Welcome to IsuzuPiazza.com :: Uniting Isuzu/ Holden Piazza Enthusiasts since 2002

Cant beleive im about to post this, im playing with fire here but here goes...

Most of you by now have seen Project No.2 - JR120 Turbo Piazza that will become my new daily - http://www.ozisu.com/forum/viewtopic.php?t=342

And, more recently, my current daily driver, E36 318i 5speed - http://www.ozisu.com/forum/viewtopic.php?t=370

So i thought it might be time to introduce you to my primary money spender [besides the Mrs] and main project. Under the new Isu-forum rules im allowed to post it Yes, you guessed right, its a bloody Gemini.

1976 TX Gemini Coupe. Being a 76 model its pre-emissions which is an absolute god-send in terms of engine mods. More about that later. She started life as a bit of a curious mix - the colour [Atlantis blue] along with the interior trims, tail lights and window chromes suggest its a TD SL\E while VIN numbers say TX. Either way, its all legit and not pinched. Not that anyone would rebirth a Gemini these days, they arent worth fuck all...

Started off as a $25 rolling shell [$25!!! CUMONNNN!!!], i was building a TC Coupe at the time and the old man convinced me this was a better shell. He also had the task of convincing mum but that was a different story. As youd expect the shell was far from pristine but all in all it wasnt too bad. Rust was confined to the rear 1/4, boot floor, chassis rail [EEEK!] and battery tray area. Stripped bare within 2 nights and it was off to the panelbeater.









Once there, they wasted no time cutting and welding rust and basically returning the shell to factory-spec straightness. Boot lock, antenna and 1/4 panel indicators were shaved, beaver was modified to accept TX tail lights and it was ready to paint. Hit with highfill, sent off to an oven and hit with 2pack PPG Daytona Blue, off the Nissan 350Z. Paint set me back close to $800 alone!!!!!















Then she got stuck in a rut. No cash, too many projects, did i mention no cash? Only recently have i actually bought something for the thing. So far, engine management is taken care of. A mate has an RA23 Celica with a 1GGTE under the bonnet, decides out of the blue if hes going to engineer it with the standard ECU he cbf changing it again so his just going to run an interceptor style ECU. So guess who got first dibs on his previous ECU?

EMS DualSport QI4 V0.602 Fuel/Ignition ecu, handcontroller, wiring loom, sensors AND a Crane Fireball LX91 coil at a price too good to refuse. The Piazza's front tyres will have to wait...

The Gem will have to wait abit longer for anything more though - Im owed abit of money by someone, so once that comes in shell get some more treatment. Once that comes in the crossmember gets dropped and fitted with:

-Competition engineering VT hub adapters, 330mm Group A Discs, VT/X Twin piston calipers
-Whiteline custom made springs, Koni adjustable shocks, new bushes and a larger Whiteline adjustable swaybar
-Paint crossmember and A arms in GMH Gloss black

I should still have change left to buy my mates Borg Warner 28spline diff out of a VL Calais Turbo. The 3.45's will be thrown in the skip and replaced with R31 Skyline Auto 3.89's, a *new* LSD Centre [~$600 mark], shortened housing and axles, Rebuilt calipers and new discs. That too will cop Konis, new bushes, custom springs along with the mandatory [to fit the diff anyway] fabricated upper and lower arms. However, instead of the adjustable panhard rod ill be going a different route - Ford EB Borg Warner rear cover which utilizes a Watts Link setup. That should comfortably eat up 3500-4k which leaves me with abit of cash to start the interior.

The car already has Piazza front buckets [and no, i didnt wreck the Piazza, someone else did] which i grabbed for $25 off the original owner - bargain! Car has the aforementioned TD SL\E full length trims, along with the hackjob attempt [again, previous owner mannn!] at fitting a TF/G Dash. The whole 'kit and caboodle' [always wanted to use that phrase] is being trimmed in Beige/Tan leather and suede. It helps having a mate whos parents own a furniture and reapholstering joint.

By now im running out of breath, but i must continue - im yet to mention engine/driveline. Currently im down to one of two motors - G200 SOHC, or....4ZC1. Before anyone jumps the gun, no i wont be killing a Piazza - i love the bloody things. Ill be killing a Shuttle. No one cares about them. And as for the engine specs? Secret Lets just say she should comfortably smash the 200rwkw mark on less the 20psi, while still having a useable power curve [fullboost should be about the 3500-3700 mark]. Only drama now is Gearbox. Gemini 5speed wont cut the mustard, Piazza 4Z box isnt the strongest [or most availible] thing in the world so im down to a shortlist of three - one realistic, two very expensive but ultra-tough. Ones the later model TF 4ZE1 5speed which will bolt to the 4Z/Gseries block. The other two require custom bellhousings - Tremac T5 [VT 5L, round the 1200 mark] or an S15 6speed [only begining to be "affordable" now, round the 1500 mark]. Better hope i dont kill one of those.

Sorry for the rant, this car rarely gets any attention and now that i pulled the cover off it for the first time in 6months im in love again.

Nick-

Ok youve pulled your pud. Now put the car cover back on it and get back to wet rubbing the Piazza.

I do have an engine thought for your Gemini. How about the 1.8L out of a Shuttle??? Bore is under 86mm and you can get forgies that diameter. Its something im going to look at.

Bob.

Why not go for a rotary.. That engine place in deer park sells recos for around the $1000 mark

Bob, if im going to go for an 1800cc engine purely based on piston selection ill use the G180 SOHC ive got disassembled at home. The 4ZC1 is a good choice because theres a hypereutectic piston availible for it thats supposed to be pretty strong, a mate was running it in his Gemini without any dramas. Im not too keen on a forged piston because of the expansion factors, UNLESS i can find someone that will make me one with, say, a silicon content level around the 9-12% mark.

Chris, . A Rotary will NEVER power ANY of my cars. I hate the damn things with a passion.

</rant over>

Now that thats done, the real reason. Im not keen on doing any form of engine conversion away from the Isuzu motors in this car. Its been an arguement ive had since i was 15, with only one person [funny, the person who built one] beleive that 200rwkw is easily acheiveable from an Isuzu 4. So ill be doing it to prove many wrong. That, aside with the fact that ANY engine conversion that gets done to this car will mean more $$$$$ BEFORE i even start any engine work. This way, drop the Isuzu 4 in and spend the remaining cash on mods.

Oh and Bob, the wet rubbing on the Piazza is finished. I just cant get 2 of the dents straight to my satisfaction.

Nick-

Actually funny story happened to me 3 years on Taylore Lakes road, driving at around 3 at night with my fully sick ford, (ready to drag anyone).. So Got to the set of lights to gems pull up next to me and listining by their engine sound I thought, OH NO.. But hey I still had ago.. Gems took off while I was still looking for the accelerator, Nicley they slowed down for me as it is, we where driving around 70ks and all off a sudden both start going sideways for about 300 meters, my farking gobb was open all the way home...... Roatary shit?? uhu..

Yeah rotisseries still suck!

rotaries.

Damn chook cookers.

I hate em. My old boss used to have one rx4or 5 auto. It was freakin scary to drive, thats if you could get it started.

As much as i dont like em the fully sic rotors at the drags sound shit hot. Any RX with a V8 in it deserves to go into the fence too i rekon.

Its got to be a twin cam then Nick. No turbo just N/A off its tits.

Bob.

Sure Rotarys make power, but I hate the lack of torque and the reliability of the thing [or lack of it]. They dont feel strong despite singing way past 8000rpm. Theres only one make of engine that belongs under that bonnet, and thats Isuzu..

Bob ive thought about the DOHC route time and time again, at the end i keep crossing it off - its just not viable. There are too many issues to sort out with the standard motor alone let alone to the extent ill be pushing it. Oil flow issues, cam bearings, plus the lack of off the shelf bits means its abit more of a pipe dream. One day ill build a PF60 ZZ/R Replica, but for the time being Ive got one Gemini and ill concentrate on that alone.

Id love to build a hypo naturally aspirated G200 DOHC with all the good gear - balanced bottom end, wild cams, quad throttles based on a 45mm IDA Twin Weber setup, peak power at 9500rpm etc etc - and to be honest, i dont know of any combo that would be more satisfying to ring its neck. Unfortunately though, it still wouldnt be fast enough. So its definately the Turbo EFI route, and for the time being looks like its going to be a SOHC G200 or 4ZC1, depending on what i come across at the time. We will see how we go. Id like to go 4Z purely because of length - at 2" shorter, thats two less inches sitting over the front cross member.

Any more comments? Suprised no ones has flamed me for putting the "enemy" up.

Nick-

but why the 4zc1 when theres so the 4ze1? bigger cubes is a good way to start of any engine

Engineering guidelines. Maximum capacity of an engine for a Gemini [turbocharged] is 2.4L, the 4ZE1 is way over. That leaves the D1 and the C1 - D1 stroke is too long so it wont be as revvy. That leaves the C1.

Nick-

Actually looks like the govt is introducing nation wide standards for car modification and has increased the possible size allowed for turbo engines in cars the weight range of the Gemini.
http://www.dotars.gov.au/transreg/vsb/P ... ct2005.pdf

The Gemini is around 950kg so multiplied by 2.75 is 2612cc so 4ZE1 would be ok

WHen are they looking at introducing that? Thats a tempting thought. With 2.6L to play with i can go one step up on turbo choice [GT30R as opposed to GT28RS 440hp] while still keeping the 3500-7500rpm rev range. As a guesstimate id also guess around the 230-240rwkw mark with that turbo/bottom end as opposed to roughly 210rwkw with the 4ZC1 and GT28RS.

Hrm. Fuck you Bugle. Make me rethink things and shit lol

Cheers,

Nick-