brad 110

I will post it tomorrow, might have to be a photo of laptop screen unless someone can tell me how to capture screen view so I can attach to post. Cheers brad

Despite what many people on the forum say, Ross is a great guy. I run his full trigger kit on my race car and turn it past 9000, the Motec trigger trace is a perfect line, even with a brand new complete cas the log would look like a saw tooth over 6800 rpm, increasing valve spring pressures only aggravated the problem. The Dyno graphs showed measurable gains at high rpm. If anyone is interested I can post the screen capture of the pre and post logs.

I've taken .120 plus " off these heads and just remilled the oil feed relief, piston to valve like Ben suggested can be an issue as the VCt in the 20 deg advanced position will net you up to .180" lift at dtc on the inlet and by reducing the deck face the valve drop to head face will be reduced by close to same amount, this will vary on where the cams are dialled in. You will need to get Hollywood to straighten it first before you surface it unless you have a special set of cams with a bend in them to suit your as stated not perfectly straight cam tunnels and then just never rotate them! What ever you need as listed above I have and no longer will be using off my shit box Datsun as heading down another path on the new engines let me know if I can help.

The Haltech idle control block uses a 4 wire delco idle motor (the gtr is two wire BAC valve). I'm not convinced the platinum nissan plug in has the idle A,B,C,D idle driver outputs available.

Fine on a gtr head with solid lifters and no VCt. You have VCt and hydraulic lifters yes? Then don't block the rear, your engine builder would know this if they don't be concerned, mention loss over distance and gauge the response , trust me block the rear and the lifters at the rear of the head will define it for you.

Don't block the rear oil feed it does matter, block the centre at 75 to 85 psi max hot oil pressure if you leave the front restrictor std (which if you want the VCt to operate you should) and block the centre then reducing the rear to as little as 0.9mm combined with using a high volume pump so as oil pressure at idle is 30 psi or greater hot the lifters won't rattle.

Whose box?? Who lol??

The drone will be caused by the rear muffler no doubt. Wrapping it will achieve nothing other than making your arms itch for two days.

I can supply you brand new power FC unit with no hand controller for 1090$ delivered cheers brad

You can reduce the rear feed to as small as 0.9 mm, block the centre and leave the front VCt restrictor std. This with hydraulic lifters is fine I have done this many times. The lifters will not be noisy and the VCt will work fine. This will not on its own stop the sump contents from jumping into the catch tank, but is a good start.

10.5 cc,s smaller than r33 head from memory . 51.5 compared to 62cc give or take a cc

The seat pressure changes depending on how far the valve seat is cut into the insert, what valves are used, the collet and retainer and any spring seat under spring. Many spring testers will vary in readings by plus or minus 10 percent. I can only comment that if your running 80 psi of oil pressure ( as oil pressure is what drives the cam gear to advance camshaft so 110 psi oil pressure will overcome a higher spring rate than 80 psi) 80 psi seat and from memory 270 on the nose is about the limit, even then cam chader can be evident on advance activation. Bear in mind the restrictors used in block will change all these findings as they will vary the actual oil gallery pressure in the head. All these tests were done on a circuit based car using a 0.9 mm rear feed, blocked centre and std front feed, with a main oil gallery pressure of 80 psi.

The buckets will not interchange from the neo (solid) head to the series 1/2 r33 hyd head , nor will the valves or springs or cam shafts . The neo head would raise the compression approx 1.25/1.5 compression points over the r33 head Why convert it to solid on a three litre engine as you won't be able to spin the engine hard enough to worry the hydraulic lifter, fit some super tech or Tomei type a springs and ensure the inlet spring seat pressures don't exceed 78 pound or the VCt won't activate. Easierly possible to exceed 450 rwkw with hydraulics and pon 256 camshafts with supporting components using e85 The boys above have a point re the neo head is a far better animal if you are prepared to get rid of the std shim over bucket and make it shim under or shim less cheers brad

Rob 82 is all over it. Have a look at your Dyno graphs how many of these graphs maintain targeted torque values. Lets say the engine can withstand 850 nm then how many of these tuned engine generate that targeted torque then maintain it to the rev limiter. Who says these high comp engines need to run 25 psi at 4500. Map the boost if you don't have flyby wire throttle mapping to maintain the cylinder pressure the engine will cope with happily. If this requires 17 psi at 4500 increasing to 30 psi at 9000 who cares nor will the engine!! Assuming we are using the fuel of quality that rob82 suggests then 11:1 and boost is no issue.

Forget looking at the cause until you have fully accessed the outcome. Get it apart and with careful inspection you will be able to pin point what and how this has happened . The dyno runs showing afr means little as it shows an average tailpipe mixture not individual cylinder mixture and shows nothing regarding detonation, which if it's drilled something would be the cause wether a lean mixture concentration promoted the detonation in the first instance.

Has anyone yet run a 6466 on e85 and made 500 plus rwkw here? Cheers brad

Split pulse is about grouping multiple pulses in two banks (in the case that the turbo is twin scroll) 123/456 (as one cylinder fires in pulse group 1 then 1 fires in group2 and so on) in the case of an rb. Nothing to do with individual cylinders having access to a shared flange nor trying to keep cylinders individual (other than grouped).

Many manifolds are built and sold as split pulse using one gate, if the waste gate pipe work isn't separated with tube work and a file fit devider right to the gate valve, then it's not true split pulse just as Micheal suggested full stop. He too is correct re two gates if one flows sufficiently to control turbine speed there are as many down sides as up in using two gates over one.

The real world gains in advancing inlet camshaft timing at low to mid engine rpm far out ways the given gains in the displayed dyno graph but it does clearly shows the result of net losses if cam timing is left in the advanced position

wanted 2 rb25 det engines, suit rebuild,prefer down on or no compression. wanted neo r34 head complete 0419362110 or reply via pm note must be in tas

anything under a 1.46 or 7 is fast on a semi there in a road going car, the last time i ran there in a road car i think we ran a 1.41 on a 265/640/18 slick but in full road trim drive there drive home, so 1.44 on semi is sensational, there was a guy running at the time called marcov or something like that from further north running in the 43,s i think too at the time in a 32 gtr

was just wondering what times you fast guys are rattling out over there now as its been a good couple of years since ive run anything at those track and at the time 1.43 on a radial at the island and 1.16 and sandown and 63 or 4 s was the goods at calder, whats the goods these day

who ever "risking" is he sounds wise, experienced and knowledgable, he qoutes you just carnt keep front diffs in them, which is correct in moderate to big hp racecars (650 plus on race tyres) so is if reliablity is an issue (which it is front diff, front shaft) wise then is the subject reffering to 1 lap wonders or time attack style racing? Out of intrest who has run there gtr at either philip island, calder or sandown?

great job of the bar and splitter old boy, should be the goods

would be one way of doing it for sure, means running ignition cut for traction control though which is pretty hard on the engine if its on a percentage of cut for the majority of the lap. would be difficult to map due to constantly changing grip levels, maybe you could swing a 9 position trim of a gain compensation to vary it like we do to ulter the target slip percentage and rate in which throttle is slammed shut on slip break out.