engine power increases in low gears vs det detection.. question for the mappers

[Mike B]

I'm no mapper and my knowledge on the subject is pretty limited right now, but i have a specific question that applies to my car;

 

I still use the VVTI FBW throttle intervention on a Vpro single setup, which will limit power when it sees det. It works perfectly and overall I'm very happy with it.

 

I have a singularly specific issue with it though; it never used to like 2nd gear. In the old days it would always sense a little det in 2nd and retard the throttle, now after lerning more about the car, fitting WI, setting the advance on a RR I get very little intervention in 2nd, but sometimes, if the car is not loostened up it will still refuse full throttle.

 

Every other gear; never ever an issue, but second... (ignoring first gear obviously) it will still have a grumble at for time to time; especially hot on a track day.

 

So what is it about the occasional 2nd gear pull that the det detectors are picking up on?

 

Could it be that the increase in power output from the engine is so violently explosive (unlike the steadier build of 3rd and above) that the engine can't fuel as precisely and it sees enough of a scrap of det to ring the alarm bells?

 

The engine is also lighter (eagle rods) and is much keener to rev than the stock engine which may compound the problem...

[JDModified]

Hi Mike you need to get this checked out.

 

This could simply be ghost knock from various places (clutch,gearbox) and not actual det itself in which case i "think" there is a way of making the ecu ignore it at that load/rev point.

 

Det usually occurs when the engine is under most (load) so 2nd gear det and no 3/4 gear det does seem odd.

 

Seek help from someone in your area with datalogging kit and det cans.

 

James

[tooquicktostop]

who mapped the car to its current map ?

[Tricky-Ricky]

Its just as likely to be mechanical noise that its responding to, as it is det, i quite often get a det reading from my monitor, on the first large throttle opening once warmed up, but never see it again, however its always good to double check it.

[Mike B]

Reg Reimer mapped; he has the Vpro map locked. He wants to come over to do updates, but she runs really well, and mapping cost plus flights, it would be an expensive service!

 

It could be noise, although gearbox on this car is the best I have ever had, having said that the noise it picked up at the pod had the det sensor twicthing in 3rd too, but on track/road she's fine; goes to show how bad the strip is for your car!

 

come to think of it, better also since the new suspension is on; the old JIC shocks I have just taken off were rose jointed and very noisey.

 

Reg's solution was to pull the ignition back a lot further, but Terry and I both agreed the current map is not struggling on road/track, it would be a shame to loose the crisp feel it has now just to fix a minor problem; that may not even be det...

 

I did think of renewing the stock det sensors... I have no idea where they are though!

 

do you think they may get oversensitive in time?

[Mike B]

You cant datalog the vpro without the softwear key, and even then I doubt if you could unless you had the key to the map. Big HKS brother for you

[Homer]

I had a slightly similar issue that would show up in first and second when the car was warming up, it was ghost det caused by the clutch/flywheel. However it didn't happen once it was warmed up. Have you logged the knock sensor signals while this is happening?

 

Edit - darn, too slow

[Mike B]

There is a det readout on the hks knock moniter in the glovebox, it's not loggable, but does have a knock level readout; it's tied into the stock knock sensor. I'll have to find someone with a strong stomach to stare at it for a while while I kangaroo though the first few gears.

 

these single strength clutches are not so smooth, but flywheel is stock.

 

It's not a big problem, just one of those little niggles... like the smaller squeak you hear once you've gotten rid of a bigger squeak..

 

and at the end of the day I like the protection being there, may save me a lot of money one day

[Homer]

Mine used the stock knock sensor but had the PFC to log the signal. The stock knock sensors should be more than adequate in terms of knock detection at less wildly tuned maps, just need something to log them...

[Mike B]

Det usually occurs when the engine is under most (load) so 2nd gear det and no 3/4 gear det does seem odd.

 

Seek help from someone in your area with datalogging kit and det cans.

 

good point about load, the engine really is not under anything like the load it would be on a 6th gear pull which it's totally fine with.

 

I get the feeling when it sees a det signal it does not relinquish throttle control for the remaninder of the gear, so even it if picks up a noise at the start of second it locks out full power until you come off throttle and re-apply again.

 

noisiest part (det style noise) of the engine is the clutch, no?

[Mike B]

just need something to log them...

 

it would be good, just so I could tell what kind of signal it was, a one off or series of signals.. I do wish HKS would give the owners logging ability, I mean, it's hardly a big deal, and very helpful.

[JDModified]

I think you missunderstood mate.

 

I keep this equipmentment at the workshop and det cans to help find nasty things like this.

 

 

 

 

You dont need a mapper to help as such to satisfy yourself that it is ghost knock.

 

 

James

[Mike B]

I think you missunderstood mate.

 

I keep this equipmentment at the workshop and det cans to help find nasty things like this.

 

 

http://i74.photobucket.com/albums/i268/team3s/LC1_Duo_500.jpg

 

 

You dont need a mapper to help as such to satisfy yourself that it is ghost knock.

 

 

James

 

 

Good stuff. Would be nice to know it was a ghost knock, which talking to you guys seems to tell me that this is logical.... but if it is then I won't be able to lock it out of the stock ecu (I can't imagine anyone could be able to re-program that) then the only other choice would be to dampen the said noisey component..

 

If the magic box said "it's your clutch" then I'd be really impressed!

 

still would be good to know.. do you know of anyone up north that has detlogging kit like that?

[JDModified]

Good stuff. Would be nice to know it was a ghost knock, which talking to you guys seems to tell me that this is logical.... but if it is then I won't be able to lock it out of the stock ecu (I can't imagine anyone could be able to re-program that) then the only other choice would be to dampen the said noisey component..

 

If the magic box said "it's your clutch" then I'd be really impressed!

 

still would be good to know.. do you know of anyone up north that has detlogging kit like that?

 

 

The magic box will log, afr/rpm/knock/signals/intake temps to give you a understand of whats happening through the gears and rev range, with det cans like (the knock box) that i use you can turn up the volume and adjust frequency to dial into the noise, det and ghost knock sound very different, so what im saying is a trained ear and some cool kit an sort this for you.

 

Unfortunatley i dont know anyone oooop north to suggest.

 

Im fairly certain the hks software can be told to ignore (varified blips) of ghost knock at (certain rev points) even with active knock control on.

 

Good luck with it though

James

[Mike B]

Im fairly certain the hks software can be told to ignore (varified blips) of ghost knock at (certain rev points) even with active knock control on.

 

Thanks james, thats good info and worth while knowing.

 

The system I use is a stock ecu/fcon hybrid; stock ecu controls the throttle and senses/administers knock control through the fbw, and the Vpro just fuels the engine.

The knock amp on the Vpro is a redundant function on this car, as the Knock amp and afr unit come as one; the afr unit is needed to fine tune the map on the fly, and the associated HKS knock function is not connected to any control mechanisms.

 

I'll keep my ear out for one of those diagnostic tools locally though, thanks again for the info.

[Tricky-Ricky]

I have a similar Innovate set up to the pic, and also the Phormula KS-4 (not in production yet) which has a dedicated data log output, which i can log along with other engine feedback, the Innovate software allows you to make a corresponding chart that you can configure to almost any ECU map, so you can see exactly where in the RPM and load range you are getting det, takes some of the guesswork out of it;)