Safe knock reading power fc??

[Munnsy]

All new to this so will probably over the next few months be hassled with many questions i need answers too lol

Anyway all mapped and loving it, car did spike tonight at around 1.27 bar and knock levels hit around 55/57.

What are you guys getting on full boost, and what would you class as safe reliably?

I have since knocked the boost down to a bar and get average readings of around 34/36 at peak boost??

Thanks i9n advance guys
dave

[JJ]

A a rule of thumb, the less the better... well, you'll know that... but occasionally, the intake temps rise.. and knock is on the increase.

In my eyes, a knock value of 60 is about your limit... mine spikes up there when I do a hard 4th on a warm day ... go drive it on an evening Dave and see if you get that spike.

Often enough, the knock sensor is a little over sensitive too, Ryan uses det cans so will be able to hear at first hand on that sort of load.. unless he was actually listening to his iPod at the time !!

The values you're getting are deemed as safe in my eyes !

[Munnsy]

i knew you would be on jj, man of all knowledge bud

I think it spiked as a vacuum pipe on the chargecooler was spat off under load, and i think this may be the reaon it spiked the way it did.
Air tempon the commander were showing around the 35 mark constantly and water temp no higher than 80

My biggest problem is solelylack of knowledge, i dont know what the limits are and what to look out for.

Can you give me jj justy a basic run on figures i should expect to see on the fc when underload for my setup??
I understnad if it will differ from car to car, but is there a rule of thumb for the baove figures?i can then work form these as my benchmark.

All i want is a safe reliable car, imnot hunting for all the horsepower available, just want to enjoy this as much as i can over the summer

cheers bud much appreciated
dave

[JJ]

Can you give me jj justy a basic run on figures i should expect to see on the fc when underload for my setup??

At 1.2 bar ???!! On a night - 320/330 bhp !! Day 310bhp !

Its the torque improvements that your car will have gained.

You'll get more with efficiency improvements .. cooler air, higher lift / longer duration cams ... Mine made 425bhp @ 1.3 bar .. couple of penquines were watching at the time though it was that cold ... turbo was a large scale one...laggy and all at the top !! Your would have annilated it around the tight twisty roads.. open road - boost for boost... I would have squeezed past.

i knew you would be on jj, man of all knowledge bud

Just a head full of crap Dave !!

Water temps thermostatically controlled, shouldn't really move much from 82 degrees circa.... only if you've stopped a hot engine, gone back to it a few mins later..... you'll find your air temps will be on the up as well....

I'm sick of my MAT sensor ( manifold air temp ) sat in traffic .. it just heat soaks and the way I've got th epower fc set up, when it see's high intake temps, it retards the ignition.... !!! Rubbish... !!! Looking to relocate it when i pull my finger out to the exit pipe of the intercooler !!

You'll notice the temps will fall when you start driving, especially when you part spool the turbo as its pushing cooler air in !!!

Whats this 1.2 bar lark ???!!

[Munnsy]

lol

Cheers jj, puts my mind at rest matey.
Will get the car done at surrey rolling road in the next few months, so should be able to tweak it a bit etc,
Thanks for the advice

What you mean as far as 1.2 bar lark??

speak soon mate
dave

[skipp123]

another thing to look out for on these is ghost knock, have a look and see if it shoots up when you change gear

[Munnsy]

i presume ghost knock is when it picks up other noises during gear change???
dave

[2barGee]

On my last track day my mate was keeping a close eye on the power fc whilst I was going round and my knock levels only shot up only when I let off.

On boost I would see knock levels at about 30-35 then when i would let off it would shoot up to 40-45.

When i do track days i always pull a few degrees of ign and always use octain booster just so its nice and safe

[JJ]

Pretty much anything that can cause a mechanical noise.. ie... wastegate shutting would simulate a knock noise ( between gear changes )

Ideally if det cans are not in place, when doing datalogging, you can see the knock values being retained in each cell under load ... which will determine if it is knock or ghost knock !

[Munnsy]

spoken to ryan, he really is a credit that guy.
Assured me its all safe etc and i have nothing to worry about

The problem i have, is i only know what i read and what people tell me.
My knowledge on all this is very very very limited so rely on imocers and the like to help me out.
Anyway guys huge thanks foir the response really is a great help

dave

no doubt ill be in touch again soon about something else lol

[skipp123]

yeah when i spoke to ryan about my knock levals he came stuck det cans on it and there was no knock but for example when you are in say 3rd if you watch the power fc will go to say 23 but change gear and it can sometimes shoot to 45ect its all fine just thought id share my findings also

[jimGTS]

ryan would have set the knock to where he felt it was safe. be it 50, or 60 or 65 in my case.
some engines are louder than others and you can get some ghost knock.

depending on where he felt it was safe, i would go by that. it usually flicks the ecu light at 60-65....

bare in mind if its set to 60-65, thats when you may "start" to get "real" knock/det. the point being from 0-59, your not experiencing any extreme knock, if at all.

[Ja99a]

Hey guys, I have just finished my build and was interested in your readings I sometimes get about 55 knock on my PFC @1.4 bar

I am making about 370 at the hubs, I am using a power FC boost module for boost control but get nasty spikes from it and a saw tooth boost patten, anyone know the best way to tidy the boost up?

Its a PITA at the mo especially hitting fuel cut

I forgot to mention how I am keeping my MAT sensor stable, I have removed the manifold heater pipes and used a bit of tuffnell to seperate the MAT sensor plate from the plenum, works a treat.

[Marf]

What kind of boost controller are you running?

[Ja99a]

Power FC boost control module

[Ryan.g]

The Powerfc Commander IMO is actually a bad bit of the powerfc package..... as i find people spend more time looking at the commander than the road half the time.

After any mapping session i always say to look out for the knock warning light on the dash rather that watching the commander.

Reason being is half the time the peak knock levels you see are just from other noises in the freq range of the stock broadband knock sensor.

Watching for the light is the best option as the mapper should have set the light to flash at the point in which they heard knock on load. So if it flashes through a run then its more than likely picking some knock up.

But sensors wear over time and change in what they are hearing so its not always the case with the knock light also

Ryan

[DavidM]

Great advice Ryan (as always)