RB25DET anyone???? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

NateMR2 · 10-17-2016, 11:32 AM

I have been trouble shooting this issue for weeks... so I just traded my 06 audi a4 Quattro for a s13 with a rb25 that has issues... mod list.. apex SAFC aem oil pressure gauge, aem boost gauge, innovate wide band, cx racing top mount with gt35 63.ar claims (450-500hp)

regardless I don't know what fuel mods it had I know there is a z32 maf on it and AEM progressive fuel regulator. I had to take the progressive part off and run static 43 cause I couldn't pull enough fuel on the top end. my problem is I cant get it to consistently run right. 10psi seems ok no sputter afr is ok but doesn't seem to pull really at all. 12+ psi sputter as soon as it hits full boost like cuts out bad. afr goes flat for a sec so I'm assuming fuel cut. I don't think its knock retarding the timing bc the afr are 10.9 or so I know its a little rich but for sweeps I like to run rich and then start to pull fuel. I insulated the coil packs. changed plugs like 5 times... regapping every time down to.22 now. I'm just so confused if it ran strong at 10 psi it would be one thing but it doesn't. the car also idles ok but from never perfect always a little rich or a little lean. I compression tested in at 90.90.91.90.86.90

seems low I am a mile high so at sea level it would be maybe 120 still low no noticeable blow by I think maybe its been running to rich and glazed the cylinder walls oil drops bring it up to like 115 psi or so , I used 3 different gauges so I know its accurate and not the guage. any help plz...

KAT-PWR · 10-17-2016, 11:51 AM

Sounds like your shit is toast. Also sounds like the car was built by an idiot. Be surprised if it made more than 300 on that safc.

NateMR2 · 10-17-2016, 12:00 PM

"shit is toast" idk what that means. I'm not concerned with power as much as making it run correct.

S14Serge · 10-17-2016, 12:00 PM

Dam good luck may be time for a full rebuild!

turbronegro · 10-17-2016, 12:03 PM

He's saying that the motor is probably on its way out. Maybe refresh the bottom end and get it to an actual tuner on a standalone ecu. I never been a believer of tuning off a SAFC.

NateMR2 · 10-17-2016, 12:07 PM

well I really don't know anything about these motors been build audis and Toyota for a while. curious if thes can be reliable at 500hp with a mild build? I see so many people going in 30 different directions its hard to decide. I woulnt mind building it. the weird thing is the guy I traded with said it ran perfect with the factory turbo and it started this when he put the top mount on it.

OBEEWON · 10-17-2016, 12:28 PM

RB25 is the most moody motor ever. First you have to get rid of the SAFC because it makes the timing go crazy. Then you have to make sure all your connections, especially at the ECU are tight. That has been the cause of numerous headaches in my experience.

hanzbrady · 10-17-2016, 01:22 PM

So wait, you traded a (I'm assuming for this bit) nice running reliable A4 for somebody's Rac3Kor?

The SAFC and CX-racing components are a dead give away that whoever built the car had no intentions of doing it right.

If you want to keep the car it's time to tear everything down and start from scratch you're going to kill yourself if you try to hunt down all of the PO's mistakes and short cuts.

5280VertDET · 10-17-2016, 01:31 PM

Quote:

Originally Posted by hanzbrady

nice running reliable A4

Not possible.

NateMR2 · 10-17-2016, 01:54 PM

Yes and a4s are very reliable ran 273hp 318t for 30k miles no issue on giac stage 2 tune i traded because to get it to 600hp would be near impossible and the car only booked for 4000 so this motor with thw brackets alone cost 4000 another 1000 in guages 1200 k sport coil overs just seemed like a decent car and i dont daily it. Well i suppose a build is in order 500whp reliable possible on these?

10-17-2016, 11:32 AM	#1
NateMR2 Join Date: Jan 2013 Location: new mexico Age: 34 Posts: 35 Trader Rating: (0) Feedback Score: 0 reviews	RB25DET anyone???? I have been trouble shooting this issue for weeks... so I just traded my 06 audi a4 Quattro for a s13 with a rb25 that has issues... mod list.. apex SAFC aem oil pressure gauge, aem boost gauge, innovate wide band, cx racing top mount with gt35 63.ar claims (450-500hp) regardless I don't know what fuel mods it had I know there is a z32 maf on it and AEM progressive fuel regulator. I had to take the progressive part off and run static 43 cause I couldn't pull enough fuel on the top end. my problem is I cant get it to consistently run right. 10psi seems ok no sputter afr is ok but doesn't seem to pull really at all. 12+ psi sputter as soon as it hits full boost like cuts out bad. afr goes flat for a sec so I'm assuming fuel cut. I don't think its knock retarding the timing bc the afr are 10.9 or so I know its a little rich but for sweeps I like to run rich and then start to pull fuel. I insulated the coil packs. changed plugs like 5 times... regapping every time down to.22 now. I'm just so confused if it ran strong at 10 psi it would be one thing but it doesn't. the car also idles ok but from never perfect always a little rich or a little lean. I compression tested in at 90.90.91.90.86.90 seems low I am a mile high so at sea level it would be maybe 120 still low no noticeable blow by I think maybe its been running to rich and glazed the cylinder walls oil drops bring it up to like 115 psi or so , I used 3 different gauges so I know its accurate and not the guage. any help plz...

10-17-2016, 11:51 AM	#2
KAT-PWR Nissanaholic! Join Date: Dec 2011 Location: US Posts: 2,040 Trader Rating: (11) Rides Gallery: KAT-PWR Feedback Score: 11 reviews	Sounds like your shit is toast. Also sounds like the car was built by an idiot. Be surprised if it made more than 300 on that safc. __________________ MRP Manufacturing

10-17-2016, 12:00 PM	#4
S14Serge Zilvia Junkie Join Date: Apr 2009 Location: Dallas, TX Posts: 337 Trader Rating: (1) Feedback Score: 1 reviews	Dam good luck may be time for a full rebuild! __________________

10-17-2016, 12:28 PM	#7
OBEEWON Post Whore! Join Date: Feb 2006 Location: Hightened State of Emergency Posts: 6,053 Trader Rating: (9) Feedback Score: 9 reviews	RB25 is the most moody motor ever. First you have to get rid of the SAFC because it makes the timing go crazy. Then you have to make sure all your connections, especially at the ECU are tight. That has been the cause of numerous headaches in my experience. __________________

10-17-2016, 01:22 PM	#8
hanzbrady Zilvia FREAK! Join Date: Apr 2015 Location: Floriduh Posts: 1,166 Trader Rating: (4) Feedback Score: 4 reviews	So wait, you traded a (I'm assuming for this bit) nice running reliable A4 for somebody's Rac3Kor? The SAFC and CX-racing components are a dead give away that whoever built the car had no intentions of doing it right. If you want to keep the car it's time to tear everything down and start from scratch you're going to kill yourself if you try to hunt down all of the PO's mistakes and short cuts. __________________ [email protected]

10-17-2016, 12:03 PM	#5
turbronegro Zilvia Junkie Join Date: Sep 2012 Location: SoCal Age: 35 Posts: 325 Trader Rating: (0) Feedback Score: 0 reviews	He's saying that the motor is probably on its way out. Maybe refresh the bottom end and get it to an actual tuner on a standalone ecu. I never been a believer of tuning off a SAFC.

10-17-2016, 12:07 PM	#6
NateMR2 Join Date: Jan 2013 Location: new mexico Age: 34 Posts: 35 Trader Rating: (0) Feedback Score: 0 reviews	well I really don't know anything about these motors been build audis and Toyota for a while. curious if thes can be reliable at 500hp with a mild build? I see so many people going in 30 different directions its hard to decide. I woulnt mind building it. the weird thing is the guy I traded with said it ran perfect with the factory turbo and it started this when he put the top mount on it.

10-17-2016, 01:54 PM	#10
NateMR2 Join Date: Jan 2013 Location: new mexico Age: 34 Posts: 35 Trader Rating: (0) Feedback Score: 0 reviews	Yes and a4s are very reliable ran 273hp 318t for 30k miles no issue on giac stage 2 tune i traded because to get it to 600hp would be near impossible and the car only booked for 4000 so this motor with thw brackets alone cost 4000 another 1000 in guages 1200 k sport coil overs just seemed like a decent car and i dont daily it. Well i suppose a build is in order 500whp reliable possible on these?