maxing out MAF??? wont rev past 5500rpm

[rbspitfire]

i have an b20 with a bigger turbo and making 15psi with a stock ecu, the engine wont rev past 5500, is it maxing out the ecu and limiting rpm. if so how can i fix this? with a chip? actually now that i think about it it cuts rev to 5500 in neutral as well?

[rbspitfire]

anybody ever had this problem??

[Booztd 3]

I highly doubt you're maxing out the MAF. On my VG setup in my Z I maxed out the MAF at ~475rwhp. Is there any way you can monitor/log the MAF voltages while you're driving, or possibly get on a dyno to do it?

[HPmakesMEsmile]

Yeah I also am havin a problem with an rb20 swap I did a year ago. it now has an rb25 turbo and boostin 15lbs. 1st gear it revs fine. 2nd through 5th the ecu cuts it off at 5400-- 5500rpms. the S-afc reads that the maf is at 60-65% when this happens so I dont believe that is the case. AFR are reading great too not too lean or nothing. it is weird that it just startin doin this when it got cold out here. If anybody else has ever had this problem please let me know if you ever got it fixed.

[USMCgetsome]

check the throttle position sensor. especially on the safc. example is when you push it half way does it read 50% or 100% open

[rbspitfire]

i checked my tps yesterday and it checked out fine? i checked the maf for a return signal and its sending a return signal back to the ecu, and when i unplug it the car will die so its using the maf??

[HPmakesMEsmile]

the S-afc reads the throttle fine. but just to check it I'm going to go out there and reset the throttle reading and see if that changes anything...

[Sil240]

I highly doubt you're maxing out the MAF. On my VG setup in my Z I maxed out the MAF at ~475rwhp. Is there any way you can monitor/log the MAF voltages while you're driving, or possibly get on a dyno to do it?

Doesn't everyone Upgrade to the VG/Z32 MAF because they max out the RB20/25/26 Mafs???

[wawazat8402]

I am right now with 12psi, 3 inch crushbent exhaust, Greddy intake mani, fmic, and base fuel pressure bumped to 52psi to keep the amount of correction down. It can take about 1/2 to 3/4 throttle before it sees 5 volts and starts pulling timing. This is using an SAFC to keep the AFRs down though, so Im def a little under how much airflow it could see without lying to it.

[Joe]

I highly doubt you're maxing out the MAF. On my VG setup in my Z I maxed out the MAF at ~475rwhp. Is there any way you can monitor/log the MAF voltages while you're driving, or possibly get on a dyno to do it?

lol

people upgrade TO that maf because the SR/RB ones dont flow at those power levels.

[BoostFab]

i have an b20 with a bigger turbo and making 15psi with a stock ecu, the engine wont rev past 5500, is it maxing out the ecu and limiting rpm. if so how can i fix this? with a chip? actually now that i think about it it cuts rev to 5500 in neutral as well?

are you running an upgraded turbo?

[rbspitfire]

yes the turbo is upgraded to a 61mm.

[USMCgetsome]

well sir. If you have an safc you can check the voltage when closed, half and fully open voltages. I suggest you do that before you carry on. This goes between the maf and the tps. I had a hell of a time with my tps and throttle cable setup. Mine was loose and while my pedal was down to the floor my car felt real sluggish. Shortened the cable to make it tight and reset the tps and VIOLA. Runs like a damn v8 now adays. Didn't figure all that out untill i started check voltages on my safc from the tps and with a volt meter with the maf. Also, might wanna swap in another ecu for ease of checking. Between the ECU,CAS, MAF, TPS are the only things that affect the revs. HAVE FUN TROUBLESHOOTING. keep us updated.

[rbspitfire]

i have searched like no other, and have seen that there have been a few people with this problem, how did you guys fix it?? the tps voltage is fine the ecu is fine, it cant be maxing out the maf because it does it in neutral too?

[BoostFab]

yes the turbo is upgraded to a 61mm.

lol 61-1 turbo and 15# of boost, you are definately maxing your rb20 maf. even a t04e at that amount of boost will max out the stock maf too. btw! you want a q45 maf? i have one for sell.

[rbspitfire]

so when the maf is maxed put it puts a rev limiter? my GN just keeps going when it gets maxed out, is there a way to get around it? i know

[rbspitfire]

yes i want to buy a q45 maf, how much, i tried to e-mail you but the adress was hidden, let me know asap, thanks

[midnightsliding]

i have one off of a 94 Q45 if u cant work something out with him.