510 Race Car Build

[Icehouse]

On 10/6/2023 at 10:31 AM, Stoffregen Motorsports said:

I do recall you telling me that.

 

Does the rack mount in front of or behind the wheel centerline? The reason I ask is, there is an issue with front or rear steer. Rear steer tends to be very touchy and you need to be careful with your steering input at high speeds, which makes it more susceptible to wander. Even a ton of caster doesn't make it go away. Front steer seems to be immune to this problem.

 

Note - this knowledge is based on experience obtained many years ago, and maybe things have changed. Tire technology could make a massive difference.

 

Speaking of tires, here's a funny story - back when we raced ITC 510s, we had a hookup with Toyo tires, and were given many free sets of tires to go test for them. They brought over a whole container of tires from Japan and just wanted input. My brother and his friend, who worked for AIM tires at SPIR, thought it would be fun to mess with everyone by marking the tires with different info, so we'd write things like PROTOTYPE SET 2 , mark them with many slashes to indicate way more heat cycles than they actually had, and other bullshit. Mind games to mess with the minds of our fellow competitors.

 

I feel like scrub radius makes a bigger difference in touchy steering than rack placement.  Adding Caster (in a 510 or similar suspension design) changes your bump steer massively. Add a bad scrub radius and the car get touchy.  the 280zx I think ran around a 205/60R15 tire then the S13 with the bolt on hubs for more positive offset wheel clearance didn't run a tire much wider. Also going to a shorter tire effects the scrub.   We add a threaded collar that requires us to once again compromise the scrub.  I did a test on my coupe recently.  I have 225's on all 4 corners.  I ran some 165's and took it for a drive.  What a difference.  The car had less return to center but it also didn't pull the wheel on all the bad roads around my house.  Makes me second guess all my street cars wheel choices.  

 

 

Lots and lots of new cars run a rear steer rack.  The only down side I know to a rear mounted rack is that if you make it into a drift car the wheels can over center and get stuck!  Suspension is a giant puzzle that was made for street use. We convert the cars for track use and wonder why so many bandaids are required.  Until you do a 3D model you really realize how complex it is.  Our mind just can't really imagine so many points all working in unison.  

 

 

[Stoffregen Motorsports]

We once lengthened the lower control arms on a 510 and then bent the strut to fit. Combined that with a heavy positive offset and the scrub was just about centered in the tire.

 

I forgot all about that. Maybe we'll try it on our new car.

 

Thanks for reminding me.

[Icehouse]

8 hours ago, Stoffregen Motorsports said:

We once lengthened the lower control arms on a 510 and then bent the strut to fit. Combined that with a heavy positive offset and the scrub was just about centered in the tire.

 

I forgot all about that. Maybe we'll try it on our new car.

 

Thanks for reminding me.

 

 

My Tan 510 I drew a simple solid works drawing of my strut wheel/tire combo.  The scrub was off by 1", I think it was the Herb Adams book or maybe a different one I read said the max you should run is 1/2". hah.  That was with 195 tires.... Not even wide! 

 

[shlammed]

On 11/12/2023 at 12:22 PM, Stoffregen Motorsports said:

We once lengthened the lower control arms on a 510 and then bent the strut to fit. Combined that with a heavy positive offset and the scrub was just about centered in the tire.

 

I forgot all about that. Maybe we'll try it on our new car.

 

Thanks for reminding me.

 

 

Do you remember the change in steering feel?

[Stoffregen Motorsports]

I never actually drove the car. Brian Rebello ended up with it and then it got sold again...

[Stoffregen Motorsports]

I just got a load of parts from a friend for the race car build. On the pallet are four cylinder head cores, two short blocks and a 6 bolt steel Tilton flywheel with dual disc Tilton clutch. Anyone have a 5 bolt Tilton flywheel they want to trade?

 

He also gave me a set of 13x7 Revolution wheels. There are 5 actually, but one is broken. When I reminded him that I had a set of those on my old daily driver 510, he said, these are your old wheels! What a stroke of luck.

 

My buddy also has a couple R180s and some carbs he might part with. I'd like to find a BRE intake. If anyone has one, let me know.

 

This morning I made a call to Dave Rebello and we discussed what I would need to get going on a motor. The short list of parts and cylinder head work is already up to about $4000. He's going to do the head for me, which will save me some cash, but the other hard parts cost what they cost.

 

Going further down the rabbit hole, I spoke with Troy, and we're going to get one of his direct drive dog boxes.  There's 8 g's.

 

Suspension-wise, I can build the crossmember, control arms, etc, but we'll need coilovers, camber plates, shocks, springs, weight jacks, etc.

 

Brakes - I'd love to use the Porsche calipers. And we're going to run the 240z aluminum rear drums, so that's easy enough. I keep hearing about Triumph TR6 brake drums as an almost direct replacement, and they are cheap, so I'll order up a pair and see how they work.

 

So yeah, we're starting down the rabbit hole...

 

 

[iceman510]

I have a spare Al flywheel that came with my race car, but with a mix of L18 and L20 B parts, I will have to look what bolt # it is.  What diameter clutch are you looking for,  7"?

 

All the engine parts L18 stuff? 

 

What are you looking for in an R180?  I have a couple units, but likely not directly usable for what you need.  One is early Z 3.36 ratio, and I have another that is a 3.90 I believe with a welded center.  If you are just looking for housing and gears for a Quaife or something, I can probably help out.

 

 

Edited February 28 by iceman510

[datzenmike]

The D21 4x4 Hardbody '86-'89 with Z24i had 4.375 R-180s in the front. '90 and on with KA engines were a mixture of 4.375 and 4.11.

 

The 87-'89 WD21 Pathfinder with Z24i had a 4.625 H-180.

 

[Icehouse]

7 minutes ago, datzenmike said:

The D21 4x4 Hardbody '86-'89 with Z24i had 4.375 R-180s in the front. '90 and on with KA engines were a mixture of 4.375 and 4.11.

 

The 87-'89 WD21 Pathfinder with Z24i had a 4.625 H-180.

 

 

Remember Mike the D21 and DW21 chassis use the stupid short R180 diffs 😞 I've been hunting for super low gears for my R180.  Gotta find the early 4x4 720 for good gears. 

[datzenmike]

Yes! up to '82 the 4x4 were 4.375 and 4.11 after.

 

The 1980 720 long bed 4x4 has R-180 4.625. Keith Law from the realm has 4.675 in his turbo 510.

[Stoffregen Motorsports]

I believe other guys are running 4.38s and 4.10s, depending on the track. If I can't find an LSD or afford a Quaife, I'll just weld one up for now. I've been curious about having a friend making us a heat treated spool. Lots of weight savings there. Rotating mass and all that.

 

@iceman510 I appreciate the offer on the aluminum flywheel, but I will buy a new steel one if I can't find a used one. I think we'll run a dual 7.25", but I'm considering a dual 5 clutch. I got one good usable L18 short block, and an L20B, which I will use as trade value with Troy or Rebello. Two of the head cores I got are crap. One is a 210 and another a W58, but I'll rob the cam towers and rockers and scrap the castings. The two other heads are buildable A87 peanut heads. As far as the short block goes, all I'm going to use is the block and caps, the crank and the front cover. If you guys need any stock L18 internals...

 

Oh, back to the intake. There was once a casting that looked identical to the BRE intake. I only ever saw them without a balance tube. If anyone out there knows what it's called, please remind me so I can search for one of those too.

Edited February 28 by Stoffregen Motorsports

[521aiden]

is the bre look alike you’re referring to this one? These are from pierce manifolds.

[Stoffregen Motorsports]

I thought it was one piece. Maybe...???

[iceman510]

18 hours ago, Stoffregen Motorsports said:

 

 

@iceman510 I appreciate the offer on the aluminum flywheel, but I will buy a new steel one if I can't find a used one. I think we'll run a dual 7.25", but I'm considering a dual 5 clutch. I got one good usable L18 short block, and an L20B, which I will use as trade value with Troy or Rebello. Two of the head cores I got are crap. One is a 210 and another a W58, but I'll rob the cam towers and rockers and scrap the castings. The two other heads are buildable A87 peanut heads. As far as the short block goes, all I'm going to use is the block and caps, the crank and the front cover. If you guys need any stock L18 internals...

 

 

You have me thinking now, is it aluminum or steel?  I will get out there later today and take another look.  I will try and text you a picture or two of what I have.

 

I might be interested in the 210 casting if it is good and flat, or any of the screw-in rocker pivots and/or springs if you aren't planning to keep them.  I have a couple heads I received with my race car that are almost completely bare.  Also might be interested in the L18 stock pistons, maybe the rods.

[Stoffregen Motorsports]

I'll send you wahtever you need.

[docbainey]

On 2/28/2024 at 11:59 AM, Stoffregen Motorsports said:

 

 

Brakes - I'd love to use the Porsche calipers. And we're going to run the 240z aluminum rear drums, so that's easy enough. I keep hearing about Triumph TR6 brake drums as an almost direct replacement, and they are cheap, so I'll order up a pair and see how they work.

 

So yeah, we're starting down the rabbit hole...

 

 

Good Euro to dollar exchange rate currently. If you're trying to find genuine ATE calipers, good luck with that!!