87lsttop

iTrader: (2)

Need a little help When tuning a car to light the turbo off while on the transbrake and 2step I have read many threads in which to run as much timing as possible to get the turbo lit and then feather it out after leaving. I have logged many times and adjusted timing in the base table going from 18 degrees of timing all the way to 39 degrees of timing and it seems the turbo will only build 4 lbs of boost in 5 seconds. turbo is a tc78 Benita series with the 68 mm turbine in 96 a.r. I would think it spool like a light switch. I have also adjusted the PE to table to command . 84 lambda at the specific rpm while on the transbrake. Method for attempting to build boost while testing is to come off idle, hit t brake stab throttle, come up on converter and 2 step and hold it there for 5-6 seconds for testing purposing then release throttle and brake button. Doing this is in the dirt for testing so I don't break anything. Is this the appropriate method and way to accomplish lighting the turbo off on the brake and adjusting the tables in hp tuners. Thanks for the help and sorry for the long read.

AgFormula02

iTrader: (13)

Have you tried increasing rpm in 2 step?
bump it up 400 rpm and see what happens.

87lsttop

iTrader: (2)

I have bumped 2 step all the way from 3200 to 4400 Still will not allow boost to build quickly. Thought it was Watergate cracking open so I put a heavier spring in to no avail

RonSSNova

iTrader: (3)

Try dumping the timing at the 1-2 psi point in the timing table.
Take it down to ten.
see what happens.
Leave it high up to 0 kpa

87lsttop

iTrader: (2)

Ok I will try that and see what it does thanks.i did rule out the turbo. It build 11.5 psi in 2 seconds on a pass earlier with a max of 17.8 psi.

RonSSNova

iTrader: (3)

Mine is a foot brake car.
my process as follows:
light the first bulb.
Bring the rpm up until it stutters.
Bump in and light the bottom bulb, then floor it.
By the last yellow it's at 10 psi.
Release the brakes and it's at 21 psi in .6 seconds.

So maybe try that process with your trans brake. I have 10 degrees in the 2800-3600 cells at 1.18 and 1.2 g/cyl. Bottom two rows

87lsttop

iTrader: (2)

On my car it will not reach that high g/cyl. The maximum it would reach is .8 ish.so I would adjust the table from the .48-.80 at 3200-4000 range on the timing table. While commanding a lambda of .84 on e85

87lsttop

iTrader: (2)

And that is a hell of a ramp rate

RonSSNova

iTrader: (3)

It is. It's time for a boost controller.
Although it works fine on a good track.

If your tune isn't scaled, it should hit the bottom row at about 7 psi

87lsttop

iTrader: (2)

Yes it will hit the bottom row but not while I'm on the brake unless I figure out how to build the boost

brandon6.0

iTrader: (32)

yea my turbo truck uses the last 2 timing rows when in boost.

87lsttop

iTrader: (2)

Ok tried it to no avail. Brought it up stabbed it on the transbrake with 2 step set at 3700 dumped the timing in the area of the timing table to 10 degrees and only built 4 lbs in 5 seconds on the brake. Not sure what the hell is going on. Here is a log and the tune. Thanks

87lsttop

iTrader: (2)

For some odd reason I noticed in the log that it is still coandimg 14 degrees of timing even though I told it 10.

87lsttop

iTrader: (2)

Any ideas? I have added fuel to command a .80 droppinh to a .75 on the brake. Played with 2 step settings and wont come on faster.

RonSSNova

iTrader: (3)

See below for why it won't go below 14 degrees timing.
Fix that, set it to 0 or even negative if you like.
The table sets the minimum timing.

Once done, try way lower timing there.

I'm a little puzzled by the low Cylinder Airmass.
Is this indeed a 4.8?

Ron

87lsttop

iTrader: (2)

Thank you very much for finding that. I thought all of those tables were strictly for knock retard. Yes this motor is a 4.8l, with 706 heads, 3 bar map sensor, ls6 intake, tc78, with fic 80lbs injectors, and isky 212/215 cam.

87lsttop

iTrader: (2)

Here is the current tune with a log of a 15 psi pull. It doesn't start til 7.30 into it where I am footbraking it into the transbrake and then spun of course(street) and then hit 15 psi. The cyl air jumps up to 1.5 in the pull. Not sure what a normal cyl air reading is. I did go ahead and modify the min spark advance table as suggested but have not tested.

87lsttop

iTrader: (2)

Here is the config Im using also.

RonSSNova

iTrader: (3)

I see it boost just fine. Starts coming on at 4000 or so.
Maybe just set your trans brake higher.
If it will go to 4k, give it a whirl.
Change that table too so you can set the timing there lower.

I just fiddled with mine a lot to get it to work.

87lsttop

iTrader: (2)

Yea i noticed that it dors come on a little better around there myself i can set the 2 step up to 4k but its harder to get on the 2 step there when im on the brake because od the comverter