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HybridZ

rt260, BMW M Powered


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Hi Brian, glad to see you're still kicking! Let me know if this weekend works for you. Clint and his car will be here Saturday sometime, so my wife is already expecting a certain amount of Z-time to overshadow the weekend. Bring your wife along and we'll make a day of it?

 

Backing up a bit, I've been tuning this car with a speed density program (MAP + RPM). I've run into some headaches with it, partially due to the pulsations in the plenum at elevated RPM's. I think it can be worked out, but I decided to take a poke at Alpha-N (TPS + RPM) for giggles. It's not without it's faults, but it did solve my high RPM inconsistencies. My point is, I just started messing with it experimentally, haven't had time to refine the tune, and the peer pressure of an audio clip was overwhelming :-)

 

So... the video below is conservative... AFR's averaging about 11.5:1, VANOS not on line (in low RPM mode), and a mild timing map. 2nd and 3rd gear pull, shutting down just shy of 90...

 

 

 

 

 

 

The exhaust is ear piercingly loud at high RPM/Load. It's downright unbearable. I've gotta stop complaining about it and DO something before it puts me in the funny farm.

 

P.S. No pedestrians, cars, dogs, livestock, iguanas, or insects were harmed or endangered during the making of said video.

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How do you like the Speedhut's?

 

Very very happy with the tach. If I had to complain, I'd like a dim-able feature... they are slightly under-lit at dusk, and slightly over-lit (or maybe just glarey with the polished bezel) at night. I see on other forums that some people disable the needle lighting to combat this. Haven't tried it myself, though.

 

The speedo serves this particular swap well, but it ain't perfect. I spend a fair bit of time on mountainous, densely forested roads and the GPS isn't sparkling in those scenarios. Anything from 'zero' reading to a wavy needle. It looks like it never reads high, but can read low with a compromised signal. What I would like to see (and aviation GPS's provide) is some type of unobtrusive 'flag' that let's you know it might be compromised. All in all though, it was a direct, simple, functional (for my purposes) solution and I would buy it again without a flinch.

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  • 2 weeks later...
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Thanks Leon!

 

My stock headlights were not cutting it. Old wiring, old technology, and about 10K miles a year are driven at night, much of it in unlit rural areas with many critters large enough to turn and old Datsun into scrap. Tony D has been beating the drum for John at H4lights.com, so I gave him a call. Fun guy to talk to, and definitely knows a thing or two about lighting. John steered me to a special he is currently running... Bosch E-Code lenses with NARVA XB3 bulbs, $105.00 shipped, for the pair. Couldn't pass that one up. They are not in the same league as a high-end HID light, but they are more than decent. My daily driver is a '98 M3, and these do a respectable job of competing with the Bimmer. Great budget oriented option.

 

The shifter throws were too long for my preference and the integral rubber isolator was too... uh... rubbery. I want to feel the engagement of the gearset, not avoid it. I tore the lever apart, off'd the rubber bits, and shortened it. It shifts sooooo much nicer. Very crisp and direct. Enough so, that I will likely do something similar to my M.

 

 

 

ShortShift.png

 

 

 

The S52 has a slight buzz around 3000 RPM. It's shows up with this conversion and it's faintly there with my stock M3. Unfortunately that correlates directly with highway cruise speed. The poly mounts are not helping with this so I ordered/installed a set of heavy duty rubber mounts from Bimmerworld. I like 'em. They removed a good amount of tingle, but they are still rigid enough to keep the motor from moving around excessively.

 

Another effort to help with civility, was an exhaust mod. Three Magnaflow's were not enough. The drone and drumming with ordinary driving was positively obnoxious. Long story short, I built a muffler to replace one of the Magnaflows. It is/was an experiment so I didn't make any effort to take progress pictures. I just wanted it done, ya know? I did model it up prior to fab and it's very close to the final result...

 

 

 

Muffler.png

 

MufflerDone.png

 

MufflerIn.png

 

 

 

Not a fully inclusive answer but it did make the car significantly more livable. It's still plenty loud, but no longer intolerably so. I'm looking forward to tomorrow's commute, and this is the first time I've felt that way since this conversion.

 

I've got a failing half-shaft. It's been sniveling for a while now... 'prolly ought to see to it before I regret it.

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The S52 has a slight buzz around 3000 RPM. It's shows up with this conversion and it's faintly there with my stock M3. Unfortunately that correlates directly with highway cruise speed. The poly mounts are not helping with this so I ordered/installed a set of heavy duty rubber mounts from Bimmerworld. I like 'em. They removed a good amount of tingle, but they are still rigid enough to keep the motor from moving around excessively.

 

Another effort to help with civility, was an exhaust mod. Three Magnaflow's were not enough. The drone and drumming with ordinary driving was positively obnoxious.

 

 

Hi Ron,

 

Really nice work on this project.

 

Question, are you using an RT diff mount and poly busing? Are you using poly mustache bar bushings? Did you have your driveshaft precision balanced? Any and or all of these things will contribute to vibration. The most important thing is driveshaft balance when using the RT mount and poly bushings. The stock rubber bushings will absorb a lot of this vibration. Poly bushings will conduct that vibration into the chassis.

 

Most driveshaft shops will do a standard balance, which is good enough for a live axle, but no where near good enough when the diff and trans are both mounted to the body. I had this issue with my RB swap, and I had to ask for the "race balance" on the driveshaft.

 

For the exhaust on my NA RB swap I used the MSA premium exhaust with a custom made down pipe. At 3000RPM, it is quiet, but below that it drones (probably like your S52 powered Z). At 4000RPM it sounds wonderful. So I was thinking of adding an 12" resonator along side the driveshaft, hoping that it will kill the drone below 3000RPM, but still not effect the sweet exhaust note about 3000RPM.

 

I'm also using my Z as a nice day commuter. At 32MPG, it make a lot of sense these days!

 

Pete

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Sorry Pete, I should have been a little more clear. I'm talking specifically about engine vibrations. Car parked, in neutral and rev'd through the range. My stock M3 with it's factory marshmallow mounts still transmits a minor amount of tingle. You really have to look for it to notice. However, with the Z and the poly mounts I was using, it's more noticeable, particularly in the rpm range where I spend the most amount of time with the car (cruise conditions). Wasn't bad, but I wanted better. The rubber did address that specific rev range pretty well (better than expected, actually), both while in neutral and while driving. If I never intended to 'commute' with this car, I would have left the poly, no question.

 

RE: Exhaust; I'm with you... the low rpm/light load drone is what takes all the enjoyment out of it. The resonator should help you. I got a huge improvement with the homebrew muffler, but I would like even more refinement. Kicking around idea's but I'm nowhere close to acting on any of them.

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  • 2 weeks later...
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Since the engine runs off individual coils, where do you connect the tach?

 

The Wolf ECU drives the tach. It's typical for aftermarket tach's to play nice with aftermarket ECU's.

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So. I guess I need a new tach as well as a new speedo. For the speedometer am going to make a notched wheel bolted to one of the half axle flanges and use the BMW VSS to send the signal to an aftermarket electronic speedometer. I was hoping the Z tach could be run off of a signal from the BMW computer, but probably not. What tach did you use?

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Ken.

 

I to was going to replicate the BMW chopper plate in the diff and use the BMW sender but its a lot of unnnecessary work. Ive just ordered a Speedhut gauge set as well as this http://www.speedhut.com/product_detail-AUTO_NUMBER-788.htm and will mount it on the gear box rear ears to pick up the 3 lobes on the output flange.

 

P1030707.jpg

 

 

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