Cars too fast?

Do Citroën understate the figures for this car?

My question comes about as I was thinking about getting a remap for my little 1.4 hdi 16v, but today I notice it's top speed is reportedly 110 mph.

"some say" my little french shoe could show 123mph on it's digital readout, not that I would know this of course, but if that was the case is this Citroën understating the figures, or, has this been remapped already and I would just be wasting my cash having it tuned again?

Wouldn't the gearbox be the limiting factor in top end in any case?

Just a bit confused by this, thanks if you can shed any light.

Hi Pill_lock

Pill_lock wrote:Do Citroën understate the figures for this car?

My question comes about as I was thinking about getting a remap for my little 1.4 hdi 16v, but today I notice it's top speed is reportedly 110 mph.

"some say" my little french shoe could show 123mph on it's digital readout, not that I would know this of course, but if that was the case is this Citroën understating the figures,

The speedo in the UK (and european union) will over read the speed on the display. They are designed to read over to comply with an EU regulation. 110/123 sounds about right.

Pill_lock wrote: or, has this been remapped already and I would just be wasting my cash having it tuned again?

Remap doesn't just give more top end speed, which wouldn't be much help for most people, but you do get a better acceleration rate and more torque, which are more useful for most. I doubt your has already been remapped.

Pill_lock wrote:Wouldn't the gearbox be the limiting factor in top end in any case?

No, its the rate at which the fuel can be injected is your limiting factor. The gearbox wheels will just turn faster and faster with more engine speed.

Pill_lock wrote:Just a bit confused by this, thanks if you can shed any light.

Remapping the 16v is a bit more difficult/expensive than the 8v because the delphi ECU checksum is not common knowledge, but I have seen the 16v diesel listed as a map candidate. Make sure your maintenance is up to date, cambelt, no faults showing with lexia and then have it remapped and enjoy

Thanks for the advice.

The only reason I was thinking the box would be limiting the top end is that at flat out it's sitting at quite high rpm (for a diesel!)

I may treat myself then as it would be nice to have a little more get up and go.

It had a cambelt service earlier this year, anything else worth doing before I take it in? I've heard vacuum hoses can often leak power as well as sticking actuators, is this worth checking out beforehand in your opinion?

Pill_lock wrote:The only reason I was thinking the box would be limiting the top end is that at flat out it's sitting at quite high rpm (for a diesel!)

I am sure the gearbox will go faster, its quite robust, but you won't be running around at more than the original top-speed for very long. You are bound to hit traffic or get caught going in excess of 110MPH.

Pill_lock wrote:I may treat myself then as it would be nice to have a little more get up and go.

If you are lacking get up and go in the 16v diesel, make sure there are no faults pending, use the lexia tool to do this.

Lexia topic https://citroenc3owners.com/citroen-c3-t ... -t655.html

Pill_lock wrote:It had a cambelt service earlier this year,

I am pleased to hear that. They are good for 150K, but its never too soon to change it.

Pill_lock wrote:anything else worth doing before I take it in?

Other than fixing any pending engine codes that have not brought up the 'fix engine light', maybe a brake service seeing as you will have all that extra power and torque it would be good to know your stopping potential is up to spec.

Pill_lock wrote:I've heard vacuum hoses can often leak power

There are not any of these in the Diesel.

Pill_lock wrote:as well as sticking actuators,

The 2 actuators are the EGR and the Variable Vane ones, they do go bad, but the lexia can show these as faults and even run them on a test mode for diagnosing them.

Pill_lock wrote: is this worth checking out beforehand in your opinion?

A complete systems check for pending faults using the lexia system is my suggestion
This should cover the unseen faults.

Pill_lock wrote:Do Citroën understate the figures for this car?

My question comes about as I was thinking about getting a remap for my little 1.4 hdi 16v, but today I notice it's top speed is reportedly 110 mph.

"some say" my little french shoe could show 123mph on it's digital readout, not that I would know this of course, but if that was the case is this Citroën understating the figures, or, has this been remapped already and I would just be wasting my cash having it tuned again?

Wouldn't the gearbox be the limiting factor in top end in any case?

Just a bit confused by this, thanks if you can shed any light.

I think citroen are eering on the side of caution with their figures, i have the same engine as you and the speedo is only about 0.9mph fast according to gps, and the car runs at about 56-57mph indicated at 2000 rpm in 5th gear, if the car can make it to 4000rpm in 5th (which it will) then it will hit 112-114mph i think its good for at least 4500rpm in 5th tbh, which would put it at about 126mph indicated. i have never hit these speeds but my dad has a 1.4 8v hdi which is supposed to do only 103mph i think, but i have seen it indicate over 115mph, (in all fairness the gps says his speedo reads 5mph fast) but even so it still acheived over 110 mph.
whilst i find my car is really quite quick anyway. i am also considering a remap as i think it would make the car a real sleeper if it had 120+bhp. here is a link to superchips who offer a remap service for the 16v hdi:https://www.superchips.co.uk/search?make ... riant=2364

a remap may increase the top end speed if the redline was changed tbf, but how fast do you want to go on these roads