JMortensen

Hi Carl. Welcome. I have to take issue with, I don't think that is right. The turbulence in back of the car is not high pressure turbulence. It's LOW pressure turbulence. The reason the exhaust gets into the cabin is because it is SUCKED in, not PUSHED in. Flow separation, the cause of the turbulence, creates low pressure. Cracking the windows creates suction inside the cabin via the Bernoulli effect, so now you have suction inside the cabin and vacuum at the rear of the car, and that REALLY sucks the exhaust into the cabin. Any little hole allows air back in, and since that air is turbulating all the exhaust, that's what gets sucked into the cabin. I do agree that opening the fresh air vents increases the cabin pressure, and that works against the vacuum which is trying to force air into the holes in the rear of the car. That is why positive pressure works. I am not an expert, I only know what I've read here and elsewhere, but the bottom line for me is that you need some sort of deflector or barrier to create positive pressure, like air hitting the radiator, the windshield, or a spoiler. Just pulling the car through the air creates a negative pressure behind. Why can't you run fast in a swimming pool? Because when you try to move you create a huge turbulent vacuum behind you, and that tries to suck you backwards. Same thing with a car through the air, just a less viscous medium. If you created positive pressure behind, then you'd actually go faster for having it there. We worry about drag, but not about "push".

I work from home. I run a mail order business, http://www.thepetdoorstore.com. The tough part is quitting your real job and trusting that you'll have money coming in to pay the bills. You probably ought to have some money stashed away if you plan on taking the plunge. I quit the most lucrative job I ever had to start this business, and it took 4 months of setting up before I made my first sale, most of that was trying to get the website working. About 3 months in it was getting hard to convince myself that I was doing the right thing. In the end it worked out, but if you've seen me bitching about how much Z parts cost lately that should tell you that at least in my case it wasn't a get rich quick type of scenario. All that said, if I had the choice to do it over again I wouldn't have waited so long to start the biz. It is a very rewarding feeling knowing that YOU are responsible for you, and you don't have to kowtow to some dickhead VP named Jeff or fear for your job on a daily basis, which is what my last job was like.

Let's keep the politics to a minimum people. This thread started on shaky ground, and is edging towards the tool shed. My father enlisted at 16 and missed WWII by a couple months, was a Provost Marshal in Germany post war, then came back to the states and was responsible for decommissioning the Presidio just north of SF and destroying the weapons and ammo there. He had brothers who flew over the hump and did other cool (or should I say COLD) and dangerous jobs in WWII. My brother was on a FFG, the USS Gary, as an EW in the Navy and was headed for Desert Storm, but it actually ended before he got there. Technically he was in the service at the time so he is a veteran of a war, but he didn't do much in the war itself. He also got to rescue Filipinos during the eruption of Mt Pinatubo, I think that was his biggest adventure. I guess I just don't like people telling me when to eat, sleep, or ♥♥♥♥, so I never enlisted...

I believe if you had reinforce the area around the hole, the whole area would have torn out. I had a similar problem where I reinforced the trans crossmember (had to grind on the original for exhaust clearance), and it tore in half right at the edge of my reinforcing plate that was welded in. The front mount/crossmember just isn't strong enough to take all of the abuse. It might work for a while, but it's not a good solution. When you leave soft bushings in the rear and bolt the front solid, the rear is no longer helping to control the diff, because you've isolated the front. So you have all of your engine's torque (600 ft/lbs?) x 1st gear reduction of say 3:1 x rear end ratio of 3.36:1. So basically you're putting 600 x 3 x 3.36 or 6048 lb/ft of torque to that bolt or if you want to be generous, the 8 sq/in of the front crossmember that makes contact with the solid mount. That crossmember is now expected to control both the twisting of the diff AND the lifting of the diff. You've got virtually no slippage going on, and the better you hook up the worse the shock load gets for the drivetrain. I am not convinced that the AZC mustache bar and poly combo helps either. With poly bushings, the bushings still allow for twisting of the bar, which means you're still stressing the front mount. I think the best thing to do is to have some aluminum rear bushings made, and then use the AZC bar. Then you would have a bar that resists bending like a spring which the stocker is meant to do, and no bushings to deflect. Even better would be a "bar" that was made to resist torsional deflection. The tall flat shape of the mustache bar makes it like a leaf spring. Just changing the material to something not springy doesn't mean the shape is optimized...

Daikin is not the OEM supplier. Their pressure plates are fine and they make a CHEAP turbo "HD" pp which is a nice upgrade for turbo guys (Bastaad525 was running one before he sold his car), but the clutch disks have a plastic hub. I've never seen the plastic hub fail personally, but I had a Nissan Master tech warn me about Daikin disks. It's been probably ten years, but I am pretty sure he said Paraut was the OEM manufacturer for Nissan clutches.

Why didn't you just get a NA cam? I guess if you had to have the transportation I understand, but it seems like a shame to go through all that hassle then put it back. I'd be looking to go back to the solid lifters, and find a bigger cam so you can use that Holset you got on there to its full potential...

I would start by getting the Zedd Findings replacement floor pans. The ones you linked to didn't look like an exact OEM replacement to me. The problem with floorboards is that a body shop kinda have to make them fit. If you can provide them with an exact fit replacment, the labor involved will go down considerably. Still quite a bit of labor there don't get me wrong, but it would be a lot easier job with exact replacement parts.

Yeah, I got the 2.5" spacing on the balance bar. Tilton apparently makes 4 different balance bars, all with different spacing. I like the way yours came out so I am doing it roughly the same way. Right now I have the plate for the masters done, and I have the original pedal box cut up. My plan is to bolt the masters in place on the firewall, then bolt the pedal box up, then tack everything together. That way it is all aligned correctly. Then I'll pull it back out and add some stiffeners.

Looks like according to Wilwood the clevises should be about .2 to .25" from the tube, according to Figure 4: http://www.wilwood.com/Products/005-PedalAssemblies/Pages/techtip/pedaltech.asp

Everything is straight and lines up nicely, but when you push the pedal the balance bar moves around quite a bit. I guess I just want to make sure that is normal...

I just looked at Cary's again, looks like he used a heavier plate and then cut the hole in the firewall so that he didn't have to make a corresponding plate for it. I think I may take what I have now, use it as a template and do the thing over in that .103" plate. I've done all the hard work, getting all the holes to line up and all of that...

Are the connectors that attach the master to the balance bar (I guess its a clevis?) supposed to be right up against the tube that gets welded into the pedal? It seems like they should be close, but I'm pushing my pedal and the balance bar is pivoting not just left and right, but also up and down. I don't think this would cause any big problems, just doesn't seem like it's right. I was really surprised at how much adjustment the balance bar has! Doesn't take much... Also starting to look at the firewall and wonder what should be done there. My big idea right now is to cut out the area where the stock master bolts up, and make a little plate to fit in there that has the hole pattern for the duals, then weld it right into that little square. It's a bit confusing because there is the level of the masters respective to the pedal, and that height has to be transferred correctly onto the firewall, otherwise it won't all plug together. I suppose the other possibility is to just hack up the firewall so that the masters just sit on the pedal assy and don't touch the firewall, but I'm not so sure I like that idea, especially since I used that .040 sheetmetal...

Also, Lunar, I got the Tilton balance bar and it looks like those washers you have are just not necessary. I don't think they'll hurt anything, but they don't really do anything other than perhaps keeping dirt out of the monoball area inside. I think you need to remove the jam nuts on the outer ends of the bar on both ends too. Otherwise they will prevent the balance bar from working.

OK, I cut the brake side of the pedal box off where it sits against the firewall. Trying to figure out what to do here. I have some .103" plate, and I have some .040 sheetmetal. My instinct is to build the thing with the sheet. I checked the thickness of the original sheet and it was .050, so a bit thicker. I don't have anything that thick, and the .103 is just so much overkill. I really think that the thinner stuff will be OK since this is the part that hits the firewall. Opinions?

I pulled my pedal box out again today and took a look. It appears as the pedal pivot to master cylinder pivot distance is roughly 3.25", and the pedal pivot to the middle of the pad at the bottom is roughly 13.625". So that means the stock pedal has a leverage ratio of 4.19. Not a whole lot of leverage. I see cary talked about moving the pivot up ~.5", and that yeilds a leverage ratio of ~5:1. So I guess I'll follow his lead on this and drill the new pivot hole up about 1/2" inch. I was kind of hoping that the ratio would be closer to 6:1, but I don't think there will be enough pedal stroke if I move the pivot too high.

Poly is a lot stiffer than rubber. I'd go poly on the rear control arm on a drag racing Z for sure, even if it's just for the rear control arms.

That's probably assuming the cowl isn't barely attached to the firewall due to rust. Mine was and I suggest that anyone who is going to triangulate the strut tower bar to the firewall should check their cowl before loading it too heavily...

Standard headgasket is 1.2mm. Felpro is .040 or 1mm. You can do a .8mm with a HKS by pulling the layers apart, I think each layer is .020 thick. If you start with the 2mm gasket, then you can get 2 .080 thick gaskets or 3 .060 gaskets out of it for the cost of one.

I think wheel hop has been discussed, and I think control arm bushings were a primary factor. You might search and see if you can find any other threads. It's been a long time, but I know it's been dealt with.

Usually one would install 8" springs instead of 10" springs to get more room. If that is your plan, then you might want to install some longer bumpstops, because an 8" 225 in/lb spring will coil bind on a Z strut before the strut bottoms, and that's bad.

OK, I stand corrected. Sorry for passing bad info.

Yeah, I did most of it. The machinist who originally installed the larger intake seats did some work in the bowl on the intakes, but that was about it. The rest I did myself. I focused mostly on the chambers, unshrouding the larger valves in the E31 head. The ports aren't opened up very much at all. There are lots of threads on L series headwork, and a lot of people go much farther with it than I did. Check out BRAAP's head building thread in the L6 forum, get a copy of the How to Modify book, and STUDY the pictures in there. Take your time. I might be one of the minority on this issue, but I think just about anyone can do a decent porting job, just don't go insane with a grinder and I'm sure you'll do fine. 2" rollcage? Prepping for WWIII???

The LS also has the following weight advantages. The camshaft is a single unit, not a DOHC so that's 1/2 the weight, and it's 1/3rd shorter. It's located right above the crank, keeping the weight low. The heads aren't sticking straight up off the crank like an inline 6. I don't know what the angle of the V is on the LS, but if it was a 90 degree V8, then the heads would be leaned over 45 degrees. So lower center of gravity, less weight in the 16 vs 24 valves, less cam length and they're lower in the head. As was previously stated the V8 is shorter in length and fits further back in the chassis than the RB. Both engines can make a ton of hp and torque although I'd think its a pretty safe guess to say that you can ultimately get more out of the V8 if you built both to the extreme. If you want to turn, the lighter weight, lower weight, and shorter weight of the LS is a pretty clear winner.

Yes it is possible to cut the tube and retap the threads, this is discussed in the sectioning FAQ. In my opinion I think it's a LOT easier to just section it the normal way, because cutting the threads straight requires a lathe, and chucking the strut in a lathe is not the easiest thing to do.

You can also cut the stock stacks out of the air cleaner. I think ZTherapy did a test a couple years back and there was a negligible difference between the stockers and the full radius TWMs.