15 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHcorrect rev range to change gear
Reported or suspected cause
novice question and really embarrasing myself
Suggestion or failed attempt
No successful repair reported for this finding.
0
Identified cause
1
Suspected cause
0
Reported fixes
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that suspect a cause
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suspected cause · Original poster
Probably a novice question and really embarrasing myself but got to learn!
Leading evidence: 'novice question and really embarrasing myself' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'novice question and really embarrasing myself' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Replace around the 5,000 rpm at road' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
so basically in the 4s to keep a nice speed/torque best to change around the 5,000 RPM at road use for track sub red line then.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
I am going to show my ignorance now but with respect to my 2003 C4S can anyone give me the precise rev point to change gear?
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
The point at which the engine is giving the greatest torque is the point at which the engine is increasing it's rate of work at the greatest rate, so if you change gear at a rev range, such that the engine maintains its work rate at or near this level, in theory it will accellerate at the greatest rate.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Changing gear at peak torque will mean you are then in the next gear below the optimal torque.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
The point at which the engine is giving the greatest torque is the point at which the engine is increasing it's rate of work at the greatest rate, so if you change gear at a rev range, such that the engine maintains its work rate at or near this level, in theory it will accellerate at the greatest rate.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
Take the car to the redline for maximum BHP, changing gear will drop the revs to the point at which peak torque will be present allowing you to accelerate faster making full use of the both the BHP and torque present.
Replace too early and you loose the optimal acceleration point
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
although to get max acceleration you would have to take it to the max bhp rpm point every time, but that ain't too good for an engine, so the limiter is there to protect the engine, change too early and you loose the optimal acceleration point...
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
15 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T044418Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Hi,
I am going to show my ignorance now but with respect to my 2003 C4S can anyone give me the precise rev point to change gear?
Probably a novice question and really embarrasing myself but got to learn!
I am assuming all cars have a power band and if you change to early you will lose the speed,....... to late and depending on the car the limiter kicks in and you are out of the band.
Does the C4S have a limiter to prevent red lining?? As I have not tracked it yet and drive like a hair dresser
not taken her to the limits so don't know.
Appreciate some advice.
Regards Alan.
Migration info. Legacy thread was 138810
Yes, the C4S has a rev limiter to stop accelerating past the redline, it doesn't stop from exceeding this if you miss a downchange and buzz the engine.
I always will rev a car to the redline when driving in a spirited manner, box-shifting whenever appropriate.
There's more BHP the higher you rev, the torque peak is lower but there's plenty of it right to the redline.
Migration info. Legacy thread was 138816
although to get max acceleration you would have to take it to the max bhp rpm point every time, but that ain't too good for an engine, so the limiter is there to protect the engine, change too early and you loose the optimal acceleration point...
the torque band is important, too low and or too high and the rate of accerelation isnt enough
but having just re-read the above, no idea what I'm taking about ! Ade !!!
a question for a C4S owner..... Damian do you know of any ???
Migration info. Legacy thread was 138818
When track driving (being the only place you can consistantly push a car), it just becomes obvious when you shift to early as the power just isn't there. As Damain says, to get maximum acceleration, you will want to push it to redline every time.
Personally if mine drops below 3500 rpm, I find it a bit sluggish when first accelerating.
Migration info. Legacy thread was 138852
But this doesn't mean you should always use the revs on track, it is sometimes better & quicker to use a higher gear, through certain corners or combinations, in which case you use torque rather than power.
Migration info. Legacy thread was 138895
Precisely, it's about balance, changing gear can upset the car when you don't need it.
One of the many good things about the GT3 is the extended rev range and the amount of torque it has from 4k through to the limit.
Migration info. Legacy thread was 138898
The rev limiter stops you over reving the engine. If you want maximum accelleration, then you should change gear at whatever point changing produces the least drop in revs. That will vary between engines.. The point at which the engine is giving the greatest torque is the point at which the engine is increasing it's rate of work at the greatest rate, so if you change gear at a rev range, such that the engine maintains its work rate at or near this level, in theory it will accellerate at the greatest rate.
However, if you just love the induction sound then change gear just before it hits the rev limiter.
Migration info. Legacy thread was 138911
so basically in the 4s to keep a nice speed/torque best to change around the 5,000 RPM at road use for track sub red line then.
I know it is not really a simple as that with cornering etc but just the basics to get my drving in some form of improved state!!
Regards Alan
Migration info. Legacy thread was 138935
Alan, sorry to barge when you thought it has been sorted.
I drive C4s auto and beginning to use tiptronic occasionally. I am a daily driver. In auto mode upshift occurs at around 2300 rpm and from stop to start from 2nd gear. When you put the foot down, it takes senses it and then downshifts a second and half later(hence generally tips are not liked).Now this is for sensible driving to work. In spirited moments, using tips and upshifting at higher revs, goes like a Porsche should do. Also, 1st gear is almost reserved for quick getaways, which I use it when I am on my own in a road, rather than in a drag race at traffic lights. I have lost the willingness to prove anything to anybody!
So, Porsche have programmed it for early upshift to be gentle to engine, I would guess.
It depends how you want to drive it.
Migration info. Legacy thread was 139111
In the 993 manual there is a bhp and torque graph - its pretty clear from it that for maximum acceleration to change up a gear at the torque peak (5250 rpm), thus will automatically put you in the correct rev range for maximum acceleration in the next higher gear because that's how Porsche designed the gear ratios.
Since the torque curve is relatively flat from 4000 rpm, strongest acceleration will be had from 4000rpm to 5250.
To be kind to the engine and avoid the possibility of over revving (over reving is logged in the ecu and can be read by the dealer) it is sensible to change at the peak torque point and not to hit the rev limiter.
Migration info. Legacy thread was 139134
Changing gear at peak torque will mean you are then in the next gear below the optimal torque. Take the car to the redline for maximum BHP, changing gear will drop the revs to the point at which peak torque will be present allowing you to accelerate faster making full use of the both the BHP and torque present.
Migration info. Legacy thread was 139148
Sorry to disagree - the point of maximum power and maximum torque is well below the redline - its therefore pointless going to the redline.
The gear ratios are arranged so that shifts below the redline produce the optimum acceleration.
Migration info. Legacy thread was 139149
Alan, you want be changing gear at a point where the next gear will be in the peak torque band. A gear change at 6.8-7k on a C4S (start of the redline) will put you in the torque power band at around 4k.
Migration info. Legacy thread was 139248
This is a source reference. Confirm exact model applicability in the original material.
