Tassuperkarts GX Turbo (Updated again!)

[tassuperkart]

Darren
Thanks dude.

I only had the bare long block to start with tho.

I used the old original stock head off the GX as it only had about 40,000 K's since a full reco.
I swapped cams and rocker gear with another shitter head since there was a problem with the grind on the original GX item.
The heel radius of the cam was not ground correctly on center and was impossible to adjust and stop ticking and "throbbing" in the exhaust note.
After that everything else on the smoky ET motor was pulled off and swapped over including flywheel and clutch.

I didnt have another running gearbox handy so i split the one I lifted from the car, gave it a good checkout and tossed it back together.
It could have used a set of bearings and seals but I didnt have them handy so fuckit!

I simply ran out of steam on Sunday night tho at about 20.30! it was hell cold as well...........
Fuggen spare radiator i fitted while the original was being fixed for a minor leak has its own minor fucking leak as wellllll... prick of a thing.
Shit happens.
L8r
E

[The Renegade]

Fuggen spare radiator i fitted while the original was being fixed for a minor leak has its own minor fucking leak as wellllll... prick of a thing.
Shit happens.
L8r
E

Selley's Quicksteel (AKA kneadit)
There's nothing it can't do.

[Panda_ET]

Agree with renegade, I have made complete copier parts with the stuff muahahahahahaha it doesnt give a shit about water or oil.

If I dont think the part works properly I Redesign it with kneadit rofl

[tassuperkart]

Nah i dun think so. I dont do patchups with some funky goolie-gum!
Only once on my first car did i do a dodge up of a leaking radiator and of course, it failed later on.
So, the only repairs done to any of my leaking radiators since day one are done by experienced radiator repairers.
Do it once and do it RIGHT, the first time.
Is why I never have subsequent cooling system failures.

A 50 dollar pressure check and repair is cheap insurance against the fucken cunt of a thing failing somewhere down the road one day.... which once, a long time ago in the middle of the cunting night, is exactly what happened.

L8r
E

[tassuperkart]

Its been a while since I posted anything on the poor old GX turbo which has sat neglected for quite a while.

Sadly, the thing has been mostly idle since i bought the 300ZX and I have been spending a lot of energy on the Ute Of Death as well so the poor old Pooser was pushed aside.
It has a cracked head, leaking oil cooler hoses and the clutch is slipping after i fitted the hot head/cam combo..... arrgh! Eats about 1 litre of water a day which is no fun but starts immediately and runs just fine....?.
I miss driving the little snotter tho and always had intentions of getting back into it.

OK, since the last installment, I sourced an uprated front brake package. Actually, the Pooser does not need bigger brakes as the slotted rotors I have on it are more than adequate.. but, i got this setup cheap as so why not?
Mitzi EVO 4 calipers and modded rotors to slip over the Pooser front hubs. Nice big 280mm vented rotors and big arsed calipers make for really powerful brakes but the brake bias is now up the shit to the rear. Its fine in a straight line, feels like its going to do a handstand, but turn the wheel an inch or two and it pinches the inside wheel.
Being a long time circuit racer, this is unnacceptable and close to undriveable to me, so i tried an atmo MC with more rear bias. It improves things to a degree but still uselessly biased to the front with those miserable little 230mm rear rotors.

Doing some hunting around, I have come up with a simple upgrade that requires little work to fit.

Im using Nissan R31 Skrine/Pintara disks and calipers.
The disks are 30mm larger than stock with bigger calipers and pads and nicely, uses the identical handbrake cable arrangement to the Pooser making this tricky part a bolt on along with the same stud pattern. Easy peasy!

I used an old pair of ET rear disks and machined the disk off them to provide flat hubs to slip the R32 disks over and making up a simple pair of plates out of 6mm mild sheet which attaches to the control arms to support the calipers.
I cannot use either the R31 or ET caliper brackets due to the deeper "depth" or offset of the R31 disk compated to the ET items which is a bumnmer but no biggie to make.

Ive not actually done the plates yet but when i do ill take some pix of the assembly.

Next i lifted the engine and gearbox out today.
The clutch is a hotted up but small 180mm NA item riding on a lightened NA flywheel with an NA box with a 3.7 diff. (3.5 stock ET)
I have a lightened ET flywheel and a tough F1 Racing Components Stage 2 organic clutch kit I bought some time back to go back on. Im using the exact same kit on the Ute Of Death and altho it has a lightening fast action, its light, smooth and predictable to use. You get used to the incredibly short pedal throw (barely 1.5" from fully out to fully in with no graunching into reverse on the ute)

I picked out the old rear main seal and replaced it with a newie as well. Disturbingly EVERY sump bolt was less than finger tight and some took 2 full turns to tighten even just lightly.... strange. I was very thorough with the original build hence no oil leaks even from the sump almost hanging off but strange the bolts, ALL of them, were so loose after 50 odd large k's.

The box going back on is an ET case loaded with N13 guts and a 4.1 diff. The new box and clutch setup should handle anything I can throw at it tho and will fry tyres even more mercilessly with the much lower final drive but pretty much stock tyre diameter from the 205/45/16's.

Next job is to pull the head off and replace.
Im at pains to replace this head as it was ported and matched to a custom cam which dynoed at 153 Kw ATW @ 16psi @ 6200rpm.
The cam is only slighty lumpy and more and angry sort of missing sort of idle rather than that typical big cam rolling lump!
You should agree thats a stonking midrange torque setup and even on modest boost from a box stock T25, it fries tyres mercilessly in the first 3 gears until the poor little clutch eventually cried enough!

I have a good clean stock head off the wifeys car which can go straight up but Im looking at another ported head at a good price to load up with my clobber until I eventually get my good head repaired. Its beautifully done by an expert hand so will be worth refitting afte repair at some point when I can be bothered!.

The last peices of the puzzle are remove the faithful old EMS Ti-4 programmeable ECU that has served me so well for so long and fit up a Microtech MT-8 I scored for peanuts along with one of my funky wasted spark ignition setups.
Along with this goes in a set of Bosch 036 Injectors so generously sent to me from Damo.
These are about 380cc @ 85% duty injectors which are miles large enough for fairly big power. Im only chasing about 14psi so I have miles of headroom in there but still keep low down tuneability which will be much helped with Microtechs Semi sequential injector triggering as opposed to the simple batch triggering of the older EMS.

I also scored and fitted an LD Astra (N13) front bar to the pooser as well. It looks kind of funky. It fits ok with quite a bit of shaping and grinding here and there. Its not perfect, but still looks OK. Once painted should look better.

Ill get some pix up when i remember to take them.

There you go ladies, The old girl is set to zoom around again with some good power and brutal brakes! I cant wait to try out the bigger rears! Fingers crossed I have th bias right and the pedal does not go too long!!

Cheers
Oracle.

[EA-73-XA]

any plans to offload that ems ecu for a price?

[tassuperkart]

Umm no M8. That old ECU is destined for another project.
L8r
E

[Callumgw]

keep us posted on the rear brakes...sounds interesting.

C

[tassuperkart]

Will do C.
I figured you and Timmzy might be onto this one! Its actually you blokes Im doing it for to be honest.
Ill take a pattern of the caliper brackets and post it up if ur interested.
Im hoping for good things.
Only thing Im concerned about is a lengthening pedal...... If so ill fit a MC off something else. Wait and see.

L8r
E

[zoomzoom]

very interested in your brake set up myself,i slowly doing the exa up for a bit of weekend track racing and brake they say are a big part of any set up,any chance of some pic's soon

[tassuperkart]

Yer. I just gotta get the camera up there. Nothing is on the car as yet. its all being done on and old trailing arm on the bench!

I was waiting until I had cut up my caliper brackets before I posted pix as the parts so far just look like ordinary everyday brake parts is all.

L8r
E

[Callumgw]

Will do C.
I figured you and Timmzy might be onto this one! Its actually you blokes Im doing it for to be honest.
Ill take a pattern of the caliper brackets and post it up if ur interested.
Im hoping for good things.
Only thing Im concerned about is a lengthening pedal...... If so ill fit a MC off something else. Wait and see.

L8r
E

Yep, send it up.
I'm not sure the exa has the same balance issue - with a different prop valve rate and MC. But the first run I did on the new set up killed the engine, so didn't get too much time to test.

Actually, do you know the piston sizes for the rear? I'd also be interested to pop that into a spread sheet I have that compares the different set ups...

C

[Timmzy]

Will do C.
I figured you and Timmzy might be onto this one! Its actually you blokes Im doing it for to be honest.
Ill take a pattern of the caliper brackets and post it up if ur interested.
Im hoping for good things.
Only thing Im concerned about is a lengthening pedal...... If so ill fit a MC off something else. Wait and see.

L8r
E

Evan - All over it like a fat kid on a doughnut!

I'm keenly interested. My conversion did end up with a longer pedal, but it seems to be acceptable to my driving style. But my bias is heavily on the front brakes - like I don't think I could actually lock the rears.

I wonder what the arear of your front pistons is compared to mine. I'm using that damn ET master cylinder - and I'm seriously thinking of getting rid of it and the FN booster which causes me issue when I run low on vacuujm.

DO you think its better to just shoehorn a complete brake setupfrom a skyline? or similar?
Darren.

[Callumgw]

Darren,
if your going that far, just do a pedal box. Then you can tune out any issues.

C

[tassuperkart]

The EVO 4 front brakes I have are miles large enough. In fact for a sub 1 tonne car overkill.
They are 280mm disks. My 300ZX only has 285mm and they are more than adequate for a 1500 kilo car!
However, its what I have on the Pooser so is why Ive been hunting around for something larger, easy and cheap to find and relatively easy to fit.
That was the criteria.
The R31 brakes fitted the bill really well being firstly, a slipon disk, and secondly, the handbrake cable is all but identical to the Pooser.
I even compared cables with a view to having and easily sourced replacement for the ET items but wont be able to use the Pintara cables straight up as they are somewhat longer in the outer casing.
The inner cable is the same length and attaches in the same manner at each end.
Ill still give them the once over in place to see iffen its viable to move the cable brackets to utillise them. Might even be able to rotate the caliper further around to take up the cable length. Its only an inch or two. ATM, the cables lay reasonably straight so cant use the longer cables without loosing some of their length.

Nope, I could not tolerate too much front bias at all.
Im known dont here as the very last of the late brakers!. Its a skill I worked on as motorbike racer and later honed in karts, but to do that repeatedly, I have to have my bias EXACTLY as I want it and on my race car, it tends to be a little more rearwards than what is comfortable for most. I tend to pinch rear calipers during "whites of the eyes" moments which really widens the eyes and threatens to open the bowels.......!!!

If your really serious and want to unload some effort, Id not bother with mixing and matching MC's and such and consider what C has mentioned.
Gives you the option of using a mechanical balance bar for bias rather than chasing rear bias and then putting in line pressure regulators to get the balance back.
Those generic master cylinders are as cheap as chips from any brake place, come in a variety of bore sizes and work really well.

As far as piston area for the Pintara calipers, I havent the slightest idea as yet, but ill shortly pull the brake pads out and measure it.
Stay tuned.

cheers
Oracle