stuck at 12.2`s now with a broken CV joint

[660Z]

Well the 11`s seem to elude me at every turn. Last month`s T&T the fuelpump takes a dump..Launch out of the hole at 6 psi and cross the traps at 3 psi...result best of 12.2 @ 111

 

so install new fuelpump, 1/2" line, regulator...Bla,bla, bla...

 

Today`s T&T with everything the same tuning as the month before, result is the basicly the same 12.3 @111...Was babying it some becaulse I had to rig...er adjust the throttle cable to get full throttle that I thought for sure there would have been an improvment...oh well on to run #2.

 

Plugs alittle lean. Up the jetting from 78 to 80`s all around..re-set carb, timimg was off, bumped back up to 35 deg overall..felt strong real strong...11`s for sure or so I thought....

 

Time for run #2...ran my cousin in his mercery comet he tells me he going to heat the slick good this time!...So I got the brain storm to do the same after all can`t let a FORD show me up!!! So I smoked them a little longer than I usually do...The slicks didn`t feel as stable as they usually do but nothing out of the ordinary...Stalled it up and let`er rip!! ...felt good and strong... real strong, pinning me back and the front end pointing skyward. This has to be 11`s or so I thought...So slowing down I hear.. thud,thud,thud from the right rear and go to make my turn onto the return road Bang,bang jerk,jerk...12.4 @ 112....DOH

 

Well I think it`s a broken CV joint.. has anyone had any luck with after market cv joints for the 280zxt shafts and if so where did you get one.

 

Mark

[Guest SBZ]

I've run 7.57 @ 94 in the 1/8, over 50 times with the stock 280z suspension, I guess i am lucky, debating a larger converter up form the

2600 stall i got now, but dont want to break stuff , what 60' times you get

[jgkurz]

Mark,

Sorry to here about your trouble. Running low 12's and the MPH you've been running tells me your 60ft time must be 1.8 or better. True?

 

Are you running the Modern Motorsports 280ZXT CV adapters? I'm a little worried because I'm going to be running a similar ET and don't want to break a CV.

 

They now have Z31 CV adapters that might be stronger.

 

http://www.modern-motorsports.com/catalog/product_info.php?products_id=56&PHPSESSID=e6f2d7059fbc3312c347c60856c6366a

[660Z]

Hey John,SBZ

 

My best 60' is a 1.7 but mostly im in the 1.8`s....when the CV broke it was a 1.9

 

Your right John I do have Ross`s 280zxt conversion set up. I`ve thought about his 300z setup but my current one is only a year old so i`d like to get my money out of it, for right now anyway. Im hoping I could buy just a single CV joint (I haven`t checked it out yet but I believe it`s the outer one) rather than trying to find another shaft.

 

Mark

[660Z]

Well tore into it today...The CV was fine, it was the carrier center pin that broke. So out with the 3:90 rear and in with the 3:54. Im thinking the 3:54`s will kill some bottom end and help quite a bit on top end thus finally putting me into the 11`s with a stock 400ci

 

I really wish it was a bad CV joint since I just bought 4 pairs....you know just in case of future abuse with the slicks Looks like i`ll have to aquire a few more rears as well.

 

Mark

[jack46]

So sorry about your CV's.

 

I recently changed to a 4.11 R 200 got my times down best a week ago was 7.53 1/8 1.64 (all three runs) 60 foots (small 383), but when I tried to juice (120 shot is all) I creamed the u joints (one axle broke then luckilly immediately the other so i never really launched could have been trouble with one wheel pulling hard). So I'm at the decision point considered going to CV's, but if you creamed em no sense in considering them further.

 

SBZ don't talk to loud the u joints are funny heard a few people going faster with solid u joints, but seems problems are more common than people having em hold up, and seems about the time you get the car running good is when they give.

 

I have heard one person juicing it like hell going 6.4's 1/8 and changing em after 4 or 5 runs. A pain but they hold for him but like i said I never saw him, and he doesn't juice until lets say .3 - .5 sec after launch then I think uses two stages they say (BIG stages like 350 total)

 

I have about decided to bite the bullet and tub and put ladder bars and 9" under it. Seems that is only thing I have never heard anyone breaking.

 

I was told a year ago by a Z guru here to do it then, I waited now I know why he is a guru here. Wish I could state his name to tell him he was right, but I'm sure he knows he was and is.

[jack46]

Mark (or others interested in R 200 setup)

 

Write me at Slow260z@yahoo.com

 

Like I said I think I'm going to go 9" and will have a few goodies others might be interested in:

 

three R 200's

4.11 welded solid

3.54 welded solid

3.90 open

 

stiffened mustache have to show you can't explain it, but basically ties the mustache to the two arms that bolt to body in back (stiffens the stache and hold 'A' frames solid, bolts thru mustache with urathene bushings)

 

also have 2 mounted 14" 26.5 by 8.5" slicks hardly used (honestly three runs and a 4" launch :>( paid like $325 plus mounting the day I went to track

 

rear strut bar stiffens the rear towers (I'm an early 260 so think it will only fit a 240 or 260).

 

I will sell all. If you think you can use R 200 this is a stout set I have I could change my chunks rather quickly and I had additional side mounts on setup as well (kept the R 200 from moving in any direction again will have to email pics I used it on solids (4.11 and 3.54) didn't need it on peg leg since it spun easilly). And I could play with open 3.90 on street or put in 3.54 or 4.11 if i wanted or needed to really dig in...Boys and their toys.

[Guest zfan]

I guess I am lucky as I am running 7.20 at 97 mph in the 1/8th. I have yet to break a u-joint with my 383. I must say that I leave the line at idle with only a 2600 stall converter.

 

If I stalled it up on the line and really hammered it I guess I would break something. I am going to buy a Vigilante 3500 9.5" converter later this year. Then I am sure I will do the R230 conversion. Currently I am running the 3.70 LSD year end.

 

Mike

[jack46]

Yeah seems many going faster and aren't breaking them (yet). What are your 60 foot times? I have a small cam and small 1.94 heads so launch hard but die out (will convert to larger once I have it right). I'm thinking since I do have a small cam 234/244 .488/.510 I launch hard then fold, is the only reason I can guess why I break them when Im so much slower, but not sure. Seems many go low 7's with joints if they are above 1.7 or so 60 foot that is a guess of mine not sure it is valid.

[jgkurz]

jack46, It's been a while since I've been involved with the SBC crowd, but your cam doesn't seem that small. I really don't know what your power goals are, but that cam seems large enough to flow 400hp. A 1.7 60ft time should yield a high 11 sec 1/4 mile given that you have the necessary power/weight ratio. Your topend problem probably is related to your cylinder heads,intake or exhaust rather than your camshaft. Just my .02C.

[Guest zfan]

I would bet the heads are the problem. That cam is no smaller that mine. I run a 236/242 duration, 553/540 lift hydr. roller cam. But the heads are 205 runners with 2.05/1.60 valve heads..Canfields.

 

60 ft.'s are 1.70-1.80. 1/4 mile is 11.30 at 121.

 

Mike

[660Z]

acually my CV shaft turned out to be fine, it was my center carrier pin that broke. Looking back I think it broke during the burnout with slicks. I talked to a guy in town here thats been running V8 turbo 280zx`s for years and he tells me he used to spit out the spider gears from doing the burnouts. Now he just drives up to the line with no burn out and hasn`t had a problem since.

 

Mark

[jack46]

660 Z Glad it wasn't your CV setup. I think you were typing as I was writing the first post. I didn't mean to steal your thread, and I apologize if it appears like I did. Seemed I redirected it without intending to. I hope you feel it has added to your post and not hurt yours.

 

My setup is Small compared to most. But small is relative.

 

The cam is 234/244 .488/.510 hydraulic ($79 Summit cam with lifters), and heads are stock cast iron 89 truck 'swirl' heads (NO porting 1.94 intake), I run 1.5 roller rockers, I will be going ALOT larger once I'm set. This was what was available so what I started with. My friend runs a machine shop and he has helped me and like most people new performace, I didnt know what I wanted to do.

 

We basically have the new chasis planned and it will resemble the setup shown on this site on another post. Have 9" ford etc I will show pics once we start it. I plan to tub it coil over ladder bar, 8 point bar then use same engine to debug chasis then change to real motor.

 

I plan to use this 383 re ringed for blower, Canfield Aluminum heads (72 cc) ~9.2 CR, O ringed 10+ lbs boost (setup will go much higher) blah blah blah and will run <6.5 1/8 late this year or next.

 

The motor now I figure has maybe 400 Gross Hp not bad just doesn't have the heads, but has gobs of torque (times at prestage suggest ~300 RWHP). I knew it was small when I put it together, but wasn't sure how far I wanted to go, now I plan to go to next level.

 

A friend is helping and essentially I will use his setup he has a Camaro and runs 6.4's weighing almost 3500 so I'm confident at 2800 lbs I will have the capability to basically run as fast as I dare by changing the boost. The setup will deliver 10 lbs through about 16+ so 6.5 1/8 is well within reach. I live in Tn and race in Huntsville Al so 1/8 is all I have, but I'm confident 6.5 at roughly 110 will be a thrill. As I said the motor pulls 1.64 60 foots on motor with no boost or juice, so that number will drop significantly. Especially once all the flex is removed and ladder suspension enables better weight distribution.

 

One thing I can say at track I hook 100% with 8.5" slicks and creaned the joints with 120 NOS shot I was expecting to run <1.55 60 foots if joints didnt break. Last year I juice once and at time I was running 1.71 60 foots and times dropped to 1.61 soo dropping .09 on 60 foot with improved gearing was possible but a moot point now.

 

Thanks again for pointers. Will keep all informed on progress

[jack46]

PS I guess I repeated myself there and forgot to add what I meant to add.

 

The intake is a Team G which is rather high flowing to 7500 or so maybe ~7000 for 383. The exhaust is open 1 5/8" headers at the track so not a problem (the 1 5/8" header will limit the future potential of motor, but at about 6.3 - 6.4 1/8). It really comes down to the 1.94 stock cast heads. Like I said I'm glad I didnt buy a set since then I would be limited on what I could do.

 

PPS ZFan

 

'I would bet the heads are the problem. That cam is no smaller that mine. I run a 236/242 duration, 553/540 lift hydr. roller cam. But the heads are 205 runners with 2.05/1.60 valve heads..Canfields.'

 

My Cam is TINY compared to yours!

 

My lift is .065" on intake and .030 on exhaust and btw you are a roller! Which makes those differences even greater. Even the 4 degree duration is closer to a cam size plus the lift so you are MUCH larger! I ran the cam change on my engine analyzer and the cam alone increases HP by 35 at 5500 and is a sizeable increase across the entire range.

 

And my heads are also much smaller valves as stated are 1.94 maybe 165 cc not sure but alot smaller. My friend has those same heads |(used straight from box) on his car (3500 lbs) and is running 6.4 soo those heads are monsters!

 

You must have a convertor that is bogging you off line then motor pulls like a beast. But like we said once you don't bog the shock to u joints will go up exponantially.

 

I had a 2600 stall but in reality the motor only got maybe 1800 I couldn't turn a cold slick on the street! I went to an effective 2600 stall with 4.11 and I can roast them on street, but hook 100% at track.

 

I guess I missed what you said on stall I think you mean the stall stated RPM is 2600 effective is less than 2000 right? Like I said on my small cam and heads I didn't have power to turn them and I beat your motor <3000 RPM after that yours quicks my pants! So I would say you aren't shocking the joints at all if that is the case and that is why you aren't having a problem, but you arent getting what the motor has. I'm getting all my motor has but it pushed me to a decision point.

[quicker240]

how about letting me know next time you go to huntsville jack! Like to see a fellow Hybrider make a few passes.Mines going 11.6@120 1/4 around 7.6 1/8th right now.R200 and halfshafts still hanging in there(knock wood).Soon as I get Fuel pump straightened out,gonna turn up the laughing gas a little more.7.0 maybe? I'll be happy with that