pparaska

Any word on why the compression was so low, compared to your as new compression numbers? I'm wondering if the heat treatment on that one guide plate was not good and that's what caused it.

If you can find a spare, try a new ignition switch. And don't let the switch supply power to the ignition, let it do that through a relay that you feed from the battery or alternator output.

From what I've read about solid roller cams, you should be concerned about the lifters too. Any evidence of valve float should be a huge warning sign that the rollers on the lifters have suffered (the needle bearings). Either replace or have rebuilt. BTW, it seems I've read that Crane did some research that said that the roller tips don't really turn much if any. My guess is, that coupled with valve float (either from bad harmonics from the rev limiter or worn springs) did the rockers in, and caused the other damage.

Another point is (even though this seems to be a setup that's not done being tuned in), that the Turbo Supra engine's stock boost is something like half the boost that Cyrus is running (17psi). And the LS1 in his V8 car is stock, from what I've read. Hardly a fair comparison, but it wasn't supposed to be. It's just the two setups that cyrus has - must be nice to have TWO HybridZ's!!!

BTW, aren't NASCAR engines limited in displacement? Yes. 358 cubic inches (their's work afoot to lower this to 325 ci). So how do you make more power if limited (an no power adders are allowed)? RPM That's why NASCAR engines rev to 9K+. They TOO are displacement limited. Sound familiar (Japan's 2 liter taxation law and it's result on smaller, higher revving engines, turbos, etc. from that country's makers.)

Did I say I never shift down now and then? Not true. I just don't want to HAVE to shift down to get good acceleration. Again, not lazy, I just don't want my STREET car to NEED to be shifted down to accelerate well from cruise. I don't want an automatic trans in my Z - that's for drag racing IMO, and I want to car to do much more than drag race, I won't give up shifting my own. You see I want it all - easy acceleration from cruise without HAVING to down shift, the brute force of accelerating after a down shift (if needed at the current cruise rpm), and being able to control the power delivery without a torque converter softening things or the valve body making decisions for me. I MIGHT have an auto if the converter was tight (or locked up much of the time) AND it had a full manual shift body - but then the auto wouldn't be downshifting for me, so it's no longer "automatic". I would knock a turbo powertrain if it made me shift down from cruise to get decent, immediate acceleration, but that's not always the case - turbo drivetrains don't have to be that way - a smaller-than-bling-acceptable, low pressure turbo on a big enough, high enough compression engine will give a good bit of immediate thrust right off of cruise at a low rpm. Just the small turbo engines with the oh-look-how-much-boost, huge turbos are known for that. That's what I wouldn't want on the street, only at the drag strip.

"Lazy drivers"???? Generalizations are always dangerous. Just because I don't want to drop down a gear while cruising but want immediate thrust doesn't make me lazy. It just means I want to have thrust in the cruising gear I'm in- so I can do it seamlessly. If you DON'T want that immediate thrust in a cruising gear, then that's you're perogative, but don't call those of us who want it lazy. I also don't want to cruise around at rpms that would have me in a position to feel the thrust I want in a small displacement NA or turbo'd car - since that RPM means that I'd be wasting fuel, and making noise that I don't want to make (drawing attention). That's not laziness, it's a driving experience that I want out of my car. Correct. Street driving preference. And my preference is to be able to push myself back in the seat with authority WITHOUT having to drop down a gear or cruise at a higher rpm that makes a bunch of noise, wears out the engine and draws attention. I love being able to pull away from little buzz-bomb bumble bee sounding Honda's while in 5th gear at 55mph. So little effort to do, so much fun! That's the only way I'd design a turbo car for the street - one that had no lag in 99% of the situations I'd be in on the street. Note that that turbo 911 you drove was the recipe I was speaking of to get that kind of operation - a nice 6 cylinder of adequate size (3.6L) and compression ratio (8:1). It's obvious that the Porsche engineers know how to tune that engine system to get it to not have lag - something that isn't so easy for the amateur, as Michael was alluding to. Oh, I don't know. Some think 1970 was the last year. But the 455SD Firebird of 1973 was no slouch.

That kick in the back just signals to me that I was MISSING power before it kicked in. Kind of like I was missing something I wanted earlier. Of course, with a large enough engine, with adequate compression, etc., the amount you were missing before the turbo started delivering may not have been too bad anyway.

You're describing a very well designed system with a 2.8L engine, and probably not a huge amount of boost. You also mentioned more compression than stock. These are along the lines of what I was mentioning. The smaller engines in heavier cars (DSM - I drive one daily) depend on boost for their power, so off turbo they are very lazy. Turn up the wick and the difference between on and off the pipe is large and when it hits, it unsettles the car if it's in a corner, or makes a ruckus on the street and draws attention. Sorry, that's only good on the drag strip IMO. Or for chassis dyno bragging rights. (Mine's bigger than yours! ) AGREED! Yeah, take a 1.6L engine, throw 30 psi at it and it'll make lots of power. Try living with it on the street though - you'll end up hating it like the guy with the 300 degree duration cam in is V8 - except when it's at the drag strip.

My first thought is that 1.3 sec of turbo lag is not common for a well setup turbo system...(that seems REALLY high) Which gets to my next point - it takes a bunch more effort to do a DIY turbo setup, or even mod an OE turbo engine setup and get it to work like I'd want it to (no lag, reliable, drivable, no boost-induced oversteer in mid corner, etc.) than it is to buy or build and install a BIG ENOUGH normally aspirated engine. Some people like the technical challenge of the turbo thing. Others just think that turbos are the only way to make the statement they want to make. Me, I like my power start out high NEAR IDLE, have a linear delivery across the rpm, throttle position, etc ranges, and I like my setup to be SIMPLE and fool proof. It's very easy to do that with a bunch of displacement, no matter if the valvetrain includes pushrods, or not. To each his own, but one things for sure - its just plain easier to bolt a large displacement engine in the bay than it is to engineer the killer 2.xL turbo setup to make the same peak power with the same drivability parameters. Which gets me to the next point. If you're going to turbo, why stay below 3.x Liters? What's the point? Don't give me the gas mileage BS. I don't believe it. My leaky, super rich burning carbed 327 got 23 mpg to and from the first SEZ. With 6 cyilnder engines in the high 3 and low-mid 4 liter displacement range out there to turbo or super charge, why stick with a teeny little 2.x engine? I think the answer is that people like to show off and brag about how much power their teenie little engine makes on boost. Then they go home and work on changing that head gasket.... It's called the "I like to be the underdog" mentality. Turbo a V6 or V8 - use low pressure boost, and high compression. You'll like it better than tweaking the tune on that grenade and fixing it all the time. High boost, small displacement is for race track and the PROFESSIONAL driver in a purpose built race car. A street based car (what the Z is) weighs too much for this to work well, on the street or road course. The one place I can see it working well is at the drag strip. But how many of us have a drag-only Z? On the street, turbo lag SUCKS. (ask me how I know - I drive a laggy turbo car every day). On the road course, the last thing you want is the lag to cause the boost to come on in mid corner and upset the car. Sure, you can tune your driving style around this, but being smooth with such an engine is a handicap, if your doing HPDE's. Any engine is legal for such uses of the car, so why shackle yourself with a puny engine with a ton of touchy technology heaped on it to make power? Answer: "Turbos are so cool and pushrods are for tractors"

Yeah, and an extra 240Z emergency brake cable spring to boot (like the one that helps the cable return to the off position, above the diff nose as well). It was a SIMPLE fix. Nothing that I should think would keep someone from using Ron's mounting idea. I had to grind clearance holes in the top of the diff crossmember for the bolt heads that mount the mount to the top of the nose of the diff. That's how close the diff gets to the lower front crossmember - and it was needed to get the u-joint angles correct too. The other solutions I've seen don't allow the diff to get as low at the nose and that precludes getting a small u-joint angle - something I was definitely wanting to make as close to 1 degree in the vertical plane as I could. No vibrations under acceleration was the reward.

Mike, thanks for showing me this thread - when I was talking to Donna yesterday in your kitchen, she mentioned Steven, the funeral, the devastation, etc. I didn't know about this until then. The couple across the street lost their only son of 17 years old a year and a half ago in an auto accident - he and his cousin (who was driving) were the victims of an aggressive driver's moves on a highway, and probably the cousin's inexperience behind the wheel. Both died at the scene, the kid across the street (Chris) died instantly when his side of the car was hit by the oncoming car. At least he didn't suffer. Chris sounds a good bit like Steven, in character. Chris was always over in my garage as I was putting the Z together, asking questions, always polite, very able to talk to adults. He kept his friends on the straight and narrow - I witnessed him gently guiding them away from the wrong path several times just in front of our house. No telling how many times he did this online (he was very much into online chat with his friends), or in person out of our sight. We ALWAYs complimented his parents on what a great kid he was, what a great job they'd done raising him, how we hoped our kids turned out that good, etc. etc. He was known to be a great kid to many, before his death...One that everyone looked at as almost not of this world, due to his wisdom and demeanor. Reading about your experience at the funeral, etc. brought back the tears of that day at Chris's funeral. I attended and was brought to tears over and over as I watched his MANY tearful sobbing friends get up and read poems, stories, rememberances about him right in front of where I was sitting. I ran out of tissues. Chris had been so much to his friends and so many of his peers - more than I even fathomed possible for such a young person. The same thought came to me as I reflected on "why". I believe I came up with the same reason for Chris's death as you came up with for Steven's - he'd fit a lifetime of good deads into a short time and it was his time for his friends to go on with their lives without his interactive input, but with his memories. Yeah, that's a bit metaphysical for a practical person like myself, but it came to mind. The only other reason I could come up with is "stuff happens", no fate, no intricate divine plans, it just happens. Doesn't really matter. It's what these people DID that matters, not why they aren't with us anymore. Chris's mother and step dad planted a tree in the front yard in his memory, then added a poem his mother wrote, engraved into flat stone that sits at the base of the tree. To see that women crash and burn after his death tore our hearts out. She's doing pretty well even a year and a half later, but you can still see the pain in here eyes. My condolences, Pete

Beautiful! The flares and wheels look great too!

I believe one key to a drivable high horsepower car is the throttle linkage geometry. I have a 375 crank hp 327 in my 240Z and the part that makes it a bit touchy to drive is the 4 barrel 700cfm non-progressive Throttle Body Injector (Holley Pro-Jection). All 4 barrels crack open at once. After lifting your foot off the pedal to decelerate, then at a low speed in 2nd gear (1.98:1 with 3.7:1 rear and 25" tire) if you tocuh the pedal anything like you would in another car, the engine comes on hard and jerks you around. I plan on making a cam/cable linkage on the TBI to slow it down initially. That said, start with the LS6 and when you're ready for it (you WILL get used to it) throw in the cam/headers/heads/etc. to go to 500 crank hp.

Thanks for the education, John. Kim's point of view on this has interested me, that is that having more forward weight was an advantage in hillclimbs. I guess that MAY be true, but I always wonder if the car was set up with less front weight and the suspension setup tuned properly if it could have been faster. I did like Mike is talking about and decided that the battery should be behind the passenger seat, not behind the tower. I have problems putting a lot of mass outboard of the axles, but that's gut feel, not engineering. I don't like the fuel cells I see hanging down so much below the back edge of the valance - it doesn't look right to me for several reasons. Unfortunately, to do otherwise means a custom job. Probably why I just run the stock tank...

Since I hijacked this stub axle thread and turned part of the responses into a rear strut geometry sub-thread, I split those responses out into another new thread: http://forums.hybridz.org/showthread.php?t=100924

I think the lowering of the attachment point and it's changing of the camber curve is probably more of the advantage. It seems on a lowered Z, the stock suspension presents a quick camber vs bump change. Making this less so seems advantageous, especially when alot of power is available. It certainly would help the straight line acceleration. I'd LOVE to have a totally camber compensating setup back there (http://locost7.info/mirror/dax.php), but that's a BUNCH of work.