Setup:

T04S
Stock Motor
1680cc Sec Inj
Other supporting Mods

Stock Ignition

Trying to tune for 7 psi and I am getting all kinds of breakup when i get into boost more precisely when the Sec Inj come on.

I have got the stuttering/breakup to stop a little, but its still very noticeable. I can't even get a baseline log, because of this.

Any suggestions?

 

Sorry mate, i cannot read or download your attachment. Is there another way you can upload it?

John
88 GT-R

 

I just downloaded it from another computer and it worked... can you not open the zip file or just not download it from the site?

 

i can't open your map... are you running a power FC? did you adjust the settings 5 page for your injectors?

howard coleman

 

yes i did... its a datalogit Map.... to be specific....

 

(1) You have not followed the DATALOGIT warning and instruction to clear out the tuner string on Settings 5 page.

(2) You have Anti Lag turned on also, why?

(3) I compared two recalcuted fuel cells at 4400 rpm around 7psi boost to mine,
one was 12.9 % richer than mine and the other was 13.7% richer.
Even though I run modified stock non-seq twins, I don't think your setup will breath that much better than mine with that low boost.

Download some dats from the DATALOGIT site and do some comparisons!

 

I think he's running a version of a *.dat that I gave him. I've got anti-lag turned on for no particularly good reason... it's always been that way. Same for the tuner string... I have no idea how those got set in there but my car runs perfectly like that.

My car had bad stumbling problems on transition until I lowered the fuel pressure to 36 PSI at 0 manifold pressure.

 

thank you Wargasm, I will try lowering the fuel pressure

 

Can't get on the datalogit site, I see no need to spend 25 more dollars to get on a site, when I paid the same price for the Unit used because they can not manufacture them or export them fast enough to meet supply in the US....

 

Gee thanks, now he is telling us that his off boost fuel pressure is ******* high!

He owes us a beer fot that "DOH"!

 

huh?

I have it set at 40psi... didn't realize that would cause a stutter in boost? thought it would just make the AFR higher, and that you could tune those out.....

 

so i take the Fuel Regulator down to 36 psi at O psi manifold pressure and it stops bucking for the most part....

 

You can tune your maps for almost any fuel pressure, but if you have the base pressure higher and on boost ratio higher than the stock normal values; then it make the injectors run richer.

If you used a perfect fuel map for an identical setup as yours, but your fuel pressures are higher, then you car will run rich.

Running higher than normal pressures is a way to compensate for injectors that are too small to handle the fuel requirements with lower pressure.

You had left out an important fact when you asked us to view your DAT.

 

lol figured people would get the idea that it is a .dat file and get the point

stuttering is still there just less prominant....

 

whats wrong with 40 basepressure? you know to set the basepressure you dont attatch a vacuum line to the fpr right? I know this may sound obvious but it sounds like what you did. So start the car up and adjust it to 40 without the vacuum line and then once its at 40 attatch it...my car goes to 33 at idle with the vacuum applied

 

or... switch the ignition on (but don't start) and then open the "diagnosis" box and ground the fuel pump (FP? from memory) connection. This will also give you a base pressure without removing the vacuum or starting the engine

 

Wow. I just did a base recalc and compared to my map...



I compared yours to mine so yellow is where you have more fuel than me and red is where you have less.

My setup:

T04S
720/1680 (maybe the 720's make that much of a diff?)
fuel pressure 32 at idle

Have you put a wideband on yours? I have tuned mine rough to 11.2 WOT and leaned out alot of the stuff at 3/4 throttle from base to get rid of stutter. I have alot of work left to do but the car is running pretty well now. Hard to believe both our cars actually run with the difference above....

 

Shawnk, your injectors are 30% bigger, so your base map numbers will all be substantially smaller...

I'm also the one that gave him that map and I took one of my old maps and added +10% (I think) in the INJ ADJ to give him tuning room so he would be safe. I do expect he'll have to remove most or all of that to get to the proper AFR... better safe than sorry though.

 

yeah, my AFR's are about right, just need to be more precise....
and I use the Diagnosis box method for setting fuel pressure.