ROCKETW19

Ok here the run down on my timming.
when stoped at a light my car goes from -2 to -16, kinda just jumps around.
in 3rd gear 3k rpms its -30
in 3rd gear at WOT it droped as low as -10

what does all this mean? is this good, bad, or normal?
thanks for your time as always guys.

Vadim @ FD

Rocket, please do not mind me correcting - it is timing.

The numbers that you see on the scanner reffer to ignition timing advance. Typically they are positive, but on our DMEs they read negative. Just ignore negative sign.

Can you data log your car? If you can, please post your graph and than we can see what is going on.

10 degrees at WOT is about stock.

V12Godspeed

I have heard too much timing and its bye bye....So be very careful.

ROCKETW19

I dont have a logger I just have the scan gauge2. I never was a speller I have to ask my 13 yr old girl to spell most thing for me.lol sorry.

out of the info I gave you can you make any guesses? like why would the timing jump around when at a stop light. and why is it at 30 when cruizing and drop to 10 when WOT?
thanks again for your help.

ROCKETW19

do you know how much is to much?

rflow306

10 deg under boost is very little timing imho, I think the dme is retarding timing most likely engine knock. If you have access to a star-diagnostic you can check the knock sensor. That is probably the reason you are down on power.

The timing should be around 15-17 degrees max under boost imho. These numbers are for 93 octane so in Cali maybe 2 to 3 deg less.

Jakpro1

Here are some runs that I did Rocket. RFLOW is right. Timing seems a bit off for a guy with a flashed ECU. Something definitely seems up with the timing.

RPM's on the left of course.

ROCKETW19

what gears are you in and when? or is that starting in 1st?

Vadim @ FD

Rocket, I just picking on you....

Ideally, one wants to see a graph of what is happening to timing under WOT.

During cruise, 25-30 degrees is normal, as load changes. Under WOT, as rflow pointed out, on forced induction car 15-16 is about all one can get on 91 octane.

Higher octane will allow up to 18-19, but that is about it, before car will start to rattle.

Stock car is 10-12 depending on the gear.

ROCKETW19

sorry for me being so stupid about this stuff but would the 5 degree in timing make a huge difference? is this why Im low on power. of coarse all is not known to you so a guess is ok with me for now.lol.

Jakpro1

Most of those are 1st and 2nd gear numbers.

You got any info from those pulls on air fuel Rocket? Even if it's just MV readings. Interested to see if you are running rich like me?

Bet with some tuning, your car is gonna be hoppin!!

ROCKETW19

Adam has the dyno sheets! I dont think it was to rich if it was at all.

E55 RUSS

Here my take:

1st: As far as I know agressive CAMS need more FUEL especially TOP...and they should make more POWER on TOP !!!

2nd: When we tested Evotech ECU with my chip tuner on my freinds car....HE said the AFRs are very LEAN !!!

3rd: If I reacall correctly Victor who seen the Rockets Dyno sheets, said that the car is LEAN after 4500 RPMS !!!



So how can ROCKETs car which runing LEAN especially after 4500 RPMs make more POWER with such agressive CAMS which need more FUEL from the START ???...Not to mention that they should make more POWER TOP and his ECU is not giving them enough FUEL and runing lean on DYNO after 4500 RPMS !!!

Ohter problem IS that no one knows what AFRS WE NEED to have to get the best results from those CAMS on our car and still be safe...

So I think VRP needs to take E55 install those Cams and tune ECU accordingly on DYNO and on the ROAD and then provide people like Rocket and Jim with proper ECU flash, so everyone would be happy

Sorry if I repeat my self or missed something out...

saman6164

There is no magic AFR that you need for the V8 compressor engine. Just as a reference leaner AFR will make more power. An AFR of 11.0:1 will make less power than 11.5:1 and so on. Actually, the most power is made at 12.5:1 that assuming that you have enough octane to support it. When we run 118octane on high boost cars, we will lean them to 12.2-12.5:1. But that is too dangerous in daily cars. I have my boosted cars tuned to 11.5:1. This allows a very safe AFR and very close to optimum power output.

With 93 octane there is no reason that you should not see 15-18degrees of timing with WOT.

ROCKET19 asked if 5degrees make a huge difference. And the answer is hell yes. Just to give you an example with my 3.4L Supra and a 76mm turbo, a 2degree difference is a 40whp difference The stock ECUs are great at picking up knock and they will retard the heck out of timing with knock.

So if you are seeing 10degrees of timing, then you really need to make sure that your AFR is not leaner than 11.5:1 and also that you are running enough octane for the amount of boost you are running.

The biggest misconception is that since the AFR looks good that you should be ok. That is completely false. I can add fuel to my ECUs map and make it extremely rich but still knock the hell out of the car if i run more boost than what the octane of my gas can support. I hope that helps.


Here is the latest dyno on the project. Now this is what you call power. 880whp at 32psi and spinning all the way on the dyno with three fat people sitting in the trunk. 36psi pulls coming up in the next 2 weeks. We should easily be in the 900s.

rflow306

On my e55 anything above 12.1 to 12.2 did nothing for power.

E55 RUSS

And I definately felt the diff btw 11.5 amd 12.2...

Albert...Do you think with VRP Cams 12.1-12.2 is the best SPOT ???

saman6164

It does change from car to car and also the amount of octane you are running. notice i mentioned that with 118 octane we will take it up to 12.5:1. I am sure you were not running 118 leaded fuel. I am surprised that you were actually brave enough to lean the car to 12.2 with pump fuel. I would never risk it above 11.5-11.7 on pump. Its not worth it

rflow306

The star-diagnostic and a good listening device works wonders. The dyno is way more forgiving than the street. I tried with both 103 and 109 unleaded and got the same results. The car did not like any thing leaner, power would stay the same.

As far as the timing 19-20 deg of advance with 93 octane would not detonate on a dynojet but on the street it would knock on the 2-3 shift. The mb knock sensors are very sensitive.

E55 RUSS

I run 98 EURO ( its like 92-93 US)...12-12.2 and OK so far....

Albert you run 12.0 on pump ???

saman6164

The key word is SO FAR. If you have tuned your car for 12.2:1, what happens if you get a bad tank of gas? Do you think all pump gas are the same? There have been many tests done that showed pump gas from even same stations on different days can show different octane rating. At 12.2 you are already at the edge, and you will destroy your engine.

A good and reliable tuner will never tune your car that lean on pump gas. On leaded 118 octane on high boost applications we will lean it to 12.3-12.5 but those are for very short runs. If you do a 2nd-5th gear pull on the highway being that lean, you might end up with a blown engine. It will benefit the tuners to claim a bigger whp by tuning cars leaner for selling more of their kits and tuning packages, but talk to some renowned tuners and they will confirm what I am saying.

I would never run my boosted car leaner than 11.7:1 on pump gas. Pump gas a MON of 89 i think and that is way too low.

V12Godspeed

SO what I am getting is that the higher the RPM the lower the AFR must be, right? it should drop below 12 to be on the safe spot on a higher RPM.

blackbenzz

Usually AFR is measured at WOT at high rpms. Yes, your car will be leaner at lower rpms or when not going WOT

saman6164

Yes, you are right. You would not want to touch 12.0:1 with 93octane gas which really has MON of 88-89. Even if you look at VRP and their tuning, notice that they lean to car out to 11.7:1 and not go any leaner. Its not worth it. You are risking big time if you are going that lean.

Jakpro1

Thanks for all the info Saman. You got any dynos you could post of A/F's that you have for that Supra? Interested to see what it looks like.

Thanks in advance.

saman6164

No problem. Ask and you shall receive. I dont have one of the dyno because we do not use the tail pipe sniffer as a guide. Usually there is a 500rpm delay between whats really going on in your engine vs. the reading you get at the tailpipe. I have an installed wideband that is tapped right into my downpipe that gives extremely accurate reading, and gives me the chance to data log it. Here is a log of a 16psi 4th gear pull that puts down about 575whp.

This is a screen capture. To explain whats going on. The screen is divided into three parts. The top, middle and the lower portion. The top graph is logging the engine speed (red line) and boost (green). The middle graph is logging the AFR and the lower graph is logging the timing.

Because the top portion has two different graphs overlayed on top of each other the y-axis is only showing a % of the total values of each. However you can see that where i have clicked on the graph (vertical black bar coming down across the entire screen), the readings for all 4 lines on the top right corner. Where i clicked on the graph, RPM=4031, boost= 13.63, AFR= 12.24, and timing=18.51. There is a very specific reason that i chose this section of the graph to show you.

This car revs all the way to 8000rpm. So you can see that at ~14psi where we are at steady state boost and 4000rpm that AFR is 12.2 and as rpm build up and boost climbs to 16psi that afrs smoothly drop do mid 11s. Even at 7900rpm where we let off, the AFR was 11.6:1.

Even if i chose an earlier section lets say at 3500rpm where boost is 7psi, the AFR=12.5. So when i see Renntech tunes where the car is in the 15s and stays there and stays in the 13s all the way to redline, makes me wanna throw up.

The other important aspect of the graph is the timing. You notice that at 4000rpm timing is 18degrees, but at my peak torque ~5200rpm, timing is 14degrees and slowly climbs to 16degrees at redline. The one thing that will let me know if a tuner knows what they are doing is if they follow that basic principle.

No matter what the car, boost, octane you are running, timing should be lowest at peak torque and slowly climbed as RPM (piston speeds) increase. If you have the same timing at peak torque and redline, the person has no business tuning. Hope that helps.