JMortensen

From here: http://forums.hybridz.org/showthread.php?t=128402&highlight=terry I'm getting that a 289 weighs 454 lbs with aluminum flywheel. From here: http://www.corvetteactioncenter.com/forums/lt4-forum/15290-lt-5-vs-lt1-lt4-weight.html Although I don't trust it as much as Terry's info, you're looking at 457 with a flex plate and 497 lbs with a flywheel. It would be nice if our "definitive weight thread had an all aluminum LSx without a trans attached... Regardless, they look pretty close to me, but the 289 (which really should be damn near the same weight as a 302) looks to be a tad lighter.

About this far: http://videos.streetfire.net/video/2000-autox-indisde-and-outside-I-think-my_8051.htm That's about 1" off the bumpstops. It isn't driveable on the street at that height but I put it there when I was autoxing and then cranked the shocks up to try and keep it off the bumpstops. Probably not the smartest idea...

If it isn't warped I'd use it.

Sounds like a stuck caliper to me. I'd disassemble, clean the pins and the holes in the caliper, use a synthetic brake grease on them that can handle high temps and not cook and make sure you can slide it easily back and forth and then reassemble. Not sure about the wheel bearing thing. I always listen for a grumble that changes pitch under load (swerving back and forth). If you don't have that I wouldn't worry about the bearing.

Do you have any tech to back up your assertion here? I thought they were really close to the same, or the 5.0 might be just a touch lighter.

Stupid question: You did turn the pistons ALL THE WAY back in with the caliper tool? Is it a one piston sliding caliper? Did you pull the pins, clean and lube them with synthetic brake grease so that the caliper can move freely?

Have you found any built LD28T engines to see what you can expect? I fear that these 80's diesels suck donkey balls (sorry for the technical jargon), and that you'll put a lot of money in one and not see very good results. A friend of mine built a mid 80s Toy 2LT engine for his 4x4 truck; ported/polished, low compression, big turbo, intercooler, etc. He was hoping to get better than 22RE levels of hp out of it, but after it's all done he doesn't think he got there. It's more driveable than a 22RE with the 35" tires he has on it, but its not a real high output engine by any stretch. Torque is definitely better than the gas engine, but he says you still have to downshift on long hills. I have another friend with a 22RET in his truck, having spent time in both I'm going to go out on a limb and say the gas turbo makes more usable power than the diesel turbo, driving at freway speeds with a 510 on a car trailer at 70 mph is pretty easy. Compare that to more utility when, uh... pulling stumps (trying to think of something the diesel Z would be better at) which he doesn't do a lot of, and it seems like the gas is the way to go. The diesel 4x4 makes sense because he is into rock crawling, but a low power medium torque diesel Z just doesn't excite me at all. As to the trucks, I think either one of them would have been better off with a V8 swap, but they're tough to do in CA. LD28T is not a Cummins or PowerStroke or Duramax or even a TDi where you can crank the boost add propane and make 1000 ft/lbs. Having no experience with it whatsoever, I'd guess if you really went all out I'd bet you might get 170 hp and 300 ft/lbs. I don't think you need much in the way of strengthening the trans or diff for those power levels unless you're going to do drag race style starts with huge tires on the back. What's the point in doing the drag race starts when the thing is going to be slow compared to gas anyway... Maybe there is a newer better Nissan diesel to use? Something that might be technologically better suited to making power?

The GC's can go all the way in on my car with 2.5" ID springs. If the slot is longer one would figure that equates to more adjustment.

Looks to me like the GC has more adjustment, look how the slot goes closer to the center of the vehicle when it's installed. It also has a needle bearing that isolates the monoball from the weight of the vehicle, which is a pretty big difference functionally. Getting the rear camber plates square with the control arm is pretty crucial too if you're welding them in. Bolt in plates don't have a lot of room to spare so you really can't screw it up in terms of placement. In terms of shocks I think you're comparing apples and oranges. The proper comparison would be with GC's Advanced Design shocks, and that would add probably $900 to the GC bill, but they are a lot better than the Tokico Illuminas. Here are some other threads with good info: http://forums.hybridz.org/showthread.php?t=105666 http://forums.hybridz.org/showthread.php?t=150039 http://www.classiczcars.com/forums/showthread.php?t=35036 This thread should really be in the brakes/wheels/suspension/chassis forum.

Sounds like hydraulic failure due to mechanical failure. Pull the boot on the clutch master up by the pedal under the dash and on the slave and see if fluid leaks out. If so, replace both the master and slave. I'd suggest that you also pull the transmission and check that the throwout fork isn't busted or the snout that the throwout bearing slides on isn't gummed up with the wrong grease. I put a clutch in my friend's Z and her pedal effort dropped about 1/2 because whatever grease was used on that part had gotten all gummy and it was really making the clutch stiff. Somebody probably used white lithium or something that cooks with the heat of the clutch and trans doing their thing...

It's tough to understand what you want by reading the post. The thing that sticks out to me that you say you're making changes and they aren't having any effect on the car's performance/times. That to me indicates that your next move should be chassis stiffening. With a sloppy chassis the chassis can actually absorb spring rate and bar changes rendering them useless. The stiffer the chassis the more you'll be able to feel changes as they're made. After that I'd suggest a tow vehicle and trailer so you can jump way up on spring rates and use the tires to their fullest potential. 2600 lbs must be with you in the car... If you don't want to spend much money, spend a little and find some pads that work for you. You might bring some real race pads with you and swap them at the track. It doesn't take that long to do and then you don't have to worry about crashing into somebody on the street because your pads were cold.

It was a spring from Barrichello's car, slow-mo in car video showed it bouncing of the track and hitting Massa in the head. There is a picture of him in obvious pain with one eye wide open and the other swollen shut as he was being removed from the car. The news is that he has a concussion, some kind of skull fracture in the front and also a basal skull fracture (same thing that killed Dale Earnhardt). Pretty gnarly accident, and really a freaky thing too. Video was posted all over youtube yesterday, but looks like they've all been removed today. http://img.mtv3.fi/mn_kuvat/mtv3/urheilu/formulakuvat/kilpailut/2009/755343.jpg

1" is pretty much standard for circle track nuts, regardless of whether they're Al or steel. I'm not a fan of Al lug nuts from my years working on Porsches. We had to have special sockets to avoid beating them up and even then they'd wear pretty bad. Plus its not like the factory Porsche wheels were that light to begin with, so Al lug nuts just seemed like a cheesy "look at how high tech I am" thing to do. On all the race cars we ran steel, FWIW. I do want to say that the angle on the wheels is different from your standard acorn nuts. Whether or not that makes a difference is another story I suppose...

Are you running DRW's? If so, I'd get lugs from them as I think the angle on the chamfer of the rim is different from other steel wheels.

I'm starting to wonder about the caliper brackets. Was it mark or jt1 that had the Wilwood bracket flexing and causing the pistons to wear in the bores??? I'm thinking something similar might be happening to you. Are your brackets aluminum or steel? You may think that it's not related because they leak in the garage NOW, but I think maybe they were damaged by what happened on the track, and now leak in the garage. As to rear brakes and heat, I've run my car with 3 drivers at an autox and at the end of the runs the rear rims were too hot to touch, so I think you can get plenty of heat into the rear brakes especially with the sticky tires Cameron is using.

Seems like the problem now is with the rears. I'd suggest a bigger rear brake upgrade, maybe something with a vented rotor and larger caliper and pad. Just to clarify are you having brake fade or boiling the fluid? Fade = you step on the brakes and the pedal is hard but the brakes don't slow the car. Boiling fluid = pedal gets soft and brakes do nothing. If it's fade, I'd just get the next step up in pads, like a Hawk Black or R4. It's about this point in the pads where you start having to put heat into them to get them to work, so not the best choice for the street. I had a near miss with R4 pads after getting off the freeway. They were cold, and the light was red...

I think you're misunderstanding me now. I think you had it at first... This thread has some discussion of flipping that part around (not over, just so that the strut is further offset to the inside): http://forums.hybridz.org/showthread.php?t=150039 Here are the relevant posts:

Jim?

Glad to help Yessim.

Looks like you have the gold part flipped around the wrong way assuming you're looking for max neg camber.

You can leave it forward like that if you're running CVs. It would be nice to mock up the CV shafts so that you could check for binding and all that as the suspension goes through its motion. I assume Cobra/Explorer CVs will be in the works. What are you going to do to make the outboard end work? Cobra upright? Custom CV shafts?

US Octane rating = RON + MON / 2 Europe and Australia = RON http://en.wikipedia.org/wiki/Octane_rating

I guess you didn't tell them about the time you threw matches behind the fireplace as a kid, eh... Glad to hear that Mat. That's gotta be a weight off of your shoulders, even if your insurance would have covered it.

I only found 2 of the articles. Not sure what the problem is, maybe I'm just brain farting, but I could only find the one linked above and this one: http://www.autospeed.com/cms/A_2159/article.html about undertrays and bonnet vents which I think we've gone over before. I can say 2 things pretty definitively about the first article. 1. I think they're right on when they say that flat bottoms and diffusers won't work unless you get the car low and heavily sprung. 2. The idea that a new car should be more concerned with drag than downforce and that for this reason they might want to run a higher airdam for instance is only marginally useful when applied to a car which has crappy aero design like a Z. Might as well try and get something useful from the .4x drag coefficient, and since the design is so bad we can actually improve drag while getting more downforce by installing a huge air dam. They did suggest that race cars have a focus on downforce at the expense of drag, but I think you might get some people who are inclined to take their air dam off of their 240 after reading that first bit and that would be counterproductive no matter whether the goal was reducing drag or increasing downforce.

Did some more checking and it looks like I can get to about 60 mph in 2nd with the 5 speed. For 70-75 I really need the 6 speed, difference being the 2nd gear ratio of 1.99 vs 1.78:1. That's assuming I'd use commonly available R200 ratios in the rear.