Gav

Hello.
Have mildly ported 241 heads with 224r cam (unknown LSA and Unknown if stock valve springs or stock pushrods)
LS6 block, M6,
Diamond stage 2 clutch with T56, light AC Cobra kit car, 1100 kgs ish...
Speed density (no MAF) tuned and left in OLSD.
Unknown if stock timing chain(would be a bitch to change now as engine would need to come out...)

Dont want to spend money on Dyno when might be doing a Turbo next year if i can fit it in....as my other threads.

Might do a £50 dyno pull though to check for baseline RWHP.

Have been tuning on street with my wideband and sort of happy where commanded lines up with actual...though you may differ??
Areas getting knock 4 degrees at 24 degree timing WOT so have reduced these areas to 23.5 as per highlighted cell area in photo attached.
Have also attached my VE table, my COS3 tune and the commanded VS rpm table in that tune and my HO timing table.
Have also done a round of the RAFig process with lots of VE tuning.

Can i get any more out of this tune?? i have ONCE gone to 6300 RPM but wont spin any higher than 6000- 6200 ATM as dont know what valve springs are or timing chain if stock etc.
I dont know the LSA of the cam either, only told its a 224r cam.

Would you alter my AFR commanded in any areas or my timing to get better WOT or light throttle response??
Its a learning curve for me but hoping i am getting there.

rpturbo

iTrader: (47)

I am a novice tuner myself. Based on what I see, I'll say IMO, for me, it's a tad lean up top, I like 12.5. Now, I will normally concur that lean is mean, but also you have a little less spark up top than I run. That will all depend on how efficient the engine is though, and you may not be able to run more spark.

Otherwise I think your pretty well there. People will tell you to smooth out the VE table, but if your wideband error is less that 5% off I personally don't get too worried about it.

Gav

Hi, thanks for looking.
Cant go higher on spark in those areas as getting knock.
May just take it to the dyno pull this week.
When i pushed it to 6300 rpm inj duty was 80%.
Hoping for 350 plus but in UK so numbers might seem lower.
Regards
Gavin

RonSSNova

iTrader: (3)

I'd help, I've tuned a bunch of these, but don't use EFI Live.

If decent CR, 20-22 degrees at torque peak works well. That cam, prob 4800 to 5200.
You can tweak the knock sensitivity a bit, but I'd rather see KR and reduce timing to remove it.

Commanded vs actual ought to be within 1-2%.

BTW, at torque peak, run it rich. It will like it. Maybe 12.2:1
That also reduces KR.

Add timing as rpm increases. And lean fuel as rpm increases.

RP, I tried to respond to your last PM, it never sent. Sorry bout that.

Ron

The Dragon

iTrader: (6)

What fuel pump and injectors?

Timing is low in cruising cells and wide open imo.

You can desensitize knock sensors but I’d spend the money for a dyno to see if more timing up top nets more power as long as you have enough fuel.

Gav

Hi,
Thanks Ron,
So if i drop Afr to around 12.2 in the 4800 to 5200 cells at 95 and 100 kpa, then ramp up to 13 afr until 6000 6200.
Best try that first before adding timing as was getting knock. Thanks for that though, will post back.
Dragon, intank 340 with an8 lines and adj aeromotive reg at 58psi. Inj are 33lb (from googling...)with ls2 intake, holley 90mmtb.
I could try timing in cruising cells but cant at wot as i get knock at 24 degrees in areas.
Wont spend on dyno as may turbo next year but want a baseline pull when im done.
Regards
Gav

Gav

Another thing, my VE table doesnt really represent my torque curve and from my logs my actual afr is very close to commanded.
In VE table the highest cells should be at 95-100 kpa at around 4800 to 5200 ish, but my VE keeps adding fuel until 6000 ish....?that cant be right??

The Dragon

iTrader: (6)

Knock with 24 degrees, at face value, means you would need 23 or less timing.

Only able to run that low of timing makes me suspect something wrong with the motor, valvetrain geometry, or the sensors are picking up external noise somewhere.

Gav

Hi, attached is where i got knock at 24 degrees screenshot. Car pulls like a demon possessed though!!! Addicted lol.
also have screenshot where i have lowered WOT areas down to 12.3 ish afr and slightly back up at top end and will load this in before i retry upping timing.
Maybe porting wasnt brilliant job i dont know that history, or springs getting float or pushrods not quite correct length.....On here though seems not all cars like 28 degrees though?
241 Heads may have also been milled for bump in compression as well....?
Regards
Gav

Gav

Hi,
Hmmm maybe i do have a problem, lots of knock....

rpturbo

iTrader: (47)

Just curious, is there a PE (power enrich) setting in EFI live? I mean I see it says PE in the pic, but not like the way its setup in HPT. I am just asking because the way you changed your AFR. In HPT, you can just change the PE setting so if your not over a set TPS/MAP setting, the AFR stays at say stoich or whatever you have it set at.

Ron, no problem it happens and my last pm was a lot longer than I thought. LOL

kingtal0n

iTrader: (1)

just throw some race gas and see if the knock goes away

The Dragon

iTrader: (6)

Yes, there is.

Gav

Hi,
Ranked the spark plugs for a check first, gaps set around 45 thou which is around recommended.
Looks ok to me though but am a novice reading plugs as well, w



hat u think?
Ac delco 41 985 12571164
Regards
Gavin

kingtal0n

iTrader: (1)

I think that plug looks like **** and its been fouled at once point, IMO put a brand new set of cheap coppers in the engine and tune it until they look nice, don't ever let them get that oily black appearance on the part thats normally mostly white (ceramic)

when the engine is tuned proper the plugs look mostly white in most of the engine's I've seen, LS also have a bit of tan/dark area in one place
notice also the electrode is mostly clean

Always Cruise and idle in a range 14.8-15.4
Slope gradually from 14.7 to 13.5 between mid-load regions (44-68KPA)
by 75KPA start with 13.0 - 12.8's ish
and by 100KPA 12.5 is fine
these naturally aspirated a/f ratios will help keep the plugs looking clean
Make sure you are also getting full complement of ignition timing on cruise after 2500rpm (~40* of timing usually or more)
I don't use PE Until 80+KPA, until then enrichment is handled via VE map like with a stand-alone

Gav

Ok, have ordered some BCPR6es - 2330. We cant get the delcos here, or ngk 55, or tr6 ones without ordering from US....and prices compared to yourselves.......
Took the time to check on piston tops with camera, guess round dimples are for the stock pistons...?
Also noticed how close my t56 side lug is in the trans tunnel, 3mm tops....? Wondering if in speed this may touch and knock sensors pick up?? Clutching at straws....

kingtal0n

iTrader: (1)

good job on thinking outside the box for the trans tunnel. a knock sensor detects frequencies associated with engine knock- so of course anything that makes a noise in the range will create counts.

However going around the car looking for potential things that make noise is a tedious task. Instead simply use the race fuel test to determine whether knock is real or fake, and THEN once you've made the determination "yeah its fake knock" you start trying to fix it (like you are doing now, with searching and improvements) or simply tune it out.

As to the pistons I've never seen that, no idea. But it looks like a manufactured area? Looks very strange to me I would research and find out for sure what that is.

Finally the plugs. the main thing is to use the cheapest plug that will let you fully tune the engine without misfires, and THEN once everything is fully tuned up and ready to hit the dyno, you swap in some high quality iridium plugs, do a final street test, then dyno the car and finish tuning it the way you want, then it will be good to go 10+ years on those plugs.

Gav

Hi,
Pulled the rocker covers for a quick few checks on one cylinder valve train.
Pushrods around 0.313 thick and 7.396 to 7.4 length, checked straight with ruler, guess stock?
Attached valve spring photo, stock?? Cant see any markings on them.
With cam on base circle finger tightened rocker bolt until tapping gone then counted turns to 22lbft. Getting just over 1 turn, just less than 1.1/4 turns.
What i did notice is that if i remove the rocker and hold the bolt hole section between finger and thumb, there is play in the needle bearings up and down. Should there be no play whatsoever?? Trunnion upgrade ??
Regards
Gavin

G Atsma

There should be NO play in the rocker bearing(s).

Gav

Hi,
Thought this didnt seem right with them out of the engine....
Question is new rockers or replace internals...
The pivot cup to the pushrod is nice and shiny but not worn down to oiling hole or scored or anything.
Regards
gav