Datsun Roadster Forum-311s.org

Alexi,

Yes, there is a roadster club here in the northbay. We try to get together once a month for a fun run or some tech stuff-working on cars. Not so much during the winter but April through October there is usually a pretty good turn-out. There are close to 10 members but only a couple of die hards like myself make most of the runs. We have a lot of fun and drive the snot out of our cars. Sonoma county has some great back roads. Yes, you and your Honda are more than welcome to come along.

As to the manifolds they are made out of solid brass. We had a tough time finding something with the correct dimensions that would work. I have already had several requests for them since you started this thread. Doing a run of 20 or so would be a lot cheaper than one or two. Let me know what you find out. Mark's drawing is right on as that is what we used to make a couple of sets.

Steve

Steve,

Thanks. I figured on doing a good sized run as I am sure there will be others in need of these. I will post my findings.

Thanks for the great site, I have found many a good idea from it already and I have been in roadsters for several years. I should have done less wrenching and more surfing.

Alexi

Sounds good and I thank you for the positive comments on the site. I appreciate it.

Steve

Woa! I cannot keep up with your posts, you guys must be glued to the computer!

Hey, on the single vs dual master cylinder issue-Does the single flow enough fluid for the Volvo calipers? The major difference between the two masters is that the dual has two pistons, one for the front, another for the back whereas the single has one for both. I don't know how much more fluid the Volvo's require...?

An S2000 will be accepted at any run...Actually, I'm curious as to how those perform? They are supposed to be somewhat light with good HP...

Sign me up for a set of the adapters. Also, I know a really good machinist and if he isn't busy, he is really inexpensive.

Maybe you could get people to prepay for the hardware, and get a discount by buying enough for all of the sets?

I'll prepay, just let me know how much and where to send the money...TR

I am not so worried about the money. IF you have a machinist contact let me know and I will persue it some more. Otherwise I am starting from scratch up here with a phone book.

S2000 is 2800lbs with 240hp. I will let you try it out at the run.

Alexi

We'll have to see which car is faster!?

I sent the drawing to my machinist, if he isn't busy, he should respond quickly...TR

TR,

Wouldn't it make sense that if your lines are filled with fluid that the pressure you put in the line would be the same regardless of how many pistons you use. I think that dual reservoirs are a "safety" thing if you lose one set you have another. Infact pressure, not fluid volume is what determines your master for the car.

I also think that your roadster would be faster since you have a better power/weight ratio than my car, but I will let you know how nice my A/C works when it is 100 degrees out!.

Alexi

Right now it is more like 30 degrees without heat or a top!

The roadster does have a better power to weight ratio as built, but it gets a bit squirelly under full acceleration and without a limited slip, I have trouble getting the power to the road...(Which is much better than all of the vehicles I have had before that get plenty of traction but do not have any power!)

As for the pressure/volume dilemma-I think you are right on with the safety idea, you still get front or rear braking if the other fails with a dual setup. And yes, the pressure from the master determines the braking effort. But, if you have more piston area at the caliper, it requires more fluid to move the pistons enough to make the pads contact the rotor. Maybe the pad movement is slight enough that it does not matter...
It sounds like you guys will find out, please let me know...

TR

TR,

Thought about having a custom made rear axle? Ford 8 or 9" with posi, rear disc and unlimited axle ratio's?

I am still debating that s14 sr20de. It is posted on in the classifieds @$1400 complete. The only thing holding me back is my ego, it is beating the hell out of me now since you are all running turbos, how could I keep up without one????

A man's life is rough!

Alexi

That would be a great way to go on the rear end! I'm not sure how many ratios I would make use of, but a modern LSD makes a lot of sense, not to mention better brakes, availability of parts, etc...Have any idea of how much $???

If that s14 comes with the tranny, and wiring harness and ECU, that is a great deal...

The turbo adds a lot of headache...All kinds of custom plumbing and exhaust, not to mention intercooler, etc...

You can always swap a turbo motor in later if you need more HP...TR

TR,

Good advice on the sr20de I think that I will pick it up. I understand having to trim the front crossmember and the area for the altenator but do you have to do all the boxing on the x member? I don't want to have to pull my body to get in there. I would still like to personally view your car.

You should be able to take you datsun rearend to any decent rearend shop and have one made up. 9" is the ultimate in strength but a 8" probably would do. They could "copy your datsun for specs and pinion angle. Custom drill rotors and axle ends for the correct stud configuration. I am not an expert but I see these 4 wheeler guys get custom rear axles for $2-3 G's, but I would think with the smaller light car and a 8" rearend you may be only at the upper end of $2g's. You could always drive your car over and tell them what you want (make sure it is limited slip not posi) and they could quote you.

Alexi

That is about what I was guessing for the rear end. A bit much for me unless I find some cash somewhere!

You could probably avoid the major boxing in the X-member if you mounted the tranny directly to the frame, without a insulating mount. The car might rattle loose, though! You would still have to do minor trims for the speedo sender and such...

Taking the body off is really easy. You could make a setup like I did or just use a few engine hoists...TR

do you have plans made up for the enigine mounts? If so I would like to buy a copy so that I can have them made up for an easier install.

Sorry, no plans...I made cardboard templates then cut them from plate, drilled, etc. The motor mounts I used are from an early 510 with the safety's cut off for clearance...

You can rent a plasma cutter, it will save you a ton of grief. I should have done the same but I kept thinking, "I'm almost done with the major cutting, no reason to get one now..." Penny-wise and time-stupid! You can easily plan all of your cutting, draw it all up on sheet and on the frame, then make all of the cuts in the time it took me to make just one...TR

IIRC, "PosiTraction" or "Posi" for short, is General Motors trademark for their limited slip unit. Why would you recommend a "limited slip" but not a "posi"? Inquiring minds want to know...

As I was driving in my Ford Ranger (with a limited slip) I got wondering why not use one of those units in my Roadster? Other than cost, the only negative I came up with was perhaps weight. Just about any unit we'd use in our Roadsters would have to be cut down in length to fit anyway. I think the 1st gen RX-7 rear end is available with limited slip and rear disks, but has to be cut down a total of 8" to fit. In Solo2, change the rear end housing and you're in Prepared, at least. Too much rear track change, and I believe you're in a Modified class. Something to consider if you're planning to autocross once in a while.

Since my specialty was autocross, I always used to wonder what the big deal with rear disks was, anyway. Fade resistance? I used to use totally stock brakes and never had a problem. Track days would obviously be a different story.

Also, as dollar amounts for changing to a different rear end are bandied about, keep in mind that a factory limited slip, if you can even find one, will be way over $1K anyway.