turbo 3400 tune

[loner666]

Does anyone have a decent tune or know where to find one for a boosted 3400? I have a dhp on the way and looking for a better starting point then the stock tune. Mostly need fueling and related but anything will be looked at. I plan to run 8psi and want to install my 36lbs injectors again

[MMGT1]

With the DHP build your own bud! I wouldn't use any tune you get over the net. Hook up, and log your AFR error. In one 20 min run you can fix most of your fueling problems. One run for stoich, one to confirm your changes, then one or two for WOT and confirm using the MAF error % while you go. I think timing is going to be your biggest factor, not the fueling...
When you put your 36lb injectors in use 4.30grams across the IFR scale with the 3400. These cars don't like a skewed scale in that one.
To start take 10* timing from the whole table and then watch for KR. Remove additional timing to match MAX KR seen, and "add" where there is none. You'll end up much better off than with someone else's tune!

[MidnightriderZ24]

if u had obd1 i could give u a pretty good tune for 30# injectors.

[loner666]

ill have to give that a try MMGT1 when it gets here

[rickykline]

loner arent you going obd2? if so ignore what has been said and talk to me on aim... ill walk you through tuning fuel with the maf... its the most precise way to do so...

[MMGT1]

That was info for a V6 OBD2 system...

This is how you tune a V6:

There seems to be allot of methods to tune the AFR on the V6 cars. Since these cars don't yet have an open loop table like the V8's and the V6 (4.3) trucks, the commanded AFR while in open loop is all over the place when not in PE. In PE the commanded AFR will be were you set it.

This is what I found is the best way to tune these cars. First leave the VE table stock. Then zero out the Power Enrichment PE Enable > Delay vs. TPS table (some models will already have this table zeroed out). Set the PE Enable TPS > Hot to 0% (at all rpms). Set the Base AFR vs. ECT to 14.7 at all temps. Zero the Add vs. Tps (note the values in this table add to the Base AFR vs. ECT and leans the AFR). Then zero out the Add vs. Rpm table.

Now install the wideband in place of the stock front 02 sensor, or the right front if a rear drive car (this will put the car in open loop). Flash this new file, then warm the engine to operating temp. Start scanning and reset the fuel trims. Now the commanded AFR will be steady at 14.7. With the Maf AFR histogram open, drive the car at part throttle to fill the histogram up to ~7500 hz. Try to accel & decel smoothly. Then copy & paste the Maf error % histogram to the Maf table using paste special multiply by %. Once you get the AFR close to 14.7, then use paste special multiply by % - half. For the low end of the Maf table that you didn't enter, just enter the error % from the lowest airflow hz cell that you did enter. So by now the part throttle AFR will be ~ 14.7.

Now change the PE Enable TPS back to stock (or were you what it as some models have the low rpm enable at 100%). Change the Base AFR vs. ECT to 13.0 at all temps for NA, or 11.5-11.75 for a boosted engine. Flash this new file, connect the scanner and check & reset the fuel trims. Bring the car to a dead stop, use the VCM controls to put the trans in 2nd gear. Now go wot till your max rpm desired. Then copy & paste the Maf AFR error % to the 7625 hz & higher part of the Maf table. For the freq. hz cells that the scanner skipped over, just average these cells. For the higher freq hz cells of the table that you didn't enter, just enter the error % from the highest airflow hz cell that you did enter. Once you get the AFR close, use paste special multiply by % - half.

Unlike the V8's and V6 trucks, if the part throttle fuel trims are negative by even a small %, you could have negative LTFT at wot. This is why you need to get the open loop part throttle AFR close to 14.7 BEFORE wot tuning the AFR.

When going to wot from a dead stop there will be a lean spike at first (under 7500 hz) that is normal if you first got you part throttle AFR right, this is caused by the split sec. delay for the richer exhaust to reach the wide band.

Now install the stock O2 sensor. If you did everything right, your LTFT's should be close and will lock at 0% @ wot.



Didn't want to scare the crap out of him with info overload, but I guess he will need this...

[rickykline]

you can simply just disable pe and run a drive cycle.. log for 10000 lines and copy and paste the maf tables to the modifier and youll have a damn near perfect tune the first time... it will be alot better then a none tuned turbo car.. watch for o2 reading around .920 to .940 at wot... i dont know about the other guys but im about maxed out with my maf... im hitting 10,500hz at wot with only 10psi.. and im about to have a built 3500... i dont think loner has a wideband as most of us dont... you can get a damn near perfect tune with the stock o2.. i did... when i hooked up the wideband it was within + or - .1 on the afr...

before you try to tune you need to re do your injector pulse width to accomidate the 36 lb hr injectors.. i cant remember the formula.. but you need to take away alot of fuel at idle to get it within +-5 ltft.. other wise as soon as you fire it up youll be +20 ltft..

[rickykline]

you can change open loop afr..

[loner666]

no i currently dont have a wideband installed but i will have one by the time i have the tuner here..i already planned on IMing you ricky but info here is good as well

[3400-95-Modified]

When you get the tuner you will need to hit up gmv6pcm.com that place will also have alot of info for you including the table modifier that Ricky speaks of...

BUT bottom line is you DONT run a stock VE table, you need to first complete a VE tune and then work your way into a MAF tune and then go to the spark tables and what not.

Read Jerry's Tuner guide once you get on gmv6pcm it will help you understand alot, and since his guide is directed towards boosted cars it will apply to you more than it has me.

Also berettas have one IFR value, not a table, and there is no IFR skew do a little research MMGT1 before you start spouting out info.

And to get a proper IFR value you take your stock LB/hr rating and find the difference compared to your new injectors... the % difference and then apply that percent to the stock IFR value, since its displayed in mSec/gram, so the number should get smaller... I went from 459 to 371, I got the 371 value from a 01 grand am, and I'm using that injector/pressure setup.

[MMGT1]

Yes, agreed. Theere are a lot of differences between the DHP and the HP.
The car in question is a boosted 3400 Corsica OBD2, is it not?

[rickykline]

from what i know its a 3100 boosted obd1 corsica for now... hes planning on ob2 swap and 3400 swap..

[3400-95-Modified]

yeah but his "tune" wont apply till he has the OBDII and 3400 in there... so there is no tuning the current application since its a 95 3100... Cant tune a 95 3100 corsica... its OBD1.5

[loner666]

^what both of them said expect its a 94..but 95 is close enough

[rickykline]

loner, jon are yall going to bfest?.... the beretta should be done and ready to rock and roll by june... cant wait fastest beretta award will be mine....lol