Dan Baldwin

Motorsport Auto has 25% stiffer lowering springs for $180, Tokico springs for $230, Euro springs for $180, and Eibach progressives for $280 (though I'm not a fan of the idea of progressive rate springs). They also have struts from $77, $100, and $150 (the Illuminas). And sway bar kits for $230. There are other sources, but I happen to have my 2000 MSA catalog here. I'd go with springs/struts first, then see if you still want stiffer sway bars. It's worth noting that a stiffer front sway bar will tear the stock mounts out of a 240z over time (I drilled through my frame rails to use the whole section in tension, rather than just the lower flange). 280z might be better in this regard, but it's something to consider.

I'd say go with the 2.8. ~same hp as a lightly modded L24, but much more potential. Displacement is the foundation. Get as much as you can and build on that. Dan "preachin' what he practicin'" Baldwin

'81-'83 280ZX non-turbo L28s had flat-top pistons, which you want. Next step is to up the compression, via modifying the stock cylinder head or using an earlier one from a dished-piston motor. Plenty of recent discussion on both of these methods. Stock compression ratio is abysmally low, you should be able to get at least 10% more torque and power by upping it from ~8.5:1 to ~10:1. O' course you'll be using premium pump fuel then, but hey, it IS a sports car.

An emphatic 3rd on the Sunbelt suggestion. I told them what I wanted, and they delivered in spades for (relatively) reasonable $$. And it was almost even on time:) Katman talked me into it, and I haven't regretted it. If you're not going to go with professionals who KNOW how to do it RIGHT, don't bother. That said, if all you want is a high performance street motor, getting yourself to ~10:1 CR (lotsa discussion on how best to get there in recent threads) with a stockish head and a mild cam would be a lot cheaper. Whutchoo gonna be doing with the car?

The Illuminas are great to ensure you can match damping rates to your springs. However, if you can get info on what non-adjustable dampers will match the spring rates you want to use, you can save quite a few bucks. I have the Illuminas and am happy with them, but they aren't really all that "adjustable", imo. You just find the one or two settings that work with the car and your set. Any softer is too bouncy for comfort and any stiffer to skatey for performance (i.e., you don't just set them to 1 for the street and 5 for the track). You can affect transitional balance with them, but if you're not competing at the track or autoX this shouldn't be much of a concern for you. FWIW, I compete successfully in high-speed time trials and don't have coilovers. Sounds like you don't need them either. You should be able to get a very good suspension setup for $500 or less. I wouldn't worry about camber adjustability, as lowering the car will get you some negative camber without being excessive. Try springs first and then decide if you want stiffer sway bars. The best thing you can do for performance is get a good set of tires. 225/50-15s fit without rubbing on 15x7" zero offset wheels, other sizes surely work, too, but that is what I run. There are VERY good tires available in that size these days. Think about what spring rate you want. I'm running springs twice as stiff as stock on my 240Z, and that makes a good street/track compromise. If you're high-perf street only, I'd consider springs 1 1/2 times as stiff as stock. When you know what spring rate you'll be going with, ask around again to see what dampers will work well with them.

Those strength numbers are listed as "allowable weld-metal strengths". They're based on 85% of minimum tensile ultimate test values (from the 60s, OLD book).

John, Off the cuff, I'd guess that the Nissan cast steel part and your welded plate part would have similar strength properties. A quick look in Bruhn's "Analysis and Design of Flight Vehicle Structures" gives 32ksi ultimate shear strength, and 51 ksi ultimate tensile strength for generic carbon and alloy steels. Please note that this is just a quick look-up on my part, I am much more familiar with aluminum structures. What material and heat treat is the plate, and what's the weld material?

To further beat a dead horse, I don't believe we're talking about 10hp. Even if we were, we still haven't seen any evidence that it would be 10hp more with the P79/P90 or with the N42.

Once more for DAW and those with short attention spans. There are FOUR E88 heads: '71 E88 has E31-like chambers, 42.4cc, 42mm intake, 33mm exhaust '72 E88 has N42-like chambers, 44.7cc, 42mm intake, 33mm exhaust '73 E88 has larger 47.8cc chambers for reduced compression, 42mm intake, 33mm exhaust '74 E88 has same chambers as '73, 42mm intake, *35mm exhaust* The '73 and '74 are regarded as undesirable "emissions" heads (whether that means they're nfg or not, I don't know). ONLY THE '74 260Z E88 HEAD HAS THE LARGER L28-SIZED EXHAUST VALVE. The E88s commonly used for performance apps ('71 and '72) both have small intake and exhaust valves.

Norm, as usual, you ROCK! Can't wait to see what you do in the 1/4.

Hey, NOW we're getting somewhere! Quick E88 review: 1971: 42mm in, 33mm exh, E31 chambers, 42.4cc, generally highly regarded 1972: 42mm in, 33mm exh, open chambers, 44.7cc, well regarded 1973: 42mm in, 33mm exh, bigger chambers, 47.8cc, poorly regarded emissions head 1974: 42mm in, 35mm exh, 47.8cc, poorly regarded emissions head Lockjaw: "Well 2 of the E88's I tried were the E31 style, and they rocked." OK, that's the head that was praised by a recognized expert in the field. Closed combustion chamber, and small valves, so not much like an N42. Not a whole lot like a P90 either, I guess. "The one we ran that sucked was one I got off a 260 I bought ( or it oculd have come off my original 2.4, not sure ), and if I remember correctly, it had the bigger exhaust valves, not sure about the intakes." Ah-HAH. Sounds like the 260Z E88. Generally avoided, and nothing to do with an N42. " I took it down and had a nice 3 angle put on it, and had it milled 30 thous, and it never ran good. Let me qualify that. It ran good, just not as good as the milled P79's. It was the open chamber design, unlike the E31, and I talked with some guy out at Nissan Motorsports about milling it, and he told me not to, so I was very conservative and should have milled it more. " Yeah, your CR was probably lower than you or he thought. "Of course I get into conversations alot with people who "know" Z's, and when I say something about an E88 head with E31 style chambers, they freak and call me a liar and such," My 8/71 car HAD that head on it. Long gone, now. Seems to me that the fact that there are FOUR different E88 heads, along with the assumption that the N42 is pretty much the same as an E88, might have led to some poorly-drawn conclusions on your part. Don't see why you would attribute your better performance with the P-heads to bigger valves as much as to combustion chamber design, as the "good" E88s all had smaller intakes and exhausts. Definitely sounds like your one(?) poor experience with an E88 was with one of the "bad" ones. (note the use of quotes, as I have no direct knowledge whether those heads are really "bad" or not)

I would respectfully submit that there MAY be more of a difference between the E88 (of which there are FOUR distinct varieties) and the N42 (not saying either is better or worse). The '71 E88 has E31 chambers, and reportedly the best-flowing runners of any L-series head (source: D.L. Potter's answer to a letter in an old ZCar Mag). The '72 E88 has a larger, open chamber. The '73 E88 has a much larger chamber than the '72, and the '74 260Z E88 has the '73 chamber AND a larger (280Z-sized) exhaust valve. The '73 and '74 E88s are regarded as "emissions" heads, and are avoided. Which may or may not mean anything. N42's had very slightly smaller chamber than the '72 E88, and BOTH valves are larger. As far as "detonation-proof-ness" goes, both TimZ and myself have reported NO detonation problems. Speaking for myself, that was with an unmodified (save for some shaving) N42, at 10.2+:1 CR, with advance 2deg beyond the optimum for peak power (fixed that at the dyno). After the head mods (porting and slight chamber work), I ran at 5 deg. over optimum advance (even did one dyno run at 7 deg. over) and still had no problems other than reduced power. We have run ACTUAL N42 heads (not supposedly N42-chamber E88 heads), and not had problems with detonation. LJ, did the E88 heads you've had experience with have the stock, smaller valve(s)? If so, obviously they would perform differently from an N42. If not, WHO did the bigger valve transplantation? Do you KNOW what year E88s you've used (aside from the E31-style which is obviously a '71)? Also, as long as you're willing to try the Maxima N47, why would you still be unwilling to try an N42, which you STILL have no direct experience with? Probably for the same reasons I'm not going to try a P79 or P90 anytime soon. It's likely not worth the effort for either of us.

One (or both) of my brake pads were hanging up in one of the front calipers. I could not believe it, but slight beveling of the edges of the pad backing plates and use of caliper grease along the edges seems to have gotten rid of the problem. Really weird, eh? Anyway, that's something to check. My symptoms were: firm brake pedal, car wants to make a left turn off the road/track under hard braking. As for squirrelly, what are your alignment settings? My car is VERY responsive, if I look down for a second at highway speeds and look back up, I may find myself in the next lane! But it doesn't feel nervous or unstable or anything like that. Just have to stay on top of it.

Just answering a few questions. Honest. Lockjaw: "Dan, have you ever actually run a P series head? Serioulsy, have you every gone to the trouble to mill one, shim it, and put it on a car?" No. "I have run just about every head out there, except the N47 and N42 ( although I used an E88 with the same combustion chamber as the N42." So you have as much N42 experience as I have P-head experience " I went from a P79 to an E88 and lost power on a flat top 280ZX bottom end." Lots of people have bolted on 3X2s and lost power. "Short of hard numbers from someone, there is no way anyone will ever convince me that the open chamber N42 is superior to a closed chamber P series head." I'm not trying to convince you of that. Just that none of us has enough info to say which is better. "Oh and on the subject of compression ratio's, a full point in compression is supposed to be worth 4 percent more power, so half a point would theoretically be 2 percent." I prefer the newhp = (newCR/oldCR formula)*oldhp formula. Probably a bit optimistic, but at least accounts for the fact that half a point from 8.5 is a bigger jump than half a point from 10.5. Anyway, that would be 5hp added to a 140hp engine going from 8.25 to 8.55:1 CR. But who give's a ratsass about those low-comp factory motors, anyway. "I believe Yo would be correct that the factory did show an increase of 10 hp going from the N42 to the F54 engine." FWIW, that's an N47-head dished piston motor to a P79-head flat-top motor. Wonder what if any more inherent power there is in an N42 head vs. N47 (square exh. ports vs. lined round exh. ports). Not to mention (again) that that 10hp is at the brochure. "Just for comparison, a pound of boost is supposed to be worth a 7 percent increase in power. But that is another thread. " That doesn't account for 1 psi being a bigger jump from 8 than it is from 18. Try newhp = (newboost + 14.7/oldboost + 14.7)*oldhp. Optimistic, but isn't that what bench-racing's about? Anyone thinking of taking Bobby up on his bet (his car) should know that his 3.1 has been sold, and I don't think he's taken delivery of the RB26DETT yet. i.e., it's a car w/ no motor! Regarding my cylinder head, it was ported, and some MINOR combustion chamber shaping was done (no material added, of course). I'd be glad to see results of a similar motor with similar work done to a P90, as the combustion chamber comparison would be almost as valid as stock vs. stock.

Thanks, John. I stand corrected, that's 305 flywheel hp. Somewhere I'd heard "way over 300", and somewhere I actually saw "320". Now I know your lame-ass motor is only making 305. You probably don't even have to use the brakes! O' course me, I can only barely beat a fricking Omni!

Lockjaw: "I don't see what is so tough about somebody making a concession that perhaps the P series could be better." I've conceded just that on a number of occasions. Key words being "perhaps" and "could be". "Why would Nissan make a change, and make it for the worst?" 1970-1972 240Z. 1973 240Z/1974 260Z. Why indeed would Nissan make a change for the worse? Sometimes it happens anyway. BUT, I'm not saying the P-heads ARE worse. "How hard would it have been for them to just make the combustion chamber a little bigger on the N42, and use the same dished piston as in an N42 block, and turbo it?" I dunno. "Why did they feel the need to completely redesign the heads?" Why not? I'm sure the redesign attempted to address more issues than outright maximum performance. As far as I know, it could've been for reduced emissions or improved fuel economy, something I don't think too many of us are all that concerned with. I'm not saying that's the case, just a possibility. "I think the power outputs you are getting are impressive, and there may not be huge differences between the N and P series" That's what I'm thinking. "but if there is a 10 hp difference, to me, on an NA engine making 235 hp to the wheels, that is significant." Again, I agree 100%. 10 hp IS significant. I just don't believe there IS that much between them, particularly if they've been modified. Which, at that hp level, surely they will have been. I could be wrong, there *could* be an inherent 10hp advantage to the P-heads. Or there could be an advantage with the N42. I just haven't seen any conclusive OR reasonable anecdotal evidence one way or the other. "Also, if you will note, all of the high performance aftermarket heads now use the smaller closed combustion chamber. " Proving... Yo2001: "Why are you arguing? between late zx and early zx, late zx produced 10HP HP at the crank. In stock conditions. So are you saying the Nissan deside to rate the late zx different from earlier one? That would be wierd. Like you said, the 0.2 did not add 10HP to the later zx. " "Weird" happens all the time with automobile manufacturers. Maybe the marketers felt like they needed 10 more hp that year. Maybe they really DID make +10 hp, or more. I agree that 0.2 cr difference likely doesn't amount to 10 net hp. Real hp gains, if any, between the N42-head N42 motor and P79-head F54 motor could as easily be attributed to flat vs. dished pistons as to P- vs. N-combustion chambers, though. Not saying that's the case, just that it COULD be. Hell, I don't know. I just don't think you guys do either

And so the circle jerk continues... For the mechanically-challenged OR for the expert engine builder, the N42 is the simplest choice. More time/effort for little to no gain just doesn't make much sense, no matter HOW mechanically skilled you are. IF the P-series heads ARE superior due to their flow swirliness, I still doubt that they're VASTLY superior in terms of absolute power production, if at all. As for the Ps being "much more detonation-proof", the ONLY times I ever noted any detonation in my motor was: 1) WAY back in '95 when it went in the car, 3.1 liter, ~10.2+:1 CR, lightly shaved but otherwise unmodified N42 head, stock N42 cam, stock 240 carbs. I STUPIDLY tried to run it at 18 degrees initial advance with the stock distributor, which would've given me ~43 deg total advance. It did ping, so I backed it down to 10 initial, which was where it shoulda been to give 35 max advance, anyway. No pinging or other issues for 6 years, ~25,000 miles, and maybe 30 or so track days. 2) I got some run-on/dieseling last year and some minor low rpm high load pinging. Turned out I was missing an advance weight spring, giving me 23 - 28 or so degrees advance at idle and low rpm. Before I discovered the missing spring I discovered that Bardahl's "Knock-Out" does a good job of eliminating dieseling and pinging, if nothing else. "Yes it is a little more expensive, but if you already have the N42 and pick up a P series for a hundred bucks, you are set, except for buying the shims." I'd say if you already have a good N42, you're ALREADY SET! No shaving, no shimming, no head-hunting and buying, no futzin' around, no nuthin'! Lockjaw has three people on his side, and I've got three different N42 engines with documented chassis dyno, engine dyno, and 1/4 mile results. 235 rwhp 3.1 na street motor, 320 flywheel hp (correct me if I'm wrong here, somebody) 3.0 na race motor, and 12.88 sec at 106mph 2.9 na street motor. Who ya gonna believe?! I know this does NOT prove the N42 better than the P-heads. Surely it at LEAST proves them worthy of consideration in performance L6 applications. OK, now I'm chafed. FWIW, don't try motor oil for more personal lubrication purposes.

Yo, Like SleeperZ said, there are a lot of things that go into factory hp ratings. Many times they change from one year to the next with NO engine or exhaust changes. Also, a 0.2 difference in compression on a 140hp engine could mean as much as 3hp. I DO have an MSD box in my car, but the motor ran fine and made good power before the MSD. Lockjaw, I'm 5'11", 160 lb., dark hair, icy blue eyes.... whoa, wait a minute. Ahem. No way we could have two cars identical save for the cylinder head. There's just WAY too much going on that would have a bigger impact on performance than the N42 vs. P-series chamber. I believe the difference would be SO small, that the only valid test would be on an engine dyno. One engine, one ignition system, one cam, exhaust, etc. Two cylinder heads, cc'd to be the same within .2cc. And identical valve events and timing would also have to be ensured. I don't see that happening any time soon. Bulding a P79- or P90-head engine similar to known N42-headed engines will likely only prove that the performance is similar. But performance differences either way, unless really drastic, wouldn't prove one head superior to the other. Again, I'm not out to say the N42 is inherently better, I CAN'T say that since I don't have enough evidence. I don't really believe it, either. It IS, however, a much more straightforward issue to plop an N42 on an F54 bottom end to get a 9.8:1 motor than it is with a P-series head. Which is why I recommend the N42. What I cannot fathom is why you would continue to say that the P-series is the ONLY choice in the face of documented performance from N42-headed motors. WHY do you think the Ps are so much better? WHERE are the 235rwhp, 320flywheelhp, sub-13sec P-head cars? Anyway, I'm not much of a street- or dragracer, but when I get my Z back down south I'd be glad to run ya, win or lose. Better yet, we could go to Little Talledega. Cut my roadracin' teeth there, heh, heh.

I run BP7ES plugs gapped to .045" (same as BP7ES-11). BPR7ES is the same, but a resistor plug (I have no radio). 300ZXTT NGK plug is a 5 heat range, hotter than the standard L6 NGK plug which is a 6 (higher number = colder plug). I'm running a slightly colder plug (7 heat range) than stock L6 because I'm at 10.8:1 CR. Your L28 block with E88 head, unshaved, should have you at 9.8:1 CR. Use a 6 or 7 heat range plug. Any plug that reliably lights the mixture, doesn't foul, and doesn't get hot enough to cause preignition will work. I don't know if the 300ZXTT plug has the same critical dimensions as the BPxxxES designated by NGK and Nissan for the L6.

Lockjaw, I luv ya man, but you couldn't be any more full of it. I *thought* we had agreed to disagree on this, but DAMN you're thick-headed. You need to show us AT LEAST ONE of the following: 1) a 235rwhp N/A L6 running on pump gas 2) a 320 hp N/A L6 race motor 3) a sub-13 second N/A L6 car running on pump gas with one of your "magical combustion chamber" P90 or P79 heads. The N42 is such a piece of crap that I know of three that have accomplished the above. The N42 is THE bolt-on head to have for performance. After you shave the bejeezus out of a P79 or P90, they're almost certainly in the SAME ballpark (not in another league, I'd bet money). OPINION doesn't count for SQUAT until it is backed up with some hard data. Sean, the first thing you need to do for an N/A L28 application is have flat-top pistons ('80?-'83 280ZX non-turbo). In MY opinion, the best/easiest setup is the 280ZX flat-top piston bottom end with an N42 (or N47, or big-valved '71-'72 E88) cylinder head. Presto, 9.8:1 compression L28, no sweat. Lockjaw's precious P-series heads will get you 8.5:1. If you want to butcher .080" off of a P-series head, or trust your local machinist to do it, and then monkey around with cam tower shims and lash pads and STILL not be able to get the stock valvetrain geometry, and have to worry about excessive cam chain slack, you can do that, too. You might even get an extra 2-5 hp, but then again you might get LESS hp. NOBODY on this forum or elsewhere that I've looked has demonstrated the superiority of the P-series combustion chamber. I do hear a lot of talk about how much better it looks and about "quench area". That doesn't count for much at the engine dyno, chassis dyno, drag strip, and road course, though.

The OLD LS-6 (~1971?) WAS basically a 454 c.i. L88. The NEW LS6 is the mighty 405hp Z06 version of the '97+ LS1 new small block. As far as I can tell, the new all-aluminum LS-series motors aren't any lighter-weight than the old iron-block Al-heads LT1. A 98 LS1 Z28 weighs almost exactly the same as a '97 LT1 Z28, 3400 lb. The LS1 is a deep-skirted, beefier design. Make mo' powah, too. I've got the lo powah LT1 in my '95 Z28 convertible. Sure does make the 240Z feel fast.

Agree w/ lockjaw, 2mm ain't worth the money or the effort. The benefit of triples over SUs or stock FI is at high-rpm operation, so choking them down with 29s(?!), it isn't worth running them, IMO. I've got 38mm chokes in my 45mm triple carbs, and it runs fine around town. I'd be thinking at least 34s, maybe 36s depending on your intended usage (street/autoX, or roadrace?). The bigger the chokes, the bigger jets you'll have to run. Either rig up your own A/F readout, or go to a dyno and see where you are. I've got 165 mains (which are too big, I'm running rich), and just switched from 220 airs to 200 (was leaning out up top, going to 200s gained me 5hp from 4500 up). There is no "correct" choke size, any size within reason can be made to run pretty well (with bigger being better for high rpm, to a point). Whatever formula you use to size your jets, you'll have to check the A/F ratio throughout the rev range to know if you're OK. Jets aren't all that expensive, and it's worth the cost of dyno time to see the effects of changes on A/F and power.

Will try it this P.M. Didn't make much difference at time trials yesterday, as it was wet and SLIPPERY during the timed runs. Short shifted everywhere. Thanks, Dan

It would be good to see the backside of this. Is there just one weld bead, or is there some overlap and another weld on the backside? i.e., is any bending taken by the one weld bead? 3 bolts instead of 4 would make for a lot more convenience in installation, and replacing wheel studs (I had to get creative the other day to sneak a wheel stud in with the Maxima brackets). BUT, Nissan engineers designed the part to be attached with 4 bolts, and to completely encircle the hub. There may be a very good reason for that. Not saying the design isn't adequate, just that these things MUST be considered and some analysis done, IMO. Dan Baldwin Aerospace Structures and Motor Scooter Engineer

That no work neither. Damn, this is infuriating. So far the only thing that does anything is hooking the black/white wire (the one that is only hot when starting the car) to the red tach adapter wire. Then I only get a tach reading while the starter's engaged. Grrrr... Goin home now. Dan