lq9 timing table copied to lq4 tune
 

so i know that most of the power difference between the lq9 and the lq4 6.0s is the tune. now i havent messed with tuning the timing, but im fairly familiar with tuning the air/fuel. so if i wanted to put the lq9 timing tables on my lq4 i would basicly compare my file against a lq9 stock file and change everything that is different to the lq9 tune? id imagine id want to do everything under the spark tab (advance, retard, dwell, and knock sensors?) then retune my fuel tables?

first off the tune isnt the main difference, the difference is the compression

and you cant just simply copy one tune into next

youre better off just tuning your motor for what it wants and not what another motor has

the compression is only about .6 higher. the research that i have done says you MIGHT see 3-5% hp increase with a full point of compression increase. so were talking 5-10 hp max from the compression. the rest is in the tune. this has been hashed out many times on this forum. from looking at the timing tables it looks like the lq9 timing comes on a bit faster (more timing on bottom) and has 2-3 degrees more through mid and top end. i know my shit when it comes to carbs and distributors but im new to tuning efi. now i figured since the lq9 has a hotter timing table, yet is still a factory tune, i could load that up and still have a safe tune, but a little better to start from. what im really concerned with is if i change the high octane table, should i change all the other tables in the SPARK tab to the lq9 tables so everything is the same.

old rule of thumb is for every .5 in SCR youll see about 15-20 hp which shows to be true for the LQ9 vs LQ4


tune is different cause its stated to run 93 only for the lq9 cause of the compression

with said dont copy and paste, tune the lq4 as its needed

and just cause something is on the net doesnt mean its correct

man i wish you could get 15-20 hp out of .5 point of compression. its 3-5% per point

http://www.bgsoflex.com/cgi-bin/crch...9.4&newcr=10.1

simple calculator

How Much HP, Per 1 Compression Increase - LS1TECH

Eaton Balancing » Milling Heads for a Horsepower Gain

How much power does adding compression make? - LS1TECH

showing posts from ls1tech is like believing everything obama says, do you believe everything obama says?


FYI that number figure has been around way before Ls1tech was ever created there bud


but to your timing topic, tune the motor for what it wants and not just copy and paste..

anyone else?

Yea, better not disagree with George C....

Ah, screw it, Yes you can copy the LQ9 high and low octane tables to your LQ4 tune. I would suggest running a min of 91 octane gas if you do.

And GM recommends 91 octane with the LQ9.

Oh crap, I did it again.

I have always believed the same thing as George on compression, .5 give around 15-20hp
when I talked to some reputable vendors when I was planning out my stroker they all told me those numbers aswell

More like 2%-3% for each 1 point increase. I've never heard or read of it being stated as a specific hp number.

/groan

I do realize that i should do a specific tune for my lq4, im not debating that, im just asking if it would work Well to use an lq9 tune, and if i should change all the tables of i do.

Also the only way i could see 1 point of compression being worth more than 2-5% would be in a low compreson engine with a big cam where the dynamic compression is shit and you add some compression to make a better dynamic compression ratio. But .6 of a point on a small cam motor isnt going to do shit

The right way is to tune your own, however you can do anything you want it's just a matter of how correct you want it.

How much timing difference is there between the two tables? Generally speaking.

The LQ4 was severely underrated by GM. The real difference btw the LQ4/9 is about 10 HP.

something to think about, compression adds power if it didnt you wouldnt have ppl with high compression setups for NA and you wouldnt have ppl with high compression builds for boost

and if you take 325 and add 5% power you around 340 hp which is in the range of 15-20 as stated

this isnt some magic voodoo for the LS motors, things been around longer then some ppl posting on this site have been alive



and youll see more power tuning for what motor wants then just coping a factory timing file into another file

can you throw a LQ9 tune into a LQ4? yes it will work. is it optimal? no. my bone stock LQ4 picks up knock at part throttle on 87 octane on the stock tune. why give it more?

Higher compression with a turbo will allow a quicker spool up at the expense of having to run race fuel. In an n/a motor, high compression is wanted with a large camshaft to combat camshaft overlap (Compression bleed off)

And my motor is 300hp 01 2500hd. So either they didnt rate the motor correctly for the early hd lq4 or its detuned compared to later 325hp version. really the only reason i posted this is a dude on a forum (i know) said he threw an lq9 tune on his 2500hd and made a noticable difference. i know its not optimal. i was just curious. Ill just play with my stock tune...

Also i am running 91 octane

so since you read it on line go ahead and do what you read

people also swear up and down that the hyper tech tuner adds 35 RWHP...

that is true. Thanks for some of your guys help

The earlier models had different (cast) heads so that may have something to do with it.

It knocks on what tune? What mods? Winter or summer blend gas? Fresh tune up on the vehicle?