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Leon

Leon's Other 260Z

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Sectioning is complete! Will sandblast and paint the struts as soon as time allows.

 

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Once they're painted, I'll reassemble with fresh bearings and finally install the rear disk brake kit I've had lying around for about 4 years now. Really looking forward to actually having some bump travel!

 

It feels good to be working on the Z again. There are a few more niggling issues to deal with, mainly refining the tune and getting the speedo and tach working reliably.

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I made an opportunistic purchase today! I've fantasized of going to 15X8 Watanabes (I know, so blasé) for years. A buddy tipped me off to a fresh set for sale locally and I decided to go for it. Really looking forward to seeing how they fit the car and keeping my fingers crossed that they'll work with the rear disks that I'm about to install.

 

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So now that this has finally happened, I'll have to liquidate a few things from the hoarde...

Edited by Leon
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The struts are ready to go in! Laid down some paint and pressed in the bearings and Nissan Quest wheel studs.

 

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The bad news is that the rear disk conversion doesn't fit the 15" wheels... 😕

 

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So the disk conversion is now for sale and I'm figuring out what to do about the rears. I've decided not to go back to drums so I'll be looking to get rear disks that fit under the wheels in relatively short order. I'd like to drive the car to Laguna on the new setup for the Monterey Historics on the 26th.

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Thanks Ryan, frankly I didn't expect the brakes to fit. Just thought I'd try and see what happens. Test fit was done with 8mm spacers, it would probably clear with a 12mm spacer but the wheel poke would be ridiculous. I took a quick look at T3, looks like their kit won't fit 15" R-Types.

 

In any case, I'm considering sticking it out with drums for now unless I find a cheap rear disk kit to hold me over. The end goal is to size some calipers and machine brackets and rotor hats to essentially make my own brake kit. I'm envisioning something similar to the ZCG "Big-Brakes for small wheels" kit but with an integrated rear park brake instead of the dual calipers. I also prefer blank rotors, especially on a classic car. I'd like to swap the struts over before the 26th and at this point, drums are looking like the path of least resistance (and cost).

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What rear disk setup were you using that didn't fit? I recently went through a design exercise to develop a rear disk setup that would give a good rear bias to my Z32 front calipers/ Odyssey rotors, fit under 15" wheels, and retain a mechanical e-brake function in the calipers. I ended up using all late model Z31 Turbo components which gave me the mechanical parking brake, a 11.1" vented rear rotor, and a matching bias to my big front brakes.

 

If you would be interested, you could take some measurements of the wheels I could pop it in the solid model to see if everything would fit.

 

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The front brakes that these complement:

 

IMG_8928.thumb.JPG.7fc3b21f023593aa960ae1043aabb7fc.JPG

 

 

Edited by lowrider

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Hi Leon,  are you using any of Keith's jets/tubes yet?  I'm curious as to how they perform.  I've thought about buying some but the cost is rather high and I feel like I a ITB conversion might be more cost effective.  I'm reluctant though as I like not having any computers in my car.

 

Very nice Z!

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7 hours ago, bradyzq said:

16 inchers for the back? 

 

If not, Coleman seems to have lots of customizable options for brakes. I mention them only because not many people seem to know about them. 

 

Thanks for the Coleman tip, Brady! Didn't think of them for brakes but looks like they have some good options for a DIY kit.

 

I'd like to be able to rotate the tires and not sure I like the staggered diameter look but otherwise that would work.

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6 hours ago, lowrider said:

What rear disk setup were you using that didn't fit? I recently went through a design exercise to develop a rear disk setup that would give a good rear bias to my Z32 front calipers/ Odyssey rotors, fit under 15" wheels, and retain a mechanical e-brake function in the calipers. I ended up using all late model Z31 Turbo components which gave me the mechanical parking brake, a 11.1" vented rear rotor, and a matching bias to my big front brakes.

 

If you would be interested, you could take some measurements of the wheels I could pop it in the solid model to see if everything would fit.

 

IMG_8929.thumb.JPG.288c526d4eadf6a356349ff7c5fbfedd.JPG

 

The front brakes that these complement:

 

IMG_8928.thumb.JPG.7fc3b21f023593aa960ae1043aabb7fc.JPG

 

 

 

Sweet setup! This is essentially exactly what I'm conceptualizing, nicely done. Do you have details on your conversion anywhere? I'll take some measurements of my wheels today.

 

I have Nigel's kit, as seen here: http://forums.hybridz.org/topic/113199-yet-another-rear-drum-to-disk-conversion-option/

 

 

It's an 11.8" (300mm) vented rotor and a Lincoln LS rear brake caliper. Interestingly, it appears to be exactly the same kit as the Silvermine Stage 4 with some minor differences.

 

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6 hours ago, Matt 78Z said:

Hi Leon,  are you using any of Keith's jets/tubes yet?  I'm curious as to how they perform.  I've thought about buying some but the cost is rather high and I feel like I a ITB conversion might be more cost effective.  I'm reluctant though as I like not having any computers in my car.

 

Very nice Z!

 

Hey Matt, thanks! Funny you ask, I've been using his VF tubes for a little while now but haven't gone back to the dyno since I tested the Weber jetting. I finally measured my idle manifold vacuum (17mmHG) and thus ordered some of Keiths weak-vacuum idle jets. I'll be road-tuning my buddy's 3.1 this weekend for which we just bought Keith's jetting as well. Dyno tuning for both his and my Z will come in the near future, he needs to break in his motor first.

 

In short, I will have a complete summary of how Keith's jets do vs the Weber stuff in not too long from now.

 

It also seems like I have a fuel flow issue which I haven't dealt with yet. I've been meaning to replace my dinky O'Reillys thumper pump with the Mallory I bought, just haven't done so yet.

 

Honestly, $300 for e-tubes and idles isn't that much when you compare to the iterations you have to go through with the Weber stuff. Plus, Keith has great support for his products and will refund you if you're not happy. Weber distributors won't do that... and if you find an ITB conversion for $300, I'm all ears!

 

Frankly, I'd love to run ITBs for multiple reasons but I also enjoy the old-school character of the car and the triples fit that perfectly. I have other EFI cars to satisfy my itch. :)

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@lowrider 

 

Rough measurements are as follows:

 

ID @ hub face = 315 mm

ID @ ridge = 355 mm

ID @ barrel = 365 mm

30mm from hub face to top of ridge

 

I'm having the inside of the wheel 3d-scanned at work next week so that I can mock things up. I can send that data as well. :)

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Edited by Leon
added photos

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I really didn’t do much sharing in the way of documenting the design and building process. The brackets are made of 4 - 3/8” thick 1045 steel pieces that are laser cut and welded together. An FEA on the assembly was conducted and the brackets have a huge 2.65 safety factor at loads that are highly unlikely for even a dedicated race car to see. I went a bit overboard in comparison to most other people rear brake setups (I enjoy the details).

 

I’ll try and model up a representation of the wheel tomorrow and toss it in the assembly to check interference. The rearward offset of these rotors/calipers really help get the caliper away from the wheel (back?) face.

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Thanks man, I appreciate it. I may want to copy your rear setup. :)

 

I'm predicting the path of least resistance is going to be to slap the drums back on. I have zero complaints about the performance of the stock system as it sits currently. The reasoning behind the swap was (1) ease of service, (2) better cooling for when I finally track it and (3) might as well do it while I'm in there.

 

This will give me some time to hash out the details.

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Thanks Leon,  I'm with you that price is not that bad and he seems like a solid guy.  I guess I should clarify what I mean.  I'm wondering if the difference in performance between Keith's products and the weber parts will be significant enough to justify the cost to take it to that next level.  I don't really have tractability issues,  I'm not sure how much better it can get and I'm not concerned about 10 peak hp.  If I can gain torque across the board that interest me.  I am also with you on liking the old school carbs so If I can improve them substantially then that may be enough to cure my itch of tinkering. 

Thanks for being the guinea pig!

Edited by Matt 78Z

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Sure thing! If your setup doesn't have any tractability issues and you're happy with your fuel consumption and AFR curve, then you won't see much value in going with Keith's products. Keith's idle jets are supposed to improve low-speed mixture stability and his tubes should enable you to match the tip-in point of the mains with the idles as well as maintain a steady AFR trace to redline. The testing has begun...

 

We had a short road-tuning session yesterday. The initial jet setup included 50F9 idles and 145/F11/170 mains in a 3.1L stroker with an unported but shaved P90 and Rebello's 278deg/.540" lift cam. Carbs are 45DCOE with 40mm venturis and exhaust is a Pacesetter header into 2.5" piping. The engine is still in the break-in phase so there hasn't been much high-load driving yet, just quick bursts. The mains seemed pretty dialed with this setup but the low-speed circuit had a lot of holes in transition. The idles needed to be upsized.

 

We dropped in Keith's VF e-tubes with the same mains and airs as well as Keith's W55 idles. The idles were set to two open holes on the collar, the engine was warmed up, and idle AFR was set at ~12.5:1. Even on cold-start, the engine was much more responsive to throttle inputs. There was no more bogging and coughing. A test drive around the neighborhood revealed near-perfect tractability with just a minor lean hole at moderate throttle inputs around 2000RPM. We attempted to cure it by removing the collar and exposing all the air holes on the idles but this caused a dramatic leaning effect below 2000RPM. We did a few bursts of WOT and high-load but there is certainly more work to be done on the mains once the motor is fully broken in.

Our next course of action will be to run the car on the dyno to dial in the mains as well as possibly upsize the idles to W60 to get rid of the lean spot and completely dial in the tractability.

 

I installed the W60s into my Z for my drive home but had no time to tune them at all. I also suspect I have a vacuum leak somewhere so I'll have to trace that down...

 

More to come :)

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I was finally able to create a representation of wheel and pop it in the rear brake assembly model. It appears that it would fit just fine. I was able to roughly measure 4.75mm between the caliper and the inner barrel of the wheel at the front face, though this is assuming that I interpreted your measurements correctly. When you get the wheel scanned (and if you would like to share) I can place that in the model and be a little more accurate. I've also included a few pictures of the caliper bracket assembly to kind-of show how it was designed, it might give you some ideas for yours. I went the multi piece route because it was easier/cheaper for me to have all of the pieces laser cut and weld them up versus paying for the machine time to whittle one out of solid stock.

 

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