white noise sound behind your center dash console?

[LancePearson]

Sounds behind the center of the dash when driving? It’s probably the ZF six speed gear noise which I believe sets up a resonance inside on the plastic housing stack which holds the DIC, HVAC controls and the Bose Gold radio head which actually sits over what becomes a cave when installed and the plastic center console trim is back in place. I bought mine in Dec. in Atlanta and drove it 515 miles home on the interstate wondering the whole way what that background “whooshing” sound as I characterized it was. I knew the tranny was working perfectly and subsequently got the fluids checked and changed to be sure that was all okay. I later found that when I folded and laid a microfiber towel on top of the cigarette lighter area and across the bottom face plate below the radio on the center console trim it went completely away which isolated it.

I needed to remove the tunnel trim to check the shift boots and fish out someone else’s dropped screws with a magnetic probe, etc., remove the radio to put a new face on it and see if I could not do some sound proofing incidentally. There is plenty of thickish, basic sound proofing between the exterior and the interior but this vertical utility stack of digital electronic controls sits both attached to and in a relatively thin plastic material with the cave below. I’m no sound engineer but it seems to me like it was a perfect place to take what sound seeps upward and, you pick the word, either magnify it or resonate it as the thin plastic vibrates a little and that cave works it too, perhaps even a miniature echo chamber.

I bought .080 and .050 sound deadening material on ebay, you need less than a foot and a half square feet in there. It is just foil faced sound deadener of some type of urethane or rubber material which has adhesive coating on the back and comes with peel off paper which allows you to cut to fit and then peel the paper, attaché it, then use a small roller to press it on.

It is not a huge task. It is not thick. It is not smooth by design.

It does seem to have completely stopped that sound for me. How? I’d argue it stopped the thin plastic from resonating and magnifying the sound which previously you might hear as a kind of annoying white noise behind the radio, dic, hvac stack as you drive with windows up and top on.

Not anymore. It worked. I believe it both absorbs some sound/energy in the plastic material and stabilizes the plastic structural frame that holds these devices by killing vibrations to a great enough degree to matter.

I actually put a piece on about half of the metal top of the radio head case and the bottom and 2” strips on the side just to be safe though I believe the metal did not hear enough sound to resonate.

I wouldn’t do this just for itself but as part of opening the center console up, I’d consider it as it takes less then fifteen minutes to do once open. I was careful not to cover any openings so that air will continue to flow nor any screws or bolts for obvious reasons. This is not the greatest thing since sliced bread but it did quiet that irritating noise down for me as I was doing other things that needed doing in the stack. I also put a piece on the bottom inside part of the center console stack finish trim plastic piece just in case since it forms the “front” of the cave below the radio head as well when it’s reinstalled. This sound deadener is thin enough that it does not stop anything from fitting.

I’m sure some sound engineer might know more about this but what I know is it worked rather well in a test drive today. We’ll see how it works out over the next few months but it should stay put and I have no plans to go back into that stack again….all other punchlist things done.

I share this as a possibility for you if you have ever wondered. Not something you have to live with it seems to me. Will post photos here and in the subsequent panel so you can see what I'm talking about if you haven't opened your console up.

Lance Pearson

[LancePearson]

a few more photos of my 1991 efforts...all done.

[vilant]

Nice job. I don't have to worry about that, though. My car is so loud because I have the power effects exhaust dial, wide open. I hear nothing besides the roar of the car, lol. I have to turn the radio up fairly loud to hear the words. With the dial closed, it's quieter, but then I hear all the other creaks and rattles. :cheers:

[Kevin]

You have my favorite exhaust joe. The only buzzing I have is when the shifter lock out ring gets loose

[LancePearson]

Follow up. With the bronze targa top in place and windows up I'd have to review and reflect that the addition of the thin soundproofing did not materially change the "white noise" working its way into the cockpit seeming to come from behind the center console under the dash....Not opening it up further as it's not something I'm not used to but I have to say it really didn't make a difference when I get further from it and across a wider set of configurations and uses.

Lance

[Schrade]

YikES! You went DEEP there Mr. P !

I did that in the '94, and took 4 days to re-assemble ( I put every screw back in the empty hole as I dis-assemble). And shoot snappics GALORE.

Perhaps get a phase inversion amplifier. Real-time processing would do it, but integrating the stereo INTO it would be necessary, to not cancel the tunes too.

Someone else might know more-so how to do this...

edit:
and then, maybe not...
Good explanation here (http://forums.stevehoffman.tv/threads/phase-inversion-button-on-the-pre-amp-what-does-it-do.197358/), although ambient (non-music signal) noise, is not addressed

[LancePearson]

Shrade,
I've decided to embrace the white noise since I rarely put the Targa top on anyway and can't hear it when the top is out due to wind noise! When in I have a microfiber towel folded which is long enough that it lays on the ashtray cover with four thicknesses of black towel and curls up the radio and eliminates about 50% of it and that's more than enough. I even put cotton round gauze in the cup holders to dampen the sound. None of it materially changed the sound so embracing it is much simpler! Mine is getting the serpentine belt changed, oil and greased and due back today so that when I drive it the 350 miles to Carlisle to the Wazoo deal April 5 for the April 6 day there with the group then home and then May 15 the drive of 646 miles on I 64 to the Gathering in Bowling Green I have a "known" belt. When I got the car there were no maintenance records and the car had very few miles put on it between 2003 and 2012 late when I bought it so despite low miles on the belt, I think its rubber is not the greatest like old tires so am doing pre emptive strike on it. It was squeaking a little anyway which is a sign of belts wearing in my experience. Should get the car back today. They started working on it late yesterday and just have the belt to do this morning. I asked them to save the old belt as I visually inspected it when I got it and it was fine but as I drove it squeaked a bit and maybe can track it back and see what it's vintage was. Which reminds me, did I put a set of jumper cables in the well boxes in the back? Will check. Are you going to the Gathering in May? Be fun to say hello if you are. Looks like a drive to one of the whiskey distilleries is shaping up on one of the less busy afternoons...80 miles each way from the museum. I leave the 15th and return the 19th. Will try my radar detector out on the I 64 Interstate drive in WV and Ky...might even see if it works for a short stretch at 150 mph. Have briefly had it about 140 mph but that's the fastest so far. Car had tons more but I just ran it up then ran it back down quickly ever mindful of John Law here in Va. where tickets are hugely expensive...like that one would be $3400 plus loss of license.

[Schrade]

Hey there Lance; will be doing lots of travel near future here.

Really would like to put some blacktop under the Z here, but ...

Just had the small claims on the auto swap, and the judge needed to go over particulars before disposition. No 'Completion' date hurt me, but they did acknowledge that all the shortcomings were their own work.

Fingers crossed here (and eyes, hair, teeth - got 'em all crossed). Will probably have to get PETE's wrench on it to get it RIGHT here.

Someone else said about sheet rubber to kill the acoustics chamber resonance. Ask at Home Depot about EPDM (or a roofing contractor, with leftover sheeting from a new job). Or maybe the hobby shop for cork sheeting - cork can be 'floating', but the rubber would need affixing between components...

[LancePearson]

Good luck geting it all put together. I got mine back late this afternoon with the pre emptive stuff done and need to call and see what they did to turn my underhood lights off. Worked fine before the shop had it. Will go out and reverse the fuse in case it's a polarity issue. You just pull the fuse down by the driver's side head light area to turn them off for long periods when the hoods up for hours and since I have leds now it is possible even the fuse has to be one way though that seems strange. the leds only work one way with polarity. Will check before bed than call tomorrow if that isn't it. Need to wash some fingerprints off as well. They do a good job but they are human. Did the work fine. The belt was new enough even though I had them replace it since it was a min. of 8-10 years old but the pulley that is in the tensioner had a small vibration at high speed which was what was probably making the sound and that was replaced and all is well with the engine now. I just want no problems on the two upcoming drives that I could have avoided and I now know the provenance of all the major systems and maintenance items because I've been through most once with me and mine here now.

I should have just stuffed a rag into the chamber area below the radio when I had it opened up but it's not worth messing further with. next time open, maybe so.

[LancePearson]

Before I even got out to double check this morning the shop and I talked and they had unplugged the lights where the wires connect at the base of the hood to avoid draining the battery and forgotten to replug them so in a few minutes I'll go out and reconnect then my entire short term punch list and preparation for the Wazoo Carlisle drive and then the drive to Bowling Green will be done. Engine runs sweetly.

[mgg]

Lance, I find you post regarding the "white" noise very interesting. I to have a shshshshshing sound behind the radio / vent area and have not been able to identify what the noise is and where it is coming from. It is not so bothersome as much as I am curious as to what it is. I seemed to notice mine after I had installed my headers. I hace checked and double checked and the headers are on fine with no leaks and actually inatalled much better thna was the factory exhaust manifolds. When I saw you post I has to laugh as I though I was the only one who experienced this and it sounds like the same issue. I am disapointed that you sound deading material did not work out like you wanted it to. If you are heading up to WAZOO and need to take a break on your drive, I am located in Hamilton, VA. YOu will probably drive right by me heading up from Chester, VA. If you need to take a pit stop you are more than welcome. I appreciate your article. Let me know if you think you might stop by.

[LancePearson]

Lance, I find you post regarding the "white" noise very interesting. I to have a shshshshshing sound behind the radio / vent area and have not been able to identify what the noise is and where it is coming from. .

MGG...Thanks for the invite. I hope to be going up I81 and Winchester is only about 20 miles each way from there so I'll keep it in mind. Right now I'm hoping it's good enough to drive the Z which has a new serpentine belt, etc. but that depends on the weather. If it's cold, wet and any snow at all up in the Blue Ridge then I might leave it at home and drive my TBSS with its LS2 2008 engine and 4:10 rear end and all wheel drive instead and take the more direct route. The plan is to go West on route 60 to Amherst, Va. then to the Blue Ridge Parkway and take it north for about 50 miles to Waynesboro then skip over to I 81 and on up to Carlisle the 5th for the 6th deal with the Wazoo group at Miller's in Carlisle. Looking forward to it but if there is any ice, snow or truly miserable weather the new Goodyears which are excellent on dry or wet roads are absolute disasters on snow. Like snowboards at best! In any event, I am hoping it's warm enough I can go up with the targa top in the back even if I have to use the heater with the windows up but we'll see what the weather says first.

With respect to the noise, I bought my Z N of Atlanta in early Dec., flew in Sat. morning, paid for it and got in it, stopped at the store for a couple things then drove it over two days to Virginia at 73 mph and loved it but the top was on with the targa in the back and the white noise sounded like a "whooshing" sound to me too...white noise I call it and it was below the dash top and behind the electronics stack in the center of the car. I was only concerned with function and the tranny worked great but I knew the water flow was different on the LT5 and all gauges and fluids checked perfectly so I drove it and had the mechanic look as well. We all concluded that it's just the ZF 6 speed with its barely beveled if at all depending on what year you have heavy duty gears making a sound as square cut gears do I'm told. So, when I took the radio out to reface it I checked the shift boots to be sure one was not torn, etc.. What I discovered is that there is a fair amount of 1/2" sort of fibrous insulation between the tranny and the interior, far superior to what my 76 came with, and it does a serviceable job on the noise except in that one area. You have seen my first attempt at damping the resonance of the thin plastic supports that hold the stack. Didn't really work much. Next time I open the center trim face and remove it I will just stuff some fiberglass insulation in the cave below the radio but I suspect that won't stop it either. I think it just works its way in and gets trapped between the fire wall and the center glove box and that's where you hear it.

In my case I have a couple of black microfiber towels that I fold about 4" wide and lay one on the cigarette lighter and the other across the front and up that center trim which hides the empty cave and the white noise, shshing and sound goes down by more than half so I think I know the place. it's not worth it to me to open it up again when it looks so nice now but when I do I'll try one last time with fiberglass stuffed minus the paper into the cave and maybe around it. The glass is not combustible so it should under any circumstances be good there.

The truth is that since I drive mine mostly with the Targa top off on good days so it's easier for me to get in and out the wind eliminates the noise to begin with and it's not an issue. I've sort of grown to accept it and am just happy that it isn't some mechanical or valve failure on the water system. When you look at the engine and the firewall relative to the dash the ZF is right below that area leading to the bellhousing and the back of the engine so it just about has to be noise from the tranny's gears or perhaps in some odd way the unusual flywheel arrangement. In any event, it is not so far worth the expense of digging into all that. Putting headers in did you notice any insulation between the bell housing and the interior? My 76 has a foam piece cut to fit to try and minimize that noise and I don't know what's on the back of the bell housing on our cars. If there is perhaps both ours has fallen out or disappeared. Truly, I haven't looked or noticed anything like it in the manual looking I've done so far but they used to do it on the C3's. I have a 76 in the garage right next to the 91, both Bright Red from 1991...someone else painted the 76.

No one else has chimed in since I think it's a non issue for most who hammer their cars with big exhausts anyway but I had a 515 mile drive in a new to me car to fret about it so I did.

Funny thing about my exhaust which is a couple Borla's and that system which I like well enough that was on the car, I hear it when I'm running the car up through the gears but from about 50 or 70 or some mph when I'm zipping along that sound is so far behind me I can't hear it anymore and I'm concentrating. I know at any three digit number up to the 140ish I've had her loafing in fourth gear that there ain't any sound and the white noise meant not one single thing to me. Lots more things to think about, very fast thinking, at 205 feet per second...2/3rds of a cotton picking football field every second.

I still like the signature line of one owner here which is irreverent as can be but is true: "I can break every single speed law in the United States and still be in second gear." True.

Glad you liked the article. There is another one the HOTB folks already have as well. I set out to buy a c5 or c6 and stopped when I saw the LT5...it's just amazing with all due respect to the C5's and C6's.

Lance

[B17 Crew]

Hello, Mr. Pearson.

Your post reminded me of a similar sound I had experienced with a ’94 LT1 6-speed coupe I used to own. I had approximately 55,000 miles on the ’94 when it needed a new clutch.

Had a local Chevy dealer perform the work; picked up the car and it functioned perfectly. I did however notice a “whooshing” sound coming from my center console. When I would open my ashtray door, the sound was more pronounced (louder) with the ashtray door open. This sound had never occurred until after the new clutch had been installed. I determined that the dealer must not have placed part or all of the sound insulation back in place properly when they were buttoning up the car. I had the targa-top off most of time when driving this car, so it didn't bother me too much. I ended up trading the LT1 for my LT4 (my current car) so I never really found out what the exact cause of the sound was.

I was wondering if your Z is on the original clutch or if the clutch has ever been replaced. Although, your sound anomaly sounds as if it’s originating further forward than what I had experienced.

I visit this forum quite often and I wanted to mention that I always enjoy reading about your driving experiences you have with your Z.


B17 Crew
:hello:

[LancePearson]

B17, probably the original clutch though the ZF six speed tranny underneath the car has a blue metal tag on it saying "rebuilt to GM specifications" so it might be newer than that. Some early Z's had one version of the ZF and some later had another and they were differentiated by labels and from what I read, the later version had slightly different beveling on the gears. Original were what I'm told were "square cut" with no bevel and the later ones had a slight bevel. Square cuts, I'm told, will always be somewhat noisier but can stand a ton of force. I don't personally know what's in mine and am only repeating what I remember from reading other's posts other than what's on my tag on the tranny.

I am glad you enjoy the experiences of all of us as I know we all sure enjoy having them. I bought my Z in early Dec. n. of Atlanta and drove it home. It was in great shape but did not have an owners manual or maintenance records. I did have a Carfax and knew the brakes were serviced 7,000 miles before I got it, the fluids were fine and it drove well, clutch and tranny included though the "whooshing" sound was different for me and made me fret a little. When I got it home I had my shop go through and change ALL the fluids including tranny and rear end so I'd know their provenance and just last week had the serpentine belt and the pulley on the belt tensioner changed so I know their provenance at 45,000 miles. The belt was okay but the pulley needed changing but we put all new in regardless. All working well.

I have about 700 miles of driving it coming up to go to and from an all day Wazoo event at the Millers in Carlisle, Pa April 5,6,7 where I'll go west and hit the Blue Ridge Parkway and do about 50 miles of it then skip over to I 81 and go N. to Carlisle to watch the group tear into and replace a set of injectors on a Z, lunch, then see the Miller car collection, dinner with these terrific owners then home Sunday. The long, looping but scenic way around, weather permitting. If the weather is bad I'll go more directly. Then I may take it to VIR May 4,5 to watch some other Z's run the track in a TrackDaze event with my cameras if they are still going to do it, then May 15 head for Bowling Green and the gathering which is 646 miles each way.

I have a 76 with 100,000 miles on it and the clutch still works fine on it. The Z's is the smoothest clutch I've ever seen.....hydraulic instead of mechanical. Don't know what it's life will be but I suspect it depends on how they are used to some degree. I'm easy on clutches personally.

Lance

[secondchance]

Lance, B17 crew,

A couple of things - when transmission work is performed and transmission is dropped rubber boot under the console is often pulled down with the shifter unintentionally. After the transmission service as the car is being buttoned up most mechanics are too careless to install the rubber boot carefully and left side of the rubber boot is rarely secured over the lip on fiberglass body trans tunnel. Trying to slip the rubber boot over the lip is impossible fromthe top without almost total disassembly of seat, console side panel, etc... B17 crew noticing more noise with the ashtry door open is indicative of this. Solution would be removal of driver seat, console trims, console side panel to gain access to the left side of the rubber boot and slip the edge over the lip on the tunnel.

Another area to check is the map sensor hose. I had a situation where the map sensor hose was loose between the rubber boot and hard plastic line resulting in vacuum air leak. This also make a subtle loss of drivability and I emphasize subtle. In my case resealing of MAP hose cured the noise also.

[LancePearson]

Second Chance....thanks for the insights. My boots, the rubber big one then the leather over are fine and the noise really isn't below my ashtray but forward and behind the radio so since I just ordered the Maps plaque when it comes I'll look around back there and be sure it isn't the hose. Thanks again...it does sound higher and more forward than the tranny tunnel next to me as the driver.

I need to remove my seat and redo one of the bolster's leather cover on the driver's seat though if I can get the back off I might just pull it independently. Have the red leather enroute and an industrial sewing machine which might make it possible without redoing the entire seats. Will see. A someday in 2013 list, possibly winter 2013.

[LancePearson]

Just went out and had the hood up so while I was there I checked the MAPS area rubber hoses and connections at the back of the engine while double checking the oil level after its recent change and three of the various ones took some light turns on the hose clamps with my screwdriver. Interesting setup and we'll see if that has a bearing on the noise as it is more nearly where I originally thought the sound came from. I thought it was a "whooshing" from some new water flow pipe or a valve that was reversed or something in my lt5 ignorance (which is still manifest, btw!).

There is a second dash area irritation with the ZR-1 and that is when driving while the targa top is off the glare off the dash board reflecting into the underside of the window which is right where your eyes look to drive. I had some soft boat indoor/outdoor black carpet so cut two pieces to fit then a piece of rug rubber non slip stuff and with my industrial sewing machine I used to use for my sailoat sails I sewed it together...end of glare if the wind doesn't fly it around. You can buy a dash rug for the whole dash to eliminate uv degradation but it's not that great a fit with the passenger side severe slope so I made one just for about half or at least what bothers my vision on a bright day with reflected glare. Dash is black and the carpet happened to be a perfect match in color and does not cover any venting at all.

[B17 Crew]

B17, probably the original clutch though the ZF six speed tranny underneath the car has a blue metal tag on it saying "rebuilt to GM specifications" so it might be newer than that. Some early Z's had one version of the ZF and some later had another and they were differentiated by labels and from what I read, the later version had slightly different beveling on the gears. Original were what I'm told were "square cut" with no bevel and the later ones had a slight bevel. Square cuts, I'm told, will always be somewhat noisier but can stand a ton of force. I don't personally know what's in mine and am only repeating what I remember from reading other's posts other than what's on my tag on the tranny.

I am glad you enjoy the experiences of all of us as I know we all sure enjoy having them. I bought my Z in early Dec. n. of Atlanta and drove it home. It was in great shape but did not have an owners manual or maintenance records. I did have a Carfax and knew the brakes were serviced 7,000 miles before I got it, the fluids were fine and it drove well, clutch and tranny included though the "whooshing" sound was different for me and made me fret a little. When I got it home I had my shop go through and change ALL the fluids including tranny and rear end so I'd know their provenance and just last week had the serpentine belt and the pulley on the belt tensioner changed so I know their provenance at 45,000 miles. The belt was okay but the pulley needed changing but we put all new in regardless. All working well.

I have about 700 miles of driving it coming up to go to and from an all day Wazoo event at the Millers in Carlisle, Pa April 5,6,7 where I'll go west and hit the Blue Ridge Parkway and do about 50 miles of it then skip over to I 81 and go N. to Carlisle to watch the group tear into and replace a set of injectors on a Z, lunch, then see the Miller car collection, dinner with these terrific owners then home Sunday. The long, looping but scenic way around, weather permitting. If the weather is bad I'll go more directly. Then I may take it to VIR May 4,5 to watch some other Z's run the track in a TrackDaze event with my cameras if they are still going to do it, then May 15 head for Bowling Green and the gathering which is 646 miles each way.

I have a 76 with 100,000 miles on it and the clutch still works fine on it. The Z's is the smoothest clutch I've ever seen.....hydraulic instead of mechanical. Don't know what it's life will be but I suspect it depends on how they are used to some degree. I'm easy on clutches personally.

Lance


Hi, Lance.

I am under the same understanding as you regarding the “square cut” gears. From what I remember reading, the change helped reduce gear noise. Sounds like it is going to be one heck of a nice spring for you by having so much seat time in your Z; I can’t think of a better car to do a drive like that in. The option to drive a ’76 and a ’91 ZR-1 is pretty nice, they must be quite a contrast from one another!

B17 Crew
:hello:

[B17 Crew]

Lance, B17 crew,

A couple of things - when transmission work is performed and transmission is dropped rubber boot under the console is often pulled down with the shifter unintentionally. After the transmission service as the car is being buttoned up most mechanics are too careless to install the rubber boot carefully and left side of the rubber boot is rarely secured over the lip on fiberglass body trans tunnel. Trying to slip the rubber boot over the lip is impossible fromthe top without almost total disassembly of seat, console side panel, etc... B17 crew noticing more noise with the ashtry door open is indicative of this. Solution would be removal of driver seat, console trims, console side panel to gain access to the left side of the rubber boot and slip the edge over the lip on the tunnel.

Another area to check is the map sensor hose. I had a situation where the map sensor hose was loose between the rubber boot and hard plastic line resulting in vacuum air leak. This also make a subtle loss of drivability and I emphasize subtle. In my case resealing of MAP hose cured the noise also.

This is great information, it makes perfect sense, thank you. If I meet up with it’s current owner, I will pass this info along to him. I sure wish the technicians would have addressed this though when they were getting things all back together. I sure did pay enough for it!

B17 Crew
:hello:

[LancePearson]

B17,
Thanks...and, yes, the zr-1 is the best mpg vehicle I own. I haven't driven the 76 since just after I got the Z and then the contrast was astonishing...the clutch is very strong to push in the 76 and the power at about 230 hp in mine the way it's setup now is great for roads and fast enough but nothing, absolutely nothing like the punch of the Z or the TBSS with the 4:10 rear end and its stock 2008 ls2 engine of about 410 hp the way it's configured and set up for road racing by gm performance.

I love the 76 in appearance and it works fine except the other day when I tried to start it it would not fire though it turned over. I keep stabilizer in the gas so don't know what that is. I may end up selling it this summer to get my garage space back as the Z is so much more car though not the work of art that the 76 is. It is sculpture just sitting there with it's flannel cover on it.

I wish I had a four car garage right now....it snowed this morning lightly at 35 degrees and we will be about 18 degrees below normal here today...cooler than normal daily by at least 8 degrees for the next week or so continues...

Lance

[LancePearson]

p.s. B17, used to fly in and out of Columbus, Ohio all the time as I was responsible for one of my responsibilities for a business just south of there in Ashville, Ohio. A continuous coating and fabricating plant on 140 acres just off the highway going due south about ten miles from Col. Good restaurants in Columbus!

[B17 Crew]

Lance,

The C3’s are works of art. Had the opportunity to drive a orange/tan ’77 in the summer. It was like no other car I had ever driven. It was an automatic, completely stock. Was very impressed with how well it handled. The sight lines looking out over the hood can’t help but make you appreciate what a fun car it is to drive. Haven’t had the opportunity yet to drive a Z, that time will come when I upgrade from my LT4 to a LT5.

I don’t see to many TBSS’s around, but 410 hp and all of that room in the back make it a practical vehicle to have in the garage.

Columbus has it share of good restaurants, they are popping up so fast left and right in this town that I can’t keep track of them.

Hope you are able to get your ’76 sorted out!

B17 Crew
:hello:

[LancePearson]

Crew,
Yes, the tbss with its 4:10 rear end and race suspension is very quick for an suv and pulls a trailer easily as well. Huge sway bars and Billsteins. It's ecm limited to 130 mph but if you change ecms you can get to 149 mph with it very quickly. I've run even with c5's to the limit though they would beat me top end for sure.

My 76 has 255's on it for shoes and new shocks and good body bushings and engine and is really fun to drive on the highway through twisties. It's stock four speed L48 but about 230 hp and moves well. I ran it at VIR for a day and enjoyed that road racing experience as those tires let it hold the road extremely well. It always gets looks when I show it or drive it.

Having said that, the 1991 ZR-1 is so much more powerful, so much more sophisticated and handles the road so much easier and better with its hydraulic clutch so much easier to push down and the 6 speed infinitely greater. I thought the 255's on the 76 were big then bought the 91 Z. Wow! The 76 has a similar rear end ratio and is a great car.

However, I can see that I'll end up selling it either this year or next as I have too many toys to use effectively and so thoroughly enjoy the Z I really won't do the 76 justice letting it sit. No rush but it shows well in local summer shows, etc.

Best to you. I am hoping it warms up by April 5 when my road journeys with the Z start. Today we are going to be about 20 degrees below the normal average high temp here.

Lance