madkaw

The 280zxt starts a new life with a new owner--The Z Bar So I have posted here that I bought my daughter a 1981 280zxt a couple of years ago. It turned out to be a fun car for here for a couple of years at college-even amongst all the fixes it endured. Her traveling became too far and often for the car to be her daily driver so we decided to part with it. She didn't mind too much since her replacement is a 2007 WRX, but it didn't compare to the fun of the T-top Z. I put the car on craigslist and had to endure the various low ballers and no shows. Then some guy says he wants to buy it and wanted to drive up from Louisville(about 2 hours) to come get it. He had been looking for that specific year,color. He told me he owned a bar in Louisville(ZANZABAR) and he would bring me a shirt---sure, I'll believe you when i see you. Anyway, he showed and loved the car, and brought me a shirt and drove off to Louisville. I'm still not buying the bar owner bit---but his cash spent just like money! He invited the family down for lunch if we were in the area. Just so happens my son was swimming in at a swim meet at Lakeside in Louisville, so we stopped in. Well the picture tells it all and the Z bar is definetly worth checking out if your in the area--very cool.

Damn,don't know how you do anything in that kind of pain. Glad to see you got KTM's stuff, I imagine it's nice, but I thought that block was going to be for a turbo? I have been following the thread because I still mess with the L24 block. Not many folks still trying to tweek power out of them, they just move on to bigger and better things---but this is HybridZ!! It's funny you mention the ticking, because I am dealing with the same thing. It almost sounds like an exhaust leak and my clearances are also to spec. For now i just drive it!

any updates on the L24 build?

Got it! I was trying to over complicate things by thinking hard lines from the log to the manifold. Thanks for the input guys.

Thanks for the tip Rossman, but not sure how to connect that to each individual runner. I just read your build thread and I know this is log is a simple project for you, but I'm not quite as savvy when it comes to this machine stuff. By the way, love your build and would like to go your same route some day, but for now -baby steps! Also love the avatar. I was showing my 14 year old son you tube videos of Ultraman the other day and he was cracking up.

that would be great-thanks

Here is a few more pics showing all the work-- which kind of tells the story. Welded and reinforced the diff brackets. Welded a stud on to the control arm pivot bolts. Slotted the holes on the diff brackets to allow for side to side movement. Attached control arms with adjustable rod ends.

Getting ready to mount my Mikuni triples with the shorty manifold. My manifold is tapped on each runner and I want to take advantage of that and create a log for a vacuum signal. I would like to make something that would double as a booster signal and an MAP signal. I have read that it needs to be removable in order to properly sync triple carbs. I'm not even sure where to start on this project and I am not having much luck searching this. Anyone done this and can I steal some ideas.

I would try and pick-up an earlier e-88 head if you can find one cheap and redo it. The later e-88 chamber design is not that great and takes a lot of work to perform.

I will add that a member on CZCC (steve911tt) is dealing with issues with detonation using the later e-88 head. He is limited to 30 degrees total advance. I know it's not what you want to hear , but information is always good. Of course everyones set-up is a bit different, but I think the chamber for the late 88's need the most work.

It was not the option I wanted to attempt, but I was looking for a quick cheap option to reduce tire rub on the rear tires inside the wheel well. Running 245's on a 8.5x17 with +4 offset put me on the raggged edge of clearing. In hard cornering and bottoming out the tires rubbed pretty badly---after almost eliminating the fender lip. When i realized it was no longer the fender lip, but rather the inside of the wheel well I knoew I had to tilt the top of the tire in. I couldn't find much info on this searching as far as what camber change i could expect from doing this. So I needed a alignmemnt anyway so why not slot the strut holes a bit and see what the numbers look like. I only slotted about a 1/4" to 3/8" out of the holes and it actually made a significant change in the rubbing. When had it checked out at the alignment shop I found out that I was only running 3/4 degree of negative camber That leaves pleanty of room for some more tweeking and hopefully eliminating the RUB and improving handling at the same time!!! I also found out that my adjustable rear control arm/diff brace worked great too. When I saw the tech back the car into the alignmemnt spot I was expecting him to come out and ask me about my set-up---if there was changes to be made. Instead he pulled the car around and said your all done! I asked how the rear alignmemnt was and he told me the driver's rear toe was out 3/4 of a degree, but he adjusted it to 0. He then said that my adjustable bar worked out great. Thanks Jon Morteson for the idea!

I don't have any ideas for you, but I thought it would be an oppurtune time to throw in a picture of my EARLY E-88 compared to your late E-88. It's just a good chance to show the difference in design between the e-88s with similiar work done,i.e biggger valves and such, 'As you can see the shelf is not there at 12 oclock. This head was only shaved .010 My chambers are around 39cc, but compression reduced with valve reliefs on the bores. So far no detonation problems with an estimated 10 to 1 and a stage 2

Bo, good luck with your new venture. You do nice work and are very thorough and it should turn out nice. Someday I might fall to the dark side, but still learning and playing with the L6. Wish i had money when your nice parts came up for sale.

Your wipe pattern doesn't look too bad to me, but I'm not a cam expert by a long shot. Here is a snipet from a great article by Racer Brown cams regarding this contact area. One highly important item may contribute some conflict of interest at this point: The actual area, and location of the area, of the rocker arm pad contacted by the cam lobe, hereafter referred to as "rocker pad contact patch." Some cam lobe profiles do not allow much if any latitude here. With these engines it is AB-SO-LUTE-LY ESSENTIAL that the cam lobe does NOT extend beyond either end of the rocker pad. For the most part, this occurs on strictly race engines, but if the cam lobe profile is sufficiently desirable, the rocker arm position must be adjusted at the pivot end so that the cam lobe does not override either end of the rocker pad. If, by mischance, miscalculation, or simply the wrong cam lobe profile, an override condition exists at either or both ends of the rocker pad, it spells instant death to the cam lobes and the rocker pads. If the cam lobe is a tight squeeze on the rocker pad, then the first order of business is to make certain that the rocker pad contact patch is as correct as it can be, and rocker arm geometry must be forced to a secondary position. Ideally, the rocker pad contact patch should be centred on the rocker pad. Assume that the opening flank of the cam lobe comes within 1/32-inch of one end of the pad and that the closing flank of the cam lobe comes within 3/32-inch of the other end of the pad. This is wrong. The rocker arm position must be raised at the pivot end of the rocker so that the contact patch is equalised at 1/16-inch from each end of the rocker pad. There is a good visual method of checking and measuring the rocker arm contact patch, and there is also a way to "cheat" a bit to gain a higher effective rocker arm ratio in some cases…but that comes later.

I thought 4psi was almost too much pressure for Mikunis? Are you running vacuum advance, if not, I would think you could tweak that timing up a bit. There is something a miss to get that bad of MPG-IMHO

Well an update on this thread. I finally got around to replacing my diff with another r200-non LSD type and the noise is gone. The catch with this is that when i went to remove the halfshafts from from the car I noticed that I didn't get the nuts tight on the stubs. Maybe in haste to get the car together to get to ZCON I didn't tighten the nuts all the way? The halfshafts seemed to have beeen sitting flush against the stubs and I could't feel any play, but now I will always wonder if that played into the noise.

Well the wide band is installed-what an eye opener. I can't explain all the info on the dyno sheet, but there are a few answers from the wideband. The richness was from the front SU being way off on the mixture setting. When I was doing my adjusting of the mixture nut, i wasn't getting the nut bottomed out from the start because the nut was hitting on a clamp on the backing plate of the air breather. So instead of starting out at zero I was stsrting out around a turn and half. The rear carb was running very lean, so maybe the two mixtures together was rich, but not enough to produce smoke-as implied. I discovere this after zcon, but before I hooked up my wideband. Infact, when I went to readjust here recently, I realized that i hadn't adjusted the air mixture screw on the linkage-so at 2000 rpm the front carb was pulling air and the rear was almost dead. It amazing that the car ran as good as it did for 3000 miles last year. Maybe that's why my MPG was so good to ZCON at about 28mpg. This may also be the reason the AFR's dropped way lean above 5100 as shown on the graph. So now I start looking at my AFR numbers according to my wideband. At the present time I have dual exhausts with a bung on each bank. The wideband is hooked up to the front bank. In my dislexic mind the numbers look good-17.5 at cruise, until someone points out my error. So I went from way rich on the front SU before discovering the mixture issue, to running lean after adjustment according to my wideband. Are you confuse yet-I am! So anyway, I have got the numbers on the front carb where they should be, running around 14.5 at cruise. Both carbs are drawing correctly also. I haven't switched the wideband to the rear bank to see those numbers yet, but the mixture screws are very close at this point. How does it feel on power, better, but not huge. I have some more seat time needed, but it seems that maybe the SM needles may be too much for my L24. The reason i say this is because my AFR numbers seem to eventually run below 12 at WOT towards the upper rpms. After some more seat time I might consider installing the original needles back into the SU's to see the number then. Don't know if it is possible to lower the SM needles into the jet to adust mixtures that way. Once i get the AFR number where I am fairly happy, I plan on going back to the dyno to play with timing. I plan on starting at 10 btdc and work my way up to the limit of power. I am still running at 36 total with no detonation, but is this where the best power is at? This wideband is not the end-all tool, but this will be a crucial tuning tool.

http://s2.photobucket.com/albums/y9/_mad_kaw_/?action=view&current=MVI_2290.mp4 Put your stereo headsets on and listen to the music

I wish i could give firm numbers to add into this conversation, but i am determined to get some. My slightly modified L24 with SU's runs great with SU's-that are almost new. My butt dyno was shot down at the 1/4 mile track and i was disappointed, but again the car feels strong. I am determined to get the most I can out of my SU's using a newly installed wideband and a dyno to tune. I have a almost new set of Mikuni 40's sitting on a shelf begging to be bolted on, but I am holding off until I have exhausted my options with my bolt on SU's. I want a real- measurable comparision of properly tune options. First the SU's and then the Mikuni's. I have the bolt-on headers and modified exhaust, cam, bigger valves, slight port work, better ignition and again I was disappointed at the track. It is all about tune at this point since the dyno showed a definite lean point at the power band. Every engine is slightly different and it is difficult to give exact comparisions-just pass along war stories. I wish that Hybridz would do a comparison with engines and modifications as was done with the wind tunnel experiments. Starting with a baseline on a dyno and start tuning and adding on "bolt-ons" and read the results. I would throw some money at that as i did with the wind tunnel tests-it would interesting!!

PM'd

Selling my 81 ZXT to someone in louisville KY and would love to find someone to refer him to for any help working on this car. Thanks

http://s2.photobucket.com/albums/y9/_mad_kaw_/?action=view&current=MVI_2290.mp4

Not sure how to describe this piece, so just check out the pic. I need the connector that is circled that connects all these vacuum lines(brass colored), I need this ASAP sfinnerty@indy.rr.com

I got one from my 71-it should work. 20$ plus shipping. you can e-mail me sfinnerty@indy.rr.com with shipping info and i'll send a pic.

Thanks for the update, I will definitely check that out. That beats tearing out the dash to find leaky vacuum hoses.