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tried to post results before but it didnt take. anyway i just had my rb25 rebuilt with gtr rods and wiseco forged pistons due to my engine trying to swallow a shoddy weld done to my new induction tract to my new gt 30 500hp internal wastegated turbo. i decided to throw in some step one tomei poncams 256 degrees duration 8.5mm lift and i thought id share my results with the forum. power went from 260rwkws at 20 psi to 277 rwkws at 21 psi! im really happy with the result. probably only do minor tweaks to the engine now like greddy plenum and 4inch magic cat, cant wait to take her to the track!! id love to hear from anyone else running this turbo? the specs are gt30 500hp internal wastegated with a/r 70 comp cover and a/r .63 exhaust. i bought the turbo from horsepowerin a box.com.au

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tried to post results before but it didnt take. anyway i just had my rb25 rebuilt with gtr rods and wiseco forged pistons due to my engine trying to swallow a shoddy weld done to my new induction tract to my new gt 30  500hp internal wastegated turbo. i decided to throw in some step one tomei poncams 256 degrees duration 8.5mm lift and i thought id share my results with the forum. power went from 260rwkws at 20 psi to 277 rwkws at 21 psi! im really happy with the result. probably only do minor tweaks to the engine now like greddy plenum and 4inch magic cat, cant wait to take her to the track!! id love to hear from anyone else running this turbo? the specs are gt30 500hp internal wastegated with a/r 70 comp cover and a/r  .63 exhaust. i bought the turbo from horsepowerin a box.com.au

Going back 12 months ago very few people upgraded cams, but now a lot of people that are making mid 200rwkw are starting to realise how much extra power can be had from changing them.

It doesn't seem to be a massive power gain (especially with a boost increase) in comparison to some others I've seen, but I can only assume the you would have set them for better boost response and mid range power rather than top end?

Are you breaking traction in 3rd gear under acceleration yet?

Congrats on a succesful upgrade ;)

I have 277rwhp at charlies motors in brisbane which is tested with out any componsaters on the dyno, and i break traction in 3rd, you should be getting wobbly in 4th by now.

I'm just talking about putting your foot down in 3rd and when it hits boost, the car steps sideways. If your car is doing this with 255 on the rears in a R33, then you must be making some serious torque.

That comes more down to suspension and tyres. R31Nismoid and myself have the same cars.

I have 265 yoko rear rubber and 235rwkw and break traction in third as it ramps up to boost.

He has generic rubber, 235 I think and his old engine made ~300rwkw and didnt blink in third.

Obviously his suspension and alignment settings are more sorted than mine.

330rwkw :P and it only slightly started to move in 3rd as it ramped onto 24psi @ 4200-4500

running 225/16's :P Just keep the right foot into it and it would come good after the slight move

@ 270rwkw it didnt move by any means, very great to drive once it was on boost. Very quick streeter.

As for power Bigcarl, awesome man. The cams help indeed.

The power can be made without them, but they will give you some increase (what i setout to do. ie no cams)

I think you'd be on the limit now of the turbo @ 21psi. Only due to that .63 rear end.

If it was a .82 then you'd be closer to 300 even @ the same boost IMO

I take it 21psi is the limit as its starting to detonate at anything more?

got a dyno sheet now? Hopefully looking a lot better than your previous one

Very nice. :D

The .7 comp cover over the stock gcg style setup definitely proves worth while. Slap a VG30/R34 hotside on it and you 'may' see 299.99999rwkw.. Wouldn't that be a bugger. :cheers: So close to the magical 300rwkw mark. :D

How does it hold boost up around peak power?

Does it tend to tail off? What EBC are you running?

I know of RB25DET with cams making slightly over 300rwkw, Tim Possingham the prior owner of Horsepowerinabox used a VLT turbine housing, unsure of the chra or comp cover, I assume he had it powerported or similiar as the turbo's cost was up at 3k.

Works well though, I remember Freebaggin telling me at 17psi it was somewhere up around 280rwkw and would ramp on hard at around 3500rpm.

Edited by Cubes

Carl well done buddy!

I just placed an order for a set of these cams, 2 days ago :cheers:. In two weeks car goes in for cams, head porting, VG30 ext. upgrade on hi-flow RB25 turbo and tunning.

Really would like to read (and see via dyno sheet :D ) how the cams effected drivability. I am hoping they wil give me more low/mid range power and torque, also that they allow the turbo to boost up quicker.

Is it worth getting adjustable cam gears with Tomei cams?

hi Al, nah you shouldn't need adj cam gears for the poncams... they have been specifically designed for the RB25 vct and work nicely straight out of the box... however if money is no concern and you would like to play around with the timing, let me know the results!

i havent picked the car up yet, just spoke to tuner. i will ley you know how it drives when i ve had a good drive. the cams were set on o in stock position no adjustable cam gears. my engine tuner seems to think that an aftermarket plenum would make a difference because less twists and turns e.t.c but for $1200 i dont think id bother. he reckons if i fit a larger exhaust housing like you guys have mentioned that would probably nudge peak power closer to the magical 300 rwkw mark but for now im really pleased with the result. apparently there was no more power to be made over 21psi, i think detonation was definately rearing its ugly head at anything over 21 psi, with the restrictive .63 a/r exhaust housing. also i think the boost spikes o 22psi or so that was the only way we could hold 21psi through out the whole rev range . i will post up shoot out graph as soon as i pick my car up. im running link ecu and electronic boost control.

I see that Nengun list two different part numbers for the 256 Poncams on the RB25 in the R33, series one and series 2.

Out of interest which part number did you order and is yours a series 1 or series 2 and can anybody tell me what the cam differences are so I don't end up ordering the wrong ones :D

I didn't go through Nengun this time as there is a Melbourne supplier that imports these parts and was only $60 more expensive. Using Nengun you run a gamble with customs charging tax, as with RMS Motor Parts the price is final.

Part Discription:

Tomei - Pon Cam Shafts

ECR33 Series 1 (RB25DET) - Duration: IN,EX 256 Lift: IN,EX 8.5mm Code: 143020

RMS Motor Parts

Unit 3, 662 Whitehorse Road,

Mitcham, VIC 3132

Phone: 03 9872 6669

Fax: 03 9872 6697

Website: www.rmsmotorparts.net

took her for a drive last night, bloody quick now. tried standing start , launched her at 3500rpm. wheelspin city, span all the way through 1st 2nd and 3rd gear. my dunlop lemans 245x40x18 were useless!!! now i can see why people buy gtrs, cant get traction!!! how am i going to go at the drags when i cant even launch it at a mesely 3500rpm???

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