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Forum nameTurbo/Nitrous Tech
Topic subjectDyno/Tuning what AFR with 91 octane?
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=63826
63826, Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-19-04 08:32 PM
Hey guys i plan to dyno/tune my car with a motec wideband and i know everyone says to tune for 11.3 AFR on the dyno. In Ca we only get 91 octane so should i tune for like 11.0 AFR with a wideband or richer? i plan to run about 14-18psi of boost depending how much my motor likes 91 octane...
Michael
99gs HRC Stage 2000 8-Injector Setup
2004 Honda Accord V6
63839, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-20-04 05:20 AM
I personally think timing advance is the key to lower octane. You might consider 12-14 degrees spark advance with 15psi on your setup.

11.3:1 is pretty rich already.

Keep an eye on EGT. If it starts climbing above 1500F, then you are getting some kind of knock. My guess is 11.0:1 AFR should be around 1400EGT max. If it goes above 1450F, you need to decrease your spark advance.

You may increase spark advance till you see your egt climb slightly and then back off where you originally had it.

The more I read/learn, I cannot believe I was running 1600F on pump gas. I should have never seen over 1500F on pump gas and 1450F would have been better.

If you do not have some sort of timing/spark retard, then you need one. The only other option is to start at a lower boost setting and work your way up until you see the spark advance retard(datalog). You should also see this on the dyno(less power/choppy reading because of timing retard).

That is all I have for now. Hope it helps, I was in a rush to type it.



63842, RE: Dyno/Tuning what AFR with 91 octane?
Posted by siueclipse, Jan-20-04 06:14 AM
shoot for anywhere between 11 and 11.2 and youll be fine.

James
63846, RE: Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-20-04 07:13 AM
cool. I do have a ignition to retard timing but my ignition is not hooked up (stock ignition now). I was thinking of shotting to keep my egt around 1580max at wot/full boost with of course timing advance at a ok level.
Michael
99gs HRC Stage 2000 8-Injector Setup
2004 Honda Accord V6
63852, RE: Dyno/Tuning what AFR with 91 octane?
Posted by 95redesi, Jan-20-04 08:52 AM
How do you guys know all of this stuff. Is it something you learn from trail and error or something you read about. I guess it might help if I had the part you guys are talking about.
63928, RE: Dyno/Tuning what AFR with 91 octane?
Posted by turbo8u, Jan-22-04 06:17 AM
pn0ymahal....look into a cheap water injection kit.

1.) lowers egt's significantly
2.) goes off a boost activated switch
3.) 0 knock = 0 worries
_________
96 talon esi-t
san clemente, ca

as needles of ice
are the ill winds' talons
the coldest of shadows
they seep unto the bone

63932, RE: Dyno/Tuning what AFR with 91 octane?
Posted by TXTurboGS, Jan-22-04 08:15 AM
Where can you buy such a device and how hard is it to install? I will be dyno tunning my car soon, again.
63933, RE: Dyno/Tuning what AFR with 91 octane?
Posted by turbo8u, Jan-22-04 08:22 AM
www.aquamist.co.uk

msd also makes a kit and putting a kit together isnt to hard either
_________
96 talon esi-t
san clemente, ca

as needles of ice
are the ill winds' talons
the coldest of shadows
they seep unto the bone

63935, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-22-04 09:13 AM
1580F is too high on 91 pump gas.

People that have 11.5:1 AFR are seeing 1400F at most. If they are closer to 11.0:1 is more like 1350F with conservative timing. 12-14 degrees advance. I can see advancing/retarding less till you reach 1450F. Do not go over 1500F whatever you do.

63939, RE: Dyno/Tuning what AFR with 91 octane?
Posted by TXTurboGS, Jan-22-04 10:35 AM
I read up on the Aquamist a little bit. Which system do you think its best to use? The first option sounds the simplest and easiest to use.
63944, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Therein10, Jan-22-04 12:21 PM
I know that I seem to say this a lot recently, but again if you haven't seen any of my posts, I am running 28psi daily on 91 octane with a 11:1 A/F and 15degrees retarded on the msd dis-2. Just something to think about.
63947, RE: Dyno/Tuning what AFR with 91 octane?
Posted by TXTurboGS, Jan-22-04 01:49 PM
28psi of boost? Daily driven? That's nice. How far do you EGT's climb to? What turbo do you have? What kind of mileage do you get on the highway? the street?

I am going to buy the MSD DIS-2 in a couple of days just to be safe. I would eventually boost to 20 psi, daily driven.

Sorry to steal the thread like this, this subject interests me very much since I am going to dyno tune my car once again. Thanks
63948, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-22-04 02:17 PM
Originally posted by Therein10
I know that I seem to say this a lot recently, but again if you haven't seen any of my posts, I am running 28psi daily on 91 octane with a 11:1 A/F and 15degrees retarded on the msd dis-2. Just something to think about.



That is not something I would recommend. You can do what you like, but when people read this they actually think this is a good idea.

There is someone on NABR that made over 500whp on 93 pump gas with almost no timing and high boost. He was running around 10:1 AFR as well. I believe he only did this to prove it could be done. He probably got less than 5 miles per gallon and changed the spark plugs daily. This is also a great way to build up massive amounts of carbon which can lead to predetonation. You are also washing down the cylinders with fuel which is not good. I am not going to debate this issue with you as I feel it is pointless.


63999, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Therein10, Jan-23-04 09:29 AM
Well since we aren't going to argue this than I will just say one thing. You are wrong.
63987, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Skrilla, Jan-23-04 07:27 AM
Originally posted by DeanoD
I personally think timing advance is the key to lower octane. You might consider 12-14 degrees spark advance with 15psi on your setup. 11.3:1 is pretty rich already. Keep an eye on EGT. If it starts climbing above 1500F, then you are getting some kind of knock. My guess is 11.0:1 AFR should be around 1400EGT max. If it goes above 1450F, you need to decrease your spark advance. You may increase spark advance till you see your egt climb slightly and then back off where you originally had it. The more I read/learn, I cannot believe I was running 1600F on pump gas. I should have never seen over 1500F on pump gas and 1450F would have been better. If you do not have some sort of timing/spark retard, then you need one. The only other option is to start at a lower boost setting and work your way up until you see the spark advance retard(datalog). You should also see this on the dyno(less power/choppy reading because of timing retard). That is all I have for now. Hope it helps, I was in a rush to type it.


DeanD is spittin some turbo knowledge and I want to listen so my question is do you think 11.5 or 11.2 is good for 91 octane and 25+lbs
64005, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-23-04 10:20 AM
11.2 or 11.5:1 is pretty close in AFR. I really don't think your output power will change that much between the two air fuel ratios. It will probably help predetonation though or help to control it. You might want to consider 11.0:1 AFR. It would be rich enough to help prevent predetonation, yet lean enough to not wash down the cylinders and build up carbon.

I have seen quite a few dyno sheets and improvements in power didn't come till nearing 12:1 AFR. I am not saying to go that lean, but leaning out the fuel did not make that much improvement in the dyno numbers. I'm sure it helped with fuel economy though. When running rich near 11.0:1, you will probably seem some decrease in power, but your higher boost setting should offset this.

I have seen timing advance give huge improvements in power. As you know you just have to balance the advance with knock, while maintaining a steady AFR.

Many of our local turbo guys run the same AFR no matter what boost, timing or fuel. They never change one of the factors(boost, timing, fuel type/octane)as it requires two adjustments.

If you up the boost, you must either retard timing or raise you octane level. If you advance you timing you must either run less boost or higher octane.

Nothing is written in stone. I also think there is a right and wrong way to make power on pump gas. I am also considering fuel economy when running pump gas. If fuel economy is not a concern, then you might as well run performance unleaded all the time.


64008, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Therein10, Jan-23-04 12:25 PM
Wait. you just told me that 11:1 is too rich and i am going to build up carbon and have the fuel wash out the cylindars. Come on make your mind. 11:1 is either good, or its bad.
64013, RE: Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-23-04 01:32 PM
for our motor 11.1-11.3 is pretty
Michael
99gs HRC Stage 2000 8-Injector Setup
Max Power 257.1 and Max Torque 249.2
2004 Honda Accord V6
64026, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-23-04 03:44 PM
I believe I was speaking of the 10:1 fuel ratio on the guy who made quite a bit of power from pump gas. This comment was also meant for the guy who has been PMing me about his richer than 10:1 AFR. His actually reads 10:1 on his wideband because it will not read in the 9's. Taking words out of context and then commenting on them to make me look stupid is childish.

In the end everyone has to make their own choices and it is best to do this on the dyno. Not every setup is the same and making concrete assumptions can cost you big money if you are not correct. Be flexible and note what works for you.

The tuning suggestions are opinions and nothing more. I have helped tune quite a few cars and every situation is different. I am still amazed at the extremely high boost on pump gas with zero timing. I have yet to see that on the dyno with good power running safe. I also have never heard of this technique as being good for anything except getting a higher dyno number. Let us know how long it lasts for those that go this route.

I think I will keep my comments to myself for a while. Doing battle over the keyboard is tiresome. Good luck on your setups guys!
64057, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Therein10, Jan-24-04 01:51 PM
You quoted me! But thats cool you made a mistake.
64058, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-24-04 02:35 PM
Originally posted by Therein10
You quoted me! But thats cool you made a mistake.



You stated in a previous post in another thread this is your setup.


"To clarify on my part, I am running 27lbs of boost on 91 octane with 15 degrees of timing being taken out after 4500 rpms(close to full boost) with an air fuel ratio of 11.5 to 11.7. rich enough to keep cooler temps. so yes yellowmustang is correct."


You also previously stated this in the current thread.

"I know that I seem to say this a lot recently, but again if you haven't seen any of my posts, I am running 28psi daily on 91 octane with a 11:1 A/F and 15degrees retarded on the msd dis-2. Just something to think about."


Therein10: Which is the correct statement? Your story seems to be changing and these are direct quotes from your posts. I did not take anything out of context to get my point across.

I think we can just leave this alone if you wish. My intention is not to make you look silly or put you down. Everyone makes a typo now and then.

BTW: where did I say I made a mistake in my last thread? My comment to the quoted message was in the first two sentences. I then left space to break away from the quoted message/comment and started another paragraph. I didn't indent though :)

Damn, now I'm starting to feel like a keyboard cowboy. I am truely sorry for the thread jack. I do promise not to reply again :)

64059, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Therein10, Jan-24-04 03:13 PM
Ok but you didnt consider that in a day or two we didn't decided to change the a/f ratio and add some boost. Well anyway your post referred to 10:1 and nowhere did I ever say that, but with 11:1 at WOT there is no problem with carbon build or fuel wash down, or plugs. So yes when you quoted me and then said everything else I and most would assume you are talking about the quote right above it. I'm not trying to be an ass, I'm just sick of being told that the things we are doing are wrong, since they obviously are not. Again I am trying things and yes probably pushing the limits of the engine with 91 octane but how else do you learn. 28psi and no problems so we will turn it up until it pings or start adding timing until it pings. Test the limits and then pass on the information. I would like to have several 2gnt's out there beating 12 second cars. And if you don't want to risk your engine that is cool, but don't tell others that it is a bad idea since we have had several cars running over 22psi daily on 91 octane. Sorry if I seam like an ass but again just spreading the findings.
64068, RE: Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-24-04 04:22 PM
post if you like. But when i dyno/tuned with a wideband with 91 octane for me 14psi of boost is the max without timing retard or higher octane. I run 14psi of boost ( 1 bar )daily. Once we hit 15psi of boost on the dyno the tuner heard the motor ping.
Michael
99gs HRC Stage 2000 8-Injector Setup
Max Power 257.1 and Max Torque 249.2
2004 Honda Accord V6
64069, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Skrilla, Jan-24-04 06:28 PM
Originally posted by pn0ymahal
post if you like. But when i dyno/tuned with a wideband with 91 octane for me 14psi of boost is the max without timing retard or higher octane. I run 14psi of boost ( 1 bar )daily. Once we hit 15psi of boost on the dyno the tuner heard the motor ping. Michael 99gs HRC Stage 2000 8-Injector Setup Max Power 257.1 and Max Torque 249.2 2004 Honda Accord V6


Your max power Dyno of 257WHP - how much boost did it take to make that? Seems low if it is for 14 or 15 lbs
64070, RE: Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-24-04 07:19 PM
"Your max power Dyno of 257WHP - how much boost did it take to make that? Seems low if it is for 14 or 15 lbs"

thats with 18.5psi of boost for me with the egr vacuum circle crap out. I notice it pop/broke when i got home with a killer idle. Im thinking that egr vacuum did not help my high boost tuning along with having a auto tranny did not help. Oh yah, not all dynos produce the same power.
A little low for my taste i might go back with 100 octane only and make sure i got no vacuum leaks.
Michael
99gs HRC Stage 2000 8-Injector Setup
Max Power 257.1 and Max Torque 249.2
2004 Honda Accord V6
64083, RE: Dyno/Tuning what AFR with 91 octane?
Posted by DeanoD, Jan-25-04 05:35 AM
Sounds like a good idea. I wouldn't change anything, but your fuel(higher octane unleaded). You might only put one gallon of 100 octane per 2 gallons of 91 octane. This would allow you to see if there are any gains to be had from reducing your timing. If you are running 1 bar daily, that is pretty smart. I noticed when you said you were at 1.3 bar and your timing consistantly pulled 4-5 degrees probably due to sensing knock. That is not that bad, but you might have only had to pull out 2-3 degrees of timing and you would have been good to go at 1.3 bar daily. Running the higher octane should prove this and I expect you to gain 25whp just from the fuel change at 1.3 bar(just a guess on my part).

I am way more conservative then I used to be. Putting more than $5K into a long block will do that to ya I guess. :)
64118, RE: Dyno/Tuning what AFR with 91 octane?
Posted by TXTurboGS, Jan-26-04 07:27 AM
It is me whom he is talking about, the guy that reads no more than 10:1 all the time. I made 299.6 WHP on the dyno tuned at 16psi. The power is ok, but it stutters and bogs like sh*t. Anyway, he meant me.
64119, RE: Dyno/Tuning what AFR with 91 octane?
Posted by thedawg, Jan-26-04 08:46 AM
Mike- can you post your dyno charts? Or if not, I'll come over and take a pic & host them. In my opinion 257 is pretty damn low for that setup. What AFR did they tune you to? I was expecting 320ish to the wheels. Maybe that's unrealistic but... yeah.

Not that I can talk... running 16.0 on 12psi ;)
64126, RE: Dyno/Tuning what AFR with 91 octane?
Posted by pn0ymahal, Jan-26-04 10:07 AM
i was expecting around 280-295hp/torque to the wheels at 18.5psi of boost. When the auto tranny shifts the power drops big time. Some others have 320hp to the wheel with 21-22psi of boost on a super 16g with no exhaust and being stick with 100+octane. I did not think being auto would cost me so much hp. ill go back in a few months and try to get 25-45hp more with some other stuff if i do so decide.
Michael
99gs HRC Stage 2000 8-Injector Setup
Max Power 257.1 and Max Torque 249.2
2004 Honda Accord V6
64135, RE: Dyno/Tuning what AFR with 91 octane?
Posted by Skrilla, Jan-26-04 11:21 AM
Originally posted by pn0ymahal
i was expecting around 280-295hp/torque to the wheels at 18.5psi of boost. When the auto tranny shifts the power drops big time. Some others have 320hp to the wheel with 21-22psi of boost on a super 16g with no exhaust and being stick with 100+octane. I did not think being auto would cost me so much hp. ill go back in a few months and try to get 25-45hp more with some other stuff if i do so decide. Michael 99gs HRC Stage 2000 8-Injector Setup Max Power 257.1 and Max Torque 249.2 2004 Honda Accord V6


FUCK you're auto that makes a difference. Anyway I think that is low because 14 or 15lbs should produce the numbers you have dude. MuRix did what 265 on 12 or 13lbs and you're makeing less with 18.5 WTF. I think it's low