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So in your opinion cams are a must for maximum efficientcy. Thats a fantastic difference from 260 to 300. I think with the housing that Robo has and most certainly my .82 there could be big gains in cams of say, 256inlet/260 exhaust due to the freeing up of the exhaust and because the turbo is is now very efficient but the motor less so.

When the cams went in the first thing we noticed was power was up slightly but it allowed more ignition to be pushed in which is where the power picked up noticeably.

I was always taught that anything you can do to reduce the restrictions on the hot side pays off by reducing exhaust gas reversion , better cam profiles help achieve this by opening the exhaust valves further and for a bit longer .

The trick seems to be matching the valve timing with the static compression ratio once the exhaust restrictions ie exhaust system / turbos hot side have been reduced . It falls in step with the greater gas throughput (air and exhaust) for less than or equal resistance to flow - pressure rise .

A .

Edited by discopotato03
Robo, The Z32 AFM what peak voltage are you seeing?

I run GTR 444 injectors. They flowed 440cc at 36psi and 480cc at 40psi.

At base pressure they were maxed as 260rwkw approached (Z32 saw 4.78volts) to hold a 11.8:1 afr.

A 1afr point drop at idle (adj fpr) and fitting cams has seen them go to 302rwkw at 90% duty and a flat 12:1 afr. 302rwkw I'm now seeing a flat 5volts on the Z32.

I'd really like a 3.5" exhaust with 2 large body mufflers in an attempt to keep the noise down.

Not sure, i will look at the volts next time.

robos i had the same turbo set up on my rb25det a few years ago. with the same problem. too much back pressure with a/r.63 exhaust housing so runs out of flow at 22psi rougthly 6000rpm. you can fix this with a/r .82 internal wastegate exhaust housing im quite sure that gcg in sydney can source one. i changed my mind last minute and upgraded to gt3040 600hp turbo with a/r .82 exhaust housing instead. as for the boost falling away from 22psi to 19psi. this is something that you will really struggle to fix running an internal wastegate. are you running a 1 bar actuater? you can buy these from gcg in sydney as well or hks one from nengun.com. the only other alternative to hold more boost is to run 24psi which will hold over 20psi at 6000rpm but obviously no good with stock internals.

and for safety sake go and get your injectors hi flowed at avo in melbourne , cheap insurance. dont listen to anybody that says hi flowing standard injectors effects idle e.t.c. i had absolutely no problems with mine.hopes this helps cheers carl. p.s. i never got anywhere near an 11second pass with this set up. too much wheelspin down low and not enough flow up high in the rev range but very nice mid range for the street! but having said this looking at what you got with the hks 2535 you and your car are both freak performers. i should have got you to punt my car down the quarter mile probably would have pulled an eleven!

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