Racer Z

We currently flat-tow our 240z to the track. We use my brothers Jeep, I forget the model, but it's the SUV version. I am setting my F250 up to become the tow vehicle and we hope to get a trailer in the future. I have done some research in this subject. A trailer of a suitable class will weight about 2500 pounds as will the race car. We need to include the weight of tools, spare parts, extra gas and of course, our own lard asses. Whether the weight is in the truck or on the trailer, the most important issue is brakes. We must be able to stop, safely. Most state laws insist on trailer brakes long before we get into these trailer weights. Most racers end up with tire racks and tool boxes on their trailers. Just like you don't want to keep your truck at maximum GVWR, you also don't want your trailer to maxed out. You need that margin for safety as well as reliability and longevity. A trailer with dual 3500 pound axles comes into play. Now we have a GVWR of 7000, 2000 over our known minimum. This gives us room for add-ons and some left over. Yes you can get a single axle with that kind of load carrying capacity, but, it won't have a drop-axle. The single axle will also require larger tires to handle the load. A dual axle uses smaller tires because they share the load. Our Z'z, like most race cars sit low to the ground, and then we make them lower. Being able to open the door over the trailer's fender is a good thing. Did I mention trailer brakes? I can't stress this point enough. Check with the manufacture of your tow-vehicle. They already know it's safe towing capacity. Don't scrimp on the hitch or safety chain either. We have all heard too many horror stories. I don't want to be the one to tell the next trailer-horror story.

Signed up for the purpose of watching your car come together. We have a 240z that we road race. We took the other approach to building ours. We work on it between races. We race about four times a year and change something between each race. It's a slower build process than your method, but we wanted to start driving right away. Good luck.

Why did I stay with the L24 that my Datsun 240z came with? First off, if I wanted a V8 I would have bought a Camaro or Mustang, not a 240z. Second off, I wanted to do some vintage racing and therefore I'm locked into the L24 block and head, because I chose a Datsun 240z. I'm not saying a person shouldn't do a motor swap. There are plenty of good reasons to swap or stay put. As popular as it is to stuff a V8 into a 240z, it almost seems natural to see it in there. But, the truth is that for road racing, the L24 can provide plenty of power. 250 HP should be easy to get. It's all text-book at this point.

Our new VTO Retro-4 wheels arrived Saturday while we were at the track. These are the 15x7 zero offset. Man-o-man do they look good. We won't be able to mount them up for a couple of weeks yet. Here's a few pictures of them. This type of deep black is always hard to photograph. We bought the wheel lugs with the wheels and that included rubber valve stems and a chrome stem cover. I'm using a bent Q-Tip to hold the valve stem cover in place. The lugs are recessed. The wheels have a tapered steel insert pressed in for the lugs to mate with. This helps the wheels last longer. Chrome plated steel tapered lugs. Because of the rules of the club we race with, we can't use the center caps. Also, we will need to machine the cap off of the lugs to allow our longer studs to pass through. As per our club rules, we have replaced the stock studs with longer studs. The studs must always be longer than the lugs. This allows for quick proof of full thread engagement.

You need a special machine to make the splines, that's not a machine most machine shops will have. The last step in making the splined axle is to harden it. Once it's hardened, your done and you won't be able to turn it again. You will need to have new axles made with the appropriate splines. I'm pretty sure the CV Joints are removable from a splined axle shaft. If you can find a CV that mates up to the stub axle of the Datsun, then you could have a new axle shaft made and use the Subaru CV that fits the output side of the LSD. John took the route of making a new output shaft and using the stock 240Z axles. Less work and for the purpose of club racing with "stock" rules, the car is still stock. There is a shop that makes CV axles to bolt into the 240Z and will fit Johns output shaft. Why don't you buy the used Q45 part and see if it even fits like you want it to. I bought a few different parts thinking they might mate up to find they didn't. I didn't spend a lot learning what did not fit. The WRX axle does not fit the STi LSD. I know cause I bought one.

The WRX axle won't fit the STi differential. You need an STi axle. Read these two threads where we did fit the STi LSD into the 240z. http://forums.hybrid...u-wrx-sti-r180/ http://forums.hybrid...__1#entry745031

You're entering uncharted territory. Good luck.

Our Tokico's did not come with bump stops either. Fortunately for us out polyurethane bushing kit included new bump stops.

When we bought our new Tokico Blues (F&R), the rears had a pipe (tube) welded on as a spacer. It was about 2 inches tall and 2 inches in diameter. I'm only guessing here. We installed them a few years ago.

At this point we're beating a dead horse, but, here is my 2 cents worth. First off, I agree with what I have read. I would have to say that they have a better understanding of the SU than I. The oil damper only effects the response time from when you press the gas pedal to the carburettor reacting. The oil will not effect the fuel/air ratio, the idle speed or how far the carb opens at WOT. We have experimented with oil weight with no noticeable results. We also have a track car that is seldom driven on the street. Around town a thinner oil should offer a crisper response to throttle opening. Please keep in mind that until the carbs are properly cleaned, adjusted and synchronized, you can't compare oils. The rest of the engine also needs to be in good repair and tuned properly as well. For street use, I'm not so sure you would see much, if any, improvements by actually tweaking the carbs. A mild cam would offer better results and you can still use the unmodified SU's The SU (Hitachi built with a license from SU) can be found on many cars including the Jaguar. It really is a good design and doesn't need any tweaking.

I used a hard rubber mallet. You could use a piece of wood as a drift to soften the blow of a steel hammer. The first one I hit with my hand, it went in and my hand hurt. Press the bolts into the flange first.

The Retro-4 is not a LeMans copy, it's a Libre copy. The LeMans wheel was also used by BRE and was popular on Z's and other cars. Real pricey wheel that LeMans. The LeMans looks like a 4-spoke version of the Thrust. I personally like the look of the Libre better, but thats just an opinion.

I don't expect them to be a 100% replica. I expect them to look good on my 240z. I hope that they are light and sturdy for track purposes (road racing). There aren't very many wheels in current production that look good, in my opinion, and are well suited for the track, and are in my budget. Most of the used wheels I would consider end up being outside my price range.

So what's your point? I'm not building a BRE replica or a Bob Sharp replica. If you do your homework, you'll find that Pete Brock and the BRE team used more than one style of rim on their cars. And the Libre was available in 14's. I don't know about 15's though. It's my car and I can put any wheel on it I want.

Why are they not correct? Will they not fit?

We ordered a set of 15x7 Retro-4's today. $210 each at http://www.futofab.com/ I'm excited. Will be running 225/50x15 competition tires. I may not go any faster, but damn our car will look cool in the pits.

No. The older units had a gold or silver sticker on them with all that info. The newer unit don't. You will need to pull the inspection cover and look inside. Count the splines in the output shaft holes. There should be 27 splines to match the output shafts you bought from John. If it's got 27 splines and the gearing you want, the type of Limited Slip you want, and 4-pinions; does the year really matter? They all use the same seals and gaskets.

We weight our stock seat with rails at 35 pounds each. That's actually light for stock seats, most cars have 50 pound seats.

Uhm, now that I've applied the antithetic, what's the next step?

rsicard is correct. The tachometer is part of the ignition circuit. If the tachometer fails the car won't run or won't run well. Jump the two leads together that go to the tachometer.

Correct! Although I haven't heard of anybody needing to change the mustache bar. The R180's are both the same on the outside and it justs bolts in. See this link on how it's been done. You may want to skip to the end to see the finished results. http://forums.hybrid...662#entry908662

We finally installed our STi LSD into our 240z. Was so easy it practically jumped in while stood there and watched. I had said once that I would document the process and post it here Well, I forgot to take pictures, but that would be redundant anyhow 'cause others have done it already. I will confirm the process and the ease of this "conversion" though. I bought a used 06 Subaru STi (not WRX) Limited Slip Differential (LSD). This is a clutch type with four pinions and 27 spline output shafts. I bought the conversion output shafts from John Coffee. I bought the all the seals and gaskets needed to reseal the LSD. I bought new bolts that fit the outboard side of the axle-shaft. These are the hex-head bolts, not the D-head head. I removed the stock R180 from the 240z and then cleaned the outside of everything. I removed the input flange from both R180 diffys. I put the 240z flange on the STi LSD along with a new seal. I used a hydraulic press to press the new hex-head bolts in. They fit perfect and the hex has enough surface area to keep the bolt from turning while you tighten the nut. I replaced the two side seals on the LSD and popped the new output shafts in. I put the inspection cover and the new gasket on. There are a few other O-Rings that I also replaced. I forgot to get a new plastic breather and had to use the old cracked breather. (Note to self: go to Dad's and turn a new breather from aluminum stock.) I installed the Subaru LSD into the 240Z, tightened all the bolts and filled it with the recommended fluid. I took the car for a test drive and ate lunch. It was that quick and that easy. Most of the "I" was actually "we", my brother and I. Before we installed the LSD, we bench tested it to see where the clutches broke at. Real close to fifty pounds if we tested it correctly. The test drive included town driving, twisty canyons and the highway. We did a full lock turn (complete circle) in a parking lot at very low speed. No hopping or chirping. In the canyons the rear-end broke loose under hard acceleration. The before drive in this same canyon would only spin the inside tire and the rear-end stayed on track. The one thing that is somewhat of a concern to us now is that there is a noticeable amount of read-end whine. I know that the 240Z has a reputation for having a noisy rear-end, but ours was never noisy before this. I don't have any reason to suspect that our Subaru LSD is worn out, it looks and feels tight. Has anybody else experienced this gear whine? Our cost in this is somewhat minimal actually. $200 STi LSD $500 Output shafts $ 40 Seals $ 40 Bolts, Oil and other incidentals ---------- Less than $800 for a stock looking LSD. Our thanks to John and everybody else that helped to make this a painless upgrade.

Only if it is a 27 spline unit.

The Subaru uses CV joints and splined shafts. Their "half-shaft" does not "bolt" together. The bolts and nuts that you want are a Datsun / Nissan part. To be specific, the bolts used on the inboard side are no longer available. The part number mentioned earlier in this thread is for the outboard side. We have not tried to use the "outboard" bolt on the "inboard" side. We have not yet found a new replacement. We feel somewhat stuck here, but, we haven't tried very hard either. Unfortunately, the answer does not seem clear. If your old bolts look good, maybe you should try them. Personally, I would prefer new hardware though.

No. I have not tried that swap. I did do some simple research on that once though. Company's such as Quaife that manufacture replacement LSD carriers have separate part numbers for the 240z R180 and the Subaru STi R180 as well as different price tags. If the carriers were the same they would not use two part numbers. I vaguely remember finding the bolt patterns of the different ring gears and making a mental note that the 240z R180 and the STi R180 have different bolt patterns. This brings up the thought, "Could a machinist safely modify one to fit in the other?" I'm not a machinist.