JMortensen

OK thanks, I stand corrected. I thought the 240 engines were allowed 9.5 because that was stock + 1mm overbore. I didn't know you could mill the head to get the compression on a 280 engine. Still think with a cam and the extra point compression and all it should be fairly easy to beat the ITS motor. That stock cam sucks. When I was deciding to change mine I read so many stories of "no bottom end" or "don't go too big" etc that I was really afraid to change it. Going .490/280 on my cam made a nice difference on the SU's, and IMO is really the minimum necessary for triples.

Well I'm only warning you because I used to work for Randy's R&P and used to sell LOTS of diff parts to F body guys who had broken their 7.5's. 27 spline axles, ring gear SMALLER than an R200. I think the R200 might be a better bet than the 7.5. Don't get confused by "10 bolt" either. There is the smaller one 7.5 or 7.625 used in the Camaro and S10, and the larger one 8.5 or 8.6 used in the Caprice and trucks. The bigger one is a lot stronger, but still has c-clip axles. The only thing worse than c-clip axles are c-clip eliminators BTW. Just check it out before they start narrowing it. Do a little searching on the web for Camaro axles and see what kind of stuff you find.

Sprung puck clutch disks don't make any sense to me. The whole idea of the pucks is to have the MOST aggressive engagement possible. Then you put springs in there which are going to supposedly limit the chattering. From personal experience I can say that with my ~230whp NA engine I've replaced clutch disks because the springs were loose. This happens because the springs get overworked. I don't drag race, so in my case this is due to shifting hard on a road course with slicks. Putting springs on a puck clutch is just asking for the springs to fail IMO. Especially since most of you turbo guys are drag racing. Strangely I have to admit that to date I haven't heard anyone say that they've had the springs come out of a puck clutch disk. I would say get an aggressive pp and a mild clutch disk. The pp's available should be strong enough to clamp down a stock disk hard enough to hold down LOTS of power. The puck disks eat up everything, so IMO they should be the LAST RESORT. When you have the super aggressive pp and the clutch still slips, then get the puck disk. You might have to replace the disk a little more because the springs go bad, but if you put the puck disk in you'll be replacing disk, pp, and flywheel at about the same interval.

That TA has a 7.5 diff in it, right??? I'd say forget about the 7.5 inch rear axle and get something decent under there like a Moser GM 12 bolt or a Ford 8.8 or 9". That 7.5 is a hunk o crap and all the money you'll put into it to get it narrowed could be used to buy a custom diff. The Moser 12 bolt is a good rear axle with 9" housing ends and bolt in axles (no more c-clips) and you can get 33 or 35 spline axles. Whatever length you want, I think the Moser axles come double drilled with Ford and Chevy bolt patterns. Ford 9" has pinion angle issues, but I think there are a few successful installations here. The 8.8 would be similar to the 12 bolt but I haven't seen any bolt in axle upgrades (I'm sure they're out there though). Congrats on the engine/tranny! That is a sweet deal.

Regardless of who wins today, I JUST HOPE THERE IS A GODDAMN MARGIN!!! All of this posturing for lawsuits makes me want to smack someone.

I agree with the above, so I think the proposed engine will fall somewhere in between. I really think the stock cam is not very big, and I would encourage anyone doing a buildup to get a bigger cam. Maybe this is true, but I don't think that's what we're talking about here. You're comparing an ITS 280 engine with 8.3:1 to a 10.8:1 forged piston 2.8 engine. From the original post... And now my issues with the idea: Max N47 head...hmm. I wouldn't just use the Max N47 head. Definitely install the larger 280Z valves and port the head to make them work, and now you've got a high compression engine with a good chamber design. Forged pistons doesn't sound budget to me. I think the things missing here are PORTING the head to fit the bigger Z valves, and a bigger cam. The SU's are going to be a restriction too. Get a set of ported SU's with the above and I think you're talking 210-220 bhp. As Drax said add triples and gain another 30-40 hp. I think if this is done RIGHT with SU's and a cam and some headwork it should be NO PROBLEM to exceed the ITS engine...

I just read an AP article on Yahoo news I think it was that 50% of Democratic voters believe that their vote will not be counted correctly. In light of this astounding statistic, I'm not surprised that they believe the war is illegal. Seems to me if you tell a Democrat anything long enough they'll believe it. Kinda like "the govt should provide healthcare for every citizen" or "when people are disadvantaged the govt has a responsibility to fix it" or "raising taxes helps poor people" or "corporations are evil"

That is called "drum-in-hat" and I don't think it's a good idea for Wilwoods on a Z. The whole idea of going to the aluminum hat is to reduce weight, and putting a little drum brake in there gains you all the weight back and more, plus a whole lot more complexity. Also, the aluminum hat would have to be machined to be used as a drum, and I don't know how well the aluminum would like being used as a drum (Z aluminum drums have a steel liner where the brake shoes ride). If you have to have a handbrake, then take Owen's advice and use the 240SX or Maxima brackets and ZX calipers would be my suggestion. The drum in hat is just too complicated, adds too much weight, and doesn't seem to be very compatible with the Z.

Maichor you and Terry have inspired me to tell my Buster Keaton-esque story: My first car was a '79 Mustang 4 cylinder, smurf blue with smurf blue interior and all of about 70 hp. I bought it from the high school auto shop. Someone had donated it to the school as a tax break I guess. It was that bad off. Man I hated that thing. Anyhow my buddies and I used to go to this little lookout and drink and talk and hang out. It was basically like driving up a fire break to get there, it wasn't really even a dirt road, just a firebreak. I really had to work the get the old Mousetang up there. So this one Saturday me and a friend were the last ones to leave (about 3:30 AM), and he says that instead of going back down the way we normally do, we should try going up the hill farther and see if there is another viewpoint. So we did. We kept on going up the hill til we got to the top, and then the headlights just pointed out into blackness. My friend gets out and looks, and says "Oh yeah, there's a trail there... go ahead." I start to inch forward very slowly, and no matter how far over the crest I go, I can't see any trail yet. I stop. I roll down the window and I say to him "Dude, how steep is this frickin trail?" He says "It doesn't look that bad, just keep going." "OK....." I say. Finally I see the "trail" when my nose is pointed down at what memory says has to be a 45* or 50* angle. The car is just on the verge of sliding even with the wheels locked. I'm about to shit myself. There is no way to back up, it is way too steep. So down we go. I'm trying to go as slow as possible without having the car get way sideways and possibly roll. As soon as the car starts to roll it just wants to pickup speed, and when I step on the brakes they just lock and the car starts sliding. Off the trail. I am completely out in the weeds as I continue down. We go down the hill probably about a couple hundred feet, and then it starts to level out a bit. Not even close to level, but now I can use the brakes and I'm regaining some measure of control. Whew!!! Glad that is over. But now the trail is GONE and there is no way we can get back to it. We grab a flashlight and jump out to take a look. Looking down this hill we see a road. We are at the back of a new development, and directly below us is a plot being leveled to start construction on a big house. Unfortunately, about 1/2 way down the hill there is a big concrete drainage ditch. We are not out of the woods yet... Looking around we find a piece of 3/8" plywood. So we take this back up the hill and lay it over the drainage ditch. I jump back in the car, and my buddy directs me to the plywood "bridge" we've just made. The hill is still pretty steep where the drainage ditch is, so it's not what you'd call a smooth transition. My buddy advises that I should "Go fast because you don't want to high center." Jesus... OK, here goes.... I hit the plywood and CRACK!!! it immediately snaps in half. My front wheels make it over then the bottom of the Stang SLAMS into the concrete wall of the drainage ditch. Momentum drags the bottom of the car over the concrete and I make it past the ditch!!! Now I'm in the clear. I make past the ditch and I'm almost down the last part of the hill. There is absolutely nothing stopping me from getting down to that nicely leveled lot! Wait a minute, I'm 17 and driving in a NICELY LEVELED LOT AT 4 AM AND I JUST CONQUERED THE MIGHTY DRAINAGE DITCH! IT'S TIME FOR SOME DONUTS!!! I get down to the lot and immediately start a wide celebratory donut at about 25 mph. About 1/2 way through the first donut I hit a big mound of dirt about 3 feet tall! I never even saw it. Just countersteering along in my big victorious slide when WHAM!!! Instantly the left side of the car is airborn! Out of pure luck the car didn't roll. I skid to a stop and my friend comes running!!! And he says, "Dude! What are you f#cking stupid!" I just looked at him like "Did you really just ask me that?" Another disaster narrowly avoided. But the ordeal is not over... We go to the driveway and realize they've put a fence around the lot and a chain across the the driveway. What to do? Simple! Find a sign post that has been pulled out of the ground and beat the chain down. Duh! So we find this piece of pipe with about a 20 lb hunk of cement and proceed to beat on the pipe clamps that the chain is attached to. Surprisingly, the clamps do start moving down the pipe, and our nemesis the chain slowly begins to inch down the pipe. About 1/2 hour on each side, and we've beaten the chain down to about 4 inches above the ground. We're going to get out of this!!! We're going to make it!!! It's just starting to get light out by this time. We're both tired and dirty. We've beaten the hill. We've beaten the drainage ditch. I almost rolled the car in the construction lot. We've defeated the chain. It's time to get the hell out of Dodge. We jump into Stang, and it's 4 banger springs to life in the way that only a '79 4 cylinder Stang running on 3 cylinders with a huge vacuum leak can. I give it a couple revs, and drop the clutch. A nice big satisfying burnout ensues. We cross the lot and hit the chain at ~20 mph. As soon as the front tires roll over the chain, it springs up and smacks the bottom of the car, and catches the rear axle. BAM!!! I look in the rearview and see hellacious sparks flying out from the back of the car. The car kept going though, and we made it home that night. I can only assume that we broke the chain and that's what caused the sparks. I miss my young and dumb adventures with that guy. There was the time we went to the lake and almost knocked the floating outhouse thing off it's mooring.... That stupid 'PoonTang kept going for another year or so until I broke the transmission racing that same friend, who was driving his VW Diesel Rabbit. Those cars were a dead heat.... Anyway, sorry the story is long but I still laugh every time I think of it...

If you have a book with torque specs just look up another 8mm x 1.25 bolt. Maybe try looking for the thermostat housing or the timing cover bolts or something. If I were to take a SWAG I'd say 15 ft/lbs. I never torque them with a torque wrench though. Never had my clutch fall off either...

The problem with L series valve springs is coil bind, not valve float. I had a theoretically impossible .490 lift cam with stock valve springs and it only floated the valves once and that was at 7500 rpms. BTW you can only get that combo to work with some REALLY crappy machine work. I just happened to find a really crappy machinist when I built my first engine. If your new cam goes over .460 (I would hope that it does) then wheelman is right, you will need valve springs and retainers. If it goes over .480 then you need the shorter valve stem seal. I know you've already seen this Bastaad, but for anyone else following this thread: http://hybridz.org/nuke/index.php?name=PNphpBB2&file=viewtopic&t=31967

Seems to me on a very basic level if there is less compression you can add more boost, and you get more power out of the boost than out of the compression. If lag isn't an issue, it seems that lower compression would be the easy choice. At least that's what all my turbo'd buddies tell me.

The Dems did this to Bush about 4 months ago. For the life of me I can't remember what the subject was, but they asked him to say something on a subject, then turned it around on him and it was in EVERY paper the next day. You don't have to have that experience too many times to learn not to stick your neck out. I think Bush knows that mistakes were made, but what he doesn't want is headlines in EVERY newspaper in the country: "Bush Says That Low Troop Numbers After the Invasion Was Colossal Error." To me it just looks like the Dems are saying, "Mr. President, would you please give us a rope to hang you with." I think if I were in Bush's shoes in the 2nd debate I would have said the same thing. "I think there were mistakes made, I know I made some mistakes in my appointments, I do not want to call those people out." The last thing I would have done is to point to Abu Graib or conceeded that we might have been able to utilize more troops after the invasion. As to the war I think it there is ONE major problem with the war. We're trying to appease the Iraqis, and yet need to take military action in their country. We should be taking the action FIRST and doing what needs to be done, then try to appease them LATER. If that means the interim govt shouldn't have been propped up so soon, then fine. The interim govt was an appeasement to the EU, so that too could be characterized as the same mistake. Once again the US is fighting with one hand tied behind our backs in the name of political correctness...

Boiling the brake fluid is... interesting, isn't it? When the brakes cool off and they come back like that, they don't really "come back". Give them about 2 hard corners and the pedal goes to the floor again. Ask me how I know... Once it boils you gotta bleed. For next time, bring a can of your favorite hipo brake fluid and a bleeder bottle and bleed them before the time trial. Always a good idea to check the pads in between runs just to make sure there is still some left too. All in all sounds like a good time to me. How did you work out the brake bias thing? Just adjust the rears a little looser?

I say do the 2.3. The L28 is going to be relatively expensive and I think you'll have a hard time getting that much hp out of it. The 2.3 should be a relatively easy swap, makes the whole car lighter, and has more power potential.

You want the NA version. The huge gear spacing on the T5 would suck with triples.

This is about the point where I should just shut the hell up. But I'll give you this much: I think I'm right about the cam, because once you've got boost it should be good to go because the turbo is just going to force more air in while the intake valve is open longer. The 3" exhaust is going to do the SAME thing as the cam. It's going to improve the engine's breathing (exhaling instead of inhaling this time), and in doing so it will move your torque band up in the rpm range. You probably want to do that 1st, then decide if you need the cam. The gearing I suppose depends on what you want to do. If you're drag racing you might want to maximize the rear gears so that you come through the traps right at your hp peak. If you're driving on the street you might want a nice cruising rpm on the freeway. If you are doing some of each you'll need to compromise.

Changing the diff ratio wouldn't change the rpm drop between shifts, but it would change the speed at which you shift, and the torque multiplication regardless of what gear you're in. So if we were saying that more torque multiplication is a good thing, then you'd want the highest numerical diff that you can get. I don't know if I've been doing the diff gearing "right" but I always looked at the theoretical top speed. My 3.70 diff with my tire size and redline of 7000 gave me a top speed of like 172 mph, which my car would NEVER go to. Likewise your 3.54 probably tops out at 190 or something. I happily changed down to a 4.11 because I still probably won't ever see 155 mph or whatever it is now, but I'll have more torque mulitplication to help the car overcome the wind resistance and get closer to 155. The downside to this is that you spend more time shifting, and especially with a turbo it's better to have a bit wider gearing and let the additional torque from the boost carry you through a longer rpm range. Incidentally the turbo is going to help with your bigger cam too. Once the turbo spools you'll have plenty of pressure to force the air/fuel into the engine. It's the NA's that really feel the effect with a big cam because we have to wait for the intake velocity to come up, and at the same time we're bleeding off compression due to lots of overlap. You won't have lots of overlap, probably just a lot more lift I would imagine. I would think you might feel a little difference before it spools, but as long as the turbo spools at a reasonably low rpm you should have more mid and more top end which should more than make up for the slightly increased lag. That is my impression of camming a turbo anyway...probably would help to get advice from someone that has done it.

A couple hard laps should take care of those pesky rear brakes... Sorry for the smartass comment. I'm pretty surprised that you have that problem. Makes me think the front pads aren't fully bedded in or are glazed or something. The fronts should be providing a lot more front brake than the stock setup would. This seems to tell me that if you hadn't upgraded the front then you would REALLY have a lot of rear bias. Or it could be that maybe the green stuff shoes start working at a much lower temp than the KVR pads. If that is the case then I wonder how well those shoes will be working when they get really hot... they might just cook right off the car. If it is a bias problem and not a friction material problem then the best quick fix IMO is to get an adjustable prop valve and just mount it under the car where the stock valve goes. It would make installation under a deadline a lot easier. Unless your a really experienced racer you probably don't need to be adjusting during a session or a race.

I think you're hung up on the torque numbers (maybe I was too) and not looking at the other factors like the ability of the engine to accelerate. Obviously Pop and I agree that gearing is crucial, even if we don't agree that the car with the most hp wins the race. Having ridden in a 1978 Toyota Pickup with a 20R with 44 inch tires, dual 44mm Mikunis and a huge cam, I'm pretty confident in the strength of my argument. HP doesn't always win. I'm not kidding by the way, that truck really existed back in 1990, and a stock 20R would have been very much better at getting that thing moving. "Show" truck. What a turd. Had one hell of a polished valve cover though... I think maybe I underestimated the usefulness of the hp curve though, and Pop's post is definitely helping me to understand. It seems to me that the area under the peak of the hp curve is where the engine accelerates the fastest. So it seems to me that you want to place your shifts and gear your transmission so that the shifting hp and the after shift hp are as close to the same as they can be. That way you are always driving over the very peak of the hp curve with max acceleration. So thinking back to the show truck maybe if that thing had a 60 speed automatic transmission which could allow the truck to be run from 5000-6000 rpm and moved from a stop at that rpm it would have been OK to drive. As it was with the limits of the 5 speed and the differential gearing torque would have won that race hands down. I'm thinking the same would be true of your S2000 example. If it was possible to keep that sucker in the 6-8000 rpm range for the whole race with the Z3 maybe it would win. But it loses a lot off the line to the Z3, and has to shift more which also costs time. I guess what it boils down to is that you have to prioritize the engine to work with the rest of the car. If you are like John C and can afford a Quaife sequetial dog ring box with whatever ratios you want, then you can have a car with a peakier power curve. The rest of us are better with a wider power band. In your case Bastaad a bigger cam is going to get you a torque shift, which will get you higher hp at a higer rpm, the question then becomes can you keep the engine in the rpms you need to maximize acceleration. As Pop said, the peakier your hp curve the closer your ratios need to be. Time to break out this old link... http://www.geocities.com/z_design_studio/transmission.html

Torque X RPM/5252 = HP The bigger the number you divide by 5252, the higher the hp rating will be. So the higher the RPM that you multiply by torque, the larger the result. So more rpms for a given torque is always going to mean more hp. Or if you think about the torque side, lets take your original example and move the torque band 1000 rpm higher. So lets say an engine makes 100 ft/lb torque at 3000 rpm. 100*3000/5252 = 57.12 hp. Now we take that same torque at 5000 rpm. 100*5000/5252 = 95.20 hp. So if you make the same torque number higher in the rpm range that makes more hp. The formula only measures at one spot in the rpm range, so you really need to compare the whole range to get any meaningful numbers. If you want to know which car is going to be faster, I think that boils down to which car is setup to USE the torque available. You can maximize the transmission ratios and the gaps between the gears, rear end ratios, tire sizes and traction. Either one can win the race. It depends on who is set up to use their power the best. Put both of these motors in the exact same car and the one that is best suited to the transmission the rear end and the tires and suspension will win. If you've got a diesel engine that peaks at 2000 rpm you will have no benefit to revving it to 6000 rpm (if it can). So if you have a lower peak torque RPM, then revving higher doesn't do you much good, because the torque starts to decline after the peak. Continuing to rev doesn't accelerate the car as fast as shifting to the next gear, because the engine's power declines. If you put a cam in your car and raise the peak torque 1000 rpm you'll have less off the line, but you'll be able to rev it higher and force that top number to be higher in value relative to the 5252, meaning more hp.

ITB's are already available for Z's and they don't use a plenum. You can run them with Electomotive TEC II or III, but I don't know what kind of sensor they use to determine how much air is going into the engine. A plenum would help to draw air at low rpms on an NA, where ITBs and triples tend to have the least effectiveness. I think this is why John C did a custom intake manifold and specifically did not go with ITBs IIRC, but it would be nice if he would jump in to confirm that. I remember him saying VELOCITY about 1000 times last time this was discussed... Just as an aside if ITB's is really where this is leading TWM already makes the TB's and they make a nice airbox that looks like it would make a great plenum, although I don't think the airbox is capable of handling pressure. http://www.twminduction.com/airbox.htm http://www.twminduction.com/ThrottleBody/ThrottleBody2000.html

Great. So you can push up on the right stick for 10 seconds and you get to hit the upshift button a couple times. Yippie...

Hughhh, hughhh,

Go look under your Max and you'll see why those coilovers won't work in the back.