USRB25S13

There are two 240sx's in the US that are making 500+ whp on stock RB25 motors. One is a neo motor and the other is a series II motor. The Neo motor dynoed 587 whp without opening the motor up. It has a custom intake and turbo manifold. He ran an 11.1 his first time out. The other 240 has ran consistent 10's on stock motor. Then he put a headgaster/studs and cams on and is now in the 9's. Last I heard his tranny broke and he is now running a powerglide tranny.

Can anyone else comfirm that? I am finding that if I set my timing to 15 degres with the timing light the car runs bad. I then add timing with the PFC and it clears the car up. So that would make sense but why would it read double?

The only side affect would be that oil that comes from your turbo (All turbos leak some oil into the intake) will coat the MAF wire and will make it dirty pretty quick. Just make sure you clean it more often.

If I had a choice between MAF or MAP setup I would take MAP. You are correct when the boost reaches it's pressure the voltage from the MAP reads the same. But the RPM's increase and that's when the injecter duty cly increases to give the motor it's required fuel. The trick is to figure out how much more fuel you need and that depends on your setup. The MAF measures airflow and caculates the amount of fuel needed. Both systems need tuning with MAP needed a bit more. I owned a turbo honda (Map based) and now the Nissan's MAF system. The problems I have with the MAF is the motor always goes rich between shifts and light throttle under slight load can cause the car to violently cutoff, Thats from going with 2-3 psi and then the bypass valve opening. The nice thing about the a MAP system is BOV's don't affect them (No anouning stalling). If you look at any aftermarket stand alone they are ALL MAP based (AEM, Motec, Haltech, Electromtive, SDS, Megasquirt, ext) It also saves alot of work when building a setup. you don't have to recirculate or worrie about MAF placement. Don't get me wrong the PFC is nice for most setups. It's plug + play and easy to tune.

I had the stock MAF and the problem was still there. No I have the Q45 MAF on and no difference. The MAF voltage looks good (steady) while it is surging.

As for changing the 02 aim settings I need a datalogit to do that correct? Also I though of some thing else. My Airflow settings are 93% at low voltage and 83% @ 5.12v. I need a good guide to seting up a PFC. Where can I find one?

Thanks for the replys My Q45 MAF will hit 5v's @ 15 psi of boost. I plan to run more boost once I get larger injectors. My turbo good for 650hp. So that is why I have the Q45 maf When I turn the o2 feedback off the car runs pretty rich at cruising speeds. between 12-13:1. I was looking at the sensor check screen while driving. Nothing looks out of place. As for the EMS I am still considering getting one since I can get one for $1300 USD and sell my pfc for 850. I would then have a map based standalone with boost controler that plugs into the stock harness.....But that's just a though and I would rather get what I have working better. Another quick question. When I check my timing the PFC will show 15 degree's timing on the comander but the timing light shows 25. Is it supose to be double the PFC's reading? If I adjust the timing to 15 on the crank the car runs really bad.

Hi, First let me list my setup; 92 240sx Series II RB25DET Motor with a larger turbo/FMIC 480cc s15 topfeed injectors Q45 MAF Nismo FPR Walbro high pressure pump The problem that I have been having ever since I had the Power FC is when I am driving down the road trying to hold a constant speed the car surges. It's kinda faint but passengers in my car can tell. I have a wideband O2 sensor and it shows the car going rich/lean and the surging goes at the same pace as that. So to keep this problem from happening I turn off the 02 feedback on the PFC. But my car gets terriable gas milage this way. I tried another O2 sensor and that didn't help. Would hooking up the speed input do anything? I didn't hook it up with the stock ECU so I wouldn't have fuel cut. Other then that I am lost. I may just get an AEM EMS if I can't figure this out.

And the cars are 10%-20% faster over here too. Kinda weird isn't it.

I got an R32 RB26 motor and was wondering if you can tell what year the motor is from the serial #? The # on the block is 030852A. Will that tell me anything?

Anyone have a picture of the two gaskets next to one another?

I have seen dynoes of Stock R33 turbos making 380-390 whp. Mods were exhaust/intakes and dumps. (Using a Power FC of course.) I was just wonding if anymore power can be made with the turbos I have since I don't have to worrie about the ceramic wheels coming apart or is 400 whp about the max the stock compressors/wheels will make?

I found out my turbos that came on my RB26 are metal but they otherwise appear to be stock (AR .42/.48) So I would assume I will basically be running stock GTR turbos that won't fly appart. With that in mind, What are the turbo's good as in power? Would 400 hp be out of the question?

So is it possable to make more power with the metal turbine wheel? Or is 15 psi maxing out the compressor side?

Are there any pics comparing in detail the N1's to the stock turbos?

Here is a pic of my turbine wheel. Booth turbo's are cleaner then the inlet pipes so I feel they where replaced.

Wow. So I got some steel wheels! That's the thing I noticed was the nut was cut on mine and the RB25 turbo had a full nut. So what kinda boost can these turbos run? Any chance this motor I have is a Nismo motor?

Thats what I was thinking. If I tap on the RB26 turbos they make a slight tinging sound and the rb25 turbo doesn't make any kinda sound other then the tap from me hitting it. I also tried an Ohm meter thinking I would see some kinda reading on the one turbine and not the other but they booth seem to be the same. Also were can I find a pic of a oil drive that is too short compaird to a proper one? I need to check that out before I decied if I want to swap the RB25 with the RB26.

I am looking at the turbo's that came on my R32 RB26DETT. I want to replace them with steel turbine wheels. I was looking at them and the turbo's are in gear shape (no shaft play at all) they look really clean. I first tried a magnet to the wheels and it didn't stick. Not sure if that's a good test or not. I then looked at an RB25 turbo I have laying in my shop and they wheel on that one looks white where as the turbine wheels on the RB26 look dark. Also on the back of the exhaust side of the head there is a stamp on the head that says N6 Also it has a nismo timing belt.

I did my injector swap a few months ago and I didn't remove the upper plenium. I just took off the throttle body and all lines under the plenium to get the rail out. It was a pretty easy job. I have an inpact screw driver to take the injectors screws out. That makes a big difference.

Now how about going the other way? I have an HKS cast manifold for my RB25. I am pondering the idea of getting an RB26 motor and was thinking how nice it would be if I could use the HKS manifold on the 26.

I would like to know as well. Is there enough ventelation in the RB motor to let all the crank case pressure releave it's self on it's own?

What turbine wheel and housing does that GT30 turbo use? What other mods do you have done to run that much boost?

Ok. Lets start with the setup. I have a T3/T4 56 trim stage 5 wheel. Turbo mounted on the stock manifold with adaptor box for external wastegate. Motor is a series II RB25DET Apex PFC Q45 MAF S15 injectors (What should the lag settings be?) Nismo FPR Pressure is set at 38 psi @ idle under vacum. Walbro high flow fuel pump. 3" turbo back exhaust (no cat) 17X9X3" FMIC. Running 14 PSI Car when 13.0 @ 112 running 12 psi. For my wide band I have a tec edge (not sure what model but it's the older one) I noticed even when I am not running the car hard between shifts my A/F goes right and peggs the meter. The meter on goes down to 10:1. I have the car street tuned to run 11.5:1 or richer. See very little knock on the moniter (only jumps to 25-28)

My car is running the stock BOV plumed back into my intake. When I shift from 2 to 3rd or 3rd to 4th I get what feels like lag but my boost is @ full boost (14 PSI) the car takes a second (more like 1/2 second) then it takes off. I am getting very rich readings on my A/F moniter. Since it only reads 10.1:1 I don't know how rich it gets but I feel this overly rich condition is why my car bogs between gears. I have even tried flat shifting but the A/F's still get rich. There doesn't seem to be anything I can do with the PFC to correct this. Is there an electronic device that will solve this problem?