Renault Clio Cup III x85 - Racing problem with losing power

[GMark]

Hello!

I am new on this forum and I will be very direct - I am looking for help.
I was a happy owner of a Renault Clio Cup III (original racing cup car) but unfortunately recently my car is struggling with power loss issue after just few minutes of racing/driving so I am desperate and seeking for a help before last event in this year.

First, lets share a few details about car - after all cup series finished car wasn’t used for few years and was storage in the garden (open field - I know that is not ideal). Before this season when we decide to rebuild a car and make Clio usable for this season of racing I remember we already had some problems with losing power - so we changed engine because also previous one had enough of racing.

So now we are in 2024 and I will describe a problem what is going on with the engine/car. I do endurance racing which is 2 Hours. On a cold engine car is working normal and you can feel that you have full power and also car can rpm to the limit. Then let say after few laps (around 20minutes of racing) first symptom that something is wrong is fact that car stops rev to the limit. At the beginning you are short just 300-500RPM and if you restart engine/computer car will be ok and again will rev to the limit with full power - but after restart usually that will last for a 1 or 2 laps (approx. 4-6 kilometres). Obviously problem is progressing and with more time on track and with each single restart it seems you topping up life to a engine less and less and car is getting weaker and weaker every 2 or 3 laps to the values that is undriveable. After around 1 hour of racing you will rev till 4500RPM and no chance to rev engine more it will just stop somewhere on low values on 4000-5000RPMs. Also, in last endurance I was driving for the last 5 minutes and I couldn't pass barrier of a 100kph of speed but somehow I crossed line.
Obviously if you will turn off car for 5-10 minutes after endurance some power will comeback but not to same values of a "cold" engine and will disappear very quickly.

Of course all indicators showing that everything and all temperatures are okay. No errors showed whatsoever. It is endurance race so in mid race we refuel car to full tank and the problem still existed. I thought that maybe is something wrong with fuelpump so I tried few tricks like driving with clutch on for a 10 sec to load pump but that didn’t change nothing.

What we changed so far:
Engine
Computer

What is old:
Wiring
Fuelpump

Any help greatly appreciated guys!
Thank you

 

[Brigsy]

At a guess maybe failing fuel pump. Can you hook up diagnostics to the ecu to determine all sensors are reading correctly.

 

[Filters]

What diagnostics have you carried out?
You've changed the engine - was it bare, or complete with ancillaries?

 

[davo172]

Hello!

I am new on this forum and I will be very direct - I am looking for help.
I was a happy owner of a Renault Clio Cup III (original racing cup car) but unfortunately recently my car is struggling with power loss issue after just few minutes of racing/driving so I am desperate and seeking for a help before last event in this year.

First, lets share a few details about car - after all cup series finished car wasn’t used for few years and was storage in the garden (open field - I know that is not ideal). Before this season when we decide to rebuild a car and make Clio usable for this season of racing I remember we already had some problems with losing power - so we changed engine because also previous one had enough of racing.

So now we are in 2024 and I will describe a problem what is going on with the engine/car. I do endurance racing which is 2 Hours. On a cold engine car is working normal and you can feel that you have full power and also car can rpm to the limit. Then let say after few laps (around 20minutes of racing) first symptom that something is wrong is fact that car stops rev to the limit. At the beginning you are short just 300-500RPM and if you restart engine/computer car will be ok and again will rev to the limit with full power - but after restart usually that will last for a 1 or 2 laps (approx. 4-6 kilometres). Obviously problem is progressing and with more time on track and with each single restart it seems you topping up life to a engine less and less and car is getting weaker and weaker every 2 or 3 laps to the values that is undriveable. After around 1 hour of racing you will rev till 4500RPM and no chance to rev engine more it will just stop somewhere on low values on 4000-5000RPMs. Also, in last endurance I was driving for the last 5 minutes and I couldn't pass barrier of a 100kph of speed but somehow I crossed line.
Obviously if you will turn off car for 5-10 minutes after endurance some power will comeback but not to same values of a "cold" engine and will disappear very quickly.

Of course all indicators showing that everything and all temperatures are okay. No errors showed whatsoever. It is endurance race so in mid race we refuel car to full tank and the problem still existed. I thought that maybe is something wrong with fuelpump so I tried few tricks like driving with clutch on for a 10 sec to load pump but that didn’t change nothing.

What we changed so far:
Engine
Computer

What is old:
Wiring
Fuelpump

Any help greatly appreciated guys!
Thank you

Where are you located?

 

[GMark]

Thank you for all answers!


I don't know yet how to answer with multiple quotes in one post in this forum (every time I get one quote and I don't want to post multiple posts) so I will reply with points:

1. We bought a new fuel pump and we gonna replace pump just before new event. We couldn’t carry that before previous event because we got that part last minute and process of changing that is more complex with losing all geometry and we were already in Estonia on away event. Also that was just after we got car with new Link computer so we thought that everything is sorted.

All sensors should work okay - I guess. Car just came back from Czech company where the computer was changed and installed - apparently everything else there was checked and in their belief car was good to go. They questioned a little bit a fuel pump so we bought this part just after we received back car. But in general they said car is fixed and checked (probably on dyno short runs or on car parking the above mentioned done all the checks because the final result after running on track is different 😭). Money were paid.

2. We hook up diagnostics on old engine and then old computer - the errors we were getting on both engines were:
- low oil pressure
- VVT

I need to contact my mechanic who has done all the checks but if I remember correctly that was just those two.

So after new bare engine we decide something must be wrong with computer and then we sent car and now we got a new computer LINK.
My mechanic is learning how to diagnose this one and with his "bad english" that is not easy task - and I am not around during this time.
But while race nothing pop up on the screen.
I will call him during weekend because last time he called me I got informed that he found some errors but he couldn't explain what was exactly that - he mentioned two English words - "injectors and 6v"

3. I am located in UK but car is racing in Poland.


Thank you for all help🙏