how much is too much?

[Lith]

iv got a mate with RB25DET with big turbo, GReddy inlet manifold 3 inch exhausts etc etc on a Llink it only made 330hp @the wheels. id like to see an engine with 2/3 the capacity make that sort or RELIABLE power

He's clearly got something wrong with his setup.... that kind of setup should be good for a lot more than that.

[~SlideWays~]

i recon ya would hard pressed to get 250RWKW out of a 4age.

Im only running 17psi on the same turbo that IH8TEC has happily run 25psi on and my power atw is only 38kw off 250kw. And thats on smallish 510cc injectors too.

EDIT: unless you're talking about NA!? If so then yeah...a bit hard!

still ill believe it when i see it.

250kW ATW = 335HP ATW = 210Hp per liter

id like to see that sort of RELIABLE power on a street car.
iv got a mate with RB25DET with big turbo, GReddy inlet manifold 3 inch exhausts etc etc on a Llink it only made 330hp @the wheels. id like to see an engine with 2/3 the capacity make that sort or RELIABLE power

Sounds like a challenge to me Lol nah 212kw atw is enough for me at the mo.

But just because a rb25 didn't make huge power, even though its got more capacity doesn't mean a smaller engine can't make more kw's.

One thing to think about is that RB's in NA for are pretty pitiful, leading me to believe they can't have very good head flow.

Compare that to a 4age (or dare I say it a b16 or 18) in their standard form they perform well. Being the fact that the heads are designed to flow well...help that along with forced induction and bob's your uncle

My setup isn't anything radical: No porting, standard cams, standard valves and valve springs, standard fuel pressure, standard 8.9:1 compression, etc etc. Slightly raised rev limit of 7800rpm.

Add 17psi and a decent tune and it made 283hp ATW.

I drive it to work in rush hour traffic, no probs, push it hard all the time, etc and no probs just a bung PS pump.

So add some cam's, port the head, bigger injectors (only reason the tuner stopped at 212kw's) and room for 8psi more. That would equate to a whole lot more than the 50hp needed to reach your 335hp atw.

Not trying to be a smart arse, just saying that 250kw's shouldn't be a problem.

[d1 mule]

iv got a mate with RB25DET with big turbo, GReddy inlet manifold 3 inch exhausts etc etc on a Llink it only made 330hp @the wheels. id like to see an engine with 2/3 the capacity make that sort or RELIABLE power

He's clearly got something wrong with his setup.... that kind of setup should be good for a lot more than that.

probably seeing as it recently blew up, but still was bloody quick.
was running 16psi on a CNR racing 430 turbo, standard exhaust mani, GReddy inlet Mani, FMIC, 3" exhaust, actually was prob in RE-mapped std ECU at that stage. another mate gor a RB30 fresh rebuild, turbonetics turbo Yada yada yada thats 400-450hp ATW (unsure as he just put a tubular exhaust mani onwas 400 before) and 1600NM from memory

[Lith]

But just because a rb25 didn't make huge power, even though its got more capacity doesn't mean a smaller engine can't make more kw's.

One thing to think about is that RB's in NA for are pretty pitiful, leading me to believe they can't have very good head flow.

Their head flow actually isn't too bad, that guys example is really bad. I did based on a bunch of wild assumptions and extrapolations and worked out that cc for cc and psi for psi my car makes about the same kw/l/psi @ wheels as flygt4s 20v (I picked him because I know enough about his setup and my car was tuned on the same dyno so should be comparable) so if my big motor is pretty pitiful and they're not sold on their flash valve setups etc, what does it say about a 1.6l 20v head?

[~SlideWays~]

But just because a rb25 didn't make huge power, even though its got more capacity doesn't mean a smaller engine can't make more kw's.

One thing to think about is that RB's in NA for are pretty pitiful, leading me to believe they can't have very good head flow.

Their head flow actually isn't too bad, that guys example is really bad. I did based on a bunch of wild assumptions and extrapolations and worked out that cc for cc and psi for psi my car makes about the same kw/l/psi @ wheels as flygt4s 20v (I picked him because I know enough about his setup and my car was tuned on the same dyno so should be comparable) so if my big motor is pretty pitiful and they're not sold on their flash valve setups etc, what does it say about a 1.6l 20v head?

Lol I should have chosen my words a bit better I wasn't saying that rb25det's aren't any good. Im sure they have the torque to pull a house down but when thinking about it nissan's RB**DE's have never been an impressive engine for their capacity/design. With the addition of a turbo its a different story, but if the DE's had a stonking NA head from factory...what a monster of a turbo motor they could make wouldn't you say?

But yeah the 20v head is a bit of a weird one, I get the feeling the silvertop cam's may not be suitable? Or maybe the extra valve was purely "look at me, I have more of these!" at the time maybe, until the blacktop made a better job of it anway, case in point: Bazda's standard blacktop head (from what I remember) flows enough for 500hp.

So if yours is around the same as Jeremy's 217kw's at 20psi, and mine is 212kw at 17psi. Both done by speedtech, as it sound yours was?

That leads me to think....we need a race!

[Lith]

Yeah definitely the blacktop head are better - but silvertop isn't supposed to be terrible and as I said, to my reckoning they seem to make similar power/litre for a given pressure ratio to my 2.5litre and require more revs to do so, so the 2.5litre can't be THAT bad. That stuff all comes down to head flow.

Me and Jeremy may be having a grudge match at Masterton even though my car weighs half a ton more and runs quite a lot less boost haha. And correct, mine was done at Speedtech.

[~SlideWays~]

Yeah definitely the blacktop head are better - but silvertop isn't supposed to be terrible and as I said, to my reckoning they seem to make similar power/litre for a given pressure ratio to my 2.5litre and require more revs to do so, so the 2.5litre can't be THAT bad. That stuff all comes down to head flow.

Me and Jeremy may be having a grudge match at Masterton even though my car weighs half a ton more and runs quite a lot less boost haha. And correct, mine was done at Speedtech.

So he's keeping it...again?

[pc]

So if yours is around the same as Jeremy's 217kw's at 20psi, and mine is 212kw at 17psi. Both done by speedtech, as it sound yours was?

That leads me to think....we need a race!

Hmmm... RWD vs FWD where do I put my money down?

We are talking about drags right?

[IH8TEC]

d1 mule. when i chuck in my 800cc injectors, get it re-tuned on the same dyno i have used all the time, and lean it out this time to make some more power.

i'll chuck it on a hub dyno to compare it to everyone in wellingtons power. and hopefully show you that reliable 250kw atw. possibly more.

[Lith]

i'll chuck it on a hub dyno to compare it to everyone in wellingtons power. and hopefully show you that reliable 250kw atw. possibly more.

You coming to megameat? People should just run on the dyno here and compare figures

Sometimes its hard to compare figures between dynos.

[rollaholic]

difficult to compare power per liter on different capacity engines, but i agree with lith that the RB series arent bad NA engines - pays to remember they are in much heavier shells than the 4A, and most of the NA RB's have autos tacked on the back as well.

i've been in a couple of looked after, manual NA RB20's and 25's, they go pretty well imo.

[d1 mule]

d1 mule. when i chuck in my 800cc injectors, get it re-tuned on the same dyno i have used all the time, and lean it out this time to make some more power.

i'll chuck it on a hub dyno to compare it to everyone in wellingtons power. and hopefully show you that reliable 250kw atw. possibly more.

sweet as man, im not saying it cant be done cuz obviously it can but ya no. I think its a pretty impressive feat, thats a load of power sor a "small" capacity engine