Power Ceiling Gt3076R

[R32Abuser]

Hi all,

I was having issues with my RB30DET related to knocking/pining.

http://www.skylinesa...1076-rb2530det/

These issue have been fixed now, however now I have a new problem. My setup will simply not make the power it should/did on another car. Its as if it is hitting a power "ceiling".

My setup is as per below:

Parts

R32 RB25DE head

RB30 Series 2 bottom end

RB26/30 CP Pistons 9:1 Static CR (CP pins, rings etc.)

Spool RB30 Rods to suit. ARP fasteners

ACL Race series bearings to suit above rods

Standard Crank. Blueprinted/Balanced/Crack tested etc

RB25DET Series II Oil Pump with extended drive "Snout" (Spool Imports)

GT3076R 0.82 A/R Garret Turbocharger (Standard oil/water lines)

Stiffer valve springs (unsure of brand)

High Energy Style Sump + Head drain (big f**k off fitting on the back of the head)

Standard valve train (RB20DET) (Cams/gears/lifters etc)

Cometic Head gasket (Spool Imports)

GTR Waterpump

550cc Bosch EV14 Injectors

Nismo Fuel Reg (Adj.)

Nismo Engine Mounts/G-Box Mounts

Bosch 040 Fuel Pump

Nistune ECU Remap

Labour

Bore/Hone Block to suit CP Pistons

Deck Block

Grind/Blueprint Crankshaft

Balance Pistons

Micropolish Crankshaft

Balance Motor

Reconditioned Head

Modify/Weld/Machine Head

Now no matter how much boost, timing, fuel etc. the tuner threw at the motor, the car will just not make anything more than about 210-220RWKW. Don't get me wrong its decent, but its no where near where it should be. This exact turbo on Cube's RB30 made (on standard RB25DE cams) 260RWkW. Id expect something a little less than this considering that I'm running RB20DET cams instead. I would also expect it to make it on less boost considering that I have a higher static compression ratio than him.

To my knowledge the motor is running 20-22deg ignition timing on full noise, 18PSI Boost, and the AFR's are sitting between 11-12:1.

Run more timing and the thing wants to ping but make no more power.

Run more boost and it makes little to no (few kW) difference in power and just generates more heat.

Run more/fuel (within reason!) and it only makes a few kW difference in power.

Another interesting fact was that previously when the motor was knocking, it was making 220kW on approximately 8 degrees worth of ignition timing. Which to me would seem as tho the car had been incorrectly timed (CAS error etc.) and that the motor was ACTUALLY seeing something closer to 20 deg of ignition timing. But I cant state that for sure...

We are dropping the exhaust/intake to see if there is a restriction in there somewhere limiting the setup. Failing this...Is there any other ideas/experiences that people have had hitting this "ceiling" with similar setups on RB20/25/26/30's?

Edited September 9, 2011 by R32Abuser

[The Mafia]

One of the cams is probably out a tooth

[GTScotT]

+1 you have a cam problem.

I would expect the ceiling to be over 300kw.

[sriver killer]

One of the cams is probably out a tooth

how does it drive?

out of curiosity. Ive just got my 25/30 up and running . un tuned still running rb25 tune.

I hear that they hit full boost 2.6-2.8k with a 3076R.

I am currently nowhere near that lol., I am presuming its because it is still yet to be tuned ?

[The Mafia]

I bet it is running as lean as f**k, mine did with the 25 tune in it. Stop driving it or get it to a tuner stat.

[kitto]

Sounds like cam timing as said. What cams are in it?

If the cam timing is out. Set it correctly then retune it

[sriver killer]

I bet it is running as lean as f**k, mine did with the 25 tune in it. Stop driving it or get it to a tuner stat.

yer man. my narrowband hits the lean as soon as she comes on boost.

i was picking that as she was starving for fuel/ no timing put into her created the extra lag,

tune time next week, should woop it into gear

[DVS JEZ]

What was the pinging/knocking issue abuser?

Post a pic of ur intake setup. What sort of dyno are u using? Tyres etc

[JonnoHR31]

I hear that they hit full boost 2.6-2.8k with a 3076R.

not unless your only running 5-10psi. in the real world they make 1 bar around 3200-3500 depending on the setup.

No matter which way you look at it the next step is to drop the exhaust and see what happens

[R32Abuser]

DVS JEZ

The pinging/knocking issue was alleviated once we fit the RB20DET cams, new CAS, and re-timed the motor. Which one solved the issue I don't know. Im just glad it is no longer pinging to be honest and the fact that the pistons weren't the issue after all

Intake setup is as the following pictures:

No rubber intake to turbo. Solid 3" aluminium pipe. Other than that, standard on the intake side besides a hole in the airbox. Possibly routing a big arse PVC (painted black) pipe setup straight into the airbox. May do this if it becomes an issue for power.

Dyno Im unsure of but here is the link to the site:

http://www.morpowa.com/dyno_dynamics.html

Tyres are as follows:

R: 235/45/R17 Bridgestone Potenza RE001 Adrenalin. Practically brand new.

kitto

Standard RB20DET cams. Possibly upgrading to custom re-grinds down the track pending how this setup goes.

sriver killer

I haven't driven it myself, but from what Im told drives very well. Nothing too ball tearing as its down considerably on power, but torquey as! Apparently (according to Cubes) this turbo will hit full boost 16PSI by about 2800-3000RPM.

Overall this could be a cam issue. If dropping the exhaust/intake doesn't fix the issue, we will be checking the timing again to make sure.

[sriver killer]

not unless your only running 5-10psi. in the real world they make 1 bar around 3200-3500 depending on the setup.

No matter which way you look at it the next step is to drop the exhaust and see what happens

Exhaust s fine. 3.5inch turbo back with 100 cell cat.

1 bar at around that RPM is what I am getting, 4th gear on highways only though.

DVS JEZ

The pinging/knocking issue was alleviated once we fit the RB20DET cams, new CAS, and re-timed the motor. Which one solved the issue I don't know. Im just glad it is no longer pinging to be honest and the fact that the pistons weren't the issue after all

Intake setup is as the following pictures:

No rubber intake to turbo. Solid 3" aluminium pipe. Other than that, standard on the intake side besides a hole in the airbox. Possibly routing a big arse PVC (painted black) pipe setup straight into the airbox. May do this if it becomes an issue for power.

Dyno Im unsure of but here is the link to the site:

http://www.morpowa.c...o_dynamics.html

Tyres are as follows:

R: 235/45/R17 Bridgestone Potenza RE001 Adrenalin. Practically brand new.

kitto

Standard RB20DET cams. Possibly upgrading to custom re-grinds down the track pending how this setup goes.

sriver killer

I haven't driven it myself, but from what Im told drives very well. Nothing too ball tearing as its down considerably on power, but torquey as! Apparently (according to Cubes) this turbo will hit full boost 16PSI by about 2800-3000RPM.

Overall this could be a cam issue. If dropping the exhaust/intake doesn't fix the issue, we will be checking the timing again to make sure.

I am picking as I have the 25 tune the timing/fuel delivery is way out. giving me the unnecessary lag.

Driving around town the 30 is THAT much better to drive.

You would't think the difference that 500cc+ extra crank weight could be so noticable. Even with the 8.3:1 comp ( I am running new cast standard pistons)

Btw it probable doesn;t help my delivery that I have a 6boost, + plazmaman, + 3 inch intercoolerpiping + 4 inch thick intercooler

[R32Abuser]

IMO a 4" thick intercooler and 3" piping is overkill for your power level. Obviously this will depend on what your using it for (street/track/drift/dyno queen). Either way, the time/airflow required to pressurise/fill these pipes would kill your delivery if you were aiming for near stock spool times. I assume that was what you were aiming for with the GT3076R turbo choice?

6Boost plenums from what I have read tend to promote power generation higher up in the RPM range as opposed to down low. So yes, this would not help your cause either.

Edited September 10, 2011 by R32Abuser

[sriver killer]

IMO a 4" thick intercooler and 3" piping is overkill for your power level. Obviously this will depend on what your using it for (street/track/drift/dyno queen). Either way, the time/airflow required to pressurise/fill these pipes would kill your delivery if you were aiming for near stock spool times. I assume that was what you were aiming for with the GT3076R turbo choice?

6Boost plenums from what I have read tend to promote power generation higher up in the RPM range as opposed to down low. So yes, this would not help your cause either.

The 4 inch cooler was a necessary upgrade as at the time, as my existing 3 inch china ebay cooler had pressure drop issues.

3076R was purchased as a good all rounder, I can;t justify a 35R as a daily driver turbo on a rb25

Ive had everything just in case I want to upgrade turbo in the future.

what do you guys reckon about the garret .70 A/R front housing(with drilled anti surge slots) instead of the hks style .60A/R front housing?

[JonnoHR31]

Exhaust s fine. 3.5inch turbo back with 100 cell cat.

1 bar at around that RPM is what I am getting, 4th gear on highways only though.

exhaust comment was aimed at the OP. yer you'll only get 1 bar at those revs under a lot of load. it'll be a fair bit higher in lower gears

6boost manifolds are generally better all round, i highly doubt you'd have noticeable more lag over a stocker

[R32Abuser]

exhaust comment was aimed at the OP. yer you'll only get 1 bar at those revs under a lot of load. it'll be a fair bit higher in lower gears

6boost manifolds are generally better all round, i highly doubt you'd have noticeable more lag over a stocker

Yup. I knew it would be touch an go with a 3". Has been done before, but figured I would just sneak it in. We'll see if its the restriction come Monday (dyno that was supposed to be used on Friday was unfortunately occupied all day due to a head gasket failure and prep. for a race on the weekend

Either way, I'm looking for a more conservative 3.5" cat-back system. Anyone know of a 3.5" off the shelf cat back exhaust which is not too harsh on the ears (read: retains a centre muffler!)?

[Bl4cK32]

twin system ftw. Ask cubes how quiet a twin is

[R32Abuser]

twin system ftw. Ask cubes how quiet a twin is

He doesnt have one does he? I know I have his front/dump pipe from his old setup. Or are you saying you have one?

Care to elaborate?

[R32Abuser]

Sooo...The plot thickens!

Exhaust dropped - Car made no extra power (210kW)

Airbox dropped - Car made no extra power (210kW)

Cam timing will be looked into...Builder is doing the rounds for some opinions for this problem.

Very Frustrating

[The Mafia]

Please give us the exact CHRA number of that turbo, the housing sizes etc.

Also, pending the turbo type, I can guarantee its either the cam timing or your engine is rooted.

[R32Abuser]

Cube's old GT3076R....

GT3076R .6 Port Shroud Comp Cover .82 Internal Gate

3" turbo back exhaust, Bell mouth 3" dump

Dont have the CHRA number on hand. Can get that for you though when I see the car...

Been talking to Sydneykid and he said that there isnt one RB30 he has built that hasn't needed timing adjustment. In this case I spoke to my builder and he said that at most it would be out a tooth but he also mentioned than although the lines are 100% spot on...they are barely noticeable out of alignment.

Adjustable cam gears possibly an option?