katman

If you want all the tricks to racing with stock calipers and drums go visit the Datsun forum at improvedtouring.com. Because of rules limiting ITS cars to stock calipers and drums, and the ARRC being held at Road Atlanta with it's nasty downhill braking zone for 10a (thanks Mr. Panoz, %$@#*), you'll find the last word on making the stock brakes work over there. But I'm all in favor of vented font and rear disks if the rules allow it.

We ran them on our ITS race car (basically stock engines) back before we knew anything. Going to a single exhaust gained about 10hp. YMMV. With dual megaphones coming out the back at 108 db they sure sounded sweet, but alas, winning races was more important than how cool we sounded...

"Simply make a form out of steel by grinding it to shape. Make it the size of the inside of the tube you want. Once the form is made, grease it up as well as the inside of the tube, then use a press or vise to press the tube over the form." +1 That's what I do. On a L head you'll need two of those mandrels because ports 3 and 4 are different shape. Now as to sizing a header, on a N/A motor you're trying to coax everything you can out of the cylinder during the exhaust stage so knowing the cam and application is everything. On a turbo, well it just ain't that important IMHO. Corky's book would for sure be a good starting point, although you can make silly horsepower even with the stock manifold.

"so I'd like some info as to their limitations before I chance it" Seems like the limit is here: 1/4 mile 10.629 128.47 MPH 1.540 60' Dyno 1/27/06 NA 404.5 RWHP/405.1 TQ 150 dry shot 517.3 RWHP/588.9 TQ FEA of this part will show it failed exactly where it should have, the minimum section with the highest stress concentration. Even with a material non-linear FE analysis you'd want to run a series of multi sample tests to determine the scatter in the failure load. Then there's the high and low cycle fatigue question. We're talking really big bucks for that test program. There's only so much load you can put through a certain sized peice of metal, unless it's made of unobtanium. Looks like jbc3 found that amount. Bottom line- any time you put on big tires, slap in big engines, or go racing in a straight line or around corners even in a mostly stock car, you've signed yourself up for this sort of thing. Let's be careful out there...

Maybe for American engines the damper is press fit onto the crank, but not any L series Z I ever worked on. There's a big F'ing bolt you know that holds them together. I've had 20 different factory dampers on 20 different factory cranks. Never needed a hammer or installation tool. The FSM's I have here don't say anything about an installation tool or requirement for same (removal tool yes, install tool no). Me thinks the aftermarket suppliers don't know L Series motors.

You'd be hard pressed to see the beach marks from fatigue in those photos and with that post failure rubbing. Regardless, I'm with JohnC on this one- there are no failure proof race parts. The other thread on the AZC control arms is another example. Coincidently an old friend sent me some pics of a fractured flywheel from a Z32 turbo the other day (proly on the net somewhere). Made a real mess of the car. You walk away from stock, and some of us are waayyyy far away from stock like this stub axle case, stuff is going to break, especially if you ain't looking at it.

Try Eddie Radatz at ERadatz Motorsports in Marietta. 770-926-6621 I think. Or Balanced Performance in Suwanee. They're online.

We ran out the side on our ITS race car. I don't know where you'd stick a muffler for a street car. I wouldn't reccomend it unless its a track only car.

What engine mods? On an L28 I can't think of a good reason to run duals. What header is best depends on what your mods are and what you intend to do with the car. If you just want the sound of a header than by all means by the cheapest thing. If you really want something for performance then you need to give a few specifics.

We used to use a restrictor in our race motors before we decided that it was just plain stooooopid to not use a thermostat. You want the engine to heat up to optimal temp as fast as possible and maintain said temp. Thermostat, duh. We ran a 190 in the ITS motors. 160-170 too cold fer sure.

"Would not facing or turning the wheel/rotor/drum mounting surface in a lathe also increase strength? Properly turning the surface and blending that cut to the inside fillet radius which keeps the rotor hat on center concentric." Nyet, not a strength problem but a fatigue problem usually started by a rust pit or similar stress concentration. Turning on a lathe leaves tool marks in the direction cracks want to start. If you want to polish the radius use a dremel and polish the material 90 degrees to the direction that turning does. I've had 2 stub axle failures on an ITS 240Z. Two different crack locations. First one on wheel centering boss fillet, second one at the root of the splines on a 240Z stub (280Z stub has bigger spline section). Neither was catastrophic because the driver caught it before the wheel came off. However, several races after we sold the car it had another stub axle failure that put it into a wall and totalled it (new owner was told it was due for an inspection, which they didn't do). I attribute all those failures to running a welded diff, and using junk yard stub axles with no prep. Next car I built we polished and shot peened 280Z stubs and ran a limited slip diff and never had a problem. I have also had fellow ITS racers break them. It happens. But JohnC has it right. YMMV.

I visit zcar.com for the same reason I visit the local dirt track about once every ten years. To remind myself why I don't go there all the time.

1. The only substitute for cubic inches is cubic dollars. 2. Adding Turbo's is like adding cubic inches. 3. Carburetors are just semi metered fuel leaks. 4. Decide on a realistic budget. Tell us how much you want to spend, then we can tell you what you can get out of it.

We set up race motors to have no shaft showing and no chain slack. In fact we use a big pair of Channel Lock pliers to pull the curved guide toward the straight guide when we tighten the bolts holding down the curved guide. Otherwise your cam is jumping back and forth all over the place...

How bout a header that produces a 15% increase in power?

You can get a one off custom copper head gasket in practically any thickness for less than $100 from Gasket Works, Richard Clark Gaskets, et al. I hope you weren't planning on making a head gasket out of aluminum.

Looks good. You'll want to head on over to the improvedtouring.com Nissan forum for killer ITS advice.

Great work Mike et al.

Very nice. What engine mods are these going behind?

I just stick a Phillips head screwdriver thru the holes drilled in the brake rotors.

Custom header that actually works like a Stahl: $1500. Rebello stepped header used to be $1200 and was just a copy of the Nismo Comp, even made by the same guy. YMMV

"The fact is I've never aligned ANY racecar (and I've done a few) that had 0 toe in the back. " Guess you never aligned a anything with a solid rear axle. Yeah, yeah, anything with a solid axle isn't a real race car.... I'll take a look over the other thread when I get a minute. If it's like most of your work it's proly thorough and accurate.

'if faster is 1/4" toe in, I'm going to set it so that it goes faster... " Absolutely, but we need to figure out how to make zero handle like 3/16, so yer not "draggin them tires around" . Ultimately that *should* be faster. Anyway, we eventually dialed out the rear toe to zero in the ITS cars with no trailing throttle or on throttle oversteer, the usual symptoms toe in takes care of. Still treating the throttle like a switch- the fastest way around in a 200hp ITS car. With real horsepower a smidge of toe might be necessary. And you have real horsepower. Heck, if somebody gave me the dimensions of the stock control arms I could do the analysis, just haven't got a "Round Tuit". If you look at the MOI of the stock arms about a vertical axis I'd bet it's way bigger than a 7/8 tube. The 1-1/2 .120 wall that these are is much better, but again I'd want to see the numbers. Also, with the 7/8 tubeular AZC arms they're triangulated better than these or stock so the inboard-outboard running structural members aren't in bending, but tension/compression.

"You say this, and then you make some mistaken points to back yourself up" I don't recall actually making any points to back myself up. Lets see the analysis comparing the bending moment of inertia at one of the inboard connections of this new design with a stock one for example. I don't think people give the stock one the credit it deserves. If there's an application that "tears out the spot welds" on a stocker then I'd sure want to see some analysis for the aftermarket replacement. "This design is "on the car adjustable". That means that you don't have to pull the spindle pin to adjust it, which also means that you don't have to rotate the rod ends to make adjustments. My understanding is that there is a threaded tube captured inside the arm which can be rotated to move the rod ends out." Ah, I see. I stand corrected. Still rather have the adjustment at the inboard end where the loads are smaller and the resolution would be greater, but clever if it works as you say. Regardless of where you set your toe, it just isn't something that gets changed all the time. We'd check it occasionally but only have to adjust it after wreck rebuilds. Look, I'll say it again, this is a very nice part. But saying "it's way overbuilt" doesn't prove it to me without some supporting analysis. I still don't understand this fascination with adjustable LCA's (especially up front) but to each his own. The stockers ARE ugly, and I'm all in favor of a nicer part, but it seems like every other week another adjustable LCA comes out and I have yet to see somebody say "okay, here's the strength of the stock part, here's the loads we assumed, and here's the strength of our part." What are you running now for rear toe Jon? If it's more than 1/32 in then I gotta keep working on you.

"Have any of you looked at a STOCK arm lately? This thing looks way overbuilt when compared to a stock arm" Well that just tells me you don't know what you're looking at when you're looking at the stock arm. If these things were "engineered" then I'm sure the builder won't mind posting a link to the stress analysis. I try to stay out of these LCA threads because frankly I can't answer the question why?. I've done a ton of road racing with Z's in various classes and can't figure out why people spend so much time on agonizing over an adjustment that happens once in a blue moon and can be made with a custom inner bushing without putting threads in combined tension and bending. Not to mention the fact that this particular design uses the close coupled end of the control arm which, combined with having to use 1/2 turn increments to the rod end, limits how precisely you can change said toe. Very nice pieces- no doubt about it. But I'll keep my stockers and spend the money somewhere that will actually make me faster. But that's just my opinion.