Poor Man's Z8 Project

[BimmerBreaker]

Sitting perfectly now!

Thanks, I think so too

Haha. Sweet. Looks like a fun swapped z!

Thank you!



Still enjoying it... haven't done a lot to it recently, been working crazy hours to stack up some money to try to buy a house soon. Market certainly isn't ideal, but I am sick of throwing away money on rent...

Here's a short little clip from today, been getting it out a bit more often trying to enjoy the weather here before it gets too hot. May try to get the A/C working this summer

[BimmerBreaker]

Few videos from earlier today, it behaves a lot better on the Koni/H&R's without so much squatting. I also took some air out of the rears, to about 18-20psi, which is helping it hook a lot better. Have a dragy I've been playing with but the best 1/4 I've gotten so far is a 13.49 - definitely still need to improve my technique to get the time down further





It's recently developed an issue where it sort of wants to "tug" to the left when steering left, and sometimes if you steer it enough to the left when parked it will slowly pull itself to the lock on that side (it did this last time I took it out but not today). I have a spare power steering pump here I'm going to try first, but if that doesn't fix it, I think it may be the rack itself. Haven't ever dealt with an issue like this before. Another thought is that it need a restrictor in the line somewhere, maybe it is just putting out too much pressure to the rack (but I don't think so because why would that only affect one direction?). It's also smoking a bit if you beat it for long enough, but when taking it easy it's fine, so I will investigate that further. In any case it'll keep me busy over the summer months when it's too hot to drive

[JimLev]

As the Roadkill guys would say, if it’s smoking you’ve got oil, when it stops smoking it’s almost empty.
Good luck with the strange steering issue.

[BimmerBreaker]

Have done some work to it recently getting it running tip top. I also recently moved and found a nice little scenic curvy road near my house I've already blasted through more times than I can count lol. The car handles very well, very light on it's feet. The extra work to get the engine placed as rearwards as possible for weight balance was well worth it



Exhaust sounds pretty good too. Need to finish it up though - still dumps at the midpipe lol

[JimLev]

Looks and sounds good, now let’s it lay down a few nice strips of rubber.

[Pink120]

Very very nice! It's great to see (and hear) this thing!

[BimmerBreaker]

Looks and sounds good, now let’s it lay down a few nice strips of rubber.

I've been laying down some rubber all over town lol, need to get someone to help me film that though

Very very nice! It's great to see (and hear) this thing!

Thanks!



Recently ordered a 53mm core radiator to replace the 40mm core Mishimoto I had in there, and a 90C thermostat along with it. I typically don't like dropping tstat temps, and the car was maintaining 105C (stock tstat temp), but it would occasionally throw "temperature threshold limit reached" for the DIVA intake, and the coolant outlet temps got a little warmer than I wanted.



The 90C tstat was from ECS. I have had reasonable luck with them in the past but moved to FCP for pretty much everything these days due to the lifetime warranty. So when ECS rolled out their own lifetime warranty I thought, great I'll give them a shot, so I ordered the 90C thermostat from them. Said it would ship that Tuesday (I ordered it on a Sunday)

Over a week passes... no tracking or anything. E-mail them, offered to pay the difference for the other low temp thermostat they said they had in stock - if they can't do that, cancel the order. After three days of back and forth (for what is a pretty simple, reasonable request IMO) I eventually just decide to cancel the order.


It's a pretty genius business plan. Offer a lifetime warranty - and by the time they even ship the part, the warranty has expired...

Ordered a 101C temp from FCP as FCP didn't carry the aftermarket 90c tstat's but newer models share tstat's with the N62 and are 101C from the factory. It arrived faster than their projected delivery date. Thank you FCP


Got the radiator and 101C tstat installed a few days ago, pressure tested it and the radiator had some small leaks. Seller refunded me, I bought a replacement large core radiator but as the seller didn't even want the radiator back I figured I had nothing to lose and tried some JB Weld radiator repair on it at the leak points. Pressure tested it with the repaired radiator and it's holding pressure perfectly, zero drop after 30+ minutes.


Have driven it about 80 miles the past two days since it's been back together, so far no problem. Holds 101c when driving, but does creep up to 105c when idling. Drops immediately to 102-103c when moving, then holds at 101c after a minute or so of driving.


Coolant outlet temp did seem to drop a significant amount too, previously it would creep up to 80c+ after prolonged drives, so far the hottest I have seen is 65c. Ambient conditions have been slightly different, but even in comparable conditions I think it's dropped it 5-10C. Car overall feels much happier.


Also installed a catch can for diagnostic reasons not too long ago. Helped the smoking a bit, when I vented the outlet to atmosphere, smoking resolved completely. A leakdown test revealed some loose piston rings, I don't know if it's worth taking out and repairing. FCP said if I rebuild another engine I can return these parts and get replacements, so I'd only be out the cost of the replacement engine. I'm gonna drive this 4.4 into the ground... it seems these early N62's share piston ring issues with the M54 3.0, go figure. Seems to not be as major an issue on the 4.8



Installed a new P/S pump as well, didn't resolve the weird steering stuff. Didn't really expect it to either... I'm pretty sure it's a rack issue. Replacement rack will go in soon.

[BimmerBreaker]

Took the car out for the longest "shakedown" run so far a few weeks ago, about 3 hours... at the end of the trip I picked a friend up who "wanted to see what it could do". On closed private roads, of course, I had it about 110 or so and hit a huge bump, steering felt a little odd afterwards. Once I slowed down I realized I had zero power steering. Pulled over, topped it up - few moments later a huge plume of smoke came out from under the hood. Lost power steering again just a moment later... figured the pump or rack was shot. Took my friend back to his place then drove the highway the whole way home slightly afraid it was going to burn down due to whatever smoking catching on fire. But luckily I made it home drama free and no more smoking

Took a look underneath and found everything drenched in ATF. You can see the damaged high pressure line here too



The line had previously been rubbed into by the sway bar and basically rubbed itself some clearance and was never an issue but after replacing the pump the line must have settled into a different position and when I hit a big bump, it slammed the sway bar into the line and a crack developed. It sprayed everywhere and puked it back out as soon as I filled it. There are signs of fluid being sprayed from that direction on the headers so that must have been the big plume of smoke after topping it up


Original plan was to fabricate a new line, maybe using the E60 style crimped end line instead of banjo bolt. But after mocking that up, clearance didn't seem any better. So had to figure something out...

I decided to also replace the steering rack at this time and while I was in there, to do some upgrades:

E30 M3 control arms
E36 M3 lollipop bushings
E36 M3 sway bar with HD end links

The E30 M3 control arms have solid ball joints, instead of isolated ball joints with a rubber sleeve that came on the E36, so it should tighten it up a bit especially with the slightly stiffer M3 lollipop bushings. The bigger benefit is the lighter weight though

Stock



E30 M3



Installed a Z3 steering rack and the upgraded control arms. Installed them as soon as the bushings were on then dropped it down and let it sit overnight to let the bushings settle at ride height



Then I got to work on the power steering stuff. I was scavenging for bits to make a new high pressure line when I found a Z3 p/s pump and after a little investigating, I thought it may be possible to retrofit it onto the N62. With a little custom work I was able to get it to fit, but the pulley was slightly misaligned. I installed the N62 p/s pulley with some shims to space it out to align it with the belt, then some longer bolts to maintain proper engagement into the pump pulley hub, it fit up perfectly



The N62 pulley is a little smaller diameter than the Z3 pulley, but the alternator idler is so close that I can't run the larger pulley with the stock idler. I am thinking it is possible the self-steering issue noted previously was due to the rack being overboosted, so if the issue persists even with the new pump and rack, then I am going to look into using the Z3 pulley. I'd have to go and measure, but there are smaller idler pulleys from other models I can install that could potentially allow the stock Z3 pulley to fit.


The pump looks almost identical to the N62 p/s pump but with one main advantage - the high pressure output is on "top" of the pump, instead of the bottom. This means the line won't be interfering with the sway bar at all


Old setup - you can see the high pressure line on the bottom there



New setup - high pressure line on top



Excellent clearance now



Just a couple small things left from here and it should be back on the road. I decided to redo the electric fan as it was protruding too much for my liking (I kept busting my knuckles whenever I'd rotate the tensioner pulley to remove/reinstall the belts). Once that is finished, I think it should be good to drive but will do a thorough pre-flight check just to verify I didn't miss anything as it's been down a little while at this point...

[BimmerBreaker]

Took it on a few drives yesterday and am really happy to report the self-steering weirdness is gone, the rack must have been shot. Feels so good to drive now, the issue it had previously was really intermittent but just enough to inspire less confidence then you'd want

On the first drive it was a bit weird, pulling after letting off throttle, revhang when shifting, intermittent throttle lag, idling high... But seemed to pull even better when getting on it. Got it back home and looked it over, and ended up one of the dual intake boots wasn't seated properly. Fixed it and all the issues went away. The way it behaved with a cleaner air path from the leak makes me suspect the foam air filters I have installed may be inhibiting airflow so I'm going to replace those with paper filters.

Other than that I think it's about finished at this point. Just in time for the driving season here too thankfully

[BimmerBreaker]

Took it out today for about two hours, went up and down the curvy road near my house a few times, already craving a more technical bit of road to run on but this is a great place for some shakedown runs to test suspension changes, and per my recent repairs, a great place to test power steering too. You can get through there a lot faster, but while I was testing everything I went pretty easy on it...



The old power steering rack was definitely shot, the feeling is now way improved, feels just like a stock car. The car feels very light on it's feet overall - you can definitely feel the difference in weight balance compared to an I6 model.
I also want to say I feel a difference from the lighter control arms but it's hard to pinpoint what in the handling is from the fixed P/S and what is from the suspension changes. I can definitely tell that it feels more direct and very go-kart like with the solid balljoint front control arms with M3 bushings and it pairs very well with the solid aluminum rear subframe bushings. I wanted that "stiff" feeling without the NVH of full poly and in that regard this setup nailed it, it feels very tight and direct but still comfortable when just cruising.

I do believe it is done mechanically at this point, unless (until) something else breaks lol - knock on wood. I do need to figure out the wheel situation, as my front tires are shot and the Apex wheels in the size I need are still backordered. So I will probably be going with a whole new set of wheels.