madkaw

Thankyou very much. I have poored my heart and soul in that thing the last 2 years. The best part is not what you see, but what you hear. I need to get a sound clip of the exhaust put up!

Wasn't sure what forum to put this in, but I thought it was interesting to say the least. In pursuit of the perfect tune requires a lot of tools or track time it seems. I thought this would be an invaluable tool in regards to tuning-especially our engines and detonation. With a noisy valve train and my loud exhaust I am not sure I am hearing or deciphering properly detonation. I plan on making this tool to help me seperate noises and troubleshoot. I want to get the most out of my engine without hurting it(timing advance), so I would think this tool would be a no brainer. It's much cheaper then the LM1 I would love to have, and the LM1 won't detect detonation. Of all the reading I have done about our problematic #5 cylinder, I want to be sure that I am not advancing my timing to the point of damage. I am suprised I have not stumbled upon a thread of someone using this tool with all the work that has been done trying to remedy the #5 cylinder issue. http://autoweb.autospeed.com/cms/title_DIY-Detonation-Detection-Part-2/A_0353/article.html Love to hear some feedback on this

Okay, I guess I have something worth showing off now!

Just by the pictures the tires look to stick out further then mine. Different make of tires are a variable too.

There is another issue to consider, rubbing inside the wheel well once you clear the lip.Ask me how I know!!!!!!! I am running 17x8.5 with +4 offset with 245/45/17 tires. I cleared the lip once I modified it with some cutting, but now the tire sidewall rubbs on the curvature of the wheel well(right above the lip). My car has 1" lowering springs. Being that your offset is 0 you are out further then me, but I have wider tires,so it will be close. What I did was remove the spring and ran the tire all the way up in the well with a 235/45/17 and it cleared. Then I got greedy and went for 245's. You need to allow for buldging of the tire under load.

Bob, I reread your post and I could just move back the bracket i have now guess. At this point I will have to get another bushing since I altered mine. Anyone see a problem(since I will be fabbing anyway) to use a urethane type bushing(similiar to the type on a RT mount) or will this be to stiff compared to the stock and harm the motor mounts. I believe the bracket i have now(horizontal) has good rubber bushings to isolate noise. Somewhere on this site someone has done this, but can't find the tread to see how's it's working for him.

yes bob that might be the easiest solution since I do have one of the horizontal cradle types somewhere. I guess I will go back to the fab shop and set it up for a urethane mount and make the angle brackets to suspend from the verticle mount so I can use the other type mount.

The plan stands that if someone will buy my fiberglass fenders I will order the ZG flares,so I'm with you there Jon. I wanted to do this in the first place but shyed away from cutting on my rust free quarters and thought I diverted the situation by checking clearances-but alais I got greedy with one more tire size and here i sit-rubbing!

I am running bump stops now, but not LARGER ones you speak of. I am also needing to check alignment and will consider camber to eliminate the rubb. If all it involved was slotting the holes topside to tilt the tire in and clear, that would be cool. Limiting travel to 1" lowering springs might mean a lot of bottoming out-is that a concern?

Nigel, thanks for the response, but that involves using the horizontal mount and mine is the vertical. It might come down to fabbing brackets that I hang the horizontal bracket from my vertical based chassis so I can use this type mount, but I was hoping for less fabbing requirements. Nice work though!

Looking for ideas for a tranny mount bracket for a bwt-5 that has been installed in a 71 that originally had a automatic trans. My chassis is set-up for the mount bracket that bolts vertically into the chassis. Right now I have reworked the original rubber mount that seats on the bracket to adjust for the offset. I also oblonged the mounting holes on the bracket. The problem that I might have incurred is damaging the integrity of the rubber mount by welding and cutting on it. I tried to be careful and took my time welding and keeping the heat from building around the rubber, but the mount seems to be too loose. So is there a better alternative? I have searched and searched, but most applications I have seen were for the horizontal type mount. I saw one that utilized a urethane type mount that would be great, but again the bracket was for a horizontal mount. I think the offset needs to be greater for us guys that started out with an automatic. The pictures show what i have now. To remedy the offset I moved the ears of the mount so that the mount would center the bracket. I also had to notch the mount so it would slide foward on the tranny to center.

I am running 17x8.5 rotas with +4 offset and 245/45/17's on my 71 and I clear the lips(after some trim work) but I bottom out on the curvature of the well above the lip. I don't see anyway around this but to ZG flare the car-unless someone has a suggestion. The tire sidewall just barely rubbs the inside of the well with my 1" lowering springs, but the sound is unnerving.

Sorry BJ, but you lost me with the NVH(what does this acroynm mean) stuff. In the beginning when I was trying to figure this out I called a shop that worked on diffs, but mostly trannies. He said that if the noise changes at all with shift changes, then the problem is the tranny-no doubt. That is sound logic since everything else behind it is turning a constant speed. My contention is that the speed is the same , but the torque amount is not. That's why I thought the pinion angle made sense-especially seeing all the movement in this drivetrain. I'll admit I am way over my mechanical know how at this point-but it is fun learning!

jared, It was a pleasure meeting you and talking cars. You are definitely a busy man and I'm glad you made it to the show. The car was very impressive in person, but i still voted for my car for the peoples choice I hope you make it to some more Z shows and take me for a ride, or if your ever in indianapolis maybe you can swing by with your ride-I hope you'll drive everywhere!

Well the noise is still there, but it didn't ruin a good time at ZCON. I did get back under the car and started probing around again. The only thing I found of interest is the tranny mount. It seems to give way too much movement. If I get under it and bench press the tailshaft I can move everything up and down a 1/4" easy-maybe more. With some gentle persuasion of a small jack I can lift the tailshaft an inch easy. Now I know that is not a jacking point, but the mount just seems way too sloppy. This was a newer mount that I modified to use the bwt-5 in my car. I cut and welded on this piece, but tried to be careful of the rubber-but maybe I still ruined it. How much is exceptable movement? I would think on hard acceleration that thing is moving close to an inch or more-but I haven't noticed any thing in the shifter. I will say that i haven't done hardly any hard driving with this car yet. Could this movement be contributing to my noise? Hmmmmmmmmm!

Well I made it guys. The noise never got any worse-or better with the redline gear oil. The car got amazing mpg and cruised great. I saw 80+mph plent of times and she was smooth. Thanks for the support for the worry wart!

Thanks guys! I actually had the same conversation with a Z guy yesterday. Same deal-blown gear in the trans and he drove it for a couple of years that way!

Sorry if I am sounding a little irrational, the time crunch is getting to me. At this point I'm going with it. It hasn't gotten any worse in the 500 miles I've driven it. I will try swapping diff next, but probably not before I go. The U joints are fairly new and feel good.

Getting desperate here, but is there any way a person can get the diff stub axles on the wrong side? I mean would the longer one fit in the shorter side and visa versa or would it be blatantly noticible

I will say that I had someone else go for a ride today, another z owner and him and I both got out of the passenger seat while driving and put our ears to work . I laid my head right against the floor in the hatch area(tire well is gone) and I am 99% positive that the noise is originating from the driver's side and loudest inboard towards the diff. Well I'm going to bed so i can put in 15 hours on the car tomorrow to get ready for the trip. Please keep the ideas coming in guys.

Okay, what are considered cluster gear bearing-sorry don't know what that is. It sounds bad and I'm ready to take a 1000 mile trip. And I said the noise is LOUDEST in 4th at 60mph

Okay, that's what I read Jon. I know it's impossible to describe a noise , but it is like a wha-wha-wha-wha which increases frequency with speed. I feel nothing! The noise sounds fimiliar in tone to the noise the diff makes during deceleration, but it has a frequency to it.

Isn't disengaging the clutch taking the load of the turning components even though they are still turning the same speed? Just coasting there wouldn't be the torque the driveline? I will search this, but didn't I read that the halfshafts were all the same length regardless of r180 or r200. I was being told today that he thought there were two different lenghts of halfshafts. Someone want to clarify this????

I'm Going!

I know there a ton of threads like this, because I have read a bunch trying to get some ideas. Here's the facts 9/71 chassis-L-24, bwt-5, 89 LSD Shortened and balanced main shaft, half shafts newer universals and also balanced Tires new, wheels new, brakes new(wildwoods), rear bearings new.Pinion angle 2 degrees and parallel Symptoms; whirling out of balance sound from 45/50--70mph coming from rear Changing gears at a constant speed affects the volume of the noise At 60mph 3rd gear noise is hard to hear-almost non existent,4th gear it is the loudest, 5th gear reduces noise , but is still apparent Disengaging clutch noise goes away Sounds like it is coming from the drivers rear Loading the tires by swirving back and forth doesn't seem to cahnge the noise at speed So if I didn't get the bearing in on that side just right(not enough torque let's say), wouldn't the loading of the tire change things and why would disengaging the gearbox affect that? Why or would gear selection make a difference? I'm thinking it's the diff and it's just has noisy gears. I ordered some high/impact redline and i'm going to change the gear oil-even though it's fresh oil. Guys-I need some ideas or input. I want to drive this thing 1000 miles in a week and i'm getting nervous