After the comments Gav made on the other thread I had a word with lotus about the possibility of up rated engine mounts causing the engine to loose power.
In short yes they can, uprated mounts can cause the knock sensor to be fooled into believing there is knock present in the engine and back off the fuelling.
When lotus are racing and using the mounts they usually remove the sensor and wrap it in bubble wrap but this is not recommended as you could (in their words) burn a hole in your cylinder should the worst happen.
Once this has happened the only way to get the car back up to power is to have a fuel re set done on the ecu.
As my car has uprated mounts and came in short on the dyno whilst showing it was running slightly lean I am guessing this could be the case so I’m removing the mounts and having a re set done before heading back to the dyno.
Thought it was worth posting up for info.
It won’t happen on every car, but how would you know? My car feels fine to drive and it will only happen over a period of time and I would guess to any car running a lotus ecu with the knock sensor enabled.
My car only has the elise shop inserts to answer that question. I have no proof either that this has happened to my car, only the knowledge that I have uprated mounts and a dyno showing 250bhp when two identical cars made much more on the same dyno on the same day coupled along with a slightly lean AFR while the other two cars ran much richer.
So all I can try is removing the mount inserts and having a fuel re set done then taking it back to the dyno to see what happenes.
The knock retard will not stay set in the ecu unless you have constant knock…
I’ve run hard mounts and never had knock sensor issues in 6 yrs…I run solid mounts and have no knock issues now…Seriously where does this mumbo jumbo come from ?
Never had a problem.Car was on a R/road just after it was supercharged[standard mounts]and again about three years ago[home made uprated mounts]240 @rear wheels first time.243 second time at hubs.
I got a U2U on seloc from Mike who is unable to post on here as he can’t get approved he says…
I have the CN260 on mine along with the engine mount Inserts, my cars running 272 HP at the engine after 11 mths of running. I know the engine transmits more vibration while at idle as everything is “tighter” bu surely when you think about it on WOT a car with standard engine mounts will have its engine held just as firmly in The forward position ? All the mounts do is prevent the rocking.
Knock detection is also constantly adjusting. Ie the car will advance timing to its preset map position on only retard it once knock occurs, it’s not like the fuel trims where the long term trims are stored and used for WOT fuel levels.<<
Now obviously I can only go off what Gav has said and the Lotus field engineer told me which seems to suggest that if knock is
detected long term if changes the fuel trim.
Due to my car seeming to run leaner than the others and being down on power I figure its worth a shot, I might stick my 3.1" pulley on at the same time as the fuel re set and see how that changes things…
I only found out about this at the ET race at Donny last year.
It all seemed a bit strange on the TD the day before the race. Nothing wrong with the car as such but all of my competitors were coming past me and clearing off into the distance, not only that but they had a passenger sat in the seat beside them… Wtf’s going on here then?!?
Sure enough qually the next morning I’m a good 2 seconds off the pace and 4th from the back of a grid of 30+, I honestly thought they had printed the sheet up the wrong way or made a big mistake, I’ve never qualified that low and I was giving it my all. something very wrong with the car then!! (racing driver basics 1.01)
Theres me going through everything I could possibly change to sort it - airfilters, plugs, air fresher from pine to vanilla… Just so happens one of the teams along the way comes along and mentions about the exact same problem they had the year before with the ECU and knock sensor. Their solution was to get the ecu reflashed and reposition the knock sensor onto the bulkhead. So a quick rustle around the paddock and a direct replacement ecu found. I went from something like 34th to 7th in the 20 minute race and 1.8 seconds per lap quicker…
We had a Lotus Motorsport technician in the paddock who couldn’t reset my ecu as he didn’t have his lap top with him, it had to go back to the factory to be reset/flashed and was then sent back to me. It was looked at by the techies back at lotus who found the O2 scalers to be all a drift or something like that… I lost interest at that point, I just wanted to know if it was fixed or not…
I can only go off what I was told, if they dont know what they are doing, looking at, how it works then I would imagine no one does!!
Someone does and really what kinda Motorsport techy doesn’t have his laptop with him at all times…
Seriously think about it the OEM ecu is designed to run on 91 octaine and car can retune its self to run on 87 octane when it detects knock… It is designed to return to it’s original tune once knock is gone… That’s the reason the knock sensor is there in the first place… retard spark and add fuel until all is well…
Maybe the tech didn’t bother to check the coolant temps because if they are over 200*f the ecu will pull timing and you will be down on power till things cool off…
