Jump to content


Photo
- - - - -

Best coil-over option for '76 620


  • Please log in to reply
23 replies to this topic

#1 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 12 December 2017 - 11:53 AM

I have a '76 620 LWB that I'm going to be doing some extensive work to, and I'm looking some swap options for suspension. This truck will be primarily street driven, but it will see some road course track time from time to time, but nothing competitive, just casual club run track days or whooping on V8's at Powercruise USA. Powerplant will be a 515rwhp/509ft lbs VQ35 swap from my G35, so I need the rear end to be strong enough to support the power and torque.

 

At first I was looking at using a Toyota 8inch rear with a 4-link, but after reading more about 4-link setups they don't handle well. After further digging I found some threads about guys using the S13 subframes, and even found a thread about swapping the rear subframe in as well. I know the S13 rear diff and axles aren't going to like the power so I'd be upgrading diffs and axles. Are there any other swaps that would be a good option to look into? I'm not sure how I feel about a rear sub-frame swap because I'm then cutting into the bed to fit towers, and I want to be able to put the motorcycle in the bed.

 

 Everything I've ever worked on and built has been uni-body and independent suspension, so this is a new realm for me. And yes, I'm well aware of the work that this will take. This is one of those "once in a lifetime" builds. I'm bored with just doing bolt-on work on modern cars, time to get out of my comfort zone and build something that fits me and my character.


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#2 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 971 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 12 December 2017 - 01:30 PM

Why don't you think an S13 R200 diff won't take a measly 500 hp ?

I know of many 700+ cars with that size diff in them, and they don't break.

 

Just don't use one with the Viscous diff, they don't work for anything....Good idea, that just never worked right from day one.

They barely hold 150 hp when they are at the right temp.

Too cold, they don't hold, and too hot they don't hold.

 

And all you have to do to put 1000 hp through one is to install an S15 helical, as it has the larger 30 spline output shafts.

Plus it being a helical, there is nothing else out there as good for road racing.

 

The IRS is worlds above in handling over any solid axle set-up.


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#3 Lockleaf

Lockleaf

    Hall Monitor

  • Senior Member
  • PipPipPipPipPip
  • 4,479 posts
  • Location:Happy Valley, Utah
  • Cars:'71 510 Goon, '90 240SX, '85 720, '69 Roadster, '96 Pathfinder, too much other shite

Posted 12 December 2017 - 09:03 PM

Exactly how much space do you think the strut towers would take up to keep you from loading a bike into it?

Also, Project Car Magazine did a full front and rear s13 suspension swap years back into a 620. The builder managed to build towers off the rear frame that fit under the wheel tubs. Invisible from outside no sheet metal work at all.

Half Pint ('71 510 Goon) http://community.rat...agon/p?=1269361

 

Audrey ('69 Roadster 1600) http://community.rat...rey-the-ratster

 

Tiny Havok ('85 720 DIY built Crewcab 4x4) http://community.rat...ache/?p=1395455

 

720 Shenanigans http://community.rat...20-shenanigans/


#4 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 13,132 posts

Posted 12 December 2017 - 10:19 PM

I would read this thread if I were you, and before people start talking about strength, this is a race truck that a well known driver other than the owner and son drove and he said it was the best balanced race truck he had ever driven.

https://www.google.c...Q5EcnmUQqgPZt7b

MX5201sttrackday.jpg

 

I could see the photo above find when I copied it, Photolame sucks, we should stand out in front of the CEOs house with signs telling the world it is this guy that did this.


 

 


#5 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 971 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 12 December 2017 - 11:36 PM

Too bad all you can do is read the story...

But Miata rear end won't take the engine 2one8 is talking about.

Pretty sure his big power idea won't work, due to it being a real miss match, and very unbalanced.

Hell, even the old GTP cars only ran at about 600HP, even though the engines were god for twice that.

They relied on state of the art suspension, and aero to go fast.

Big engines mounted over the front axle, in a pick up isn't there.

Maybe a drag truck, but not something meant for a road course.


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#6 datzenmike

datzenmike

    KING RAT

  • User Administrator
  • 70,898 posts
  • Location:Vancouver Island
  • Cars:'74 710 sedan, '76 710. prevoius... '78 620, '71 521, '68 510 new '76 B-210

Posted 13 December 2017 - 07:38 AM

Make it a mid engine.


Posted Image

#7 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 13 December 2017 - 11:35 AM

Exactly how much space do you think the strut towers would take up to keep you from loading a bike into it?

Also, Project Car Magazine did a full front and rear s13 suspension swap years back into a 620. The builder managed to build towers off the rear frame that fit under the wheel tubs. Invisible from outside no sheet metal work at all.

 

With a rear sub-frame swap I'd want to run a strut bar from tower to tower which would prevent me from loading the bike. Granted I can remove the bar if need be. However I may have to run the radiator in the bed, so I may be SOL as far as loading the bike anyways.

 

Too bad all you can do is read the story...

But Miata rear end won't take the engine 2one8 is talking about.

Pretty sure his big power idea won't work, due to it being a real miss match, and very unbalanced.

Hell, even the old GTP cars only ran at about 600HP, even though the engines were god for twice that.

They relied on state of the art suspension, and aero to go fast.

Big engines mounted over the front axle, in a pick up isn't there.

Maybe a drag truck, but not something meant for a road course.

 

Yeah these HP levels in a light truck aren't ideal, but I can run multiple maps and with proper tuning I can down-tune to manageable power. Chances are I'll tune down to 450ish for daily, can get down to 350ish on low boost but she will be sluggish low end due to lower compression. Either way, I'm fully aware this thing will be tail happy.

 

Make it a mid engine.

 

This is already going to test my fabrication skills lol
 


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#8 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 13 December 2017 - 11:46 AM

Anyone have a link to or copy of the Project Car Mag article I can look at? Google didn't come up with anything and I cant find it for digital purchase anymore.


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#9 Lockleaf

Lockleaf

    Hall Monitor

  • Senior Member
  • PipPipPipPipPip
  • 4,479 posts
  • Location:Happy Valley, Utah
  • Cars:'71 510 Goon, '90 240SX, '85 720, '69 Roadster, '96 Pathfinder, too much other shite

Posted 13 December 2017 - 08:32 PM

You shouldn't need to run a radiator in the bed. The vq shouldn't be THAT deep of a motor. Fairly sure the vq fits 510 engine bays with a radiator.

I will check over the next couple of days to find my collection of project car mags. I'm only missing 2 which bums me out. I want them all.

And you can always use pins to lock the rear bar in place when you need it or disconnect it quickly when you use the truck to haul.

Half Pint ('71 510 Goon) http://community.rat...agon/p?=1269361

 

Audrey ('69 Roadster 1600) http://community.rat...rey-the-ratster

 

Tiny Havok ('85 720 DIY built Crewcab 4x4) http://community.rat...ache/?p=1395455

 

720 Shenanigans http://community.rat...20-shenanigans/


#10 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 14 December 2017 - 05:10 AM

You shouldn't need to run a radiator in the bed. The vq shouldn't be THAT deep of a motor. Fairly sure the vq fits 510 engine bays with a radiator.

I will check over the next couple of days to find my collection of project car mags. I'm only missing 2 which bums me out. I want them all.

And you can always use pins to lock the rear bar in place when you need it or disconnect it quickly when you use the truck to haul.

 

Radiator in the rear will depend on intercooler fitting. My current intercooler is 12x31x4. I've been looking at some of the SR20 swaps and it looks tight even with smaller intercoolers.


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#11 Lockleaf

Lockleaf

    Hall Monitor

  • Senior Member
  • PipPipPipPipPip
  • 4,479 posts
  • Location:Happy Valley, Utah
  • Cars:'71 510 Goon, '90 240SX, '85 720, '69 Roadster, '96 Pathfinder, too much other shite

Posted 14 December 2017 - 12:14 PM

Wallrocket just posted this setup recently. His build is in the projects section.

Inter cooler was pretty simple. I just had this Honda FMIC laying around in the shop. It had 3 12mm bolt size holes on top to bolt it to something, I just drilled the holes out on the Datsun radiator support and called it good. Its very sturdy, and i am happy with it. To help others with this inter cooler, i think its for a Honda, has 3 bolts top and 3 bolts on bottom, inlet is 2.25 and outlet is 2.25. I will get the length and what not later for you guys.
uY6YDu.jpg


Half Pint ('71 510 Goon) http://community.rat...agon/p?=1269361

 

Audrey ('69 Roadster 1600) http://community.rat...rey-the-ratster

 

Tiny Havok ('85 720 DIY built Crewcab 4x4) http://community.rat...ache/?p=1395455

 

720 Shenanigans http://community.rat...20-shenanigans/


#12 distributorguy

distributorguy

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,177 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 18 December 2017 - 05:56 AM

If you try to put strut towers where the rear tires belong, you'll run out of room for the tires you'll need to hook up 500hp.  

If they go inside the rear wheel wells, you won't be using space you need for a bike, although you have to get creative with strut tower braces.  

 

Personally, I'd build a 9" and run a 4 link with a custom Watts linkage setup so you can turn corners.  Or build a quick-change for fine tuning later.  Make your suspension loading adjustable for up to a 45/55 weight balance so the back end stays in back.  



#13 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 19 December 2017 - 08:13 AM

If you try to put strut towers where the rear tires belong, you'll run out of room for the tires you'll need to hook up 500hp.  

If they go inside the rear wheel wells, you won't be using space you need for a bike, although you have to get creative with strut tower braces.  

 

Personally, I'd build a 9" and run a 4 link with a custom Watts linkage setup so you can turn corners.  Or build a quick-change for fine tuning later.  Make your suspension loading adjustable for up to a 45/55 weight balance so the back end stays in back.  

 

I've been looking through Chad Copelands build and how he did his rear suspension (I would post a link, but my computer wont paste anything). He cut the rear tubs to make room for the suspension. Take away the rear strut bar and there looks to still be plenty of room for the bike. While I'm hauling the bike I likely wont need the strut bar as long as the rest of the suspension is solid. If I'm hauling the bike its probably just to BIR for a track day(I see youre from MN), or to a show where its just going to sit in a parking lot. I'm also planning to go wide wheels and flare out the wheel wells, so I can make up some lost wheel size that way. This is just one option I've been looing into.

I'll look into the Watts setup for sure. Solid axle suspension is a whole new world for me. I already have a Toyota 8inch that I'm told by a local shop should be plenty for this, but I'm not opposed to running something else.


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#14 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 971 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 19 December 2017 - 09:17 AM

A 9" is overkill for your power...

The Toyota 8" damn near is also.

The stock H190 is fine, if you want to go 4-link, and their are pleanty of gear ratio sets available.

LSDs can be had. If you can't find one, let me know, I get them in the 29 spline for the truck on a regular basis.

 

I did my 4-link, and kept the stock fuel tank & spare location, and run a Watts Link.

 

DSC08381.jpg

 

But an IRS will still out handle a solid axle any day.

 

Oh, and you don't need a strut bar on an IRS system like an S13, where you have upper & lower control arms.

Strut bars only help if you have struts....

Damn kids sticking strut bars on things like Supras, that don't have struts, is retarded.

All it does is add 'bling'.


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#15 distributorguy

distributorguy

    Senior Member

  • Senior Member
  • PipPipPipPip
  • 1,177 posts
  • Location:Metropolis, MN
  • Cars:77 Datsun 620, 73 Datsun 620

Posted 19 December 2017 - 10:55 AM

Ummm.... putting wider rear wheel wells in the truck's box isn't going to do anything for you unless you narrow the frame.  That's quite an undertaking without a frame table.  It CAN be done, but it'll be 50 hours of extra work and you'll need a fuel cell mounted somewhere else, as well as likely having to re-route all plumbing.  

 

The Toyota is a good potion, but it likely is too wide.  53 1/2" is your goal drum to drum, or narrower, to fit wheels inside the fenders.  What's the Toy measure - 59?  A 10-bolt 2WD S10 measures 54 1/2" but a truck axle can't use c-clip eliminators or a lot of the other goodies unless you're big on doing your own machining.   Then brakes become an issue - custom brackets.  

 

Where in MN are you?  



#16 2one8

2one8

    Newbie

  • New Members
  • Pip
  • 10 posts
  • Location:Minnesnowta
  • Cars:I like them

Posted 22 December 2017 - 05:56 AM



Ummm.... putting wider rear wheel wells in the truck's box isn't going to do anything for you unless you narrow the frame.  That's quite an undertaking without a frame table.  It CAN be done, but it'll be 50 hours of extra work and you'll need a fuel cell mounted somewhere else, as well as likely having to re-route all plumbing.  

 

The Toyota is a good potion, but it likely is too wide.  53 1/2" is your goal drum to drum, or narrower, to fit wheels inside the fenders.  What's the Toy measure - 59?  A 10-bolt 2WD S10 measures 54 1/2" but a truck axle can't use c-clip eliminators or a lot of the other goodies unless you're big on doing your own machining.   Then brakes become an issue - custom brackets.  

 

Where in MN are you?  

 

Flaring the rear, not tubbing it, so trimming the body for wider wheels and running a flare.

 

I'm leaning more towards IRS and swapping an S13 rear sub-frame in. I've been looking at different ways others have don't IRS and have some ideas. I like the way it was done in this photo, it looks like most of that would fit in the wheel well, or at least in place of the wheel well and shouldn't affect any central bed space. I would like to see if I could notch the frame vs moving it, but in this case the upper control arm would cause an issue but I've seen it done differently in a couple other posts, so I might be able to come up with something that will work. I'm not concerned about moving frame if need be, but avoiding it or keeping it minimal is ideal.

 

And I'm in Brainerd.

 

scontent-a-sjc.xx.fbcdn.net-16874-138976


2015 BMW S1000RR - street bike

2010 BMW 328xi - daily

2006 Yamaha R6 - race bike

2003 Infiniti G35 - track built 515rwhp

1976 Datsun 620 LWB - next project


#17 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 13,132 posts

Posted 22 December 2017 - 10:25 AM

Did you read that MX520 thread, did you see this photo of how Bob did his rear suspension?

This is a winning race truck in it's class, some pro driver from the past that has drove race cars all his life said this was the best handling truck he had ever drove.

mx52012-7-08007.jpg

This truck still has the stock uncut box as far as I know, you will have to hack the shit out of your box to do what is in the last photo you posted.

If this photo disappears let me know and I will replace it with one that doesn't disappear.


 

 


#18 G-Duax

G-Duax

    prickly in San Antonio

  • Senior Member
  • PipPipPipPip
  • 971 posts
  • Location:San Antonio, The Republic of Texas
  • Cars:73 620 & 90 Toyota Cressida

Posted 22 December 2017 - 11:27 AM

Nice.

What subframe is that ?


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#19 Lockleaf

Lockleaf

    Hall Monitor

  • Senior Member
  • PipPipPipPipPip
  • 4,479 posts
  • Location:Happy Valley, Utah
  • Cars:'71 510 Goon, '90 240SX, '85 720, '69 Roadster, '96 Pathfinder, too much other shite

Posted 22 December 2017 - 12:47 PM

Wayno all I'm getting is photobucket warning.

Half Pint ('71 510 Goon) http://community.rat...agon/p?=1269361

 

Audrey ('69 Roadster 1600) http://community.rat...rey-the-ratster

 

Tiny Havok ('85 720 DIY built Crewcab 4x4) http://community.rat...ache/?p=1395455

 

720 Shenanigans http://community.rat...20-shenanigans/


#20 wayno

wayno

    Datsunahaulic

  • Senior Member
  • PipPipPipPipPipPipPipPipPipPip
  • 13,132 posts

Posted 22 December 2017 - 02:22 PM

Wayno all I'm getting is photobucket warning.

Postimage will not upload anything right now, it says something about maintenance(I just tried again), I have the photo saved to my computer, I just need Postimage to work, when it starts working I will fix the photo.

I looked at the properties and it says it's hosted at Photolame, at first I could not see that part in the text, I had to expand the box to see who hosted it. :(