Jump to content
SAU Community

Rb25det Questions


Recommended Posts

Guest RaceBreed25DET

Hey All,

Alright i got a few things to be clarified:

I am pre-planning the modifications for my future R34GT-T lol which i will own as soon as june!

I am aiming for a 300rwkw power range. As much as this wont be possible on the stock RB25DET, well it can be possible but dont want to murder the car over time. So to the question will i need to forge my motor and if so what prices will i be looking at just for parts and additionally what be the labor costs.

BUT say 300kw will be "ok" to run on the stock motor how long will it be able to take the abuse considering it will be a WEEKEND car only so driving will be twice a week. I dont know guys i need your opinions/advise's.

Cheers

Link to comment
https://www.sau.com.au/forums/topic/207563-rb25det-questions/
Share on other sites

  • Replies 60
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

ive seen cars make that power for years.... and others last only a few months, there are just too many variables to answer it simply. Tune, oil, kms etc all play a part in longevity.

GeeTR says that if you want good response, you'll need a smallest turbo you can fit, that makes the power you want, then put yourself at the pointy end of the compressor map... which means 1.5bar +

Spend 5h on SAU looking around, talk to your preferred tuner if your not keen on planning it yourself, then rebuild your motor.

300rwkw at high boost pressures, means your using a turbo thats small and sharp; a butt load of fun on the street.

Congrats on purchase, you must be stoked

Edited by GeeTR
Guest RaceBreed25DET

Cheers for the replies.

GeeTR, No i havent purchased it yet will be purchasing in June.

Jase-R34: Well applying for 35g loan will purchase r34 for around 25g leaves me 10g in the pocket may be even 1-2g more saved.

This is my plan so far.

Wheels:

20*8.5 HP Design - Gold -$2,600.00

Engine:

Muffler:

XforceVarexMuffler - $500.00

Straight Through System - $700.00

Blow-Off Valve:

GFB Deceptor Pro - $733.95

Engine Management:

Apexi Power FC Computer with Hand Controller - $1,600.00

Apexi AVC-R Boost Controller - $765.45

Engine Internal Hardware:

Arias Forged Piston Kit - Nissan RB25DET 20-over - $1,480.00

Crower Steel Billet Connecting Rods - Nissan RB25DET - $2,203.95

Fuel Management:

BOSCH 044 600hp External EFI Fuel Pump - $344.00

As you can see ^ thats only those two listed in the engine internals section and total altogether is: $10,583 without installation/labor.

Now i have to decide weather i should get those in the list or spend the money on the rebuild/forgies that way i know im starting off with a tougher and healthier motor and slowly build my way up with the mods.

What do you guys think

Edited by RaceBreed25DET

You'd honestly have to consider weather it would be cheaper to sell the RB25DET as a complete motor and run an RB30 by the time you go to the expense of fitting forged internals etc. a GT35R will get you to 300kw with room to expand. If you still want 300rwkw but with more low end a 3076, or GT3082r (aka 3040) would be a good trade off.

I agree on the 'wait til you've got it' front. Have you driven this kind of car before? 140-150rwkw might be enough for you for a while.

Anyway, going by previous car purchases (performance cars OR not): Allow 5-10% of the cost of the car in repairs in the first 2 years. Something WILL break, regardless whether you mod it or not. That's been my experience so far.

Then WRT mods: You'd be looking at another 3-4K or more in labour if you're having all that stuff done. It may be because I'm at work and none of the pics you've added are coming up, but I don't see anything about suspension or clutch. Add another 2-4K depending how far you go with them.

By the way, before you apply for a 35K loan (like I did), please be aware that most of the major banks have 30K as a glass ceiling that people without "assets" can borrow. And by assets, they mean if you don't own land, or a (resaleable) car, or stocks or anything, and you don't have a LOT of disposable income, it's HIGHLY unlikely they'll lend you over 30K. And rejected loan applications from one institution impact on applications to other places. Just sayin', cos that's what I found and ended up going through a (knee) broker ( :D ), you might be in a different situation.

Because 3 years ago, I had the same wonderful dreams you currently have: My R33 GTST (so same engine as what you'll be getting):

Car: 25k (bit more than should have paid, but was close and in pretty good nick)

Instantly needed new coilpacks (fault was hidden by the seller, only figured it out a few months later), 500

Water pump and radiator were knackered after my first really 'spirited' drive, few hundred

Front rotors had signs of cracking after 1 year, 500

About a year ago the suspension was found to be on the front bump stops + other issues, 2K

And none of this was power upgrades or appearances etc (which I have also done, but they add up to way more than the boring 'fixes').

Get the best car you can afford to, keeping 10% money spare. If nothing falls off/blows up in the first year, THEN think about upgrading it. Just bare in mind that upgrading one thing often breaks other bits.

Ever thought of just buying an R33 GTR? If you look hard, you *might* find one for 35-40K You'd have a bit more power than a 25DET, and the GTRs are built a bit stronger. Plus, you hopefully wouldn't feel the urge to upgrade it for the first year (if you do.... eyes bigger than your stomach :) ).

Edited by sl33py

Don't take this the wrong way but I have a few questions.

How long have you had your license and have you had a turbo rwd car before?

Not trying to put you down.

But when I saw this..

20*8.5 HP Design - Gold

and this

GFB Deceptor Pro

and then this

RaceBreed25DET

I immediately assume that you have just finished your Provisional License, have never owned a rwd turbo car or Nissan of any sort.

I also assume you've done some research on these forums or car mags as you've bothered to get details and price of correct pistons.

If you have never owned a turbo rwd car before, then may I just suggest that you buy the car first and do the usual simple mods.

exhaust, filter, cooler, boost and ecu to tune.

on an R34 GTT, the above will give you about 220rwkw.

That is a fair whack of power.

probably enough to run a 12 second pass.

replacing injectors and turbo and AFM will get you to the next level of about 250-260rwkw.

that is serious power for most if not ALL street cars.

even at that level, unless you have great suspension and really good quality tyres of at least 255 wide, you are going to struggle for traction on most gears.

And I might also mention that at that level, you haven't needed a rebuild etc etc.

you will need clutch and suspension and wheels and tyres etc which you don't seem to account for in your $10K spending money.

there are a few people with this sort of power.

it might be a good idea to have one of them take you for a spin in it.

of course, if you have already had that sort of power and have had rwd turbo cars, all of the above is wasted intrweb space..

Guest RaceBreed25DET

Tell you what guys the advise's you are throwing at me is really good and i appreciate it.

sl33py you are right about things breaking after all its a 98 model 10 years if somthing hasnt broken with a previous owner then your in for it. - cheers for the wise advise especially about the loan stuff.

Delljit: Ummm for me it's really really necessary its kind of a wank factor but two main things cops love pulling you over for is bov & exhaust.

GTST: Yes i admit the error with the extra e in breed lol and also your F****n good with the assuming shit lol Yep im on my P's and will be on my full license in april and no dont start feeling sorry for the future r34 im getting i have learnt my lesson with the last two fwd (yes you have my approval to laugh :D) i have written off. Yes with all the advise on here its best for me to get comfortable with the stock power then work from there.

Two questions though GTST: Whats wrong with those wheels..the sizes may not be correct but i had the info as a base and also what is wrong with the bov, its volume controllable i know its bit of a wank factor but it most likely will save my ass when cops are around.

oh and btw this was in no way a waste of interwebz space lol all of you guys have have made me choose the right decision.

Edited by RaceBreed25DET
Guest RaceBreed25DET

Also guys just because ive listed all those things are more important that the ones not mentioned. No doubt i will be doing mods in a proper order.

Other questions is: i love turbo lag lol yeah call me weirdo but i just love the feeling where you hit the pedal to the floor and all i is doing is pumping out the motor power and then around 3500rpm it pulls like crazy, i guess i like more torque than power what setup will make me achieve this im guessing bigger turbo due to longer time to spool n shit.

With the BOV, its really not needed... The standard one is quite sufficient, and if you need a larger one later get one off a GTR

It looks to me like you like a bit of car bling, so I assume that you will eventually stretch some tyres on your rims to get some JDM offset, so look at getting 9.5" rims for the rear, and you will need the money from your BOV to cover them.

Can I ask what your previous fwd cars were?? I went from an S12 (rwd) and with standard power it took a couple of months to get a good feel with the car and its power, so take your time on the mod front unless you want another write-off on your hands. its not a race! lol

Guest RaceBreed25DET
there was a guy on the M5 forums that posted up something like this. Don't repeat it.

Nope not me only a member of this site.

With the BOV, its really not needed... The standard one is quite sufficient, and if you need a larger one later get one off a GTR

It looks to me like you like a bit of car bling, so I assume that you will eventually stretch some tyres on your rims to get some JDM offset, so look at getting 9.5" rims for the rear, and you will need the money from your BOV to cover them.

Can I ask what your previous fwd cars were?? I went from an S12 (rwd) and with standard power it took a couple of months to get a good feel with the car and its power, so take your time on the mod front unless you want another write-off on your hands. its not a race! lol

those two fwd cars were a Honda Accord and a Celica

Keep it stock for a few months at least first is my suggestion. I've just been through the same thing.....gone from owning slow fwd cars to my first turbo RWD car....my GTT

Even standard they are quick enough and i highly recommend driving it round until you get used to it.

If you want to do cosmetic mods first then go for it. The BOV is a waste of money IMO as well...

After you get used to the stock power just do what GTST said (he seems to know his shit :D), and 200rwkw will be great fun!

And trust me 10K won't go far, especially if you're buyin rims n tyres as well as performance mods.

But overall you will love the 34 when you get it, I know I do!! :D

Guest RaceBreed25DET
Keep it stock for a few months at least first is my suggestion. I've just been through the same thing.....gone from owning slow fwd cars to my first turbo RWD car....my GTT

Even standard they are quick enough and i highly recommend driving it round until you get used to it.

If you want to do cosmetic mods first then go for it. The BOV is a waste of money IMO as well...

After you get used to the stock power just do what GTST said (he seems to know his shit :D ), and 200rwkw will be great fun!

And trust me 10K won't go far, especially if you're buyin rims n tyres as well as performance mods.

But overall you will love the 34 when you get it, I know I do!! :D

Yeah man decided just that and i agree GTST knows his shit honestly i cannot wait for june!! Loved 34's since year 10 now it's been 5-6 years finally this is the year!!

GTST: Yes i admit the error with the extra e in breed lol and also your F****n good with the assuming shit lol Yep im on my P's and will be on my full license in april and no dont start feeling sorry for the future r34 im getting i have learnt my lesson with the last two fwd (yes you have my approval to laugh :D) i have written off. Yes with all the advise on here its best for me to get comfortable with the stock power then work from there.

Two questions though GTST: Whats wrong with those wheels..the sizes may not be correct but i had the info as a base and also what is wrong with the bov, its volume controllable i know its bit of a wank factor but it most likely will save my ass when cops are around.

oh and btw this was in no way a waste of interwebz space lol all of you guys have have made me choose the right decision.

I wasn't refering to the spelling error.. I was refering to you thinking the RB stands for Race Bred. It doesn't. I stands for nothing. other wise SR20 would be known as SOMETHINGS RATTLING...

What's wrong with those wheels are the size.

20 inch wheels are for Gangstas on their hummers.

8.5 inch wide wheels are for gangstas who can't get wide wheels on their cars due to the fact that they got such large diameter wheels (20's y0!)

Performance wheels need not be larger than 18x10.

in most cases where you haven't got brake discs bigger than what stock Brembo's are, 17's are fine.

17x9 on the rear and 17x8 on the front are perfect for 255 on the rear and 235 on the front.

this gives great traction, and doesn't throw off the speedo reading.

AND, you can get good quality tyres for cheap compared to 20x8.5.

You answered your own BOV question there..

the stock item is a good thing.

You'll see posts by user The_Mafia on here about his 314rwkw using stock bov.

And I will guarantee that if you have a electronic noise adjusting, coffeee making, $700 bov in your engine bay, set to 100% plumback and the cop looks at your engine bay, you will receive a defect notice..

some guy on these forums has just started a thread about it and how he was defected for it.

same magical bov too.

I will not ask how you wrote off 2 underpowered fwd cars.

however, I am curious to know if you have ever been in a skyline, driven a skyline, and driven a skyline in anger.

if so to any of the above, what motor and power?

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



  • Similar Content

  • Latest Posts

    • Jdm DC2R is also nice for a FF car compared to the regular hatches of the time.
    • Now that the break-in period for both clutch and transmission is nearly over I'd like to give some tips before I forget about everything that happened, also for anyone searching up how to do this job in the future: You will need at least 6 ton jack stands at full extension. I would go as far as to say maybe consider 12 ton jack stands because the height of the transmission + the Harbor Freight hydraulic platform-style transmission jack was enough that it was an absolute PITA getting the transmission out from under the car and back in. The top edge of the bellhousing wants to contact the subframe and oil pan and if you're doing this on the floor forget about trying to lift this transmission off the ground and onto a transmission jack from under the car. Also do not try to use a scissor jack transmission lift. You have to rotate the damn thing in-place on the transmission jack which is hard enough with an adjustable platform and a transmission cradle that will mostly keep the transmission from rolling off the jack but on a scissor lift with a tiny non-adjustable platform? Forget it. Use penetrating oil on the driveshaft bolts. I highly recommend getting a thin 6 point combination (box end + open end) wrench for both the rear driveshaft and front driveshaft and a wrench extension. These bolts are on tight with very little space to work with and those two things together made a massive difference. Even a high torque impact wrench is just the wrong tool for the job here and didn't do what I needed it to do. If your starter bolts aren't seized in place for whatever reason you can in fact snake in a 3/8 inch ratchet + 6 point standard chrome socket up in there and "just" remove the bolts for the starter. Or at least I could. It is entirely by feel, you can barely fit it in, you can barely turn the stupid ratchet, but it is possible. Pull the front pipe/downpipe before you attempt to remove the transmission. In theory you don't have to, in practice just do it.  When pulling the transmission on the way out you don't have to undo all the bolts holding the rear driveshaft to the chassis like the center support bearing and the rear tunnel reinforcement bar but putting the transmission back in I highly recommend doing this because it will let you raise the transmission without constantly dealing with the driveshaft interfering in one way or another. I undid the bottom of the engine mount but I honestly don't know that it helped anything. If you do this make sure you put a towel on the back of the valve cover to keep the engine from smashing all the pipes on the firewall. Once the transmission has been pulled back far enough to clear the dowels you need to twist it in place clockwise if you're sitting behind the transmission. This will rotate the starter down towards the ground. The starter bump seems like it might clear if you twist the transmission the other way but it definitely won't. I have scraped the shit out of my transmission tunnel trying so learn from my mistake. You will need a center punch and an appropriate size drill bit and screw to pull the rear main seal. Then use vice grips and preferably a slide hammer attachment for those vice grips to yank the seal out. Do not let the drill or screw contact any part of the crank and clean the engine carefully after removing the seal to avoid getting metal fragments into the engine. I used a Slide Hammer and Bearing Puller Set, 5 Piece from Harbor Freight to pull the old pilot bearing. The "wet paper towel" trick sucked and just got dirty clutch water everywhere. Buy the tool or borrow it from a friend and save yourself the pain. It comes right out. Mine was very worn compared to the new one and it was starting to show cracks. Soak it in engine oil for a day in case yours has lost all of the oil to the plastic bag it comes in. You may be tempted to get the Nismo aftermarket pilot bearing but local mechanics have told me that they fail prematurely and if they do fail they do far more damage than a failed OEM pilot bushing. I mentioned this before but the Super Coppermix Twin clutch friction disks are in fact directional. The subtle coning of the fingers in both cases should be facing towards the center of the hub. So the coning on the rearmost disk closest to the pressure plate should go towards the engine, and the one closest to the flywheel should be flipped the other way. Otherwise when you torque down the pressure plate it will be warped and if you attempt to drive it like this it will make a very nasty grinding noise. Also, there is in fact an orientation to the washers for the pressure plate if you don't want to damage the anodizing. Rounded side of the washer faces the pressure plate. The flat side faces the bolt head. Pulling the transmission from the transfer case you need to be extremely careful with the shift cover plate. This part is discontinued. Try your best to avoid damaging the mating surfaces or breaking the pry points. I used a dead blow rubber hammer after removing the bolts to smack it sideways to slide it off the RTV the previous mechanic applied. I recommend using gasket dressing on the OEM paper gasket to try and keep the ATF from leaking out of that surface which seems to be a perpetual problem. Undoing the shifter rod end is an absolute PITA. Get a set of roll pin punches. Those are mandatory for this. Also I strongly, strongly recommend getting a palm nailer that will fit your roll pin punch. Also, put a clean (emphasis on clean) towel wrapped around the back end of the roll pin to keep it from shooting into the transfer case so you can spend a good hour or two with a magnet on a stick getting it out. Do not damage the shifter rod end either because those are discontinued as well. Do not use aftermarket flywheel bolts. Or if you do, make sure they are exactly the same dimensions as OEM before you go to install them. I have seen people mention that they got the wrong bolts and it meant having to do the job again. High torque impact wrench makes removal easy. I used some combination of a pry bar and flathead screwdriver to keep the flywheel from turning but consider just buying a proper flywheel lock instead. Just buy the OS Giken clutch alignment tool from RHDJapan. I hated the plastic alignment tool and you will never be confident this thing will work as intended. Don't forget to install the Nismo provided clutch fork boot. Otherwise it will make unearthly noises when you press the clutch pedal as it says on the little installation sheet in Japanese. Also, on both initial disassembly and assembly you must follow torque sequence for the pressure plate bolts. For some reason the Nismo directions tell you to put in the smaller 3 bolts last. I would not do this. Fully insert and thread those bolts to the end first, then tighten the other larger pressure plate bolts according to torque sequence. Then at the end you can also torque these 3 smaller bolts. Doing it the other way can cause these bolts to bind and the whole thing won't fit as it should. Hope this helps someone out there.
    • Every one has seemed to of have missed . . . . . . . The Mazda Cosmo . . . . . . what a MACHINE ! !
×
×
  • Create New...