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HybridZ

IMSA GTU vintage racer build


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Wow...that's a lot to go through at any age, Clark.  Sorry to hear that; but very glad that you're feeling better now and on the mend.

 

Question on the dampers:  it appears that Redshift integrates the BC strut housing (and associated spring perch HW) with their own proprietary shocks.  Is that correct?  I wasn't aware that was an available option, but it really does sound like a great solution. 

 

Which springs (and spring rates) did you go with?  According to their website, it appears that Swift is the preferred option, which I would wholeheartedly agree with.  In my limited experience with BC hardware, they typically use a 62.5 mm spring ID.  Is that the case for the ones Redshift built for you?

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Thanks for the kind words.

 

Basically Redshift purchases a full coilover package from BC.   I tried to pick and choose some components since I already have camber plates and springs, but was not successful.  It comes as a kit. They then take the strut cartridge and revalve to your specifications, in most cases is based on unsprung weight, sprung weight, and motion ratios or your own recipe if you prefer.  They dyno at multiple settings and ship the kit to you.  

 

The struts are 32 click adjustable and the adjustment combines both rebound and compression.  The nominal setting is at the bottom 1/3 of the click scale or around 10 clicks.  A sample dyno is below (not mine).   I also ask if they were racer rebuildable.  He said they were theoretically, but the parts they use were not available to be purchased retail anywhere.  As I said before, Chris was very patient and helpful.  He offers a full rebuild service and his reputation seems very solid.

 

As far as spring rates, I plan to start with 250F/225R springs which I already have.  I also have a pair of 275 and 300's.  So I ordered the Redshift's with 6k/7k (336/392lb) to have another heavier set.  Springs are cheap.

 

 

 

 

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  • 1 month later...

To fit the struts I had to get creative. I already had camber plates welded and did not want to modify those. The BC setup is nice but not a large amount of camber adjustment. 

 

Not much problem for the front. I only needed a 1mm thick bushing to fill the gap between the shaft and camber bearing. After I tried to drill something several times I ended up just 3d printing one.

 

The rear required some fabrication. I had slotted the towers and built my own camber plate/spring perches.  To retify I duplicated the plate in aluminum and bolted the BC bearing holder from the bottom.

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  • 1 month later...

I suppose it is time for some updates. Lots of work accomplished since holidays but not much to photograph. Finished all the strut builds and got them bolted up. Completed the clutch build and mated the tranny. Dropped engine back in and found if I raise the engine mounts 1/8" on each side it will clear my steering rack. Yeah.

 

Finally caught up from my last minute changes and medical setbacks. I feel 10 years younger now and kicking ass in the shop. Getting closer to first fire. Have a 2nd Z car in the shop now and a 3rd coming. More on that later. 

 

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Nice work Clark! Getting close! You are where I was around 5mo ago. Glad to hear your health is improving as well. I have high cholesterol so your experience was personal to me. 
 

what do you plan to do for the rear axle shafts? Custom length CV’s? I learned the hard way that CV’s have less travel than our OEM half-shafts. I pulled the spider gear out the diff-side collar over the weekend :( 
 

love me some Z31 (your car show post). It’s a shame it’s a dog in the track on account of the trailing arm rear suspension, weight, well… I can go on. But I absolutely loved mine, and it was my first car (85’ NA). Great street car, and under appreciated in my mind. 

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  • 2 weeks later...

All the Z iterations can look good with minimal modifications. I personally think the z32 had perfect proportions not surpassed since. So simple but so exact.

 

For this build as all of my builds, I am sticking with stock half shafts and Spicer U-joints. Never had a fail road racing yet. Cheap and effective only if you limit the angles generated and minimal power loss.  I currently plan to raise/lower the diff as required to keep them in their sweet spot. They even withstand high power drag racing if you can keep them close to straight when launching. If it looks like I will struggle with this when I final assemble the rear, I will be scrambling for some CVs. 

Edited by clarkspeed
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