Jump to content
SAU Community

Max Power Out Of Neo

drgnball34

By drgnball34,
in Engines & Forced Induction

 Share

Recommended Posts

drgnball34 Rising Star

drgnball34

Posted
Posted

I've been hearing that the Neo engines can only crank out around 240rwkw on stock internals due to compression setup...Surely this is a load of crap huh? Its the last of the RB25DET... Engineered to perfection. If any, it should be able to pump out more then the R33.. My aim is for 350wrhp on stock internals. Does having a oil cooler help with reliability or is it only for track? Also geting a head gasket to lower the comp help much either in terms of reliabilty?? Or is it only needed for extreme boost levels?

Link to comment
https://www.sau.com.au/forums/topic/112779-max-power-out-of-neo/
Share on other sites
MR331307 Experienced

MR331307

Posted
Posted

From what i have seen

they do have GTR style Rods in them as i have pulled one apart and compared the rods sizes between regular RB25 & RB26 ones.As for the buckets in the head i compared them to gtr ones i have sitting here and they look similar but the shims underneath are different and to me they have different length Valve Springs.As for the oil pump they look the same didnt take to much notice to the difference between them.

As for power

More Timing + More fuel = Big Power = good for drag racing

Less Timing - Less fuel = Average power = good for track use

I am making 540 hp now out of a regular rb25.Thread Max HP out of Rb25.I aint gonna go on to much but its all to do with tuning and sufficent intercooler ETC to make safe Reliable power out of the RB standard Motors.

Comp in the NEO motors is what holds them back.Your tuner will need to work around this

Tex Willer Apprentice

Tex Willer

Posted
Posted

The power output of these engines are often a question of fuel quality.

Long duration cams will lower compression pressure.

Bigger turbos/exhausthousings will lower backpressure.

Very high peak power numbers are possible at high revs, because of the short

stroke and rodlength/stroke ratio.

500nm at 4000rpm gives 380hp.

500nm at 8000rpm gives 760hp. both with the same combustion pressure.

my answer is I don`t know the limits..

Abo Bob Grand Master

Abo Bob

Posted
Posted
Ok then who wants to buy a few sets of NEO RB25 rods to Upgrade their R33 Rb25s?Their the same as R33s sorry.Did you see that the intake buckets are Alloy?

I suggest anyone doing an RB25 rebuild take you up on this offer. Not only do they look the same but I've had someone look up the part numbers for R34 RB26 and R34 RB25DET and the numbers are the same.

Also the R33 and R34 RB25DET's both have 9:1 compression ratio which can be a limiting factor in putting lots of boost into them.

Bass Junky has about 250rwkw without lowering the compression ratio but he does have cams as do I.

There doesn't seem to be many people succesfully putting a lot of boost into a NEO without cams or lowering the CR. I can't think of any offhand.

The NEO does have solid lifters as does the RB26 but they are not the same.

The NEO exhaust valves are 1mm bigger than the RB26 items. This could help get more power from the same or less boost all other things equal.

It seems to me that without lowering the CR the NEO can take about as much boost as a non NEO. Depends how far you want to push it, how good/consistant your fuel is, and how well tuned it is. The power levels are probably similar, perhaps a slight advantage to the NEO. If injectors aren't being changed the NEO ones are 350cc but earlier ones are 370cc. which could be a limiting factor.

Bass Junky Grand Master

Bass Junky

Posted
Posted

Yeah, we ran into a brick wall at about 250rwkw.

We have pulled timing for the most part and dial in 2 degrees for a squirt every now and then.

The engine wouldn't take any more timing or boost. I'm running about 0.9 bar with Bp Ultimate.

260 degree cams.

If the answer to a bucket load more power is a hea gasket, I'll be wrapped.

BASS OUT

Sydneykid Grand Master

Sydneykid

Posted
Posted (edited)
Yeah, we ran into a brick wall at about 250rwkw.

We have pulled timing for the most part and dial in 2 degrees for a squirt every now and then.

The engine wouldn't take any more timing or boost. I'm running about 0.9 bar with Bp Ultimate.

260 degree cams.

If the answer to a bucket load more power is a hea gasket, I'll be wrapped.

BASS OUT

Try some Shell Optimax Extreme 100 ron, dropped the knock from 70 to zero in the R33. No other changes. :mage:

We have had 305 rwkw out of an R34GTT. Tomei 260 Poncams, R33GTR intercooler, ported and polished cylinder head, standard head gasket (I don't use thick ones) and a Garret GT30. It wasn't all nice to drive, too peaky, lots of lag, poor throtle response. So we went back to 265 rwkw (GCG high flow) at 1.1 bar, much nicer to drive and ultimately faster point to point. With Extreme I reckon we could have got to 280 rwkw at 1.2 bar, which would be plenty.

:D cheers :)

Edited by Sydneykid
  • 4 months later...
infected flow Rising Star

infected flow

Posted
Posted
I suggest anyone doing an RB25 rebuild take you up on this offer. Not only do they look the same but I've had someone look up the part numbers for R34 RB26 and R34 RB25DET and the numbers are the same.

Also the R33 and R34 RB25DET's both have 9:1 compression ratio which can be a limiting factor in putting lots of boost into them.

Bass Junky has about 250rwkw without lowering the compression ratio but he does have cams as do I.

There doesn't seem to be many people succesfully putting a lot of boost into a NEO without cams or lowering the CR. I can't think of any offhand.

The NEO does have solid lifters as does the RB26 but they are not the same.

The NEO exhaust valves are 1mm bigger than the RB26 items. This could help get more power from the same or less boost all other things equal.

It seems to me that without lowering the CR the NEO can take about as much boost as a non NEO. Depends how far you want to push it, how good/consistant your fuel is, and how well tuned it is. The power levels are probably similar, perhaps a slight advantage to the NEO. If injectors aren't being changed the NEO ones are 350cc but earlier ones are 370cc. which could be a limiting factor.

im getting 291rwkw with 8.9:1compression.. and 20psi boost...

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

    • Steal01
      Torana Lx Gtr Hatch, Lots Of Pictures

      By Steal01 · Posted

      It’s going to be a beast!
    • soviet_merlin
      Stagea Front CV Axle Question

      By soviet_merlin · Posted

      Man, different parts but the same numbers is terrible @dbm7! And it doesn't help that most online shops don't list the part numbers at all. They just give a list of compatible models...
    • MBS206
      R32 GTST - 600KW+ RB28/CD009 Build

      By MBS206 · Posted

      Slow when hot could also be because its getting more dynamic compression, OR things are getting a bit tighter once it is all expanded. If it were an earthing issue, typically I'd expect you to have it have issues all the time. Unless it's really a combination of both things. Where the higher compression, and things being a bit tighter, is giving that bit of extra load and you do need a slight clean up on the cables/connections.
    • dbm7
      Stagea Front CV Axle Question

      By dbm7 · Posted

      Yeah, this is one of the most annoying things about nissan part numbers... I've got an unrelated example... Image is of the AT output shaft ~ they have the same part#, but clearly the shaft on the left is beefier design to that on the right ...the difference (essentially) is the 'lighter' shaft on the right, is for engines up to RB25DE (this includes RB20 variants) : the shaft on the left is for RB25/26DET(T)....are they interchangeable? Yes...but obviously one shaft is going to be stronger than the other...and, the lighter shaft is around USD115, but the heavier shaft closer to USD150...same part#... ...epc-data usually tells a tale ~ the amayama listing for 39100-23U60 has a note "Longest side is between 60 and 105 cm" ; no such info is there for 39100-23U70 ...and given the great disparity in price between the 2 parts, it makes me at least curious (to the point of caution) where the 'extra money' went? ...ie; these 2 parts have a cost difference that (to myself at least) isn't explained by 'plastic boot'...ie; with amayama there's AUD700 price difference ...plastic versus rubber?...I'm not seeing it like that...and 60cm ~ 105cm...??...that's a huge disparity....something hinky going on here... I'd try searching by VIN, not model... /2cents
    • Duncan
      Stagea Front CV Axle Question

      By Duncan · Posted

      I don't know for sure, but I'd expect them all to be interchangeable given the diff end and hub end don't move/change between any C34 series. Often Nissan will change part numbers and the aftermarket follows those year ranges; but the original part number change doesn't mean other parts won't fit. The change could be a change in material, internal parts or even just supplier. For example, all the RB gearbox to engine bolts are no longer available and there is a new part number instead. The only change is they went from cadmium plated bolts to zinc plated due to the issues manufacturing with Cadmium. They look different but work the same.
×
×
  • Create New...