Ok so I am having some issues tuning and cant seem to get it right. Here is the breakdown, I am running a zz4 cam with vette heads and edelbrock performer intake with adapter plate. I have the EBL set up for tuning as well. I currently run 350 injectors at 22 psi. What I need to know is : one, for anyone else running a fuel pressure guage does the pressure drop for a split second while opening the thottle. Mine drops about 1/2 psi but then goes right back up to 22 psi within a split second. Is this normal? Second, anyone with similar mods, how much ae do you run I cant seem to solve my wot backfire issue and I think i am running a lot of ae already.

 

Nobody is running a similar set up?

 

I run 80lbs at 20 lbs but it is a VAFPR. I suspect that drop is minimal and the regulator eventually catches up. You could have a helper watch gauge while you apply brake and depress accelerator creating a load and see what happens to FP.

As far as AE I would keep adding until you see results. You have RPM modifier to work with as well as lag filters in addtion to the base AE-TPS and MAP. That intake may require more AE than the stocker.

 

Ok I will add some more AE. The only place I have been adding ae is in the tps setting. If I sent you a copy of my bin do you think you could take a look at it, I am still very new to this whole thing. I need to get this thing up be the end of sept.

 

Sorry only have access at office and cannot run any TP software/program to open.

AE has two facets. Initially TPS AE and then shortly thereafter comes in AE MAP. With the movement of pedal the TPS I believe is recognized first. With a corresponding drop in VAC or increased MAP enrichment continues. AE is a blend of both. In my WB datalogs I see two enrichment spikes followed by PE if I approach 70% TPS. I think I have equal amounts in both tables currently.

Every car differs. Posting your specific tables wont be of much help. For quite a while I had too much AE in tables and I continued to pull AE out and car responded better. Adding IAT control helped as well.

AE filters: reducing % will bring in AE sooner and produce more AE. Bringing it in sooner was very helpfull to me. Here I vary considerablely from stock .bin.

 

ok ill play with the ae settings and see what i can come up with, thank you for your help. What is the IAT control and what changes can be made to it, ie multiply, divide %?

 

That pressure drop you describe is normal.

I would go trough the calculations again to make sure you used the right numbers, here you can find the formulas:
https://www.thirdgen.org/forums/diy-...o3-lt1cam.html
https://www.thirdgen.org/forums/diy-...-360ci-sb.html

 

I will go over my numbers again, but I used Rbob program for figuring out BPC and came up with 22 psi to support 300hp with 61lbs injectors. I think I have too much AE but I will have to go back and double check my numbers. The car seemed to run better with the 305 injectors at about 20 psi but I still had a problem getting my AE right, either having a lean pop or it bogged down. It is frustrating trying to get my WOT right.

 

Look into the AE PW's which need to be adjusted for increased flow.
See tuning part 2 dynamicefi site.

 

I suspect you need to get AE PW and AE TPS close https://www.thirdgen.org/forums/post...461-post4.html

The EBL federal LO3 bin should be a good starting point once fueling is adjusted.

I experienced that #55's with over 17-18psi will always be rich at idle, the VRFPR is almost a must at high pressure.

 

What vrfpr are you running thomas1976? I was looking into getting one but do not know much about them.

 

I have this one, because it replaces the stock one, same place and size.
http://www.turbocity.com/product_inf...roducts_id=602

 

post your AE TPS tables....

 

I already have the AFPR from turbo city, can i make it into a VRFPR instead of buying a whole new one?

 

The LO3 bin should be a ok start, I suggested LO5 because I thought you had a 350.

Have you tried:
1) EBL federal LO3 bin, multiply "AE - TPS PW" and the "AE - MAP PW" by 1.24 with #55's @ 20 psi. Then work on the VE table's and SA tables?
2) for #61's @ 22, multiply by 0.6926 and work with the VE tables and SA tables?
Of course with the correct "BPC-BPC vs VAC" for both.

The turbocity AFPR loks like it has the same housing as the VRFPR.
A little male to barb connector at the place of the adjusting screw and stacked shims under the spring to optaind desired FP should work just like their VRFPR.

 

based on the numbers you are giving me, i will be taking a significant amount of ae out of both parameters. i will try it and see what happens.

 

I tried the ae muliplier, but as I suspected it caused the lean pop at WOT. I can try to keep adding ae again, until the pop goes away but I feel it will bring me right back to where i was, with either too much ae causing the bog or not enough causing the lean pop.

 

Could try adding AE in 80% up TPS and see what happens.

Are you using the stock SA table?

 

no the SA table is far from stock. here is my sa table



Here is the new ae tps and ae map tables I am running, still not right but closer. the WOT pop is prominant from a stop with a quick stab of the throttle. when the car is moving the car wont back fire but it seems slow to respond to the throttle like the ae is still not right.

 

That is a lot of WOT SA, have you desactivated PE SA?

Make sure the knock sensor is working.

 

Knock sensor works.

how do i deactivate sa pe? right now if i look at PE max retard it goes from 8 degrees to 10 degrees starting from the bottom of the table.

 

I only adjust the main, extended SA tables and IAT related SA. You will have to go trough the calibration document, there may be some other tables with WOT SA influence.

Have you tried the stock LO3 bin with adjusted fueling?

 

I started with the stock LO3 bin and have ended up where i am now. I will keep playing with the parameters and see what i can come up with

 

The changes you made to the TPS & MAP filter & PW tables are global. They affect AE throughout the RPM range.

Work with the AE RPM table. Add AE at lower RPM and less AE at higher RPM. The pop off idle is from lack of AE. The sluggishness at higher RPM is from too much AE. Check the data log and look at the O2 value at these times.

If you keep adding AE to the lower RPM area and it doesn't get any better. Then the fuel delivery isn't keeping up with the demand.

RBob.

 

Ok, I played with the ae rpm parameter and increased the lower rpm ae. I dropped the tps ae at the higher end of the scale because it was bogging down. It seems to have gotten better but i think the 1000rpm-1400rpm is still sluggish I may have to pull some ae.

Does anyone have a good picture of how their vrfpr is setup, what vacuum are they using?

 

Lol, not much to see.

 

ok. so you are running a vacuum line from the front of the throttle body into the regulator. what is your pressure set at idle? I am thinking about making me vacuum referenced

 

8 psi at idle and 15 psi WOT (#80 injectors)

 

Did you have a hard time getting it tuned with the vrfpr or was it easier?

 

Mostly got lucky and the tunig part was easy regardless of FPR.

 

Yes it seems there may be more AE than you need. I like to work lean witness intake pop and then come to enrichment.

RBob refered to the AE RPM table. That allows you to fine tune based on RPM. I stopeed using AE TPS-MAP and am now using only RPM modifier..

I run the Aeromotive VAFPR. It allowed me to get a better control at idle( 19.5 lbs FP with 80 lbs injectors). I suspect off idle (rising MAP) VAFPR may help as well.

 

I have not switched over to a vrfpr yet but i played with the ae tables, dropping my ae-tps because it was so high. I am getting closer to getting it right but i notice upon cold start up the car runs bad and almost sounds like it is drowning, Could that be due to the ae being high? SHould i have the car run in closed loop all the time?

 

Ok well I have pretty much got the ae down, but I need to figure out cold start up. is there a choke setting i need to adjust?

 

AE tables do not affect cold start.

I believe there is a coolant based modifier table. You may want to reduce that table a bit. It modifies the open loop A/F-RPM-VAC table especially when cool coolant. Choke and crank are seperate tables and choke I beieve isin affect just a few seconds then decays. Here is where a WB is helpfull.

 

How much should i decrease it by and i am not sure which coolant based modifier table should I be adjusting?