RB FAQ

[Ghost240]

Can the R34 (RB25DET Neo) bottom end be mated with an RB25DET S1/S2 head?

[singlecamslam]

Just found this because i needed one. Quoted from nico.

I'm new here but I've been an Import Tech for over 15 years. I've done every things from Up grading brakes to full on engine builds! I've owned my own shop now for awhile. I believe in sharing information when I can with fellow car guys! I just thought there might be someone on here that could use this information!


I just ordered a clutch slave cylinder from one of the big suppliers of RB swap parts out on the West coast! It was for a customers car. I payed $80 shipped for it. When it got here it was in a Centric Parts box. The little paper that came in the box said it was a Touge Racing Products RB25DET Slave Cylinder.It had the Centric part number removed. I got on the phone with Centric and sent them some pictures of the slave cylinder. They told me it was one of theirs but had the mounting holes drilled out. They gave me the part number.

I called my local NAPA store and had them cross the number for me. I payed $16 for the same cylinder! All I had to do was drill out the holes!

Here is the good stuff!! The part numbers!!

Centric part# 13844106
NAPA (United) part # 37487
LUK part # LSC213
O'Reilly part# 37487

I hope this information helps! I hated giving $80 for a $16 dollar part that took someone an entire 60 seconds to make fit!

Cheers,
Jon

[Zacho]

^ Wow, good info. Thanks!

[marshallpre1]

When it comes to oil coolers...

I just want to know where the oil thermostat is located. I understand that to properly install an oil cooler, you should get a sandwich adapter plate WITH a thermostat to ensure that the car gets to operating temperature (which is difficult with an no-thermostat installed oil cooler). So question is this:

If I just buy a generic kit (from say Mishimoto) and the sandwich plate does NOT have a thermostat, can I just directly bolt it to where the oil filter bolts into? Or is it imperative that I bolt the Mishimoto sandwich plate directly to the block (and therefore is NOT a proper install, as I would not have a thermostat)?

Thanks,
Jeremy

[240sxwanted]

do r34 rb25det turbos have a steel wheel? i just blew my ceramic turbo right after i installed a boost controller, which it only boosted up to 7.5 psi. Need some input from people. Find a cheap rb25 turbo, or go with the r34 rb25 one, which some people say that it does and some say that it doesn't have a steel wheel. Also will it hold more boost?

[Sergio180sx]

i have a rb25 s2 and a rb25 tranny in my coupe with the HUD if u use a z32 speed sensor for my mph and tach does it matter if its N/A or TT???

Thanks

[GSXRJJordan]

Originally Posted by marshallpre1

When it comes to oil coolers...

I just want to know where the oil thermostat is located. I understand that to properly install an oil cooler, you should get a sandwich adapter plate WITH a thermostat to ensure that the car gets to operating temperature (which is difficult with an no-thermostat installed oil cooler). So question is this:

If I just buy a generic kit (from say Mishimoto) and the sandwich plate does NOT have a thermostat, can I just directly bolt it to where the oil filter bolts into? Or is it imperative that I bolt the Mishimoto sandwich plate directly to the block (and therefore is NOT a proper install, as I would not have a thermostat)?

Thanks,
Jeremy

You can always add an inline oil thermostat (I use Permacool and Earl's units), and any decent kit will let you plumb it in with new lines. The problem is that with aircraft lines and fittings, adding 4 fittings and 4 hose ends is pricey!

Originally Posted by 240sxwanted

do r34 rb25det turbos have a steel wheel? i just blew my ceramic turbo right after i installed a boost controller, which it only boosted up to 7.5 psi. Need some input from people. Find a cheap rb25 turbo, or go with the r34 rb25 one, which some people say that it does and some say that it doesn't have a steel wheel. Also will it hold more boost?

The R34 Neo RB turbos do stand up a little better, but they're generally not worth the price premium. You shouldn't have had any problems at 8psi, I say if you want to stay stock get another S1 turbo, if you want to go bigger get a T3/T4.

Originally Posted by Sergio180sx

i have a rb25 s2 and a rb25 tranny in my coupe with the HUD if u use a z32 speed sensor for my mph and tach does it matter if its N/A or TT???

Thanks

I believe Z32 NA and TT use the same VSS, but I don't know for certain that it's the right signal for your HUD.

[240sxwanted]

can an rb26 turbo be used on an rb25 with an adaptor flange since its t2 flanged, and will it the downpipe and elbow line up?

[battle_240sx]

i have a extra rb20det and i am getting the head redone and i need some help cause i want to use a rb25 block. i have looked everynight on the net and have not found any answers to my qustions. some say that it will just be like a rb25 without the vtc and others say its gonna be like a rb22 or 23. i just want to see what u guys think. thanks

[tt99ol]

Originally Posted by 240sxwanted

can an rb26 turbo be used on an rb25 with an adaptor flange since its t2 flanged, and will it the downpipe and elbow line up?

Of course with an adapter it will bolt up to the manifold however, the rb26 t28's are tiny, yhey are smaller than an sr20's t25, if you use 2 of them then go for it but i wouldn't use it as a single unit on anything larger than maybe 1.6L and the downpipe would not fit nor would the intake side piping

[bardabe]

Originally Posted by GSXRJJordan

I believe Z32 NA and TT use the same VSS, but I don't know for certain that it's the right signal for your HUD.

Z32 Twin Turbo and N/A use different VSS due to the Different Final Drive. The VSS itself is the same but the gear on on the tip of the VSS is different between N/A and Twin Tittie. You want to use to the N/A One to match the Final drive and gearing of the tranny to the S13. you will still need to modify the Cluster though the S13/S14 cluster will still read too slow. you need to recalibrate it. What i would recomend is getting a Km/hr cluster and modifying it to read 180pmh

-Juan

[GSXRJJordan]

Originally Posted by bardabe

Z32 Twin Turbo and N/A use different VSS due to the Different Final Drive. The VSS itself is the same but the gear on on the tip of the VSS is different between N/A and Twin Tittie. You want to use to the N/A One to match the Final drive and gearing of the tranny to the S13. you will still need to modify the Cluster though the S13/S14 cluster will still read too slow. you need to recalibrate it. What i would recomend is getting a Km/hr cluster and modifying it to read 180pmh

-Juan

Thanks for the correction Juan!

[jlawdet]

Originally Posted by speeddreamz

I had to bang mine for a half hour =T

Werrrrrrd i just did an RB swap last night literally. you dont have to bang the actual firewall but the transmisson tunnel. especially on the passenger side cause the starter. The RB was 25 that i swapped and we used McKinney mounts with the stock s14 kouki crossmember. it went smooth (as smooth as an RB swap can go). there is some fab required but not a crazy amount.

[eklips3]

Originally Posted by battle_240sx

i have a extra rb20det and i am getting the head redone and i need some help cause i want to use a rb25 block. i have looked everynight on the net and have not found any answers to my qustions. some say that it will just be like a rb25 without the vtc and others say its gonna be like a rb22 or 23. i just want to see what u guys think. thanks

its not a bad idea if you want to experiment. but its just gonna be considered a rb25 with a rb20 head. so it will stay a 2.5 liter
to be honest i dont know what your results will be , but a rb20 head flows a little less then a rb25 head. for electrical install you're lucky, you wont have to change anything with your harness cause you are keeping your rb20 head.

[battle_240sx]

Originally Posted by eklips3

its not a bad idea if you want to experiment. but its just gonna be considered a rb25 with a rb20 head. so it will stay a 2.5 liter
to be honest i dont know what your results will be , but a rb20 head flows a little less then a rb25 head. for electrical install you're lucky, you wont have to change anything with your harness cause you are keeping your rb20 head.

i looked at it today at work and it looks like the only thing im gonna have to swap is the knock sensors. the head is gonna get a mild port. the only other thing i need to find is a aftermarket intake mani so if any one knows of any just let me know. thanks for the help

[eklips3]

Originally Posted by battle_240sx

i looked at it today at work and it looks like the only thing im gonna have to swap is the knock sensors. the head is gonna get a mild port. the only other thing i need to find is a aftermarket intake mani so if any one knows of any just let me know. thanks for the help

nice !

for intake manifold, i know it sucks but you gotta go ebay or kontact KU engineering directly. i got mine from ebay but its still legit.

[smoked240]

With swaping on the rb20 head you should get more Compression and a little more power.

[eklips3]

Originally Posted by smoked240

With swaping on the rb20 head you should get more Compression and a little more power.

how would you get more compression with a head ? compression relies on how close the pistons come to the top of the head.

RB20 compression ratio is 8.5:1
RB25 compression ratio is 9:1

so with him using the 25 block his compression will stay the same

[battle_240sx]

Originally Posted by eklips3

how would you get more compression with a head ? compression relies on how close the pistons come to the top of the head.

RB20 compression ratio is 8.5:1
RB25 compression ratio is 9:1

so with him using the 25 block his compression will stay the same

well thanks for all of the help. i think my rb20 that i just put in this weekend is f..ked cause im getting a noise that sounds like the valves are hitting the piston and i dont know how that could be cause all of the timing marks are lined up so if anyone else has had this problem let me know.

thanks again

[eklips3]

Originally Posted by battle_240sx

well thanks for all of the help. i think my rb20 that i just put in this weekend is f..ked cause im getting a noise that sounds like the valves are hitting the piston and i dont know how that could be cause all of the timing marks are lined up so if anyone else has had this problem let me know.

thanks again

sounds like loud lifters to me if your timing is all correct. dont forget the factory injectors. you can really hear them tick which could be mistaken for something.

if it actually lifters, pull out the cams the lifters are right under them and all you gotta do to take them out is put a magnet to it and pull.
see how they look , bleed them and put them back in.

[battle_240sx]

Originally Posted by eklips3

sounds like loud lifters to me if your timing is all correct. dont forget the factory injectors. you can really hear them tick which could be mistaken for something.

if it actually lifters, pull out the cams the lifters are right under them and all you gotta do to take them out is put a magnet to it and pull.
see how they look , bleed them and put them back in.

it dont sound link the lifters it more like a hard tap. the moter did sit for a year. when we first started the motor it ran fine just a little miss but it was due to my old spark plugs but we fixed that and a bad alt. then the noter started to make the noise. ive been looking all day and cant get a answer about the rb20 being a interference motor or not. you seem like the person to know when it comes to rb's so thanks for all of you help

[Sileighty_85]

Originally Posted by eklips3

if it actually lifters, pull out the cams the lifters are right under them and all you gotta do to take them out is put a magnet to it and pull.
see how they look , bleed them and put them back in.

RB lifter are self bleeding, Its in the FSM.
You gotta hold the RPM's at like 2,000 for a few minutes or somthing.

[repda916]

just got my rb running one problem,
sounds strong and everything but when i give it gas (pedal to the floor)
It takes days to get up to speed. as if the brakes are on but they are not.
no boost leaks. any ideas?

[battle_240sx]

i need to find the oem part number for a rb20det headgasket if anyone has it let me know so i can get my car back on the road before the weekend..

[eklips3]

Originally Posted by battle_240sx

i need to find the oem part number for a rb20det headgasket if anyone has it let me know so i can get my car back on the road before the weekend..

i have one . and im willing to ship it to you

[Pandapants]

Originally Posted by battle_240sx

it dont sound link the lifters it more like a hard tap. the moter did sit for a year. when we first started the motor it ran fine just a little miss but it was due to my old spark plugs but we fixed that and a bad alt. then the noter started to make the noise. ive been looking all day and cant get a answer about the rb20 being a interference motor or not. you seem like the person to know when it comes to rb's so thanks for all of you help

Bent valves have a distinct sound, like metal on metal, way different than stuck lifters. RBs are interference motors too.

[battle_240sx]

Originally Posted by eklips3

i have one . and im willing to ship it to you

thanks but i got one from work today i paid 20.00 for it. i guess that it one of the good things about working for nissan.

[battle_240sx]

Originally Posted by Pandapants

Bent valves have a distinct sound, like metal on metal, way different than stuck lifters. RBs are interference motors too.

yeah they where bent but i got new ones and installed them just aiting on the head gasket but it will be back together this week just in time for the drift event yey

[blkkouki]

Do any of you guys know if I can use the RB25DET fuel rail and injectors on an RB20DET?

[singlecamslam]

Ok noob question, do i need to use my s13 temp sensor (for the gauge cluster water temp) on the rb25 for the cluster temp to work? mine doesnt work after i hooked it up.