Stumbles at high rpm then loops
 

ok so i finally got my car tuned for zero knock at around 16-17psi..

sometime when im in second and i smash it to around 4-5k rpm, it will studer, then will loop when i put it in neutral.. what kind of spread should i gave on the safc2 as far as percentage when im climbing rpms

i checked my IC piping, fixed my boost leak, could it be bad plugs/wires?

Re: Stumbles at high rpm then loops
 

Considering you're on stock injectors, near stock boost, stock turbo.. I wouldn't think you need to go over even 10% correction on pump.

Re: Stumbles at high rpm then loops
 

im at like 40%.. maybe my injectors are clogged

Re: Stumbles at high rpm then loops
 

Are you logging? What's going on under these circumstances?

Re: Stumbles at high rpm then loops
 

well i seemed to get it better.. also ran some seafoam in it

i looked at my fuel trims Low is 129%, mid is 99% and high is 85%.. but i also dont have an adjustable FPR so i was told leave them alone??

cant remember how to adjust them, i had a write-up somewhere but lost it.. but i did get my idle to where i wanted it (750rpm)..

right now it seems like it will stop pushing at like 5k-6k, but is boosting..? rich??

Re: Stumbles at high rpm then loops
 

If what DB says is correct and you are indeed on stock injectors you should not be running so much correction. Are you on the stock fuel pump as well? If so I'd say turn the boost down a few PSI, zero out the SAFC and log it. Tune from there.

Re: Stumbles at high rpm then loops
 

im on 255lph pump

Re: Stumbles at high rpm then loops
 

btw how can u tell if u have compressor surge??

my bov flutters

is that bad?

stock 1g bov

Re: Stumbles at high rpm then loops
 

If you have to go positive on the hi-throttle map, then you are possibly going to run into fuel cut. You shouldn't really ever have to go much positive on a DSM, unless something else is wrong or your MAS is really hacked or you are trying to run a 2G MAS with stock 450cc injectors in a 1G.

If you are running a stock 1G MAS, you might be hitting MAS overrun.

Re: Stumbles at high rpm then loops
 

im running a 2g mas in a 1g..

should i tune with Lo-throttle map or high??

ive been tuning with high, but adjusting idle with low

what does fuel cut feel like

Re: Stumbles at high rpm then loops
 

Like eating the steering wheel.

Re: Stumbles at high rpm then loops
 

more discriptive???

as bad as an IC pipe blown off

Re: Stumbles at high rpm then loops
 

fuel cut is basically your car coughing and jerking you forward. Eating the stearing wheel isn't a horrible description. You'll know it when you get it. You should probably get some new plugs. Maybe some BR7ES...I've got a set for you for $15

Re: Stumbles at high rpm then loops
 

I wear a mouth guard to protect myself from fuel cutoff

Re: Stumbles at high rpm then loops
 

i got plugs.. im going to pull the old ones out and check em..

but like i said should i be tuning with lo or hi?

Re: Stumbles at high rpm then loops
 

btw what are 450cc good till

Re: Stumbles at high rpm then loops
 

I'm know pro at this stuff but maybe any information can help you. I have my safc2 programmed to road race engineering settings. I'm just waiting on my fmic to get in then i'm going to set up an appointment with DB or Map to get it tuned.

http://roadraceengineering.com/newafcsetting.htm

A list of what you've got on your car would really help.

Re: Stumbles at high rpm then loops
 

stock 14b..
fmic..
i want it tuned at least 18psi
safc2
450cc
255lph

Re: Stumbles at high rpm then loops
 

LOL! Anyways fuel cut sounds similar to an IC pipe blowing off but feels like IC pipe On and oFF. Picture a little midget pulling the IC pipe off then putting it back on constantly for couple hundred rpm or however long your fuel is.

Oh yea, check your plugs, sounds like spark blow out since it's only in the upper rpms (WOT?).