Dyno clips

A

Ant

Member +
My EP91 on the dyno this morning. Reaching the top of the rev range in clip 1 there are some puffs of smoke from the exhaust. The dude seems to think it's running a little rich (which is debatable IMO)

Watch for the sparks as the anti roll bar clips the rollers, as the chassis is pretty low the guy doing the power test started to get worried about damaging the dyno equipment & would not continue! :haha:

 
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Fro

Fro

Member +
as far as im aware its something to do with the brakes(?) on the rollers putting the engine under load and is normal, but i could be wrong! Mine done it too during mapping.

Whats the spec?
 
A

Ant

Member +
I find that a little odd bud that there could be any braking/resistance situation (of the dyno rollers) when it's reaching top revs under that load? My thought is that it could be a pre cursor of fuel ignition, to the point of popping a flame out in slight over fuelling due to running a little bit rich. I have noticed over recent weeks there are lots of tiny carbon spots appearing over the back of the bumper & tailgate too.
 
Rory

Rory

Lifer
Dyno's have to put a load on the motor to try and simulate the load thats on it while on the road.

It could well be running a bit rich, what was the fueling graph like?
 
A

Ant

Member +
I understand this point Rory, take a look at the images I have loaded onto the other page on this section. You'll see all the readouts inc AFR figures.
 
Rory

Rory

Lifer
From your readings its over fueling a good bit...
Christ it drops into the 9's at the top end.
 
A

Ant

Member +
Here's the interesting bit. For arguments sake: If it's overfuelling but not spitting flames? & if the AFR figures don't match my LC1 readings? who is to say anything is 100% accurate. The LC1 was reset for calibration during mapping (not by this guy doing the dyno) & all was well.

So, the power gains to be had by leaning out a little won't be worth worrying about. I'd rather have the car a 'little' rich than too lean.
 
Rory

Rory

Lifer
Just because its overfueling does not mean you automatically get flames. ;)
I would lean it off a good bit. Im presuming you are on a stock motor? If you are id be looking for around 11.0 / 11.5 AFR at full chat.
Hell you are wasting fuel for fun with them AFR's!

What does the AFR do on the road?
 
A

Ant

Member +
Yep, stock 4E. Idle/'normal' driving is 13 - 13.5 & full muller is usually in the 10's. Don't get me wrong, this is not something that is worrying me, I was just curious after seeing the puffs from the exhaust on the rollers!
 
Rory

Rory

Lifer
Cars will normally puff on the rollers, but from what you have just said the car could be doing with a little leanining off.

BUT its up to you at the end of the day :)
 
G

grum-glanza

Member +
my car was the same was told it was way too over fueled had it like that over a year no problem decided to sent it too another fella with good experance took one look at the afr and laughed so i finaly decided ok fix it let him fix it a week later conrod out through the block my advise from what i have learned if its running perfect and no problems just leave it that way my afr was down it the 9s before i changed it
 
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