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Cams in RB25DET, R34 GTT

Hey Guys.

Just had the cams fitted, tuned and the like.

They're Tomei Poncams B, 260 duration, 9.15 lift.g

Made no extra power, all it did was drop the power through 95% of the power band by about 10kW, cost me three hours of my life, and money for the Cams, Install and tune.

Bottom line, don’t do it.

However, we did play with the adj cam gear on the exhaust cam, at 4 degrees retard, was too close to the edge, 2 degree advance, dropped 30 kw, at 2 degrees retard made reasonable power.

I have a straighter graph, not as much of a fat curve as before.

Bigger drop in torque at the 3500 to 4500 range than before.

All in all, a disappointing experience.

BUT, when the turbo goes on, we expect to make much better power than with stock cams.

Graphs to come.

BASS OUT

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Cams, $840 delivered

Fitting including major service, cam belt, water pump etc. $1200

Tune $300

Therefore, about $2340 wasted, but I needed the service anyway, so I guess only $1240 wasted.....

But when the high flow goes on, maybe not wasted.

BUMMER BASS!

Hope you pick it up with the new turbo but once lost, can it be regained on top of what the turbo will do anyway?

Hope I dont have as bad experience whith my GTR cams for my RB20 soon.

Fingers crossed!

the NEO must have better airflow than the 33 RB25... I had the 256's installed and whilst there was no power gain it was noticably smoother (better curve) and it made power all the way to redline instead of dropping off... nicer exhaust note too

oh and it made the same power at .1bar less

so yeah I have no answers just more questions... SK what say thee

ps. definately not a bang for buck mod

Bass Junky,

You over cammed the motor since you only have a stock turbo. Like you said the high flow will like those cams however. GTR's are a different story due to the larger flow on the twin turbos.

On my old R33 gtst I ran a standard inlet cam with a larger duration and lift exhaust cam. There was an improvement through the power band. I did my selection based on advice from someone who does camshafts for a living.

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