Turbo help

[bigwoofer]

I just installed my spool stage 3 turbo kit. I am running 7lbs boost, a vortech FMU, Flying Miata voltage clamp. Now we didn't get to finish the exhaust, so i am running an open downpipe (it will get connected to my custom exhaust system on monday).

Now I noticed 2 annoying things on the way home...

1) if you let of the gas, sometimes the revs drop right down to 100rpm and the car almost seems like it wants to stall.

2) Occasionally the car is backfiring as well.

Are these problems due to the fact i am running no exhaust whatsoever and the turbo isn't getting any backpressure??? Also my 2nd O2 sensor has the mil bypass, so it shouldn't be giving the ecu any funky reading should it?

Help

 

[KzA]

OK I GOT YA MAN..

The rpm stutter/stall is DEFINATELY going to be becuase of a vacuum leak. Search all of your connections for the smallest of a vacuum leak, because since it lets you run and idle then it will probably pretty small. Also, make sure your recirculating the air with the blow off..That would do it also..


The backfire is the total lack of restriction in your open DP, combined with how rich the mixture is now that your turbocharged..once you get your exhaust, this should go down considerably...Although some members say they can backfire on command..

 

[KzA]

actually, give your fmu a look...you might be running reallly really rich, which would explain the backfires definately....Also, if you were that rich, then the left over fuel right when you get off throttle could be bogging you down, hence the almost stall..I would say looking at your plugs would be the best to check the mixture..if they are all sorts of black, lighten up that mixture and get some new plugs

 

[mp5jeff]

open dp has nothing to do with your almost stauling problems, i ran open dp for like a year no problems, your BOV is your problem...adjust it and rev it in nuetral to see if you can get it to stop dropping rpms, or recirculate it.

 

[KzA]

D34th t00 j00r Bo\/

 

[insanoman2005]

using anything for EMS?? just an fmu and a prayer?

 

[mp5jeff]

fmu is sufficient enough for low boost...obviously won't make as much power as if you tuned the a/f's but still works.

 

[bigwoofer]

open dp has nothing to do with your almost stauling problems, i ran open dp for like a year no problems, your BOV is your problem...adjust it and rev it in nuetral to see if you can get it to stop dropping rpms, or recirculate it.

So I adjust the BOV with the harder/softer setting then???

 

[Emode]

harder, till it can rev in nuetral without stalling

 

[bigwoofer]

harder, till it can rev in nuetral without stalling

so just slowly turn the nut towards harder, rev and listen. Repeat until i don't stall???

I am using a greddy BOV by the way

 

[bigwoofer]

And the backfiring? I can check the plugs, not a problem, how long until they show signs of being too rich? Or should I wait till I get the exhaust finished, the backfiring happens once in a while, not all the time. Maybe 5 times last night in 3 hrs of driving...

 

[KzA]

yea it should be alot better once you get the full exhaust..I would wait to problem solve the backfiring until then to be honest..

 

[Matthew]

no you are stalling with the BOV because you are not recirculating. you will have to learn how to downshift, because unless you have a different design than the other spool kits, they decided to design it so you COULDNT recric without a new intake (IIRC). i know mine couldnt. had to learn to drive that way. you get used to it after a while.

 

[Matthew]

And the backfiring? I can check the plugs, not a problem, how long until they show signs of being too rich? Or should I wait till I get the exhaust finished, the backfiring happens once in a while, not all the time. Maybe 5 times last night in 3 hrs of driving...

the backfiring is caused because 1) you have no cats 2) you have extra fuel not being used that combusts in the exhaust causing the backfire.

if you get yourself a catted exhaust it may eliminate all the backfiring, BUT still with a FMU especially you will be hopefully running super rich and therefore backfiring like a mofo. when i was running 8psi on my spool setup with the BEGI RRFPR i would shoot flames and backfire like crazy - and that was with ONE cat. so with no cats its going to be worse.

now i have zero cats and i am sure once i can start boosting again i will be backfiring out the wazoo.

 

[accuser]

aren't those begi units adjustable?

i've got one, but haven't installed it yet (or looked at the manual)... but by just looking at the unit makes me assume it is adjustable

-pedro

 

[Matthew]

yes here are some pics of the way it should be installed