jining

iTrader: (7)

Hey guys, as some of you may know, I have had some rough time getting a good tune for my APS TT (stockblock) g35.

I was comparing my maps with the Turboxs APS 550cc Basemap that you can download on the turboxs website. I scaled all the values to be 650cc values, basically multiply by .85.. I hope I did that math right...

Anyways, it seems that the maps I have are much leaner then the basemap... so I looked at the dyno graph and it seems that my tune is high 11's, like on average 11.8 A/F.

Is that too high?

I also was experiencing some knock earlier so I retarded the timing a few degrees in some spots, but now I compare with the basemap and my timing is WAY retarded (as some of you might have seem in my previous post --->) https://my350z.com/forum/tuning/308049-hows-my-tune-please-comment-on-my-maps.html....so now Im thinking (hoping) it was the fuel being too lean instead of the timing being too advanced.

Your thoughts?

athenG

iTrader: (2)

11.8 is a little high especially if this is on high boost and around your peak TQ. Since you are a little lean, I would first get the A/F right.


I was about to make another thread but I'm also having issue with my A/F.

Dave 90TT

iTrader: (4)

On my JWT (stock boost, 6.5) with UTEC, my tuner targetted 10.5 I'm of the opinion that that is a bit rich, but I would rather run a bit rich, than blow my engine.

Matt at PF

hey man, you really need to get that thing professionally tuned before you start a thread asking about who can build you a new engine.

jining

iTrader: (7)

I have gotten it "professionally" tuned 3 times so far times lol... going back this saturday for some more tuning they are going to retune my car for free

XIceDragonX

you shouldn't have to go back 3 times to the same tuning place just for them to figure out why they can't tune your car before you realize they have no clue what they are doing with a 350Z. there is just no way I would let a shop screw up my car twice and go right back to them.

SGSash

iTrader: (3)

11.8 is "a bit rich"

10.5-11.5 is very rich

12.5 is perfect for power, however is very aggressive for a turbo car.

11.5-11.8 should be your air fuel target. any richer and you are starting get too much fuel in the oil from my experience.

anything leaner than 12.2 in high boost with a high(ish) compression motor is dangerous

the reason people say 11.8 is because it is 0.80 lambda, so it is a good target to shoot for, anything leaner than .85 or richer than .75 is a nono (11:1 - 12.5:1)

athenG

iTrader: (2)

at 11.8 and 6-7 PSI and 79deg weather, I knock like crazy. Tuner tune for low 11's around peak TQ/Boost for safety especially on pump gas.

Edit:

by the way this only happend to me when my car ran Lean for no reason in the middle of the day.

SGSash

iTrader: (3)

too much timing then dude!!

could just be my backround, different tuners do it differently, you will most likely make more power your way, it is just more extreme in my opinion

athenG

iTrader: (2)

Most VQ tuner run their A/F around low 11's at peak TQ just for added safety.

jining

iTrader: (7)

This is not the same tuner that I originally went to. This tuner I am going back to on saturday tuned me once but we discovered I had issues with the actuator, so we fixed it, and we tuned again with better results (410hp/400tq). I am going back because I have a few counts of knock, maybe because it is a bit lean for this stock motor(around 11.8 or so)AFR.

I dont really understand how the timing being so retarded and the fuel being pretty good could cause knock, but maybe there are some spikes in the fuel graph we will see.

Could too retarded timing cause knock or false knock from the utec?

We are going to richen it up slightly to hopefully get rid of the knock as well as increase the timing as it is a bit too retarded.

Good tuner just isnt too familiar with VQ. Anyways, hes tuning me for free this saturday, they are good guys. (Dyno Authority in Redmond,WA)

athenG

iTrader: (2)

Quick way is check if the ECU is pulling timing. If it's not then it might be false knock.

Julian@MRC

iTrader: (28)

No, he said his AF went all whacky on him, not his timing.
OP-----11.3-11.5 on the VQ35 stock motor.

jining

iTrader: (7)

Thank you Athens ill check my logs, and thank you MRC, we will tune for that on saturday

SamuraiSam

What kind of detonation monitoring equipment are you using?

I am willing to bet that you do not actually have knock unless you are using det cans. Stock knock sensors on modified cars do NOT work accurately.

11.8 is conservative. Most low boost pump gas setups are good within 1 point of 12.5:1. Base maps as a rule are too rich and do not have enough timing so I wouldn't worry that you are leaner then the base map.

However there is NO magic number as far as what a safe AFR is and the correct AFR for your motor can only be determined by a good experienced tuner paying attention to everything going on with the engine.

If you are familiar with the Gunmetal R32 GT-R owned by Marc up here(it has a big wing, roll cage, R34 rims, looks aggressive as hell) I tuned his car to about 12.5:1 AFR's at about 16psi and extrapolated the untuned area of the map so that it should be in the 12:0 range when we re-do the wastegates for higher boost and it drives perfectly and has no knock. Fueling is all about thermal management really.

My offer still stands to tune your car free of charge, all you pay for is dyno time. It sounds like you are going to somebody who has an idea of what they're doing though. I took my EFI 101 course at Dyno Authority in mid-october of 2005.

athenG

iTrader: (2)

/\ If you target your A/F around 12's then you don't know enough how weak the VQ engine. The first few years VQ has been blowing left and right and that is why most VQ tuner on this site will not run 12's A/F even on 7psi. You are comparing an Iron Block engine that is build to handle boost so your margin is bigger in term of tuning.

Julian@MRC

iTrader: (28)

11.8 is the leanest we go on the VQ motors on 93 octane. The car pings in N/A form at 12.5 AF..

jining

iTrader: (7)

Thank you for your offer, im actually going to dyno authority tommorow at 8am, but if for some reason the tune is still not doin it for me, I will be glad to take you up on your offer. Thanks again.

Ziggyrama

iTrader: (15)

No one even asked yet what octane the OP is using. Are you running 93? Any alcohol in the mix? They're important details that need to be clarified.

Generally, depending on what gas you get, you can get away with more or less. If you get alcohol in your gas, great. If you don't, it's still OK. If you're running 91oct, you will be limited to some degree (pun intended) as to what you can do with your tune.

So, take all advice here with grain of salt. What I can do here in MA is not the same as what you can do with your gas. Basically, you start with a conservative tune, measure what is going on and move forward, SLOWLY, and see what the car does.

IMO, 11.5 is ideal on 93oct. I think that is as close as you'll get to optimal torque without killing your timing to keep knock at bay. Here's basic steps on how to tune it:

1. Set fueling to 10.5 Set timing to very conservative values. Don't worry, you'll fix this later.

2. Now that you're safe with fueling and timing, establish boost targets. Get that squared away. Since you're not running high boost, the turbos will be well within their optimal efficiency on the compressor map. I don't think you have to worry about over revving the turbines at this point and turning the turbos into flame throwers. Make sure to take note of ambient conditions when tuning, ESPECIALLY IATs. That will be your base line. As temps change, you'll have to adjust wastegate cycles to keep your boost on target with respect to your baseline. I think this is something a lot of people miss and end up retuning the car multiple times as seasons pass by and temps go up and down. Make sure your get your boost the way you like it in this step.

2. Once you get the boost right, work on fueling. You should target around 11.5 and you should hit it since your timing will be conservative at this point. Check your EGTs at this point. You should be fairly high at this point since your timing is low. DO NOT venture above 1600F. That's the magic mark. Your fueling map should be smooth, no big bumps, hills or valleys. Nature like smooth transitions and so will you since the power delivery will be very good.

3. Fince tune your timing at this point. Slowly turn it up and see where you start knocking. If you're knocking somewhere, adjust the map and make sure it's smooth. The same rule applies here as well. Sudden timing changes will produce flat spots in your power delivery and will feel weird when you drive the car. Check your EGTs again. As you turn up timing, you should see your EGTs drop slightly. Once you find your timing limits, back off a couple degrees and you're done. Note the conditions again and establish the baseline again for timing. As IATs drop, you will be able to advance the timing slightly. If things get hotter, start retarding. You should always see highest EGTs near redline and highest loads. You will always have the highest tendency to knock around your engine's VE which is around 4000RPMs. Pay attention to that area especially with high loads since this is where detonation or god forbid, preignition can do some serious damage.

Word of advice....do not tune for WOT only. I see a lot of people doing this and ignoring all the other areas which are just as important as the WOT situations. Make sure to cover as many areas of the maps as possible, various loads and RPMs. Record and review your results.

That's how I tune and it works very well. Tuning FI vs. NA is 2 different things. If you're smart, you'll have a solid tune that will work year round and will not require constant retuning and adjustment which is what a lot of "professional" tuners can't seem to do. My attitude is that no one will take the time to perfect it like you will.

Also, make sure to get a road tune. IN your situation, I almost don't see a point in doing the tuning with the dyno until you're pretty much done and you want to see what numbers you'll get. You will not be limited by your snails. You will be limited by your octane on street gas so you will never come even close to MBT or surpass it. So, go as far as you can with timing and that will be your best setup. No need for dyno to tell you that if you turn up boost or advance timing, it will make more power. That's a no brainer. Good luck!

athenG

iTrader: (2)

Great Post!!! I'm not sure about the timing part, it is really hard to tell if advancing the timing really did add some power to a point without putting it in a dyno. fixing the fuel curve on the street is great but I feel that the timing part should be done on a dyno since there is no point of adding timing if it actually not giving more power anymore. JMHO.