Remember, I said could. It's not an absolute, as there are so many variables, but in general terms what I said is correct. Now when we are dealing with small hits, and depending on your starting timing, sure I could see you making more peak power. However, I would be interested in seeing an overlay of both dyno runs. Peak numbers do not effectively relate volumetric efficiency. Hell I can show you dyno graphs of a car with peak high 6xxrwtq, that pukes the rest of the run, whereas with 500rwtq peak it runs a linear TQ curve and is much more powerful through out, so apples to apples is not always apples to apples. Maybe Al could comment, as he really can explain things much better, and correct any over sights.

Robert

 

this was not the case. it made more power and more torque through the whole run. i chose to leave a little less timing on spray since i am still running a stock botom end (even though it would clearly be quicker with more timing). there was no detanation on either run.

 

I wasn't trying to say you wouldn't also make more tq. Rather, that peak numbers do not always tell the whole story. I can gurantee you that a race car will generally not make more power or run quicker with more timing and bigger hits. Some run their best numbers and ETs with like 8° to 10° total timing, and/or pull additional timing through out the run. Our quickest dry car on this site runs 10°, IIRC. There has been a long standing belief that we want to run the most timing we can until detonation, not true. The real way, is run timing up until peak power n/a, and no more, then remove timing for the spray. Detonation should not be the goal when setting timing, and I am not saying this is what you did, but just for information purposes.
Robert

 

thats cool but your first post is kinda miss leading.

 

To the top for stainless40cal.


Stripstar here's what mine looks like (more pics in my personal web site):


Robert

 

thanks for the bump robert i appreciate it.

HSW im still confused on timing with this unit can you possibly give me a run down on the phone of how my settings should be ?


https://ls1tech.com/forums/showpost....21&postcount=4

 

Stainless, did you see post #128? There i show the stock tables, if you set the dip switches to a temp in the graph you will be pulling that timing down the full column, very simple, just pick a target temp to use.

Now, in post #154, I take the stock table and choose 158° as my target temp with dip switch settings as per directions. OK, now we know anytime we spray we will be going to the 158° column. So, the stock 4° was not enough pull for my big hit, and I then change 4° to 12° all the way down the column. When ever I spray the PCM will see the target 158° column and pull what ever timing is in the boxes, which in my case is 12°.

one thing to point out. The temp is across the top and corresponds to the boxes below it all the way to the bottom. The g/cyl on the side starts at .08 (low air flow or load) and as you go down the page it increases all the way to 1.20 (highest flow or demand). You can view the g/cyl as the RPMs as they climb, and the temps from cold to hot as the motor warms up and or over heats. I choose 158° just because it will never be running there when i am spraying or racing.

Does this help clarify anything? Or do you have a different concern/question? The only reason I am helping is cause it's Sunday and HSW is at church, not because I am in bed with them, lol.
Robert

 

Thanks Robert yes i checked them it i guess im just new to the tuning thing with efi and all and this is a bit much im starting to understand a little better. Thanks again for the help.

 

The car this is acutally being done on is a frc vette with an ls6 motor in it. So thats where im kinda confused as to what my settings are going to be. I want to spray a 250 shot at the forged motor and want to be able to pull 10 degrees for it, with no timing pulled on the n/a tune of course.

So am i understand this correctlty. Could i set my iat for 158 per the tuner as well as be able to set that iat for 10 degrees of timing retard? Then with all the timing retard switchs on it would equal to 15 on the interface itself and pull 10 degrees? And if i wanted more i could just set it for a diffrent iat (ex:167) and set it at 12 degrees to be pulled? Am i on the right track at least lol?

 

Yes, your on the right track. Not sure how you got "would equal 15° on the Interface" (existing value plus new value, no, drop the original value it will be gone). We are working in the "Appendix: Advanced Timing Retard Feature" section (Installation Manual), not the standard timing pull section. Anyway the rest of what you say is correct. Set your dip switches (1, 2, 4, 8) to all on, add them up and it equals 15, and 15 targets the 158° column on your "IAT vs Cylinder Air Mass" look up table. Now, we can physically change what ever factory pull is in this column, mine is 4° as my screen shots indicate, we can high light the entire column and delete then replace with your desired 10°, all done. Next time you make a run and log you will see your total timing with 10° missing, very cool. In the future, you know putting your combined dip switches to a value of 15 will equal a timing pull of 10°. Now we want a different timing pull for a bigger hit, so we set up the 149° column to pull 16° of timing and note that this requires a setting of dip switches "on" to equal 14, bingo we have a second timing pull set-up. All we have to do is remember the dip switch number to set and we can have multiple timing pulls.

Now, when you get more comfortable with your tuner program, you will be able to see where your motor's torque peak is compared to your Cylinder Air Mass. You can log g/cyl and also rpm, then by looking at a dyno sheet you can see exactly where torque peak is vs RPM. Why is this important? Well to get the highest volumetric efficiency we can do a custom timing curve for the spray. What we want to do basically is to have the most timing we need pulled at the torque peak, then we can add a little bit back into the run as we gain rpm past the known TQ peak all the way to red line. This will in fact give us our best power over all and can result in a quicker run using the same size shot, we will just be using it more efficiently. Hope i didn't get you confused by adding this, but it's something to consider in the future. I currently have 3-timing pull curves set up for my motor using the Interface. I can clarify this a little better if you would like.

By the way, we all learned this stuff somewhere, no one was born knowing it all, though there are some that claim to have invented the wheel on this site (he knows whom he is), lol. So, don't worry, I still seek what ever it is I need to know at the time, it's a long learning curve for all of us hobby tuners. Any questions you have, and ask, actually help hundreds out there, so anything you want to know, just ask.

Robert

 

Robert, that helped a TON. I understand now exactly what is going on for the basics or most part i should say.

You are exactly right it is one big learning experience lol

Sorry about that i didnt mean 15* on the interface i ment the dip switchs adding up to 15 on the interface.

Thanks again i actually understand how this thing works now LOL. The way you explained it above made it a lot simpler and im sure a lot of people will be able to understand the timing portion a lot better.

 

Glad I could help.
Robert

 

quick question. is it possible to use the interface for a 2 stage?

 

Robert Do You Use The Iat Modifer Tables To Adjust Timeing Pulled By The Interface When Setting Up Your Timeing Curves...?

Also Calis I Think You Could Piggyback 2 Interfaces Or Just Tune For Your Small Shot And Use The Interface For The Bigger Hit..

 

Alos Not To Keep Revisiting This Argument But My Interface Has Trouble Holding The Specified Iat Matter Of Fact When Setting The Unit For 158 The Most I Ever Got Was 156 And It Was Semi Irratic (with A Soidered Iat Wire)...

This Is What Lead Me To Pull The Unit(will This And The Fact That The Stock Iat Becomes Heatsoaked So Easily That I Found My Self Running A Nearly Full Time N20 Tune Just By Setting N20 Settings For A Iat Of 158


Im Gonna Go Back And "re Try" The Interface On My 5 Wire Maf In Hopes That The Iat Buld Location Change Will Provide Better Protection Against Iat Heatsoak .. This Being Said I Still Cant Figure Out Why I Couldent Get The Unit To Hold A Constant Iat

 

If we get worried about heat soak, then we can just set the column up corresponding to low temps, then we won't have a chance of hitting them. This was likely your issue? Around here, we really don't need to worry about that. I normally see 100° or less with the Vararam as it sends only ambient temps not under hood hot temps, something to think about and something good that you have pointed out. This is so new, we may have heat soak problems in some areas, maybe anyway, at this time. Now with all that said, depending on what pull we have in the 158° column, it certainly will not hurt the motor in any way shape or form to pull this timing n/a, we might loose a couple HP, but would likely not even notice. Besides, we are only racing at the drag strip right, where we would be spraying anyway, right.
By the way, did you ever clean your IAT sensor, maybe it was a bit dirty?
Robert

 

The Iat Works Fine Under Cursing Conditions.. Just In The Hot *** Fl Weather..the Stock F-body Iat Location Allows For The Iat To Get Real Hot And I Think Its Kind Of Out Side The Main Airflow Path So It Takes A Good 2-3 Min Of Driving To Cool It Back Off... The End Result Is On A Hot Day If You Sit At A Stoplight For Too Long Your Start To Reach The 140-160 Range And Even After Leaving The Light It Still Takes A Min To Cool Back Down, During This Time You Begin To Pull Timeing (this Is Not So Noticeable With The Stock Iat Table And Its Modifer But When You Set Up The Iat Advance Table For -6 Spark Thought The Rpm Band It Really Sucks)


Anayway I Believe The Iat Will Be Less Prone To Heatsoak When Located Inside The Maf And Accordingly Have Ditched The Stock Iat Sensor For A 5 Wire Maf Setup.. Im Gonna Do Some Logging Here And I'll Let You Know What I Find....

Also On The Interface It Wiuld Be Helpful If I Could Get It To Hotter Iat ( Say 190+, Or Even -40) ... This Would Ensure Im Not Pulling Timeing Due To Heatsoak

 

Just curious but why would it pull timing regardless. If you are just driving around and it begins to get heat soaked the interface wouldnt kick in anyway would it? Not unless you had your nitrous activation switch on right?

 

Because The Interface Tricks The Stock Computer To Believe The Car Is Sucking In 158 Deg Air So When You Modify Your Pcm To Pull -6 Deg Of Timeing For A Iat Of 158 And Your Iat Actually Reaches This Temp You Will Pull The Timeing


The Main Difference Between The Interface Other Timeing Devices Is That The Interface Works To Trick The Pcm To Pull Timeing While Other Devices Do It Mechanically

 

Even So The "main Reason" I Pulled This Device Is That I Would Not Consistently Pull The Desired Timeing Because It Couldent Hold A Specfied Iat (even With The Wire Soidered To The Iat Wire)

Looking Back This Problem Could Be As Simple As A Bad Ground In The Harness But After Thinking It I Decided It Was Just Safer To Run A N20 Tune All The Time..