun anyways...not an issue.

Well, with a 6 speed it's even easier to drop 2 to 4th, really.... and I'm appreciating all the knowledge from everyone, I just don't get the difference between simply laying into the throttle a little gradually vs shifting down and bringing the RPM's up even higher when you have so much power on tap at 3k RPM's already, can anyone explain how that's safer?

 

[RAAMaudio]

Gradually using the throttle might be OK, not sure, probably better than really getting into it though it will only open so fast anyway, at least it should do so if programmed right.

I use a three way shift light, 200 RPM below redline, at redline, 200 above, if I do the "money shift", drop into the wrong gear as soon as I start to release the clutch I get a very bright rapid firing warning so just pop the clutch back in before even all the way out. I installed it so I could use the light instead of the tach on track but it works great everywhere else as well. Really helps on a short straight were I can float just below redline for a bit and skip and up and down shift, keeps the car more stable, focus more on braking and turn in, etc....

 

[alexrex20]

I don't need to floor it in 6th gear at 80+ to pass someone. Half throttle is plenty. If I need to floor it I will downshift to 5th.

Sent from my SM-G950U using Tapatalk

 

[Quisp]

Until somebody with the actual engineering knowledge or takes the time to fully research this and prove it's unsafe I will continue to drive in 6th gear at 80+ mph.

Sent from my SM-G950U using Tapatalk

Theve all been ran off. Lol

 

[FireRedFiesta]

Yeah, I never let it bog. I always downshift, so I've never had an issue with pre-ignition or anything. If you can remove the "ST" emblems, then you can make this car a little sleeper as people will think it's just a regular Fiesta.

 

[alexrex20]

Mine doesn't bog at 3200 rpm lol

Sent from my SM-G950U using Tapatalk

 

[FireRedFiesta]

Mine doesn't bog at 3200 rpm lol

There's a lot of nice torque at 3200. I'm sure it doesn't.

 

[RAAMaudio]

Theve all been ran off. Lol

How about frustrated by armchair qtr backs that think they know more than real engineers....

 

[alexrex20]

I'm an engineer. Are you?

Lmao

Sent from my SM-G950U using Tapatalk

 

[alexrex20]

Go post on an actual enthusiast group and see what they say when you tell them flooring it at 3200 rpm is bad for the engine. [emoji23][emoji23]

Sent from my SM-G950U using Tapatalk

 

[RAAMaudio]

I have out engineered quite a few engineers due to vastly more real world experience in many different fields. A degree does not trump a lifetime of actually designing and or redisigning things.

Reminds me of the head of QA at a very big rocket manf, hired 10 new graduates from MIT each year then assigned them make believe projects, end of the year one or two left got a job, the rest quite due to ego, could not make the cut, etc....everything the plant built had to be signed off by this guy, at the time 38 years experience, started out sweeping floors, never went to college. That is a real engineer.

I do not know your specific background but I do highly respect the engineering field and wish I had pursued it myself but I just have to rely on my 50 years of modding cars and listening to those that really know, no matter if they have a degree or not.

The keys to being able to do the many varied things I have done is having an open mind, knowing there are those that know more than I do, research, ask questions, never believe I know it all as that is impossible for anybody, willing to learn, willing to actually listen...ego in check....

Show us actually scientifically proven (within the limits of real science as it can always change the more that is learned) explanation of why it is safe to "floor it at 3200 RPM" under various real world load conditions if you want us without a degree to believe you, until that happens it is just posing

Have a great evening
Rick

 

[alexrex20]

Tl;dr blah blah blah

You've done one track day in your Fiesta. You are the Fiesta equivalent of the mall crawler.

Sent from my SM-G950U using Tapatalk

 

[RAAMaudio]

Two actually and the car was very fast and reliable and easy to drive but that has nothing to do with the current discussion, where are your proofs?