Is anyone auto crossing their Roadster?

[jr02518]

Yes, I am new to the world of Datsun Roadsters. I have acquired a 1970, 1600 and am getting it back into "driver" condition. The car had been driven regularly until two years ago when a cascade of things overwhelmed the previous owner. It is now running, unmasking a number of issues that need attention. But the reason for the post...

The car has 135,000 miles. Stored indoors when not used. There is no need to "restore" the car, I can live with a driver. But "drive", I will. Locally we have a very active SCCA Solo2 program that has a class/group for older Historic cars. They incorporate a Supplemental Regs section into the bylaws that reflect reality of using and driving old cars. The SCCA HCS/HCR bylaws are also incorporated. If you are a "rule purest", it could drive you nuts. Bottom line, it's a place for old cars to compete, in Southern California. www.solo2.com

My car will compete in Historic1, H Street. I will be running a set of first series Falken 615k, 195/60 14 tires on the Ansen rims that came with the car.
Getting the car running is the first task, shifting is next and then stopping. Lots of parts have been ordered, received and are getting installed. The previous owner had RnR'ed lots of the suspension. At the front the upper and lower ball joints were addressed and it has a set of new "KYB's" at all four corners.

So, anyone up for "insite, advice or go fast parts you might have on a shelf"? I have a bunch of Morgans to chase.

David

[rwmann]

Back in the day (late 1970s, early 1980s) the 2000 ran in CS or CSP (C-Street, or C-Street-Prepared, with wheel and tire width, bigger front bar free) and was quite competitive. On a solo course, with wider rubber on wider rims, the enhanced grip and greater lateral stress on the front suspension caused strain and interference between rims and hard front brake lines, so have fun, but watch for witness marks as you work on your times.

[SLOroadster]

I autoX mine from time to time, used to race it monthly. The Falken tires are junk (I do realize there aren't many choices in a 14 inch tire). Simple as that. The car will either understeer, or swap ends in the blink of an eye. Sometimes it will push until it finally decides to rotate, then spin. I'd look for a set of R compounds if you can run them. As far as suspension setup, I'd say a set of Mike Young's comp front springs, and stock rears with at least a set of Koni or Bilstein dampers are the way to go. The KYBs are again, junk. You will want at least a 4.11 rear end, a 4.38 with a limited slip will likely help you along through the turns. The 23mm front anti-swaybar is also the way to go.

When I went from running Falkens to my first set of R compounds I was 15 seconds faster. I did a back to back check, ran with the Falkens, then ran with the R compounds, same course, same conditions. The tires were the difference between an also ran and a serious contender.

Will

[jr02518]

Thank you for the input. In the world of SCCA, Street and Pre-Pared are a world apart. The easiest way to identify a line in the sand, is tires. Today the array of 200tw tires is the domain of the Street level of preparation. The challenge with these tires for the current crop of tires, is how big they have become. A "new" 205/50 15 looks closer to a 215/50. That and the reality of the 200tw is actually a much softer tire. I am running a set of the new Falken 660's on a '81 BMW 320 and can attest to the difference in both size and durometer of the tires. I had the 615K's sitting unused, and they fit.

An R comp tire is not going to happen anytime soon on this car. If ever. If I live with 14 inch tires I will look for a 2000 differential to install a LSD. The 4 speed in my 1600 on the smaller, lighter tire will hold second gear longer. Yes, I give up acceleration. On a local basis our courses are more a "miniature road course" rather than a parking lot point and squirt.

I would agree the KYB shocks are not going to be a long term solution. Locally we have a number of options as to shock builders. It all boils down to money. Again, this will not be a $3000 a coroner car. Nope.

[gtrbg]

There are archived stories on Grassroots Motorsports on a Datsun 2000 that was autocrossed. You may get hints from that series of articles.

[Daryl Smith]

1) Electronic Ignition
2) A good carb tune (needle change?)
3) Comp. front sway bar
4) Good quality oils in motor, trans, and diff.
5) Wheel alignment
6) Clean up casting flash in intake manifold (remove from engine), use a sanding roll (60 - 80 grit) with a die grinder and, while removing as LITTLE material as possible, put a rough finish on the manifold runners.
7) Header (1 1/2" ceramic coated - I'd say smaller, but it's not available) and 1 3/4" exhaust system with straight through muffler.

If you decide to spend the money....in no particular order
- A good 3 angle valve job (open valve throats to 89 - 90% of valve diameter), and minor porting (bowl/casting flash cleanup, rough ports - as intake manifold above - as little material removed as possible!!)
- Cam with more lift. (requires pulling the engine)
- Koni or Bilstein shocks

All of the above together will make a marked difference while still being basically stock, other than the cam...and shouldn't be too bad on the bank account.

[jr02518]

Daryl,

Thank you for the list. I have started working on items 1-5.

David

[Daryl Smith]

If you pick up a spare head/manifold (not hard to find) you can have the work done on those, while still driving, and then make the swap in an afternoon....likely 2-4 hours. Really easy with the pushrod engine.....At least, it is when you've done it as many times as I have .

[Pjackb]

The 615K is a great tire for what it is and when compared to it's peers , you can check out some actual tests from racers on the web
Comparing a street tire to an R compound is irrelevant and like comparing an R16 to a U20 , obviously you will be faster in a U20

Bilstein shock are transformative for handling and really reasonably priced
4.xx LSD would be great but that's at least 2.5-3K and you mentioned not wanting to go crazy on the spending so If you're pulling the engine for some work a Lightweight flywheel with the 195/60/14 and stock 3.9 is really quick out of the gate without having to spend thousands for an LSD
Good luck

[Daryl Smith]

Weight can be reduced also....
1) Smaller, lighter Battery...Odyssey PC 680?
2) Electric Fan (also better access to front of engine, perhaps a bit more power to wheels when not on)
3) Small modern Alternator
4) FlexForm rear mono leafs (handling and weight)

[jr02518]

Daryl,

On #4,FlexForm rear mono leafs, the web site requests an order that wants a demential layout on a preorder basis, any one the forum that has worked out the details and are running the leaf springs? What spring rate did you request?

David

[Gregs672000]

They have made them for me before, and I believe that JT68 has some kind of connection. I'd have to go way back into 311 posts to find info on mine (you can search for flex form), but I think I went with 230lb. The weight difference vs stock is night and day. You will want the Billsteins to control them. I'm no racer, but I do drive my car hard from time to time and that combo has been the very best in all ways... handling and ride. I used lowering blocks to match my front comp springs... 3/4 inch I think. You will likely need to install them with your best guess on the block size and see, as each car is different. If they keep customer records, you can ask them to look up customer Greg Burrows' order.

[Cyclewrks]

The car in the Grassroots magazines is the Harvey Bros out of FL. The car was an absolute brute (still is as they still turn up at an event here and there) and was the car to beat every time it was there. Prep was really pretty simple comp springs and comp bar up front and stock springs and no bar in the back with a LSD dif. Key to making the roadsters work is get as much roll stiffness in the front as possible to keep the rear wheels on the ground. There were (probably still are) lots of photos of that car with the inside front tire off the ground.

[Daryl Smith]

I think Greg is right in that they have done enough of the Datsun Roadster springs that you should be able to order with just the application.
I was among the early adopters of the Flexform and had some issues with the eye size and bushings. AFAIK that has been worked out, and JT68 had some kits put together earlier, don't know if he still has/does them - recommended if he does...
I used a stock curve and 180 lb. rating as I just wanted the 'stock' height/look, along with stock front springs. It looks level front to back on my car, and the ride is nice. I haven't autocrossed the car, but, do drive a bit aggressively at times. No problems. Others, like Greg above, have gone with 220, 230 lb. rating, some saying it's a good improvement over both stock and Nissan comp springs.
If your intent is to autocross, a heavier rating, and possibly the lowering blocks, might be better for you (maybe do the front comp springs first, if you lower it?).
I once read a piece that stated 'soft springs and stiff sway bars' were the way to go, but, not doing any racing, I never delved any further....

Last little note....I had the Flexforms and KYB's for quite a while on my car, and for everyday driving, they were more than adequate.

[bmccarthy67]

Greg called it on night and day for weight on the Flex Form springs. My comp roadster springs were 22.5 pounds each with the small leaf removed to soften the ride. My mono springs from JT are 6.14 pounds each. Dropping 30 pounds from the rear while improving the ride is a win win. There's old photo's and a video of (I believe in was Andy?) a monster roadster purpose built for for autocross. Always loved the video when it lifted it's inside rear tire.

v/r
Buddy