tube80z

They are worth the 30% just for the CAD models of all the hardware they sell. Another company I've been very happy with is MSC. While I haven't bought anything in the last couple of years they always seemed to have it in stock and shipped it very quickly

I think one thing you have to temper the don't use braided line for all the brakes is probably based on hose that was available 30 to 40 years ago. Someone respected said it and then it was passed down as lore. I think you have proved modern lines are fine and it's really up to the owner in what they want to run. The one area where a single master cylinder can help is when they use fast fill. That's where they use a stepped piston to move a lot of fluid initially and then it steps down so you have even force between the axles. I don't know if fast fill is the right term but that's what I'd heard from the McLaren/Ferrari spygate scandal where they had redacted court docs but only drew over the top with black rectangles so it was easy to remove and secrets were spilled.

The flow by the time it gets to the back of the car is a total mess. If you want to extract a better option would be to create a vent behind the spoiler and wing to help extract any high pressure air. Ideally your duct would be on top of the tire somewhat forward of centerline. This is where you'll see many of the fender louvers on race cars. This could all be done and contained in a duct that can be bonded into the inner fender. I'd run some pressure taps to see where the high pressure is and if the differential is enough either for the side exit to work or a rear exit. You don't need to drill any holes in the car to do this. Another option is to make sure you have the front of the tire/wheel combo not exposed to the airflow. You can create spats or s-flaps that can be used to aid in extraction.

Makes perfect sense to me. If they haven't been built maybe something to look at. Cary

One thing I add to these are safety washers on the outside of the rod ends on the strut. In case you need a link here you go, https://www.amazon.com/Safety-Washer-Prevent-Twelve-Through/dp/B07RB7RWMB. I think if you search around you can get a better price but it's been years since I've bought any. Cary

For the lower mount you can probably save more weight by doing away with the bolt that goes all the way through and rotate those mounts 90 degrees and it can be a double shear mount with two smaller bolts. I know that's not much weight but every little bit helps. And ideally use a toe-link rear arm design. Just a thought.

I'll take a moment to reply to the tone of this comment. On HybridZ we (admins) are not suppressing feedback about vendors. What we are doing is trying to make sure a thread stays on topic so that future users will be able to use search and find good quality content that is helpful and relevant to their search. Ideally the original thread should have stayed on topic and a new thread started about vendor feedback. A link could be left in the technical thread and both discussions could happen and be more likely to be found be search in the future. Hope that helps, Cary

I have locked this topic as it has strayed far from the original post. I will leave this up and if there are relevant replies that address the actual topic I will approve. I think there is enough good information to leave it rather than sending it to the shed.

I guess one question is how low RPM do you plan to drive? When racing I'd think most of the time you'd be above 2500-3500 on the low end and a light flywheel will be helpful.

I used to street drive a 10 pound flywheel with no problems. I personally think it has a lot to do with you set the bite point where the clutch hooks up and this can vary widely between pressure plates. That requires some fiddling between master and slave cylinder pushrod lengths. This isn't so much a problem for the inline 6 because they make decent torque off the line. It also depends on clutch disc material and if it has a sprung clutch hub.

They do. But I've seen this interpreted different from time to time. My car has a separate metal box over the cell and the lines where they are in the cabin. I got busted at a hillclimb (GCR rules) that I didn't have metal over my fuel lines (braided hose didn't count) so I did what any normal person would in the middle of nowhere. I built a cover using aluminum foil and riveted it to the floor here and there. Technically it was a metal cover. Rules were changed after that to be more specific.

Congrats on the first drive. You have an amazing project. I've helped a number of friends get theirs running but yet to have my own so I'm more than a little envious. Cary

This is done time-to-time on various suspension bits, like a-arms. The one problem is that any bending will cause bind in a setup like this. So while it may have really low static friction when you put lateral and longitudinal loads into the bushing/bearing. Anyone who used the old Delrin/Al replacements up put on caster or toe in the rear would see that it often lead to wear patterns on the bushings. While the stock rubber bushings may not be ideal for our cars the poly versions are often upgrades. The downside is that unless you take very good care of them they'll lead to stiction (friction that Jon mentions) and that can lead to an abnormally harsh ride over certain sections of road in a street car or lead to weird handling irregularities. I'm not saying all poly bushings do this as there are clearly really good one. But unless you give them care and feeding you may run into some down sides. Newer street cars still use rubber bushings, which I used to hate. But now modelling has gotten a lot more refined and rubber bushings are designed to limit flex in one area and allow more in another axis. Think of running into a pothole and the suspension has a little extra lateral movement that allows for the jolt that you normally feel to be reduced. So you get a win/win. And even sportier models often use the equivalent of spherical bearings (BMW M cars) but they have proper seals for long term use. Hope that helps, I know this is somewhat off topic to the original post. Cary

The spindle-pin bolt doesn't rotate. If it does then you have bigger problems. In a stock car the inner bushing tubes are all compressed by the spindle pin nut against the strut. The rotation comes from the rubber actually winding like a torsion spring. That's why it's typically stated in the manuals that you need to torque at ride height or off jack stands. As Jon mentions with poly the inner bushing tube is locked in place and the poly slides around the inner bush tube. A rod end setup works exactly the same.

For a friends street car that used the toe-link design and rod ends on the strut side I used a special capture washer on the outer side so if the ball in the rod end is to pop out the control arm still stays attached. On the inner strut side I used a rod end spacer that's similar to a conical design. The bolt was torqued to 125 ft-lbs (grade-8 torque spec) and a Stover nut was used. I used the same setup for a number of race cars but used a nylock instead of the Stover to make it easier to work on at the track. One thing I should point out is that I used a properly long 5/8 fine-thread bolt. Meaning the rod ends were all supported by the non-threaded section of the bolt. I had to find some really long bolts and cut off the extra threaded section. I see a lot of the kits sold with bolts that have rod ends on the threaded sections, which shouldn't be done.

The idea behind the spindle locking pin is that it is an extra safety mechanism. If you lose one or both nuts and washers on the spindle pin it can't slide out, assuming you have one that can actually be removed without the use of a large press. I have used a bolt in mine an no pin or similar mechanism and have no plan to ever again. That said I do regular bolt/nut checks on my car as part of their maintenance, which a large portion of the public think is either silly or a complete waste of time. Probably the same people who shouldn't be driving an old car without all the modern nannies or insert version of onstar they need when they lock themselves out of their car because it doesn't need a key to start.

On an old formula car I used to have it did the same thing sitting overnight. I found that the supply line to the pump had enough oil in it to supply the bearings on start up. I always would spin the engine a few cycles without ignition or fuel turned on to build pressure and then start. My system had to be ran for some time to get the oil temp up and allow the pressure to come down to a reasonable level. Cold my system would make close to 100 pounds of pressure. Once everything was hot that would drop to about 65.

The problem with this when you adjust your ARB or turn the car you also change the motion ratio. I also don't know if the ARB would act as a filter for some of the frequencies the damper would normally see.

Morgan Smith, who has the red Z with the large IMSA flares was running 550 lbs/in springs on his Z and using the 15 inch GY FA tires and the bushing died after a season. He was complaining the car was inconsistent and when he took the strut off I shook it and it rattled. The top busing was toast.

You'd be in revalve territory or very close. Just as an FYI try searching for "used race shocks" on ebay (https://www.ebay.com/sch/i.html?_odkw=penske+shock&_osacat=107057&_from=R40&_trksid=p2045573.m570.l1313&_nkw=used+racing+shock&_sacat=107057&LH_TitleDesc=1) You can get a few that aren't in the best of shape for 30 to 40 dollars and you can decide if this will work for you. I bought some Penske 7300 adjustable shocks with base valves, two extra sets of pistons, VDP pistons, and a s-load of valving shims for $1400. I bought new coilover tubes from Allstar, scored on a used shock vice, and fill cup. To do this on struts would be more than I have in the rest of the car.

Unfortunately when I saw it I wasn't smart enough to know what I was looking at. A friend explained it later and they called it a Preston strut at the time. When I asked what the hell that was I was told Don Preston (maybe faulty memory) got fed up at IMSA and used coilovers that were mounted to the lower control arm and then hooked to the strut tower but used an old strut as the normal top suspension element. This was all to do with rules that said you couldn't do this or that. I can't remember if this was a 200SX Datsun or an RX-7. Both had a live rear axle. I think I was around 15 at the time helping my dad's friend who raced a super vee. I only noticed this because we were pitted across from each other. I wish I had pictures. I tried Google but I can't seem to find any. It may be one of those things that are lost to time.

I know this has been the prevailing wisdom but it makes no sense. When it's wet the weight of your car and the suspension don't change. That's primarily what the shocks work with. While it's true the grip is lower it's the same as saying I need to valve my shocks for 50 MPH or I need valving for 100 MPH. I can anecdotally share I tried softening everything on the wet and ended up going back to my normal rebound and compression on the DA shocks I was using. I did remove the rear ARB and soften the front ARB but that was it. Left springs alone. I also suggest running your normal hot pressures when it rains.

In XP suspension is free. That means you could use an old strut and stay that way and add a rocker and use real coil overs. You won't get the advantage of an SLA but you wouldn't have to pay tons extra just because you have struts. This would be more like your ARB project as far as work goes.

There are two versions of these spacer/steering arm out there. The old version has too much of a pocket in the steering arm and can break if you use them on track days and autoxs. The other problem is they are flat. So any spacers under them aim for the wheel. A friend tried these and they wouldn't work when we went for enough of a spacer to lower bump steer. Personally this is one item I don't think I'd use aluminum for. One other general item I'd add around the spacers is to weld it to the steering arm and then use thin spacers to finish of the bumpsteer. This is stiffer then adding a spacer to the top and a long bolt torques down.

Hi Clark the rod end works better in most cases. If you have a roller bearing it can still bind when the arm flexes in the middle. A common problem people run into is they install collars to hold the ARB in place but when it bends these hit the inner ARM mounts and cause bind. Give it 1/8 to 3/16 space and the binding stops. The rod ends are also great on older cars that may not be as stiff as a tubeframe chassis. I stole the idea from a Riley & Scott trans-am car but have seen it all over the place. The Realtime racing Acuras that raced in IMSA used this method as did a lot of older BTCC cars. All you have to do is mount a normal bar in a poly mount that's all greased up and see how much force it takes to move. Now jack on the end of a frame rail at the front of the engine bay and try again. I usually saw very different numbers. Sometimes 50 or more pounds from a fish pull scale. With rod ends that have been burnished it will be in the 2 to 3 pound range. That's free grip and helps make the car more consistent. Cary