2JZ in a Z4 Coupe - Custom Project

[dre99gsx]

Been busy... Designed a small guage pod for my wideband gauge. This inserts into the CD slot. Temporary until I get the car tuned and setup


3D printed it at home on my one of a kind printer



Installed:



3D printed a small cover with grommet for passing wires through the firewall:



No room in this car for anything - had to fab up a firewall plate to mount wideband and boost solenoid:


Did I mentioned how tired I am of wiring??


Found some hard to find connectors/pins for the IVM module. This is needed to power up many other modules in the vehile.


Wiring harness coming along:



For some reason, Collins was dragging their feet getting me this darn pilot bearing adapter. I said screw it and just designed my own. I had a ProtoLabs machine it for me, came out great!



Turbo oil lines done. Engine primed with pressurized oil, ready to rock.


Fuel rail in. Ebay fuel rails SUCK. Had to modify this one to fit these injectors. Also, this is on a returnless fuel system (for now). Will deal with a proper fuel system later on...

[dre99gsx]

[E86Z]

Ahh she lives, well done!

[GPower]

Please be my mechanic

[NickyC]

Killer!

[inTgr8r]

Fantastic!!!!!

[dre99gsx]

More updates:

Started building the downpipe so that I can run the wideband and do some tuning


Lovely 44mm Tial


Tial sits down at the bottom, will be vented back into the downpipe


Got the shifter installed!


And - went out and purchased the FORD Fuel Pump Driver Module, wired it up (rigged for now)


For those who don't know, these cars utilize PWM fuel pump control, but since I can't fool the DME (yet), the pump would run full duty at 73psi base. Couldn't get the engine to lean out further than 11.2 AFR at idle Since I can't run a mechanical regulator, had to find another option. Decided to remove the Z4 EKP fuel controller from the picture and found a Ford solid state relay controller which accepts PWM as an input, and outputs PWM ~30A capable to run a fuel pump!

So, with the AEM, I mapped out PWM vs fuel pressure, and got it working at ~37psi idle, 43psi at base, and climbing to 70psi as if it were running a vacuum-sourced fuel pressure regulator. Works like a charm! Never thought I would be running a BMW with Toyota and Ford parts mixed in

Had to re-route coolant hoses since I wasn't getting coolant flow into the cabin for heat. Now using the Toyota rear coolant hoses.

Spent quite a bit of time tuning the PID parameters for the N52 throttle body (not easy when 1% to 2% throttle position correlates to 700rpm and 1200rpm! the N52 plate is huge). Engine purrs like a kitten up to 180deg coolant temp.

[dre99gsx]

Started the exhaust.. checking clearance


Mid-pipe, 3.5" SS


Custom muffler and dual tips


Some welds came out Ok, others were rushed. whatever...


Full exhaust sans downpipe. Yes, that's a cutout for a 3.5" valve. Rest of the exhaust is 3" to the muffler. There is BARELY enough room for this under the floor pan!


Closeup


Attached BOV - the only place I could fit it. Absolutely no room in the engine bay...


Custom intake charge pipe and filter mounting. Will eventually get blocked off for cold air


And, she moves! Preparing for some tuning and checking vibrations/driveline, etc


Check this out: Front suspension is supposed to be identical in wheel gap as the rear. Heavy Engine = unequal weight distribution


Lift your bra shot


Some weight figures:



Here are some interesting specs:
Stock Z4 3.0si Coupe weighs 3073 to 3108 lbs (google), 50% F, 50 % R, don't if this is w/o fluids or full tank of gas
Stock Z4M Coupe weighs 3231 lbs (half tank) to 3275 (full tank), 50.5% F, 49.5%rear confirmed by a few members on bimmerforums
My 2JZ Coupe weighs 3175 lbs (half tank), 52.7% F, 47.2% R.

Now, the interesting bit here how my weight is now between the 3.0si and the 3.2M, yet my front to rear balance has changed drastically. Just by adding 75 ~ 100 lbs to the front with the engine swap, front suspension shows it. I may need to upgrade to coilovers with heavier front springs to compensate.

Initial driveability showed some minor issues, but holding together so far.

[crfine88]

Originally Posted by dre99gsx

Started the exhaust.. checking clearance


Mid-pipe, 3.5" SS


Custom muffler and dual tips


Some welds came out Ok, others were rushed. whatever...


Full exhaust sans downpipe. Yes, that's a cutout for a 3.5" valve. Rest of the exhaust is 3" to the muffler. There is BARELY enough room for this under the floor pan!


Closeup


Attached BOV - the only place I could fit it. Absolutely no room in the engine bay...


Custom intake charge pipe and filter mounting. Will eventually get blocked off for cold air


And, she moves! Preparing for some tuning and checking vibrations/driveline, etc


Check this out: Front suspension is supposed to be identical in wheel gap as the rear. Heavy Engine = unequal weight distribution


Lift your bra shot


Some weight figures:



Here are some interesting specs:
Stock Z4 3.0si Coupe weighs 3073 to 3108 lbs (google), 50% F, 50 % R, don't if this is w/o fluids or full tank of gas
Stock Z4M Coupe weighs 3231 lbs (half tank) to 3275 (full tank), 50.5% F, 49.5%rear confirmed by a few members on bimmerforums
My 2JZ Coupe weighs 3175 lbs (half tank), 52.7% F, 47.2% R.

Now, the interesting bit here how my weight is now between the 3.0si and the 3.2M, yet my front to rear balance has changed drastically. Just by adding 75 ~ 100 lbs to the front with the engine swap, front suspension shows it. I may need to upgrade to coilovers with heavier front springs to compensate.

Initial driveability showed some minor issues, but holding together so far.

Can't get enough of this epic build!

Thanks for sharing the data points

[Jumbosock]

^ Agreed! I get excited when I'm sitting at work and realize there is an update on this post I need to read.

[NickyC]

Wow!

[Vanne]

Awesome progress!! Love it!!

[DEG]

Flat out impressive engineering. Well done.

[dre99gsx]

Thanks everyone!

Quick protoboard of the circuit: Two pics 64mhz, one converts AEM Hz signal to Crank and two cam signals specifically matched to the N52, which then plugs into the Z4 DME (this fools the DME into thinking there is an engine running, which makes the tach work); the other pic micro is fooling the DBW pedal and throttlebody signals so the ECU thinks something is connected and doesn't go into limp mode (not that it matters, but once in limp mode, germans love to have the DME yell at all the other systems that they should also limp, and that is no bueno). I have the circuit schematic capture and layout, but there is more that will be needed before I have a real PCB made...


I was getting massive EMI on the signals, even after adding some decoupling caps - some investigation lead me to using non-resistive spark plugs. Went to BK7ES and scope showed it all cleared out.

Quick snapshot of the undercarriage - pretty much done. No leaks, clean and everything clears


Overview of engine bay, 95% done, all the wiring tucked in that small box near the firewall.



Still need to fab up a catch can, air filter box, and many more minor things, but the good news is IT DRIVES, and thanks to the quick AEM Infinity setup and tuning, it drives OEM like down to throttle tip in! Took it for a 100 mile trip and aside from the noticeable 2JZ sound and BOV flutter, you would think nothing had been done to the vehicle. Love it

I did have one very nagging issue: Had to replace the battery, which forced the Z4 into "Transportation Mode". Essentially, many of the systems stop working (heater/AC, for example). To fix this, had to download BMW DIS software package. I'm not very thrilled with German engineering. Took me hours and hours to figure out how to install this thing: Virtual machine, unix runtime, massively large installation, virtual networking/bridging and learning some unix commands??. Finally communicated with all the systems and disabled transportation mode. what a night mare. Germans.......

Won't be much updates here on out as other things are taking precedence. Supra needs some love. Aside from that, there is a new project on the horizon - it involves a 2JZ and it involves a "SWAP".

[Arsonism]

I am just thoroughly impressed by damn near everything in this thread and I can only applaud the work you've posted. Seriously dude, well fucking done.

[dre99gsx]

Thanks.

Started to do some tuning, but sticking to 2nd gear pulls at 11psi. Here is what I've noticed:

1. 11psi ~ 40% duty on 1100cc injectors, .65 BSFC, ball park 387bhp (or 320whp). Big grain of salt there, but this is at 7200rpm. Gives you an idea of what I'm dealing with now...

2. The car feels like a boat / Cadillac / unsafe. I ordered Poly front lower arm bushings, and have to inspect all the bushings on the car. Car feels very loose

3. Perhaps it is the non-LSD rear, but it wants to pull to one side frequently in 2nd gear. I haven't done pulls in 3rd for fear of safety. I kept the Auto diff ~ 3.64 ratio. I believe there are LSD options for this specific diff? May have to investigate soon

Coming from the land of the Toyota Supra, at 110k miles, all the suspension was still in tip top shape. I couldn't believe how worn out the Z4 is, underneath, at only 90k miles Shame...

I'll also be pushing this GS6-37BZ 6-spd, auto diff, driveshaft and Z4M half-shafts to their limits. Being that they seem to handle 300ft.lb. to the wheels quite well on Supercharged variants, I should at least get to that power range reliably (one would hope!)

[Jumbosock]

Yeah BMW bushings don't seem to last too long. It is not unheard of for the RTAB to go out before 30K in some BMW vehicles. It makes for a scary/squirrely hard pull or a freaky sweeping turn on the freeway.

[dre99gsx]

All four wheel bearings needed to be replaced Had to purchase new socket for this one!



Welded up external wastegate return stub. Has an internal slip joint to allow expansion



Almost all my bushings were worn! Had to replace every suspension bushing - what a pain in the ass


Went with Poly in some areas, OEM in others


Replaced the automatic half shafts with the manual versions. You can see the difference in thickness


Parking brake shoes were a joke - metal to metal


Finally got manual boot and cover from junkyard! 6-spd conversion complete


Started welding up my custom catchan


Unfortunately, received a shaft with a bent threaded section. Had to improvise and cut an old nut in half, then retread. Worked.


More catchcan pics - custom made with internal wall/structure to separate liquid from gas. Catchan plumbs back into pre-turbo pipe to help suck in the blowby



Catchcan hose plumbing


Installed BC coilovers to even out the ride height. Still more work to do...

[yousefnjr]

Amazing

[RPIpower]

This work and attention to detail is absolutely amazing! Major respect for you and this wonderful project! keep up the awesome work! I can't wait to see more!

[Beedub]

wow..

the wiring looks better than my stock ///M which is SO messy from bmw factory

[dre99gsx]

Thank you! I was pleasantly surprised by the reduced wiring mess on the non-M Z, compared to a Z4M and even my Supra. I'm a big fan of keeping things neat and tidy where possible.

Having had both the Z4M, the 3.0si and now this frankenstein, I believe the driveability, power delivery, and engine responsiveness are on par with my previous Z4M, if not a bit more refined. Yes, refined. Keep in mind that although this engine is an old technology staple, it is a 2002 year with VVTi technology. Couple that with the Z4 drive by wire throttle body, properly tuned engine management, small (60mm) turbo, and short piping, and this thing is very responsive. It wants to boost almost immediately at part throttle (which I can reduce via the Sport mode switch as I have that activated in the AEM).

Also, I'm still on the 3.64 auto rear gearing, which makes for a very nimble vehicle on canyon carving. I was surprised that 80mph cruising in 6th gear, it sits at 3krpm. A bit higher than I anticipated, but if you only knew how effortlessly it is to pass vehicles without downshifting.

Hopefully this year I can bring her out to some events, and would like to get some feedback from some of you. I plan to start dynoing soon and tuning the AEM as everything breaks in.

Based on my fuel consumption of ~40% duty cycle at 55psi, calculations put me near 300whp, this on just 12psi of boost.

Also, comparatively speaking, if I were to invest in a Z4M AND do a VF570 or such supercharger, I would be roughly $10k on top of what I've spent, and that includes every nut and bolt, replacement parts, upgrades, etc to date! Plus, having full knowledge of the engine's tuning at my fingertips and NOT having to rely on outside tuning assistance gives me piece of mind.

Yeah, the electric power steering is weird, I have smaller brakes, single out exhaust tip, and no M badges, but you quickly forget about all of that when you drive it! This 3.0si I picked up came fully loaded with all M-sport upgrades (sans the steering wheel), thus it is great value for the money.