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Budget Coilovers with Stock top-hats


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Hey guys,

So from my searching on here, most don't recommend camber plates for a plain old street car. I'm going for a good handling street weekend cruiser with occasional spirited driving (and definitely the possibility of auto-crossing for fun). Most say the camber plates and lack of isolators transmit a LOT of noise into the cabin...not something I'm fond of.

 

So the info isn't that clear on how to adapt from the common coilover kits to stock top hats. But from another member on here (280zcar) I've seen it can be done on a budget with just generic coilover sleeves.

 

So what do people think about the following:

 

1) Use a standard 2.5"ID coilover sleave and perch.

5" threaded sleave (could get 7" if desired)

http://shop.a1racing.com/cok12450.aspx   $15.53 X 4

Adjusting nuts

http://shop.a1racing.com/cok12460.aspx   $12.87 x 4

= $113.60 + shipping

 

2) It's unclear whether a 2.5" ID spring will work with the stock top hat, so something like the following would probably be necessary:

2.5" to 3ID Spring adapter (stock spring is roughly 3" ID, 4" OD)

http://store.resuspension.com/product.php?productid=18887&page=1 $17.85 x 4

= $71.40 + shipping

 

EDIT: I failed to remember the 240z uses steel spring perches. This kind of adapter will not work into the top hat. Disregard the rest.

 

3) Pick your 2.5" coilover springs and go! Of course you will need to do your due diligence on what length and stiffness to get to get you in the ballpark for ride height.

Likely $200 for springs.

 

Coilover and springs to suit driving style in under $400.

 

So does anyone see any downsides to doing this? I have an early 260z which has the front spring perches in a different position relative to the 240z. This means getting my ride height right is going to be a big question mark not to mention the front may sit a little lower with an RB25. This seems about the most economical way to do it.

 

Note that this would obviously require cutting off the stock spring perches. You wouldn't necessarily have to section (depending on how much you lower the ride height). I'm only going for a mild (1-1.5" drop) drop so it wouldn't be absolutely necessary.

 

EDIT: I see now that the ground control's are more or less exactly what to use. That said, I've seen conflicting info on how it interfaces with the stock top hat. Anyone have any insight into that? Some people machined the aluminum top hat, others used spacers. Looks like it comes with spacers.

Edited by mtnickel
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If you're looking to do budget coilovers, it's hard to beat Cosmo Racing:  http://www.ebay.com/itm/Racing-Coil-over-Coilover-fit-DATSUN-260Z-280Z-74-78-Adjustable-Lowering-Springs-/251457469605?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item3a8c087ca5

 

A few guys here are using them....search and you should be able to find their threads.

 

Good luck and happy motoring.

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If you're looking to do budget coilovers, it's hard to beat Cosmo Racing:  http://www.ebay.com/itm/Racing-Coil-over-Coilover-fit-DATSUN-260Z-280Z-74-78-Adjustable-Lowering-Springs-/251457469605?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item3a8c087ca5

 

A few guys here are using them....search and you should be able to find their threads.

 

Good luck and happy motoring.

 

Only issue is the bone jarring spring rates of 300+ coupled with a short sleave and short spring.

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I don't recall the user but I know of a story where a guy running the cosmo coilovers bounced the car off the road (crashing it) because of them being so tight and driving on the street.  Call it what you want, lack of driver anticipation or knowing his setup well enough but it happened either way on his street Z.  They are stiff. 

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Having been thru this before myself, I would discourage you from trying to nickle the coilover conversion to death.  You really have to maintain suspension travel.  Two ways to do this: sectioning the tube, or camber plates and elimination of the top strut insulator.  If you do camber plates, the top spring perch is higher in the tower, effectively lowering the car without reducing travel.  If you lower the car by lowering the bottom spring perch, or by shortening the spring, you have to re-gain that lost suspension travel by shortening he strut above the lower perch, ie "sectioning."  I recommend that you wait until you can afford to do one or the other.  I also want to say that I love my spring rates for both track and street:  225F/250R.  Firm but not harsh.

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Saw your PM but decided to respond here.  

For the stock top hat, there are two different type of stock hats. One has a center perch for what I think was a shock boot. Its a flattened section that has the perfect diameter for a 2.5" spring.

All I did was weld in a 2.5" piece of exhaust tubing in the center to keep the spring centered

 

this pic is a comparison of the two types of stock spring hats and this is before i welded in the exhaust tubing in the center. I used the one on the right, you could probably weld a center ring on the left one as well. 

 

DSCN1235.jpg

 

As far as saving a buck to install coilovers, unless you get a deal on springs it will likely come out to similar a price as just going with Ground Control. 

Edited by 280zcar
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Having been thru this before myself, I would discourage you from trying to nickle the coilover conversion to death.  You really have to maintain suspension travel.  Two ways to do this: sectioning the tube, or camber plates and elimination of the top strut insulator.  If you do camber plates, the top spring perch is higher in the tower, effectively lowering the car without reducing travel.  If you lower the car by lowering the bottom spring perch, or by shortening the spring, you have to re-gain that lost suspension travel by shortening he strut above the lower perch, ie "sectioning."  I recommend that you wait until you can afford to do one or the other.  I also want to say that I love my spring rates for both track and street:  225F/250R.  Firm but not harsh.

Ya, I will likely do the sectioning of the struts anyways. I have all the tools and know-how to accomplish it. My only push back was the possibility of a weld penetrating too far and causing some headaches, but I figured I could use the cutout to do some test welds.

 

Saw your PM but decided to respond here.  

For the stock top hat, there are two different type of stock hats. One has a center perch for what I think was a shock boot. Its a flattened section that has the perfect diameter for a 2.5" spring.

All I did was weld in a 2.5" piece of exhaust tubing in the center to keep the spring centered

 

this pic is a comparison of the two types of stock spring hats and this is before i welded in the exhaust tubing in the center. I used the one on the right, you could probably weld a center ring on the left one as well. 

 

DSCN1235.jpg

 

As far as saving a buck to install coilovers, unless you get a deal on springs it will likely come out to similar a price as just going with Ground Control. 

 

Thanks for chiming in 280zcar. I didn't realize the top hats had reasonably flat spots there. Without the need for adapters then it seems like it could still be a good deal. Not much more the 330 shipped or so. Plus you get to pick the exact spring rate you want.

Will keep people updated and maybe post a few pics of the top hat modifications if I go that route.

 

Regards,

Mark

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  • 2 weeks later...

If you look around you can find ground control coil and sleeve kits for basically the same price.

 

Don't see how this is any more budget, just a lot more foot work.

True enough. It's only really worth it if you can get a really good deal on springs. Additionally, you can run, arguably, a better spring like hyperco's or swifts.

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True enough. It's only really worth it if you can get a really good deal on springs. Additionally, you can run, arguably, a better spring like hyperco's or swifts.

From the spring shoot outs I have read, the eibachs are already pretty darn good. I guess it would be nice to save weight and avoid coil bind with the swifts, but we can run pretty long springs as it is. Also, the ground control kit comes with the weld on rings, not an issue if you can fab but will add to the price if you can't.

Edited by 1vicissitude
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From the spring shoot outs I have read, the eibachs are already pretty darn good. I guess it would be nice to save weight and avoid coil bind with the swifts, but we can run pretty long springs as it is. Also, the ground control kit comes with the weld on rings, not an issue if you can fab but will add to the price if you can't.

I would be sectioning struts, so I would just cut the sectioned piece into 120 degree pieces (3) and weld them around to suit.

 

And the eibachs are probably just fine you're right. So I will keep my eye out for a good set of used springs or just a good price on the ground control kit.

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