Quick question about cruising speed timing for L67

[AkursedX]

I just have a quick question. Is ok to be running between 38-40* of timing when I'm cruising at 70-75mph?

I have no KR and my AFR's are 14.3-14.5. It seems to me like it's ok, but I just want some more experienced opinions.

[Eddie-98GTP]

I run upwards around 48* during light throttle cruise.

[bigbrian442]

Are you under boost while cruising?? I run 40*+ while cruising but I'm NA.

[Eddie-98GTP]

No, no boost while cruising. There isn't much difference between between SC and NA during cruise conditions.

[bigbrian442]

Should be no problem running lots of timing during cruise then. I'm guessing a stock cam wouldn't like 48* timing. Cylinder pressures should be higher in the cruise range with a stock Vs after market cam.

[AkursedX]

Thanks for the replies! I tought I was ok but I just wanted to make sure. I really only know about tuning in PE mode for the 1/4 mile. I have recently started working on my regular driving tuning and I just wanted some opinions to make sure I was going in the right direction.

I guess I'll bump the timing up a bit more.

[starks]

eddie, do you get good gas mileage? i recently cranked my timing up to the low 40's range while cruising because i had disgusting gas mileage, and only 22-23* light throttle cruising, 40+ while coasting. i havn't had a chance to see what my mileage is, but i hope it gets better.

anyone here run e85? Im curious how much that would effect cruising timing, being 105 octane. i may get mine up to 48 as well, seeing as how you can pull it off with 87 octane gas...and im assuming a 3.4 pulley?

[Eddie-98GTP]

Yep, 3.4 pulley but I've started running 89 octane (need to change sig.) since our drive time temps are over 95*F this time of year. I drive in a lot of stop and go traffic, so the engine gets a good bit warmer then if I were cruising more.

Anyway, I started with 2005 GTP timing tables (High and Low Octane Spark Advance and Max Torque Timing tables) and tweaked from there.

Not sure about the E85. I know it has higher octane, but it also burns cooler if I'm not mistaken. This should help you run higher timing, just don't go too high. The trouble I see with using E85 is the AFR and price difference. I've thought about trying it out since a station down the street from me carries it, but the price is about $3.50 compared to $3.90 for 87 octane. That's only about 11% difference in price, and from what I've heard the MPG difference is closer to 18%. How is the E85 working for you? How is your fuel economy compared to gasoline?

[starks]

ill have to check out the 2005 tables to see what they look like

where i live, the price difference is $3.25 to $3.94...I live in minnesota, and there are more E85 stations here then anywhere else, probably why the bigger difference.

my mileage has been pretty bad for a while, i dropped from 17 average to 13.... i should be able to get it back up to 16-17 from what other people with 3800's are saying while on e85. ive gotten bad mpg for a long time, and i hope it was all related to low timing during cruise. i believe the last time i had good mileage was when i had a dhp 1.0, but its been so long.

i mostly do it for a performance / safe for the engine standpoint. since i run a 9.4 cr block, i wouldn't be able to run a 2.8/2.9 pulley without it. i could probably run smaller, but i dont have any desire to try.

[mtcrusan]

I run upwards around 48* during light throttle cruise.

Attached are my stock timing tables. What do you think I could bump my timing up to? I see knock in the higher RPM's, but nothing during cruising. Would it be safe to increase timing by 5 degrees at a time (in cruising)? What range is cruising? TIA!

[Eddie-98GTP]

starks: What did you have to do in order to run E85? Did you have to replace any injector or fuel rail o-rings? I should be able to run it as far as injectors size goes, but I've heard storys about the E85 eating stock o-rings. I'm not sure about the year, but something else I've heard is that E85 compatible o-rings and fuel lines have been used in just about all cars from 1997 to present. Not sure what is true though...

mtcrusan: I would raise the timing in 1-2* increments in the 1400 to 2800 RPM range and .12 to about .44 g/cyl range for cruise. 5* increments are a lot, I would not try that although you may enmd up being able to raise your cruise timing as much as 10*. Do not try to go over 45* or so, there is no gain after that.

[mtcrusan]

Thanks Eddie. I will try it out.

[starks]

Eddie, when i put the siemen #60's in, i also put viton o-rings on them. i believe they were stock on 3100 cars as when i went to the parts store to get them, he gave me o-rings for a 3100. not sure on the year. you can they are viton's because they are purplish instead of the black rubber ones. i also use a flex fuel filter. its made for a tahoe 5.3 flex fuel. it fits perfect, but installs with the flow arrow facing opposite of the actual flow. stock rubber o-rings will swell, then leak eventually

with the 60lb injectors my IPW's are in the 16-17 range when its about 70*, so i still have some headroom (thats with a 2.9 pulley). e85 would let your car run a 2.8 probably, but i dont know if your injectors would be good down to a 2.8" pulley...with a fuel pump re-wire, that would be close. right now its my fuel pump thats pretty much maxed, injectors have more room.

[starks]

still crappy gas mileage....about 41* cruising timing.

im going to switch from e85 2.9 pulley to 92 octane 3.1 pulley.... see what happens.

i even put a new motor in (spun 2 bearings) and went with a 9.4 cr block, and added a full size IC as well. no change in mileage.

eddie, would it be possible to take a look at your tune?

[Eddie-98GTP]

Sure, I'll post it tonight - if I remember

[Eddie-98GTP]

Here is a list of the tables that have been changed from stock.

The AE tables are mostly 2005 GTP, everything else is custom

The Operating System ID is 9352809 and contains 440 tables.

Accessories
==============================
Fan 1 Coolant Temp
Fan 1 Keyoff Coolant
Fan 1 Keyoff Time
Fan 2 Coolant Temp

IAC Desired Idle RPM

A/C Disable RPM
A/C Disable/Re-enable TPS
A/C RPM Re-Enable
Immediate A/C RPM Disable

Alternator RPM Cutout

EGR Air Temp Disable
EGR Disable TPS Threshold
EGR Enable TPS Threshold


Fuel Related
==============================
Base Fueling

Cat Protection Coolant
Closed Loop Fuel Enable RPM
Engine Runtime for Closed Loop
O2 Sensor Rich/Lean Threshold
Open Loop Base AF by Coolant Temp
Possible Closed Loop Fuel Disable RPM

PE
Base PE A/F
PE A/F vs TPS
PE Enable TPS - Hot
PE RPM vs Time A/F

MAP
Default Max MAP

MAF
MAF Airflow Table
Volumetric Efficiency

Fuel Injector
Injector Flow Rate
Injector Skew Percent

Acceleration Enrichment
AE Modifier vs Speed
AE Modifier vs. Baro
AE TPS Re-allow
AE vs TPS Max Delta
Disable TPS Closing Delta
Enable TPS Delta vs. ECT
TPS Filter Coefficient

Deceleration Enleanment
Decel Enlean vs TPS


Spark tables
==============================
Base Timing
AFR Spark
Air Temp Spark
Closed Loop Idle Spark Correction
High Octane Spark
TCC Spark Advance Correction

Knock Sensor
Knock Retard Recovery Rate

Speed/Timing Limiter
High MPH Limit


Transmission Changes
==============================
Shift Point - Performance
1st to 2nd Performance Shift
1st to 2nd Performance Shift RPM
1st to 2nd Performance WOT
2nd to 1st Performance Shift Line
2nd to 1st Performance WOT Shift
2nd to 3rd Performance Shift Line
2nd to 3rd Performance Shift RPM
2nd to 3rd Performance WOT Shift
3rd to 2nd Performance Shift Line
3rd to 2nd Performance WOT Shift
3rd to 4th Performance Shift Line
3rd to 4th Performance Shift RPM
3rd to 4th Performance WOT Shift
4th to 3rd Performance
4th to 3rd Performance Shift Line

Shift Time
1st to 2nd Normal Shift Time
1st to 2nd Performance Shift Time
2nd to 3rd Normal Shift Time
2nd to 3rd Performance Shift Time
3rd to 4th Normal Shift Time
3rd to 4th Performance Shift Time

Shift Pressure
Shift Pressure 2nd Performance
Shift Pressure 3rd Performance
Shift Pressure 4th Performance

TCC
TCC DC Min - Line Pressure vs Trans Temp
TCC Pressure Apply Rate

Supercharger tables
==============================
Boost Control
Boost Control - Timer Max
Boost Ramp Rate
Catalyst Protection Boost Shutoff
Decel Boost Control by Throttle
Excess MPH Enable by MPH


Torque Managment
================================
Fuel
Disable All Injectors High MPH
High RPM Fuel Cutoff
Torque Abuse A/F
Torque Abuse Differential Score A/F
Torque Abuse Drive Injector Disable
Torque Differential Score Injector Disable
Traction Control # of Injectors Disabled vs TC Mode
Traction Control Desired A/F

Spark
Torque Abuse Spark

Transmission
Brake Torque Limit
Max Turbine Torque TCC Unlocked
Torque Reduction 1st to 2nd Performance Upshift
Torque Reduction 2nd to 1st Downshift
Torque Reduction 2nd to 3rd Performance Upshift

[e85grandprix]

I run E85, however i didn't know changing the cruising advance would do anything.... Sound interesting... someone must enlighten me more, there isn't enough info here for me to change my timing tables while cruising... is there a benefit?

[Eddie-98GTP]

someone must enlighten me more, there isn't enough info here for me to change my timing tables while cruising... is there a benefit?

There is a huge benefit. Better performance and better fuel economy for example.

Have you changed your timing tables at all?

[e85grandprix]

i have changed all my wot stuff, i am currently running 23-26* of timing at wot on a 3.2 pulley and no intercooler on e85. I have not changed just regular driving lol, this is the first time i've heard of it. If there are gains then i'm all over it. What would you suggest i start off with? i have stock stuff, like idle is 25, and i see 39's in some places , but mostly low 30's. this is good to hear...

[Eddie-98GTP]

Honestly I'm not sure how much to tell you to add with E85. I know with gasoline, running 26* at WOT is not real good. Anything over about 21-22* offers no gains for for those that can even get that high.