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Sectioning struts on a 240z vs a 280z


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Alright well I'm in a bit of a pickle..

 

I followed the instructions on this link... http://forums.hybridz.org/topic/38589-strut-sectioning-faq/ to section my 280z struts to run Tokico Illumina strut inserts...

BZ3099 in the front (from a Toyota MR2 rear)

BZ3013 in the rear (which happen to have a 2-7/8" spacer pressed on the bottom)

 

I made sure the final front strut tube casing measured the following : 13.5"

I made sure the final rear strut tube casing measured the following : 15"

 

I sectioned 1.25" off the front strut tubes to make the final measurement 13.5"

I sectioned 2 7/8" off the rear strut tubes to make the final measurement 15"

 

The strut tube inserts fit perfectly and the gland nuts can tighten down perfectly. Now in the rear I ended up knocking out the rear spacer to allow the strut insert to fit. Everything fits perfect and nice and snug.

 

HOWEVER, after reading some threads about the car being too low (I can't test it because my car is on a rotisserie).. Im heavily concerned about something. I read the 280z strut towers in the rear are much higher up than the 240z. Which is why the rear rubber insulators that go on top of the 280z struts are so much thicker.

 

Im 99% positive that I screwed up and cut too much off the rear and I should have cut 1.25" off the front AND the rear and simply trimmed down the spacer.

 

So I need to know if I can run my struts as they are on my 280z, or if I have to go back, cut the tubes again and insert a piece of metal to make up the difference. I need to add 1.625" inches back into each strut tube, then compensate for each cut with a 1/8" blade thickness... so a 1.375" chunk back in the middle of the tubes.

 

EDIT - I will be running camber plates

Edited by proxlamus
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I'm at the beach right now. But, I think my struts (240z) with coilovers measure 24" total extended length from the bottom of the strut tube to the top of the strut rod. With your strut extended, what is the measurement from top to bottom? With the strut out of the car, put a tape measure on it and tell me what you get.

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I sectioned my 280z and based on what I did it looks like you did cut too much out of the rear. I cut about 1.5" out of the fronts and the rears (strut tubes) as I am using the same strut cartridge (MR2) all the way around.

 

The 280z rear strut tube is much longer then the front so to compensate for this I added a 3" (about) aluminum spacer which goes into the strut tube first. This makes the inside dim of the rear strut tube the same as the front strut tubes (since I have the same cartridges in the front and rear).

 

If you have the tube pieces you cut out of the front and rear you could reweld them back in????

 

kerry.herr@gmail.com if you need any help

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You know there are other options to raise the rear end back up, including longer insulators and/or upper spring perch.  It's probably better to have the strut tubes the right length, but if you didn't want to re-do it there are other options. 

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  • 2 weeks later...

I am making a some 1" spacer to put between my T3 camber plates and car body. Same basic shape as the T3 camber plates.

 

The issue on mine (280z) is when the stock insulator was removed to install the camber plates I lost about 1" of height.

 

T3 can make these (they make them for other cars, just not the Z). He said if he gets more requests he can make them.

 

I am supersized more people haven't had this issue. I only removed 1.5" from the rear and now think I should have only removed about .75" since I knew I was using camber plates.

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I got the ones from TTT and they are too short in the back for my 280. I've been meaning to call him to see what can be done. It may be a little hard to tell since the car was on skates when I took the picture. but this is just with the springs hand tightened with no preload. I had to crank about as much preload as I possibly could in the rear, and the front has an inch or 2 of slack in the spring when I jack up the car. and I used 240 insulators in the front and 280 in the rear. It still sits lower in the back.  post 88.

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Alright here's an update for anyone who searches and needs more information.

 

For a 280z only...

The final front strut tube casing measured from the bottom inside of the strut tube to the top of the threads is the following : 13.5" (originally 15" total)

The final rear strut tube casing measured from the bottom inside of the strut tube to the top of the threads is the following : 16.75" (originally 18" total)

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Alright here's an update for anyone who searches and needs more information.

 

For a 280z only...

The final front strut tube casing measured from the bottom inside of the strut tube to the top of the threads is the following : 13.5" (originally 15" total)

The final rear strut tube casing measured from the bottom inside of the strut tube to the top of the threads is the following : 16.75" (originally 18" total)

 

I would caution to cutting too much off. I added a 1" alum. spacer to the rear of my 280z. I only removed 1.5" from the rear and was unable to get enough height from my GC coilovers.

 

I attributed this to using T3 camber plates and losing the added height from the stock insulators. I think .75" is more then enough to take out of the struts and still get full travel, unless you are going for a low car.

 

With 1.5" removed and 24" dia tires, the rocker panel seam was 5" above the ground at the highest setting and I could go as low as 4" (IIRC). I wanted to have about 6" at the rocker seam to make the car usable on the city streets, which I am now at with my spacers (with1-2 turns of preload) 

 

Just my observations from my car.. Best of luck

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  • 9 months later...

Fixed... finally

 

20170208_120343.jpg20170208_120408.jpg

20170208_120431_1.jpg

 

One of the struts fell out of the vice when I was hammering so it dented the top of the threads. Luckily it still threads the gland nut and life is good.

 

Anyway.. I added a 3" spacer to the bottom to make the struts work properly.

 

So 17-3/4" measured on the inside from the bottom of the tube to the top of the threads... or a total outside measurement of 16".

 

I also ordered these from Techno Toy Tuning. 1213142.jpg

 

https://technotoytuning.com/nissan/280z/riser-blocks-camber-plates. It's a rear riser plate that is 1" thick just I'm case I need it and it's too low on my car.

 

Thanks for the help everyone

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Hey guys today I wanted to weld on the spring perch for the rear and I'm not sure where to weld it?

 

I have 10" Springs. The only information I could find was from ground control regarding a 280z is the following..

coil1005.jpg

coil2006.jpg

 

This shows that the 280z should have the spring perch welded at 5" on the front and 8" in the rear using 12" springs... compared to the 240z showing 5" front and 7" in the rear using 10" springs.

 

So I have 2 questions - depending on how much you section off the strut, does the spring perch remain same?

If I am using a 10" Spring compared to 12" Springs should I move the weld ring in the rear up 2" to compensate?

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One would assume so. Although I feel like that diagram should have spring rates accounted for to really be useful. If you have the top hat you can figure it out pretty straight forward.

 

Lookup weigh distribution, find your vehicle weight, distribute the weigth then divide by 2 (number of wheels, front, back), then divide by the spring rate to find how many inches the spring will compress. Find the ride height that you plan on running and mark the height then leave yourself room to go lower or higher (leave more room to go lower if you plan on adding flares or something at some point) then weld on.

 

280z curb weight (2875) wiki

Weight distribution (50/50) speedhunters

Number of wheels (2)

 

Weight being held up by spring ~715ish

Subtract unsprung weight 50lbs? (keep in mind things like the rims, tires, calipers, rotors, etc are unsprung weight) 

 

Down to 650ish per corner

 

Running a 225/275 setup you would expect the front to compress the spring 2.9 inches, and the rear to compress 2.64 inches.

 

So with a 10 inch spring the front spring would take up ~7 inches of space and the rear would take up ~7.4 inches. 

 

Keep in mind additionally if you add helper springs they will have some height even when fully collapsed especially if you run the separating collar thingy.

 

You can see that adding a taller spring would just affect the compressed spring height, so I would think that would work given our struts are pretty much vertical allowing this kind of crude math.

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I know I posted 2 pictures above but they were kind of blurry and hard to read.. I e-mailed Ground Control and they sent me some files..

 

Check this out... they even have a new "FAT tire" 8" spring setup.

 

Screenshot_20170216-133052.png

Screenshot_20170216-133120.png

 

 

Crazy. So they list this for the rear.

280z with 12" Springs weld the ring at 8" from the bottom.

280z with 8" Springs weld the ring at 11" from the bottom.

 

So 11"-8" = 3" difference.

12" Springs- 8" Springs = 4" difference.

 

Find the middle with a 10" spring and it looks like I should raise the perch height by 1.5" bringing the total perch height at 9.5" from the bottom.

Edited by proxlamus
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One would assume so. Although I feel like that diagram should have spring rates accounted for to really be useful. If you have the top hat you can figure it out pretty straight forward.

 

Lookup weigh distribution, find your vehicle weight, distribute the weigth then divide by 2 (number of wheels, front, back), then divide by the spring rate to find how many inches the spring will compress. Find the ride height that you plan on running and mark the height then leave yourself room to go lower or higher (leave more room to go lower if you plan on adding flares or something at some point) then weld on.

 

280z curb weight (2875) wiki

Weight distribution (50/50) speedhunters

Number of wheels (2)

 

Weight being held up by spring ~715ish

Subtract unsprung weight 50lbs? (keep in mind things like the rims, tires, calipers, rotors, etc are unsprung weight)

 

Down to 650ish per corner

 

Running a 225/275 setup you would expect the front to compress the spring 2.9 inches, and the rear to compress 2.64 inches.

 

So with a 10 inch spring the front spring would take up ~7 inches of space and the rear would take up ~7.4 inches.

 

Keep in mind additionally if you add helper springs they will have some height even when fully collapsed especially if you run the separating collar thingy.

 

You can see that adding a taller spring would just affect the compressed spring height, so I would think that would work given our struts are pretty much vertical allowing this kind of crude math.

Thank you for this

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