Jump to content
SAU Community

Recommended Posts

Good day everyone,

I just recently started buying all the parts i need to rebuilt my RB25DET engine. My CP pistons arrived couple of days ago and I was wondering if i need to buy a set of eagle rods too to achieve a reliable 300 rwkw or can the stock rods handle the pressure? Its a street car but will be going to the tracks ones a month.

Some ppl here told me that the stock rods can handle it with no problems as long as i dont over do it but i wanna know what the ppl here would say about it cause you guys know a lot more about these cars.

Thanks in advance for the help.

Link to comment
https://www.sau.com.au/forums/topic/285784-rebuilding-the-rb25det/
Share on other sites

Good day everyone,

I just recently started buying all the parts i need to rebuilt my RB25DET engine. My CP pistons arrived couple of days ago and I was wondering if i need to buy a set of eagle rods too to achieve a reliable 300 rwkw or can the stock rods handle the pressure? Its a street car but will be going to the tracks ones a month.

Some ppl here told me that the stock rods can handle it with no problems as long as i dont over do it but i wanna know what the ppl here would say about it cause you guys know a lot more about these cars.

Thanks in advance for the help.

Standard rods will definitely do the job. Just make sure you get them resized and replace the rod bolts with ARP items.

At the end of the day, it doesn't matter if you get titanium rods or stay with the standard ones. If your tuner mucks up, it's all over anyway. Spend more money tuning the engine than you think necessary. Don't get this mixed up with going to the highest price tuner though.

Depending on where you are, there are plenty of great tuners around.

Status Tuning down south

EFI Performance and Gavin Wood in Brisbane

Could name more but I don't really trust anyone else.

Standard rods will definitely do the job. Just make sure you get them resized and replace the rod bolts with ARP items.

At the end of the day, it doesn't matter if you get titanium rods or stay with the standard ones. If your tuner mucks up, it's all over anyway. Spend more money tuning the engine than you think necessary. Don't get this mixed up with going to the highest price tuner though.

Depending on where you are, there are plenty of great tuners around.

Status Tuning down south

EFI Performance and Gavin Wood in Brisbane

Could name more but I don't really trust anyone else.

Thanks for the reply. I will order a set of ARP rod bolts this week, to be honest i never thought of buying these :D good thing i asked :D

Wish i could go to those tuners but i'm half way across the world D: but there's a very good tuner here thats gonna tune my car. A lot of ppl here trust him, he has built a lot of high powered cars.

Stock rods are OK.

but...

You could put GTR items in though, 2nd hand they are super cheap and very strong. :D

Plenty of 400rwkw motor's around with stock rods (forged pistsons, arp bolt, better bearings etc etc).

Stocker GTR rods are excellent, some people have pushed higher than 400rwkw without any issue at all as well.

And better rod bolts = great idea, a must have IMO.

I will see if i can get the GTR rods, it will probably be a very difficult find though but i'll ask around. I've ordered a set of ACL main and rod bearings for rb25, they should be arriving this week. Will they fit the GTR rods?

They are all exactly the same. Why go out and buy GTR or Neo rods when you can just use the rods you have in the engine already?

Oblivion makes almost 300rwkw on standard rods in his RB25 with ARP bolts. His limitation is that he has standard injectors but it's still a strong engine and capable of well over that. The weakest link in the RB engine is the factory rod bolts. Replace them and get a good tune and there is no reason why 400rwkw is not out of the question in a reliable engine.

Only 4 things will break these rods at those power levels:

1: Severe detonation

2: Stretching the bolts by over revving

3: Oil starvation causing the bearing to run, then seize.

4: Incorrect resizing or assembly of the rod or rod/piston

Indeed, i'll stick with the original plans and keep the stock rods and get them resized. Ordered the ARP rod bolts this morning, they should be arriving sometime next week. Thanks again for the replies everyone, really appreciate all the help :P

I currently have a RB25DET running all stock internals. Just reconditioned it with new bearings and ARP rods and all. Making 298kw (400hp) no problems (aside from the stupid gearbox :D ) since build and running strong. I would also agree that tunning is vital after build.

I have a R33gtst and the engine was rebuilt all std but with forget acl pistons. I have upgraded alot of things like injectors, ecu, highflow turbo etc.... And the car has a very SAFE tune of 265.5kw because my tuner doesn't know how much the engine will take before it breaks (Because he didn't rebuild the engine). Will just replacing the rod bolts be a good idea and push more power through? Or would it be much better to just enjoy the current power and get a full rebuild later down the track? Can the rod bolts be changed while the engine is still in the car by just dropping the sump?

Edited by shotter
I have a R33gtst and the engine was rebuilt all std but with forget acl pistons. I have upgraded alot of things like injectors, ecu, highflow turbo etc.... And the car has a very SAFE tune of 265.5kw because my tuner doesn't know how much the engine will take before it breaks (Because he didn't rebuild the engine). Will just replacing the rod bolts be a good idea and push more power through? Or would it be much better to just enjoy the current power and get a full rebuild later down the track? Can the rod bolts be changed while the engine is still in the car by just dropping the sump?

There is no telling when it will go bang. Some people have blown them up at less power output than that, others have them over 350rwkw without issues.

It's not exactly the power that kills them, it's the rpm you take it to. Anything over 7k on the standard rod bolts and you're asking for trouble. I would even be inclined to keep it at 6500rpm to be safe and just enjoy what power you can make up to that point.

No you cannot just drop the sump and change them. Well you can but it will not last very long.

Rods need to be resized which means complete engine strip apart.

Sorry i was meaning just to replace the bolts.

Yea i am reving it no more than 6500rpm.

It's a handfull sometimes so i think i will just enjoy the current power.

Thank You

Yes I know what you meant. The answer is the same

I have a R33gtst and the engine was rebuilt all std but with forget acl pistons. I have upgraded alot of things like injectors, ecu, highflow turbo etc.... And the car has a very SAFE tune of 265.5kw because my tuner doesn't know how much the engine will take before it breaks (Because he didn't rebuild the engine). Will just replacing the rod bolts be a good idea and push more power through? Or would it be much better to just enjoy the current power and get a full rebuild later down the track? Can the rod bolts be changed while the engine is still in the car by just dropping the sump?

For my engine rebuilt i got ARP head and rod bolts, ACL main and rod bearings, metal gasket, cp pistons. Gonna resize the rods, prep the the block and head just so i can enjoy a reliable 300 rwkw or more depending on the tune. My plan is to do it right the first time. I dont think by only replacing the rod bolts would help you get a reliable 300 rwkw without any of other standard parts letting go somewhere down the track. A lot of rb25det's have met a faith like that on this island.

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

    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
    • Hi,  Just joined the forum so I could share my "fix" of this problem. Might be of use to someone. Had the same hunting at idle issue on my V36 with VQ35HR engine after swapping the engine because the original one got overheated.  While changing the engine I made the mistake of cleaning the throttle bodies and tried all the tricks i could find to do a throttle relearn with no luck. Gave in and took it to a shop and they couldn't sort it. Then took it to my local Nissan dealership and they couldn't get it to idle properly. They said I'd need to replace the throttle bodies and the ecu probably costing more than the car is worth. So I had the idea of replacing the carbon I cleaned out with a thin layer of super glue and it's back to normal idle now. Bit rough but saved the car from the wreckers 🤣
    • After my last update, I went ahead with cleaning and restoring the entire fuel system. This included removing the tank and cleaning it with the Beyond Balistics solution, power washing it multiple times, drying it thoroughly, rinsing with IPA, drying again with heat gun and compressed air. Also, cleaning out the lines, fuel rail, and replacing the fuel pump with an OEM-style one. During the cleaning process, I replaced several hoses - including the breather hose on the fuel tank, which turned out to be the cause of the earlier fuel leak. This is what the old fuel filter looked like: Fuel tank before cleaning: Dirty Fuel Tank.mp4   Fuel tank after cleaning (some staining remains): Clean Fuel Tank.mp4 Both the OEM 270cc and new DeatschWerks 550cc injectors were cleaned professionally by a shop. Before reassembling everything, I tested the fuel flow by running the pump output into a container at the fuel filter location - flow looked good. I then fitted the new fuel filter and reassembled the rest of the system. Fuel Flow Test.mp4 Test 1 - 550cc injectors Ran the new fuel pump with its supplied diagonal strainer (different from OEM’s flat strainer) and my 550cc injectors using the same resized-injector map I had successfully used before. At first, it idled roughly and stalled when I applied throttle. Checked the spark plugs and found that they were fouled with carbon (likely from the earlier overly rich running when the injectors were clogged). After cleaning the plugs, the car started fine. However, it would only idle for 30–60 seconds before stalling, and while driving it would feel like a “fuel cut” after a few seconds - though it wouldn’t fully stall. Test 2 – Strainer swap Suspecting the diagonal strainer might not be reaching the tank bottom, I swapped it for the original flat strainer and filled the tank with ~45L of fuel. The issue persisted exactly the same. Test 3 – OEM injectors To eliminate tuning variables, I reinstalled the OEM 270cc injectors and reverted to the original map. Cleaned the spark plugs again just in-case. The stalling and “fuel cut” still remained.   At this stage, I suspect an intermittent power or connection fault at the fuel pump hanger, caused during the cleaning process. This has led me to look into getting Frenchy’s fuel hanger and replacing the unit entirely. TL;DR: Cleaned and restored the fuel system (tank, lines, rail, pump). Tested 550cc injectors with the same resized-injector map as before, but the car stalls at idle and experiences what feels like “fuel cut” after a few seconds of driving. Swapped back to OEM injectors with original map to rule out tuning, but the issue persists. Now suspecting an intermittent power or connection fault at the fuel pump hanger, possibly cause by the cleaning process.  
×
×
  • Create New...