Jump to content
SAU Community

Need Help! Difference Between Rb25det And Rb25de

Judasentinel666
 Share

Recommended Posts

Judasentinel666 Rookie

Judasentinel666

Posted
Posted

Hi there.

I am curious to know what differences, if any, exist between the internals of RB25DET and the RB25DE (N/A). I am currently running an RB25DE with a turbo on it, but due to higher compression, cannot run more than 10psi of boost.

I have been informed that the internals of the RB25DE are WEAKER, not made of the same material as the RB25DET, and since the compression of the motor is higher, I cannot run more boost, which also means that I am limited in my options for upgrades to get more power out of that motor. My RB25DE also does not have oil squirters in the pistons. I didnt know that there were oil squirters in the BR25DET pistons.

So, my issue is as follows:

I can EITHER buy an RB25DET (full motor), OR change the internals on my RB25DE to make it the same as, or better than, an RB25DET. All I want to know is that if I want to run more boost (like 15-20 psi or 1.4 bar) on my car with the N/A motor, what all do I have to change inside of it? And how do I go about doing it? What pistons, crankshaft, camshaft, etc., is recommended? Do I keep the same head and valves or d they need to change as well?

Please help me, I desperately need someone to guide me here.

joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted
Hi there.

I am curious to know what differences, if any, exist between the internals of RB25DET and the RB25DE (N/A). I am currently running an RB25DE with a turbo on it, but due to higher compression, cannot run more than 10psi of boost.

I have been informed that the internals of the RB25DE are WEAKER, not made of the same material as the RB25DET, and since the compression of the motor is higher, I cannot run more boost, which also means that I am limited in my options for upgrades to get more power out of that motor. My RB25DE also does not have oil squirters in the pistons. I didnt know that there were oil squirters in the BR25DET pistons.

So, my issue is as follows:

I can EITHER buy an RB25DET (full motor), OR change the internals on my RB25DE to make it the same as, or better than, an RB25DET. All I want to know is that if I want to run more boost (like 15-20 psi or 1.4 bar) on my car with the N/A motor, what all do I have to change inside of it? And how do I go about doing it? What pistons, crankshaft, camshaft, etc., is recommended? Do I keep the same head and valves or d they need to change as well?

Please help me, I desperately need someone to guide me here.

i wouldn't put 15 pounds through a stock DET either...

and esp for 20 psi... you'll need forged internals on either

Krishy Grand Master

Krishy

Posted
Posted

stock i think its ok to run 1 bar but not for long....anything higher then that you will need some internal work done like forged pistons and stuff.....running more then a bar is really bad for the stock turbo.....so i say upgrade the internals or your current motor and see how it goes....i guess which options would be cheaper/better suited for you!

NISZILA Grand Master

NISZILA

Posted
Posted

With the higher compression ratio, i wouldn't be running more than 7psi... unless you want things to go BANG!!

To change the compression ratio, get a really think gasket... this will lift the head and make the compression ratio less. Then you can increase boost a bit more safely.

As the others have said... I wouldnt't run the numbers you're taking about on a stock engine...

To better answer your question... what other supporting mods have you got... or is your engine totally stock with a turbo wacked on and the boost cranked?

  • 3 months later...
steelmanac Newbie

steelmanac

Posted
Posted

Are you running an R32 or an R33 RB25DE ? I'm not sure about the internals of the R32 block. The R33 DE crank and rods are the same as the DET. The pistons have a hair larger dome, and are not really strong enough to support a lot of boost. The DE heads have a slightly smaller combustion chamber, but are otherwise identical to the DET. DE compression ration is 10:1 as you know, but that is fine for a turbo car that is well tuned. Most people reduce compression ratios for ease of tunning, and to reduce the risk of detonation. Detonation kills, but with proper tunning higher compression makes a ton of power.

ssshonky Grand Master

ssshonky

Posted
Posted (edited)

dont forget though that the higher compression motor should make MORE power than the equivalent boost on a DET motor. So running 7psi thru a +T conversion will net you more power than 7psi on a standard DET motor.

I have always been of the school of thought that going a DET motor straight up is going to be a hell of a lot easier than doing a bolt on turbo. But mind you done correctly a +T motor can give you good reliable power day in day out .. just need to be realistic about how much HP you want to get out of it.

Are you running an R32 or an R33 RB25DE ? I'm not sure about the internals of the R32 block. The R33 DE crank and rods are the same as the DET. The pistons have a hair larger dome, and are not really strong enough to support a lot of boost. The DE heads have a slightly smaller combustion chamber, but are otherwise identical to the DET. DE compression ration is 10:1 as you know, but that is fine for a turbo car that is well tuned. Most people reduce compression ratios for ease of tunning, and to reduce the risk of detonation. Detonation kills, but with proper tunning higher compression makes a ton of power.
Edited by ssshonky

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      Mistakes were made, my R34 Story

      By Duncan · Posted

      Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • funkymonkey
      Jacks that fit under GTR lips that can reach the subframe?

      By funkymonkey · Posted

      I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...