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just got my car tune last week and the result was very disappointing.

Before with the GCG stage 1 i've 220rwkw boost start at 18psi and dropped to 14.5psi. Now with Poncams and hybrid with vg30det rear exhuast housing i only managed to pick up 12rwkw and boost from 20psi dropped to 16psi. ;)

The tuner reckons that the valves springs are weaken or something. Has anyone experience this before? or is it right with the amount of boost?

engine: r33

3'" exhuast, pfc, 550cc inj, reg, pod, trust fmic etc.

just got my car tune last week and the result was very disappointing.

Before with the GCG stage 1 i've 220rwkw boost start at 18psi and dropped to 14.5psi. Now with Poncams and hybrid with vg30det rear exhuast housing i only managed to pick up 12rwkw and boost from 20psi dropped to 16psi.  ;)

The tuner reckons that the valves springs are weaken or something. Has anyone experience this before? or is it right with the amount of boost?

engine: r33

3'" exhuast, pfc, 550cc inj, reg, pod, trust fmic etc.

if that exhaust is turbo back, and you have a high flo cat, this car should pull some decent figures.

Either your engine is worn out, Or I'd start looknig for another tuner.

I make 210rwkw on a completely stock turbo, full exhaust, fmic, and pfc.

No reason why your car shouldn't be 240rwkw - 260 rwkw with a decent tune.

Allowing for the fact that the dyno might read a little low and The Mafia's dyno is a little on the happy side, there is still something wrong.

Boost should not be dropping like that.

What boost controller are you using?

Is the exhaust 3" from the turbo back?

Is it series one or two?

Can you post a dyno graph with boost and another one with AFR as well as power?

if that exhaust is turbo back, and you have a high flo cat, this car should pull some decent figures.

Either your engine is worn out, Or I'd start looknig for another tuner.

I make 210rwkw on a completely stock turbo, full exhaust, fmic, and pfc.

No reason why your car shouldn't be 240rwkw - 260 rwkw with a decent tune.

Mafia:

the exhaust is turbo back with highflow cat. last tune just with GCG stage 1- at 10psi i got 200rwkw and only pull 220rwkw at 15psi. now with Poncams and hybrid turbo i only on 232rwkw. with my stock turbo i've got 200rwkw with mines ecu! ;) yeah, i was expecting atleast 240rwkw with the setup!

Allowing for the fact that the dyno might read a little low and The Mafia's dyno is a little on the happy side, there is still something wrong. 

Boost should not be dropping like that.

What boost controller are you using?

Is the exhaust 3" from the turbo back?

Is it series one or two?

Can you post a dyno graph with boost and another one with AFR as well as power?

i'm using the hks ecv 3. The turbo comes with hks actuator as well.

the exh is 3" turbo back and is series 1.5.

sorry dont have scanner. the AFR is 1:12 starting from 4000-7000rpm.

3200rpm - 82rwkw

3800rpm - 120rwkw

4400rpm - 166rwkw

5000rpm - 190rwkw

5600rpm - 208rwkw

6200rpm - 222rwkw

6800rpm - 232rwkw

I would have thought with the cams and no other upgrades you would have picked up 15kw and then with the bigger exhaust housing/turbo you would make more power on the same boost with less drop off at the top.

Stupid question but is it possible that you intercooler has a small leak? resulting in pressure drop at high velocity?

I think you should be pulling 250rwkw

just got my car tune last week and the result was very disappointing.

Before with the GCG stage 1 i've 220rwkw boost start at 18psi and dropped to 14.5psi. Now with Poncams and hybrid with vg30det rear exhuast housing i only managed to pick up 12rwkw and boost from 20psi dropped to 16psi.  ;)

The tuner reckons that the valves springs are weaken or something. Has anyone experience this before? or is it right with the amount of boost?

engine: r33

3'" exhuast, pfc, 550cc inj, reg, pod, trust fmic etc.

The problem is the boost drop off, the R34GTT with the GCG ball bearing high flow makes 265 rwkw at at 1.3 bar (19 psi) and it doesn't drop 1 psi all the way from 4,500 rpm to 7,500 rpm. It also has Poncams, and is not the only one, there are 2 others that we have done and several on here that do similar. For example Ian's R33GTST has the VG30 housing and makes a bit more.

My guess is you have a restriction that is limiting the airflow, something in the inlet or exhaust becomes the weak link. The first thing I would do is drop the exhaust before the cat, give it one quick power run and see what the differences are. Look at the graphs for A/F ratio and boost as well as the power curve (not just the max power).

The next thing I would do is check the boost drop between the turbo outlet and the plenum. If it is more than a couple of psi, then I would start looking for a restriction, too small pipework, poor bend quality, intercooler etc.

:) cheers ;)

PS, have you tried playing with the HKS EVC? Stick another 5 psi in it and see whether the boost still drops off to 16 psi. If it still does, then there is a restriction in the inlet or exhaust as per above.

I hate threads like this.

It's always bad when you don't make the expected power.

Question. Did you get the cams dialled in? I have a feeling that my inlet cam it not in the right spot on it's standard semi-adjustable gear.

I'll be playing with the cams and trying to get the best out of my setup whilst I source all the bits for my upgrade.

BASS OUT

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