My 1995 GTR project thread.

[cortexx]

Talking of simplest tasks taking forever , a few pages back I showed a pic of my lathe with a bar of Techtron mounted in the chuck. I finished the parts tonight - took 3 hours of machining to get the pieces i wanted to spec. There are 6 halves of the spring retainer bushings that needed to be replaced.

Measuring the ITB housings i noticed how random the size of the outer casings were. They averaged around 3.4cm +/- .03mm .

I was intending to make a set of bushings to friction fit with a tolerance of .002 mm but i had to widen the gap to make sure they fitted on each casting with no problem. The factory units are a sloppy fit but i wanted to do a better job.

I ended up making 3 sets , the raised lip ended up being around .2mm thicker , and the OD of the main cylinder was around .3mm thicker. The spring seems to sit and rotate on this size alot happier and it stops the spring from distorting sideways when the throttle is activated.

Here is a comparison shot of the old 17 yr old units that are falling apart compared to the new ones...




Here is the ITB with the parts located into position , not finally installed yet because i have yet to replace the seals on the shafts . Thats the next thing to make once the material gets here ..




and another shot just for the hell of it ...



I spent ages trying to find these pieces . No luck from Nissan - or from places like RHD japan etc . You actually have to buy the whole ITB fully assembled . And they arn't cheap ..

The material for this set was around $30 and maybe 3 hours of machine work to make them . It would take alot less time if they were not made of plastic. I had to run the lathe very slowly or the cutting edge heats so quickly that it just melts the piece. Still cheaper than a new set from nissan And the material is far superior .

Maybe I should tool myself up and sell some rebuild kits lol .

The shaft seal replacements are next. I have a 1ft bar of flurosint 500 bar on order ( it's $97 per ft 1 inch diam ) . Its an exotic plastic that is based on PTFE (teflon to the uninitiated of you) that is partially filled (plastic alloyed) with Mica. This makes it less likely to deform under stress , it has excellent heat resistance characteristics and has a very low friction coeficient thanks to it's self lubricating nature. This means I will be able to machine the shaft to bushing clearance of aorund .0001 thou , which will be enough for free rotating movement of the shaft and a small enough gap to stop vaccum leaks altogether . Another great property is that it's thermal expansion rate is nearly identical to aluminium meaning that the close tolerances will remain under normal running conditions.

I am seriously considering buying a tiny cnc mill so that i can cut out some thermal barrier gasket to go between the ITB's and the inlet manifold , these would stop the conduction of heat from the culinder head to the intake assembly and help keep things a bit cooler.

[SlidingSideways]

soooo fresh sooo clean

it almost a shame that you're going to have to put oil in it when it done and make it all durrty

also, did you end up making those bushings/itb pieces out of that special extraterrestial material/moon rocks?
how'd it go?

[cortexx]

LOL well , im going to machine them a soon as the material arrives hopefully soon

going to mock up a set in nylon bar first so that i can make a tool to perfectly turn on the inner bearing face that the shaft slides through , i have to make up 2 sandwich plates to seal the ports on the ITB with an air attachment so that i can pressure test them once done , ill compare with old set of seals vs new bushings and see the difference.

The FLourosint is very expensive , well over $100 for a 12 inch piece 1 inch diameter. But if i can get the tolerances right it has the potential to pretty much provide a complete seal AND reduce shaft friction at the same time at high levels of boost

Lubrication of choice for the bushings above is fluidfilm

[cory]

Great job... This car has to be one of...if not already cleanest r33s.

Where did you get access to the lathe? Or it that part of your company

[cortexx]

Its a mini lathe, bench top one like this ....

http://littlemachineshop.com/4200

They have to be disassembled , cleaned and reassembled and calibrated when you get it but once set up properly you can turn out some very nive and precise work on it. Practice and experience make a shuge difference.

[steveo1502]

Nice little machine, would be handy to have, and not a bad price compared to the bigger ones. May I ask what u do for a living? You do very nice work,making this stuff yourself is intense, sounds like you have a lot of experience, can wait to see it finished. I'm sure you'll post some nice dyno sheets

[cortexx]

Actually making things like this is relatively easy once you get started. As for my occupation ? I run a computer retail business/service center that specializes in onsite service , corporate networking and security

After leaving my original career I was originally trained for electronics specializing in analogue and digital microprocessor control systems, trained to repair TV's and videos later on then took a complete change of direction and did a 3 apprentiship as an auto technician . After another 3 years i went back into electronics programming and repairing pinball, slot machines, juke boxes, and arcade gaming equipment, then i spent 5 years reclothing snooker tables and pool tables before retraining yet again for computer tech , then i moved to canada 16 years ago and have been repairing and networking computer equipement since.

I have also picked potatoes for farmers , gutted and prepped fish for sale in a fish market, worked in a fish and chip shop, delivered booze to retired military personel , construction labourer and a few others i could go into ...

Basically what ever it takes to make a living - I lived in England and Germany most of my life - moved around a bit because of different deployments and postings .

[steveo1502]

Wow, lol

[ms33]

What a fantastic thread, just been right thru it, any new updates?

[cortexx]

Thanks for the comments

We'll nothing very exciting at the moment .. but ill shed some light on whats going on in the meantime ...

I finally managed to get my hands on my much anticipated Borg warner EFR 7670 twin scroll internal wastegate turbo . I threw it on the engine to see what fitment was like but the 6 boost manifold make the integrated wastegate actuator clash with the exhaust side cam cover so i will be fabbing a new bracket for the actuater that re-positions in under the turbo instead of above it.

I got my new clutch from Japan at last , a dual plate carbon Excedy race clutch that has a very light flywheel , its pretty , purple , and much lighter than the nismo one on the car at the moment. Going to help response on the new engine.

I ordered some new rims - a set of bronze TE37 18 X 10.5 -15 al round with a set of 275 35 18 R888 tires for mostly track use , should be here in July .

Obvioulsy being 6ft 7" means wearing a helmet for the track became a headache with a lack of headroom so a Set of bride Vorga seats have been ordered that will pretty much sit me on the floor and give me plenty of headroom , also baan on a diet and lost almost 40 lbs to make sure i fit in them properly


A set of Takata black edition harnesses are about to be ordered , also want some kind of rear cage that will not intrude into the front of the car or make me decimate the interior , looking at cusco cages and HKS kensai service cages at the moment .


The efr turbo means i can dispense with all of the recirculation pipes , valves and such and cut down on alot of junk under the hood so i bought a Miller 180 diversion TiG to make up some nice new shiney piping ( there will be lots of pics for this ) .

Upgraded my small lathe to a much larger floor standing unit so that i can work with larger pieces . This has just been installed ready to use.


Got a new CAT to replace the 17 year old tired unit .


The engine is not being swapped in until end of the summer as im driving the car now and i want to take it to the track some time this year . Looking at transmission options to do at the same time as the engine swap , might just as well do it all in one go ...

[MattiasJacobs]

Jesus murphy! That's a wicked parts list! Very jealous...

[bimmertech]

just skimmed through, nice car.

I too have a 7670 with a 6boost manifold. I experienced the exact same fitment issue you are having.

i am very eager to see your solution. mine was to flatten out the bracket, then twist it a bit. however i moved the bracket to the last two holes on the compressor housing thus only using two of the three mounting screws. wastegate adjusted well, and clears everything pretty good. i haven't driven it yet though.

[sb119]

Obvioulsy being 6ft 7" means wearing a helmet for the track became a headache with a lack of headroom so a Set of bride Vorga seats have been ordered that will pretty much sit me on the floor and give me plenty of headroom ,

Awesome build man! I'm about the same height as you and have the same issues with headroom while wearing a helmet but every race seat I've sat in the holes for a harness are half way down my back. I've sat in a few Bride seats but never a Vorga. Are the harness holes any higher than other seats? Or do you just have your harness come up and over your shoulder?

[cortexx]

Hi Guys

Its been far too long with no updates so i figured id post up some pics for you tonight and some info on what ive been up to.

The one thing i have been working on is making the Borg Warner turbo fit on the 6 boost manifold without fouling the cam cover , i did fist the old one until it fitted but when i tested it with a air line for operation the waste-gate canister actually had movement with the bracket flexing .

This was mostly because i had hammered it flat and twisted it to make it fit but was only able to utilize 2 of the countersunk mounting holes on the turbo casing.

Constant usage would eventually break something due to fatigue so i set about to make it better. And a flexible plate allowing the waste gate canister any movement is obviously going to create latency int he waste gate operation - not good for my responsive to be engine

[cortexx]

ok on with the details - I am beginning to assemble a list of fittings to plumb in the turbo oil and water lines . I have spent hours researchingt o find out what everyone else has used and there is a suprising lack of info on the net about it .

Found a website that has alot of fittings and this is what I have figured i'll need for the oil .. ( minus the lines themselves and the oil drain fitting on the actuall turbo case )

www.anplumbing.com


earls and XRP fittings for oil lines .


3/4” NPT to -10 AT981609 (oil drain to block)
90 Deg. Ti-Tech Hose End -10 209010TT (90deg oil drain hose end)
Straight Ti-Tech Hose End -10 100010TT ( straight from oil drain flange hose end)
M12 x 1.5 -4 871204 (oil feed from block ADAPTER)
90 Deg. Ti-Tech Hose End -4 109004TT (oil feed from block hose end)
150 Deg. Ti-Tech hose end -4 115004TT (oil feed to top of turbo hose end )


Ill be adding to this list as I go so hopefully it'll help others out with a list for a single turbo conversion.

I started with retapping the rear water feed on the block tonight , not to change the thread , more to clean out any rust etc ..

this is an m14 x1.5 thread if anyone was wondering what fitting to use ...




after chasing out the junk i smeared some lithium grease in it to keep the thread clean and prevent corrosion .




The Borg Warner EFR 7670 was a long time coming but it did finally arrive earlier this year . I bought the internal wastegate unit on the T4 twinscroll flange with a 92.AR . These units should spool faster than my tomei twins and give me more than enough power to have fun ..

In Hindsight it may have been easier to buy the fullrace unit but i did buy the 6boost (both of which are great manifolds and are widely used) , so im going to make it all work .

The first small issue was simply that the studs in the mainfolds t4 flange were too long for the turbo's exhaust casting ....




2 options are , gring the turbo or use a shorter stud , ill be removing the stud and grabbing some shorter ones soon (tm) .

The next issue is a bit more or a pain in the ass in that the waste-gate actuator is mounted on the left side ( looking at the turbo from the front ) . On a 2JZ engine this wouldn't be an issue but this is an RB26 and the turbo is on other side of the engine - which means the waste-gate canister clobbers the cam cover . We either machine the T4 flange to tilt the turbo out and get clearance OR I guess i could relocate the bracket on the cannister ....

This is the original canister location as it comes from the factory ...



This is not good , i needed to drop it down below the level of the cam and have it sit just about the manifold.

So i had some scraps of T304 stainless steel bar and plate in the workshop that i decided would make great bracketry

This is my first attempt - took about 2 hours to drill , machine and grind this to shape . T304 is not the softest metal to fabricate things with ....



put the wastegate back on , tried it with 20 psi carefully and it worked but this plate had alot of flex in it , need to modify it to stiffen things up .

So i set about to make another bracket to brace this one and stop flex .... more stainless and a cobalt drillbit to make a hole , i have a pile of melted HSS bits from trying to drill this stuff , the cobalt bits are the dogs bollocks for doing this on slow speed in a drill press with more lube than Freddy Mercury and Elton john would use in a single night ..



Then i loosly assembled it all on the turbo and clamped it down on my Welding table ready to tig ...



Here is a closer shot to show this clearer ...




Once tack welded , I removed it from the turbo so that i dont damage anything on the turbo assembly and finish welding the bracket . I dont like welding t304 much , it's a bit easier with a mig but i wanted the cleaner finish of the Tig , although It's not exactly a piece of sculpture it'll work




I also countersunk the 2 screw holes so that the original countersink screws could be used ..

BOlted back on the turbo to make sure it all fits and to make sure the welding didnt warp anything ...



a slightly different angle . What you can see here is that the extra piece has affectively braced the plate i made and rendered it completely rigid . No flex - good wastegate response



Voila .. view front the front and you can see the relocation , it now has plenty of room and doesnt foul anything ....




and another angle so you can see the orientation a bit easier ....



I connected 20 psi to it and checked the operation of the wastegate and it's tight precise and nothing moves that shouldn't .

Next up i have to assemble the list of parts for the water lines , then i can put an order in for the parts and hopefully they dont take too long to arrive ...

More soon