What Could Be Causing Lack Of Power?

[Ruffels]

Hi guys, i've been scratching my head trying to work out why my car isnt making power, and im fairly sure there is nothing wrong with my car, but its only making 230rwkw when the hyperfear turbo I have is supposed to make 270-280rwkw

heres a quick run down of what i have

1997 r33 gts-t unopened rb25det with 110,000kms - manual

* Hypergear 3076 equivelent in standard front housing and op6 rear housing (76mm 52 trim compressor wheel, gt30 turbine wheel in 84 trim)

* 550cc injectors

* 3" bellmouth dump/front

* 3" highflow catco cat

* 3.5" fujitsubo catback

* Z32 AFM

* Bosche 040 fuel pump

* Power FC

* highflow panel filter in standard airobx

running 20psi boost

OK well the Turbo is a Hypergear and is supposed to make 270-280 rwkw ... but Trent (from Status) could only safely get 230rwkw out of the setup

In the top end only 10 degrees of timing could be put in, before the car started to knock badly! Trent comented that usually he can get around 16 degrees timing, and that extra 6 degree of timing is most likely where the lost power is! but the car wont accept any more timing without becoming unstable

we tested the exhaust, by dropping it before the cat and it made bugger all extra power, so the exhaust is not a restriction

there are no restictions on the intake side, the intake pipe is not closing!

we removed the airbox lid and filter with minimal gains there also

and the turbo was glowing red/orange during runs with the fan going and even letting the turbo cool down sufficiently between runs

base timing is perfect

timing belt allignment has been checked and is also perfect!

im out of ideas as to why the setup is only making 230rwkw and why it pings at anything over 10 degrees timing in the top end!

anyone got anything i havent thought of?

[R31Nismoid]

The fact the turbo is blowing as red as you say would suggest the cam timing/belt is certainly something that needs double checking.

The only time i ever saw my GT30 glow red hot was after extended periods of repetative dyno work or 20mins up in the hills.

Are the injectors new?

What is the fuel flow & voltage like? Did you rewire the pump (and not use stock wiring)?

Fuel filter been replaced recently?

Any interesting bumps/dips in the power curve at all?

What happens @ say 1bar? Same power or does it increase progresively until 20psi?

[Ruffels]

cam belt timing has been checked and checked again... definatly ok!

doesnt take much on the dyno to get it glowing!

injectors are brand spankers

fuel filter has been replaced quite recently

just used standard wiring on the fuel pump and have not checked voltage/flow ... although afr's seem fine, so i assume its getting plenty of fuel

The power comes on fairly hard.... but pictures say 1000 words... so i'll go grab the dyno sheet

[geraus]

hmmm wierd, so your using an op6 rear housing?.... and whats controlling your boost?

[Ruffels]

not running a boost controller... just a high pressure wastegate actuator

here are the graphs!

[R31Nismoid]

What happens @ say 1bar? Same power or does it increase progresively until 20psi?

Need this one too

[GTScotT]

Have you considered charge temps before the throttle? That's something I would like to know.

Checked spark plugs for heat?

[hypergear]

I found this car's abit strange. Its running a .63 high flow, same profile has pulled 260rwkws on another RB25det, infact same turbo on a RB20 also made 260rwkws.

I also run a .63 rear with same profile pulled run after run nothing turned red like this one did just after 1 run.

The only way I can cool it down is using a .82 rear. which's been proven 260+rwkws on R33s. I will machine one for you comming week, If it doesn't work I really don't know whats the go with it.

[wolverine]

I would remove everything and re-install the timing belt from scratch.

Ask Guilt-Toy about the issues he had with his car, it sounds very similar.

[Ruffels]

I would remove everything and re-install the timing belt from scratch.

Ask Guilt-Toy about the issues he had with his car, it sounds very similar.

i did ask him, but he wanted money for his advice

[GTScotT]

i did ask him, but he wanted money for his advice

Did he offer you a vipec too?

[Ruffels]

also checked compression at got

1. 160

2. 161

3. 160

4. 159

5. 160

6, 159

using new bcpr7es 0.8 plugs

[geraus]

hmmm, what about your VCT? or the CAS?

[R31Nismoid]

VCT won't affect power.

CAS won't either if timing is not wavering on the run.

Was more making sure it's perfect from the start.

[Ruffels]

how obvious is a tooth out on the timing belt in terms of behaviour of the cars running performance, it idles fine, revs fine, and still feels fast! doesnt spit or splutter!

i did the 100k service myself.. changed; timing belt, idler and tensioner pulleys, front crank seal, water pump, thermostat, top and bottom radiator hoses, rocker cover gaskets, half moon seals, spark plugs, oil, oil filter, fuel filter, air filter, a/c belt, p/s belt, alt belt, radiator cap etc etc

and the only thing i can think of that could be affecting all this is the timing belt, but i was confident when i put it on,

And to double check, just the other day i pulled off the top timing case and pulled out #1 spark plug using the long screw driver trick to find TDC on #1 and then looked to see if the marks lined up, which they did!

so i got no idea

[JonnoHR31]

did the mark on the bottom cover line up with the mark on the balancer aswell as the top marks?

[Ruffels]

i didnt check the bottom line, but assmed it wold be right as i was quite confident when i installed the timing belt, bt also because when i checked it the other day i found tdc on nmber 1 cylinder and the two upper marks matched,

[JonnoHR31]

sounds like its right but worth checking anyway, the old screwdriver on the cylinder isnt always spot on, as theres few degrees where the piston doesnt really move. take 5 mins to pull off the top cover and turn it to TDC. not doubting you at all, just better to be certain than confident

[lotsalag]

Turbo will always glow red after some dyno time dont worry.

No harm in triple checking timing on the cam belt, was the keyway on the crankshaft ok? if its slightly moved and damaged the cutout in the crank it can give u false timing readings when checked with a timing light.

When u check the mark on the crank pulley to the timing cover, the timing may show 15btdc but in fact it may be totally different!

If possible maybe try changing CAS, as although it may seem fine, it might be getting noise interference or similar, or may just be on the way out.

As a result iginition timing may be jumping around everywhere up the top, causing the pinging at conservative timing.

Good luck mate!

[Ruffels]

ok, so short of re-checking the timing belt for the 3rd time.. does anyone have any other ideas?