Turbo Tuning

[WicketMike]

i searched alot and couldnt find much help

I am getting a STS turbo installed on my stock T/A right now and i want to make sure i do the tuning right.

Its a 98' so i wont be able to get the EFILive O.S. and i wont be able to get a 2/3 bar.

So how should i got about tuning it to make sure i dont have any problems? here is what i am thinking.

Im going to put WOT afr around 11.3 and timing at 11 at the WOT cells and then move up little by little.

What AFR and timing should i shoot for? 11.5 and 15 degrees?
What area in the octane tables should i edit?

what about part throttle?

thanks

[bink]

Why not buy a 2001 or later PCM?? Wouldn't you be far ahead in the long run?? Just a thought :D.

I've been looking at the STS Twin Turbo setup for the C5 - With upgraded Garretts and forged bottom end........monster with a capital M. Just dreaming tho.

Cheers,
joel

[WicketMike]

Why not buy a 2001 or later PCM?? Wouldn't you be far ahead in the long run?? Just a thought :D.

I've been looking at the STS Twin Turbo setup for the C5 - With upgraded Garretts and forged bottom end........monster with a capital M. Just dreaming tho.

Cheers,
joel

isnt there more to it then just buying a later PCM? isnt the harness and wiring different?

If i can just buy a later pcm and plug and play, then i will do it really soon, but in the meantime i need to make sure my tune for now is safe. thanks

[eboggs_jkvl]

Wiring harness is different on the 98 vs any other year. PCM + Appropriate Wiring harness would be needed to upgrade to the 2001 PCM


E:)

[WicketMike]

how should i scale the Injector flow rate table for the new injectors im getting? they are the ford 42's rated at 43.5 fuel pressure

Ive seen the excel spreadsheets to help scale them, but what about with a turbo.
Do you have to put the amount of boost into the equation somewhere?

[eboggs_jkvl]

I Set and scale my injectors for normal non-wot running. That is where I run most of the time. WOT tuning is different. You need to adjust the fuel for PE or WOT. My rising rate fuel pressure regulator adds 1 PSI of fuel pressure for every 1 PSI of boost. My injectors are set and boost is not a factor in that base setting. My wideband readings at WOT are set via the PE table and I am in the mid 11s for A/F.

[WicketMike]

ive had this link saved from when i had ls1edit
http://www.ls1edit.com/pipermail/ls1edit/20021023/003682.html

It says to subtract the amount of boost.
but you just tuned the IFR table like you would N/A. and then tuned the PE for WOT.
which makes since because your not always at full boost.

[eboggs_jkvl]

Boost has nothing to do with scaling the injectors. Why is that even a consideration? You tune the injectors to drive the car under normal conditions. When you have boost, it's only at WOT, so you deal with fuel flow parameters and A/F only when you have both PE and Boost. The injectors simply squirt more as required from commands read from the PE table.

Elmer

[redhardsupra]

injectors will always see the same range of fuel pressure, boost-independent, so just use my IFR spreadsheet and you're good to go. you might wanna verify fuel pressure on the rail before you calculate it though, it's worth to get that much extra precision.

[WicketMike]

im going to tune the IFR table by using the excel spreadsheet, after that should i watch the LTFT's and adjust the IFR table? or do i need to do the AutoVE and tune the VE tables? will the turbo make the VE table be off?

[redhardsupra]

do NOT adjust IFR table for any other reason than changing injectors or fuel pressure!!!
once you have these figured out use autotune and the change the VE tables until fuel trims settle down right below 0

[eboggs_jkvl]

Tune the car! Use the autotune and get it rock solid. Get you LTFTs as close to 0 as you can. Anything in the negative range is fine but it's best to be small negative (-1 or -2). Now, Tune the WOT portion AFTER you are happy with the NON-WOT tune. Then leave it alone. You are not going to use autotune for WOT are you?

If you have COT, you'll need to increase the limit or you will get fuel dumped in at WOT and that will really mess with your mind.

Elmer

[Brains]

With a turbo car, you can be in boost well outside of PE -- or at least with my girlfriends 370cid T76 car you can. Heck, you can slowly roll the throttle in 4th gear with the converter locked up, and it'll wind up to 10psi well before you get your foot into it hard enough to downshift.

On her car, we're using a MegaSquirt ECM to handle fueling though, but damn I really want EFILive 2 or 3 bar on that car instead!! Damned curse of the 1998's :)

[eboggs_jkvl]

Well, mine doesn't spool prior to WOT. I can accelerate pretty briskly and no boost. When I dump the TP, then it spins up and I go + PSI. Quickly but not until I request it.

Elmer

[WicketMike]

do NOT adjust IFR table for any other reason than changing injectors or fuel pressure!!!
once you have these figured out use autotune and the change the VE tables until fuel trims settle down right below 0


Thats what i was going to do, adjust the IFR table for the 42lbs injectors i have, then do the AutoVE, now after i do the AutoVE and i get everything dialed in, then i go back to closed loop and check the LTFTs, right? now what if the LTFTs are not between 0 and -5. does this mean that i have to do the AutoVE again?



Tune the car! Use the autotune and get it rock solid. Get you LTFTs as close to 0 as you can. Anything in the negative range is fine but it's best to be small negative (-1 or -2). Now, Tune the WOT portion AFTER you are happy with the NON-WOT tune. Then leave it alone. You are not going to use autotune for WOT are you?

If you have COT, you'll need to increase the limit or you will get fuel dumped in at WOT and that will really mess with your mind.

Elmer

Im not going to tune WOT with AutoVE, i this car i have to keep the cats so i cant turn off the COT like on my other one, so what will i need to increase so i doesnt mess with my mind?

thanks everyone!

[dfe1]

If your tuning is at all close, you shouldn't have any problems turning off COT. I've had COT turned off on my C5 for over three years and haven't had any problems. I originally turned off COT because I couldn't get AFRs at WOT where they should be. In fact, I've turned off COT on every converter-equipped car I've tuned and there have been no converter problems wth any of them.

[eboggs_jkvl]

I didn't turn off the COT, I simply raised the numbers a little to stop it from splashing in gas during WOT. The gas splash screws with the A/F and you go in circles trying to get it to stabilize.

E:)

[WicketMike]

I did the AutoVE and then returned it to Closed loop and most of my LTFTs are -5 to 0. There is some that are still plus though. What should i do? should i do the AutoVE again and start with my new VE tables?

also LTFT1 and LTFT2 are about 3 points off from each other. why is that and how can i fix it?

thanks again

[redhardsupra]

you're never gonna get them perfect, as long as you're good for most of them, leave it be, it's gonna change anyway. let it settle in for a while, see what are the natural boundries in which the LTFTs move.