I just tweaked it to 32 degrees, and then I will use the BTM to pull 1 degree per pound. Should help with the mid range over just having it at 26 for all psi levels.

 

I could feel each degree of timing I added as I got closer to the limit.

That thar sounds like a good idea if you can get it working well.

 

80 to 100 kpa timing @ 32* to 34*, with, 9.5:1 static compression.
No timing roll back, but, run a Spearco IC and Meth/H2O Inj.
383ci D1 15psi @ ~6500 rpm.
I also run Evans NPG waterless coolant, (really made a difference).
I had a pcm_forless OBD1 tune that rolled timing in 80 -> 100 Kpa to 26*. No power up top. B.

 

Awesome info. My pcmforless tune drops from like 34 to 26 degrees from the 80-100kpa.

 

Why..?

 

In my case, that was the way pcm_forless programmed it. No documentation to let the customer know. In the end, I purchased tune_cats software and corrected it. It think Mr. pcm_forless was being too carefull. With my mods, I am way past being carefull. I guess it was a bad purchase by me. B.

 

I guess the question that me and MikeGyver have is what is the purpose for scaling you timing reductions back in the 80, 85, 90, and 95 KPA ranges as well as the 100 KPA? What is the max KPA on naturally aspirated motors? Thanks Eric L

 

Max atmospheric KPa is about 104.
The only reason I can see for pulling timing under non-boost conditions is to create a smoother timing transition to the 100kpa cell where timing must reflect max boost. Youd also be removing power from the (safe) factory timing settings, which is dumb unless you have to (motor's internals or fuel is modified or something).

 

I did it as you do want a smoother transition going into boost which will be less likely to knock.

 

That is what went thru my head when I saw it. I understand the 26 degrees in the 100kpa cell, but it dropped off alot before then. I plan on wiring up my 6BTM and pulling timing with the box, so I can get more power in lower boost levels.

 

My suggestion is to buy LT1_edit ver_2.2 (OBD2) and do it yourself. I had informed pcm_FL of all my specs, and, that is what I got. You would think he (pcm_fl) would have a better flash than what I saw. His PE vs rpm curves were choppy and not smooth transition. The PE vs. temp curve was stock cal. No edit to the stock knock trigger cal. No correction of the BLM on WOT mode. No modification of the BLM/ rpm matrix.

My OBD2 flash is very much more advanced than the pcm_FL OBD1 purchase. It is difficult to tune a FI application by mail order. But, in view of his bizz, he could have made additional money by offering a program tweak with the customer's choice of e_mailing a re_edited file. I ended_up with a purchase of OBD1 programming software to re_fllash the OBD1 PCM on my own.

I have also consulted with Ion, and, he has advised potential customers of the difficulty to program highly modded FI applications with mail_order. That's what we customer's want... straight answers.

The LT1 likes advanced timing. 26* is way low. Sorry, a very low pcm_FL cust_service grade from me after view of the OBD1 flash file. You would think some documentation of the file cals would be shipped with the product. I will not be returning, or, offering recommendation.

I have sent OBD2 flash files to some buds. They called back and I edited the file. Sent back and friend/ customer satisfaction.

As Rush said... "Do it yourself if you want it done right." Live and learn.

 

I can understand Bryan being conservative because he doesnt want to blow people's motors. Everyone should get a dyno/street tune eventually. I have Jet/Tunercats, so that is what I am using.

 

This is exactly right. Can you imagine what it would do for business if people started blowing motors with Bryans tunes. They are just base tunes and if you really want to squeeze every bit of power out of it you must dyno or street tune. I use tunercat for OBD2 also. Its not just locked to just one vin like LT1 edit.

 

2 bar open loop sd tune. I wouldnt do it any other way. Why complicate things with a box etc. I can scan my car during a run and know exactly what my timing is. Plenty of room for smooth transitions, and you can keep the timing up until higher psi's

 

How does pulling timing in non-boost areas effect longevity of a boosted motor? Thats the timing it's been running for over a decade.
The smooth transition idea makes sense if thats actually the case. Most people don't do this and have no problems controlling knock...