Rb25 + Gt3076r

[Simon-S14]

full boost by 3700 rpm, peak torque of 480nm at wheels by 4000 rpm... strong midrange!

to give an indication of its potential we had a boost spike on the dyno thanks to a hose blowing off the gate so it overboosted big time to 25 psi at 4900 rpm and made 320 rwkw at that rpm... crazy...

[GTScotT]

full boost by 3700 rpm, peak torque of 480nm at wheels by 4000 rpm... strong midrange!

care to clarify what setup that is?

fairly standard RB25 or worked or more?

3076 56t?

.6 surge slotted cover?

.63 or .82 rear IW or gated?

i dont like to assume, and would help me in picking the winning combo... i dont want the surge cover unless i truly need it.

[Simon-S14]

no prob, my sig link has a lot of the build up info also.

My set up is stock Neo 34 rb25 with AM Performance high mount manifold with merge collector, HKS 38mm gate with 3076 56t with the .6 surge slotted housing. .63 rear 4 bolt garret housing.

the rest is basically bolt ons. running nisstune board on stock 34 ecu, fmic, larger injectors and so forth.

my mates set up is a r33 RB25 and has exact same turbo as me, but with tial gate, stock rb25 manifold with am performance adaptor to low mount the turbo, adapter has port for wastegate which sits high up. runs a Rb20 ecu with chip, no vct.

now my mates makes a few rwkw more then mine, both cars tuned on same dyno. however whats interesting to note is that mine makes more torque and earlier in the rev range, and less boost to do it also. Dyno is a dyna pack unit so all runs done without hitting limiter. Mine keeps climbing and making power right to the point where the dyno brake hits where as my mates makes peak power at 6000rpm then starts to fall off.

i put this down to the exhaust manifold and cam differences with our engines. but rest assured for sub 300 rwkw they are awesome even for a basically stock 25 set up!

[R31Nismoid]

Dyna pack - the hub dyno's?

[Simon-S14]

thats the one, i quite like them as in the past all ive used is dyno dynamics and had tyre rubbing issues and wheel spin issues. none of that with hub dyno's

[rad100]

im planning on using jeff to remap my rb20 ecu..

is not having the vct gonna make big difference?

im gonna be using the stock wastegate that comes with the hks manifold, anyone know the spring rate of this? will it be suitable?

[Simon-S14]

prob 8 psi... like mine. its a 38mm gate yeah?

lack of VCT wont be an issue once its tuned correctly. but in saying that if you do a lot of city driving you might miss a smidge of low down torque... i have a RPM switch that you could buy to control vct if your interested.

[GTScotT]

thanks simon, appreciate you clarifying the setup so well gives me alot more faith.

[rad100]

for drift simon.. but im keen on the switch!

[Simon-S14]

no prob! I havent driven the car much, just took it out to the track for the first time but i will say this... a lot of how driveable on the street 300 rwkw comes down to grip and diff ratios. My car had a 3.7 diff and grippy tyres, would not wheelspin any gear it just pulls and goes hard. my mates set up is a 4.3 and being an r32 with slightly less grip will bake 3rd in a roll on acceleration....

since our cars are drift cars i just changed my diff to a 4.3... found it to be a little too doughy with the 3.7.

[badhairdave]

Im interested to hear your thoughts on the difference between the cropped 3071 you had on the old r32 and the new 3076 setup in the s14.

[Simon-S14]

both are good turbo's but the 3076 seems to do the job better. spool time and response is the same but makes more power, the 3071r capped out at around 280ish rwkw.

[Don Dada]

Finally getting to see some results of the true Gt3076 with the .63 turbine using an ext gate.

I know u haven't driven yours much with the 4.3 diff installed but from what u say about your mates car that shit might be scary to drive on the street with boost coming on so hard.

For drift this set up sounds ideal, but for a daily do u think the .63 might be a little too aggressive combined with the 4.3 ratio?

Also, has your mate had any probs with boost control with the 38mm gate on the stock manifold?..... ie. with the gate being so small?

[Simon-S14]

my mates (his name is hayden) set up has better boost control then mine... his ramps up and holds boost steady as. I put this down to the tial gate having a 1 bar spring where as mine has a much softer spring

i think for street you'd want 4.1 gears and a an EBC to control the boost and give a nice progressive ramp rate. would be an awesome set up... hayden's car still looks fairly stock under the bonnet and the only thing that gives it away is the high mounted gate, if this was positioned much lower you could get away with all this on a street set up haha

[R31Nismoid]

thats the one, i quite like them as in the past all ive used is dyno dynamics and had tyre rubbing issues and wheel spin issues. none of that with hub dyno's

So as its a hub dyno, it is not RWKW.

The difference with HUB vs RWKW (roller) is around 30-40kw.

So you are making 300rwkw @ the hubs, 260rwkw @ the rears... and that sounds much more accurate for a .63 rear turbo on PULP.

[Simon-S14]

you do not lose 30-40 rwkw through a pair of wheels and tyres. more like 10 rwkw or so. Oh and dynapack dynos have correction software to take into account of wheel inertia and so forth. Maybe have a read of this http://home.earthlink.net/~spchurch/id12.html

Edited February 17, 2010 by Simon-R32

[R31Nismoid]

Well the plentiful results across this forum from Hub vs Roller would suggest that is quite the opposite unfortunately. One result will not sway me on this one.

Hub's pretty much float around all of NZ, and all their figures are roughly 30rwkw high, which is perfectly fine.

Once you know it's a hub, then you just factor in the difference... no big deal really.

Without water/meth, E85 etc etc i cannot reasonably accept a .63 housing is flowing 300rwkw the same as a .82 would.

Fact is, hub dynos are not RWKW.

Please refrain from quoting hub dyno figures as RWKW. All that does is confuse people that do not know that there is a key difference.

[Simon-S14]

im afraid your wrong on this one. as i said, dyna pack dynos take in account the lack of wheels and tyres and adjust accordingly.

another result i can quote is Ev's R31 with 25. exact same turbo again. has steam pipe manifold, [forward facing inlet manifold, internally stock motor. Dyno'd on a roller dyno and what do you know... made 292 rwkw on 19psi http://www.nissansilvia.com/forums/index.p...t&p=5548203

[R31Nismoid]

They know if you are running 15" or 18" wheels do they?

I cannot reasonably see that being something software can guess, let alone guess right.

Sounds the same as "shootout" mode on Dyno Dynamics Chassis ones, which is useless as well.

Either way, it's not RWKW. It's a guess. It's like me saying my car will run a 9 sec pass based on "X" power... you know... because i calculated it.

[gotRICE?]

^ I think they can input whatever they want.

I can see this being another classic SAU discussion.