Jump to content
SAU Community

Recommended Posts

That does make helping harder, where are you located

What you might have to do is rip off one of the cam covers and get the part number off the end of the cam cause if their not poncams but full aftermarket then poncams may not be "boltin" any more in which case you may as well go the 260 x 10.8 procam or better yet the unigroup cams

Located in Warrick Farm area, between Cabra and Livo, hmm, i'm not very confident in doing that myself xD might need some help.

I didn't intend to get involved in the usual FIP section pissing contest.....just to make the point that if your tuner says they "tuned for response" without changing anything mechanically you better find a tuner who isn't talking shit.

Jimmy, I was listing mechanical factors that affect response; once the mods have started most people forget how early the standard setup gets on boost. I built the stagea deliberately for response which is why it has standard zorst manifold, standard cams, standard head, small turbo and 3 litre bottom end. And it makes 18psi by 3200 rpm

stagea_dyno_2012.jpg

If I wanted more response I would add cam gear (as I have on the race car), it can bring on boost a few hundred revs sooner at the cost of top end power. But frankly it comes on hard enough early enough to empty the fuel tank quickly.

For a race car I would say it is a very different concern. Full boost at 5 or even 5.5 is adequate especially if you have short gears and a standard or raised rev limit.

  • Like 1

You can't because it wont sounds nice

Not that I'm sure that anyone would be able to hear the difference.....but if all you are worried about is the sound, you must also be the type that buys cars on how many cup holders it has!

Not that I'm sure that anyone would be able to hear the difference.....but if all you are worried about is the sound, you must also be the type that buys cars on how many cup holders it has!

Shut up mate, I do that, my new car has 10 cup holders ?

For me,

Bottom end:

Standard rb26 crank, nitrided, chamfered oil holes, Standard rods resized and shot peened,

Hypertectic pistons, id have to look into brands before deciding, but i do not believe forged slugs are required, pistons to suit 10.5:1 comp with valve relief's, steel comp rings, low tension oil rings, restrictors fitted to oil feeds and head/block returns drilled out

Head: stock valves, heavy springs, cams 260/262 10.5 lift dialed @106/110, a good throat job and trim valve guides, head decked to suit chosen pistons,

Turbo and pipes: small diameter high mount turbo manifold, hks 3037s, 50mm gate with 2inch open screamer, 3 inch dump, no cat or mufflers, strait to the rear

2.5inch stainless cooler pipes to replacement factory sized cooler, water/meth nozzle directly before inlet to plenum,

Id run 18-20psi, i believe a good tuner could really lean on this combo and make a rediculasly responsive weapon that packs a punch

Hmm, first question to get a post out of me in a while lol

Lets not forget the key point to making response as to a revy engine.

Light recipricating weight in the engine.

Lightest pistons and rods, crankshaft and flywheel.

Gearing helps to enhance the free rev nature when on power.

Dont get too carried away though, a clutch dump start can lead to a serious bog down on launch. :)

Turbos, cams etc work with on power driving response as does a smaller volume intercooler etc.

Edited by GTRPSI

You can look at this another way by thinking what Nissan would have done if they wanted road car like characteristics in a GTR . I think the logical solution is to start with a Neo 25T Stag engine and build it up to a level rather than trying to convince RB26 to do what it wasn't intended to . Don't hate me people but I consider an RB26 a dumb road engine in some ways because Nissan didn't put any of the smarts into making it a nice road car engine . It was intended to be a bit of a hero drive because the basis was for a road race GT car not an all round street car .

The Neo has a higher CR and the last big bore (86) turbo RB revision of chamber and piston crown shape . The whole inlet exhaust and turbo systems are designed to make good part throttle torque which is what any successful ROAD car formula HAS to be based around .

This is not to say you can't build a pretty healthy RB25T that still retains good road car characteristics . Neo head I reckon better basis than RB26 because of the chamber redesign and the two stage inlet cam phasing . On the other side of the coing the RB26 inlet system is a better performance design and better suits a GTRs air plumbing .

Production 25s always had single turbos and they have developed to the stage that singles can be pretty good nowdays .

Consider this clean sheet approach .

Neo Stag 4WD RB25DET .

Graft RB26 inlet manifold onto Neo head .

Bore to 1 OS to have similar capacity .

Standard exhaust manifold .

GT30 based turbo ie 0.82 AR IW 3076HTA .

Don't think 300-320 RWKW is an unreasonable expectation and non of this stuff has GTR/RB26 "tax" attached . Legally no capacity or rated power issue and Neo is emissions approved engine in Australia . You lose all the TT complexity and service bastardisation you have with the hot side of a factory RB26 .

I reckon this combination would give a stdish GTR in the same shell ie 32/33/34 a bloody quick hurry up and be better to drive in Camry mode .

A .

  • Like 1
Part numbers they have listed in Ebay are for tybe B cams. which are 260 degree 9.15 lift.

http://www.tomei-p.co.jp/_2003web-catalogue/e070_cam_RB26.html

I sent tomei an email last week about those cams to check out what was the go with them and they replied that they were legit and we're a small special order item to some dealers

I sent tomei an email last week about those cams to check out what was the go with them and they replied that they were legit and we're a small special order item to some dealers

This is about the ex 270 9.15 lift right? Got told that they don't make them anymore, thats why they're not listed anymore.

Thanks log in. :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • GCG is a good company, they're a major distributor for Garrett in Japan as well.
    • Nah, OEM washer bottle and brake fluid reservoirs are fine I don't know what it is with the plastic that Mazda used, some plastics, like the washer bottle and brake fluid res are fine, and still look new after 20 years use, where as the coolant expansion tank, and PS reservoir, that I replaced with new OEM items when I first got the car, turned yellow and started getting brittle a few years later If the dirty yellow stained plastics didn't trigger me there wouldn't be an issue, but they did, much like the battery bracket....... Meh As for going back to work full time to support car stuff, nope, why, because I own a Mazda NC MX5, not a Nissan R series Skyline 🤣
    • I've never heard of CJ-motor, so can't advise you on them. I'd just go straight to GCG for a GCG highflow though. Seems no point to use a middleman. I'm somewhat surprised that the price on the CJ site is lower than the GCG retail price. Even though CJ would get a discount of some sort, you would hardly expect them to give up so much margin. Maybe the price is out of date? Having said that "I'd go to GCG"...when I did my highflow, I went to Hypergear. I did this https://hypergearturbos.com/product/rb25dethighflow/#tab-dyno-results with the R34 OP6 450HP profile. With the BB centre (extra $400) and intially with the standard boost actuator, but I eventually got him to send me the high pressure one when I got to the point of being able to actually use it. Ends up costing the same sort of money as the GCG highflow, but this is, of course, the turbo that I KNOW has a shorter length core and so moves the comp cover rearwards. The GCG apparently doesn't do that. My mechanic also swears by the GCG highflow, given that we have another turbo rebuilder who does something essentialy the same as theirs, using Garrett wheels. He says it stands up at really low revs and makes good power. I haven't pushed my HG highflow past ~240-250rwkW yet (should have a little more in it, but unclear how much) and it does have a fairly gentle boost ramp. OK, it's much better now that I have gotten my boost controller tuned up on it.  A lot of my earlier unhappiness was because I couldn't keep the wastegate flap as closed as it needed to be (including some mechanical issues). I'd still prefer it to boost up nearly as quickly as the stocker, and it certainly a bit slower than that. So maybe the GCG one is worth the first look (for you).
    • Ok thanks 🙂 I will higly consider this. Any "known" company for a good reviews and experience to send that off? Is that CJ-motor good one? Or go straight to GCG site? I need to use VPN to even find some of those "shops" let alone access them 🙂 
    • You can literally put in as much WMI as it takes to quench the combustion totally (and then back it off a little, obviously), and it will keep making more and more power. The power comes from the cooling effect of the water (and the meth) and the extra fuel (the meth, which also has massive octane). It is effectively exactly like running E85. One might be slightly better than the other, but they are damn close. But with either you can lean on the boost or the timing (or both) waaaay more than with just petrol and the results are similar. Here's the first thing I googled for an anecdotal bit of evidence. Can't access the attachment without being a gold member, but it is there for the getting if able to, or searched up elsewise perhaps. https://www.hpacademy.com/forum/general-tuning-discussion/show/wmi-vs-e85/
×
×
  • Create New...