Chris Wilson

Got a pair of Apexi hydraulic cams from an RB25DET, they are stamped "LA1" does anyone have any spec sheets for Apexi cams, there seems very little info, even when doing a Google search? Thanks.

My wife wants a fairly big auto estate, I have loads of RB25DET / RB26 /R33 GTS-t / GTR bits (engine, suspension and transmission) knocking around. So when I saw a Stagea RS-4 for sale at handy money in good condition the other day, I thought of her My question is, what is the 4WD set up, is it the same as a GTR, gearbox and transfer box wise, but with an auto box, or totally different? I'd be leaving it stock, so just curious, but as an aside, could they be converted to run the GTR manual transmission set up and take big power? Thanks.

So using RB26 engine / GTR bodyshell engine mounts into an R33 GTS-t subframe with an RB26 twin turbo engine line up OK? Thanks.

I think I could be about to have issues with the different LH engine mounts in a GTR and GTS-t R33. I am putting a twin turbo (stock set up) R26 engine into an R33 GTS-t shell. It appears some of the front turbo oil or water feed piping could interfere with the different engine mount used in a GTS-t. Has anyone doe this swap and can tell me about the issues? i am still assembling all the pipes and unions for the turbo plumbing, but from what i can see so far this could be an issue, in particular the steel pipe with the cops tail curl in it to the front turbo? Thanks.

Looking to buy a 33GTS-t as a base unit for race use, shell will be stripped bare and sent for a weld in cage fitment, carbon doors and leaxan glass. I am now wondering if I could buy a none turbo GTS 2 door and use the shell from that? is the shell exactly the same? I have a GTS-t with an RB26 engine, with race running gear, so issues like diff, suspension and hubs won't matter. It's just the basic body shell I am after. GTS ones are cheaper and less likely to have been "abused" especially in automatic format. Thanks.

Has anyone suffered with these cracking or warping at all? What's the situation with those wishing to use stock 18mm thread size wideband O2 sensors in them? The stock cast elbows have adaptors with small thread size, but on removing them the major thread size is bigger than 18 mm... Thanks.

Measured a stock head today and it was 63 cc +- 1.5 cc across all six chambers. My new ported head is 65.5 cc on all +- 1cc. With Tomei cooling channel pistons with stock valve reliefs, a 0.9 mm thick, 87 mm opening gasket and stock deck height on 86.5 mm bores on a stock stroke crank I get 8.61 to 1 CR, which is what I was after. Thanks

Thanks, I am about to do just that, it's a brand new head that has been ported, and a bit of chamber tidying done. I'll post up the volumes, just needed a guide as to what a stock head chamber volume is. I have the piston crown volume from Tomei, so I can then, with the bore (86.5) see where we stand with a stock gasket fitted. Thanks

What's the stock head chamber volume for a virgin stock head please? Thanks.

I know the forum has been a bit slow and jittery so I am bumping this in hope of some replies, thanks guys!

A very few manifolds were dual drilled to mate to either head. example: Apexi cast iron single turbo manifold. With forethought it is trivial to make tubular header manifolds with a flange pattern to fit either head, but very few people do this. The bolt positions on cylinders 3 and 5 are opposed. Otherwise they fit.

Just want to stress it's the cam duration that's worrying me, I think if I choose a turbo(s) with fairly small turbine size the back pressure versus the long duration may cause flow reversal. I went with 280 degrees so I could build something a bit stouter when I get bored with 600 FWHP, or decide to put it in a 4WD car. Thanks

I am wondering if the turbo experts here could offer their advice please? I have nearly finished my RB26 engine and the spec is as follows. What I need to decide now is the turbo(s) to use. I am after total manifold reliability in long distance circuit race usage, so tubular manifolds are not an option as I can't afford something with slip joints, in Inconel, and anything other will, to me, be suspect. I have 2 brand new HKS low mount cast iron manifolds for single turbos, and I have stock RB26 manifolds. I am not totally sure what material spec these HKS things are, so they may well crack, but I do have a spare and maybe access to a good used one as well. So I need advice what set up to run. I am looking for about 580 to 620 flywheel horsepower, with as little lag as possible, on UK pump fuel (98 RON), ad maybe more on race fuel for a bit of fun, with a second map. Engine spec below. Thanks. New N1 block, new head ported and cleaned up casting. Steel crank, steel rods at stock stroke and 86.5 mm bore. Tomei cooling channel forged pistons, CR 8.5 to 1. A pair of Tomei 280 degree cams with 10.8 mm lift, SARD 700 cc injectors in modified stock rail, stock throttle bodies bored out to 50 mm with bigger throttle plates, Tomei oil pump, wet sump, external head drain assistance. ECU is a Motec M800, running closed loop with wideband. Fuel pump is Bosch 044 fed from a swirl pot. Chassis is race spec RWD R33 GTS-t run as a 2 WD set up on slicks. Gearbox is uprated T5 dog box. Thanks.

This is something I am interested in doing, too. As far as I can see the issue would be you lose the spring loaded oil bypass system, should the oil filter clog or collapse internally. I am thinking of tapping the block to take a filter thread adapter straight on to its side, and binning the cooler and associated bits altogether. I would then accept that should a filter block that safeguard was absent, and I would also take care to not rev the engine hard from cold, in case the bypass was used to pass viscous oil around the filter in such circumstances (which I think is doubtful). Please critique this.

Apart from the stock, common or garden cast iron twin turbo manifolds, what other ones have Nissan produced? I believe that the N1 engine may have used different, freer flowing cast manifolds, but what did the Group A cars (Gibson Motorsport, for example) use? Were they limited to production cast manifolds? Did they "interpret" the rules broadly and have one offs cast with better flow, or did they port stock parts? Just curious as to what the ultimate cast manifolds are for the TT set up. Many thanks.

Why not just cut and re swage the hard pipes on the turbo side of the block, and run flexible hose to the other side of the engine, routed to avoid any oil return fitting? I intend using a hose of much greater internal diameter, as the drain is purely gravity, and I would like to see at least a 20mm ID pipe down to the sump region. I may use an alloy pipe and flatten it locally if clearance to the bulkhead is an issue. Great discussion, and pics sure help get the ideas over. Excellent stuff

But will it flow as well, bearing in mind we are talking gravity feed here?

The big HKS stock mounts, for example, I can't recall if thsy call them RS or SS. Basically I am wondering if this "shuffle" on the aftermarket large stock mounts can be dialled out by NOT running MAF sensors, and running a MAP system. Probably talking 600 'ish flywheel HP.

Some of the bigger twin turbos on stock manifolds, on the RB26 engines give rise to shuffle. Some say it's curable by a balance pipe between the 2 exhaust manifolds, but I want to stay with STOCK manifolds. I have also heard that this shuffle is really caused by the AFM's getting reverse, or pulsating air flow at some load / RPM levels. My question is, do people get shuffle on engines with a decent aftermarket ECU, like a MOTEC, well mapped and using a MAP sensor, and NOT AFM's, on stock cast iron exhaust manifolds?

If I were to run Garrett 2860-5 turbos on ported stock manifolds is there a worthwhile improvement using Tomei or HKS fabricated elbows? Unless there is documented dyno evidence I am loathe to forego the reliability of the stock elbows for something that may crack, warp or blow. Car is for track use, and I DO NOT want to be pulling the turbo package apart tracing blows, cracks et cetera. Thanks. As an aside does anyone know what the Gibson Motorsport Group A R32's used in the way of turbo packages? Thanks.

Thanks, having a bad day

Thanks for that, a nice bit of machining, but are you not concerned about running an in lijne 6 with no crank damper? Cheers.

I am going to run a Motec M800 on my new RB26 engine build, and over here in the UK someone has logged scatter of up to 10 crankshaft degrees from the stock CAS sensor. I was therefore considering using the CAS as just a cam position sensor, and using a crank trigger wheel for crank position, with a dedicated sensor. Have many here done that, and if so, are they willing to show how they designed the set up? I know Hugh Keir in the UK used the 18 OS Giken clutch to flywheel bolt heads as a 18 "tooth" trigger, but I think I prefer a front mounted assembly. Thanks.

Would you be interested in a brand new one, complete with exotic one off stainless Tial wastegate adaptor and Tial wastegate, also brand new? I have pics of it all, they were for an RB25 engine, but I have now built an RB26 instead. Parts are in the UK, i can give you the link to a Toyota Supra twin turbo forum in the UK where I have been active on for years and sold thousands of pounds worth of stuff to members, for an independent verification of my trading status. I can send you photos, too.

Was going to go single, but am now considering twins on ported stock manifolds, for the sole reason they never seem to crack, and if they should are cheap and easy to source. Engine spec is as follows, intended use track days, with occasional road usage, in a modded R33GTS-t New ported head with stock valves, modded to take Tomei 280 degree cams with 10.8 mm lift. New N1 block with 86.5 Tomei cooling channel pistons, Tomei steel rods and Farndon steel crank at stock stroke 9so still around 2.6 litre) Matched stock throttle bodies on matched manifold. Motec M800 running MAP sensor, no AFM's. What is an honest and conservative at the flywheel power and torque figure on 2860-5 turbos? On pump and on race fue? Will they shuffle on the road? I don't want lots of lag, I intend to use 9K revs maximum. Don't forget car is a lot lighter than a GTR, and yes, it has proper brakes and suspension, and will run a none Nissan strong dog box, and a proper clutch Thanks, any other turbos that fit the stock manifolds worth considering? 650 BHP should be plenty.